diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 475f1bfa..cb67f5fc 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -1,3971 +1,3996 @@
 <?php
 
 /**
  * Calendar plugin for Roundcube webmail
  *
  * @author Lazlo Westerhof <hello@lazlo.me>
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2010, Lazlo Westerhof <hello@lazlo.me>
  * Copyright (C) 2014-2015, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 class calendar extends rcube_plugin
 {
     const FREEBUSY_UNKNOWN   = 0;
     const FREEBUSY_FREE      = 1;
     const FREEBUSY_BUSY      = 2;
     const FREEBUSY_TENTATIVE = 3;
     const FREEBUSY_OOF       = 4;
 
     const SESSION_KEY = 'calendar_temp';
 
     public $task = '?(?!logout).*';
     public $rc;
     public $lib;
     public $resources_dir;
     public $home;  // declare public to be used in other classes
     public $urlbase;
     public $timezone;
     public $timezone_offset;
     public $gmt_offset;
     public $ui;
 
     public $defaults = [
         'calendar_default_view' => "agendaWeek",
         'calendar_timeslots'    => 2,
         'calendar_work_start'   => 6,
         'calendar_work_end'     => 18,
         'calendar_agenda_range' => 60,
         'calendar_show_weekno'  => 0,
         'calendar_first_day'    => 1,
         'calendar_first_hour'   => 6,
         'calendar_time_format'  => null,
         'calendar_event_coloring'      => 0,
         'calendar_time_indicator'      => true,
         'calendar_allow_invite_shared' => false,
         'calendar_itip_send_option'    => 3,
         'calendar_itip_after_action'   => 0,
     ];
 
     // These are implemented with __get()
     //  private $ical;
     //  private $itip;
     //  private $driver;
 
 
     /**
      * Plugin initialization.
      */
     function init()
     {
         $this->rc = rcube::get_instance();
 
         $this->register_task('calendar', 'calendar');
 
         // load calendar configuration
         $this->load_config();
 
         // catch iTIP confirmation requests that don're require a valid session
         if ($this->rc->action == 'attend' && !empty($_REQUEST['_t'])) {
             $this->add_hook('startup', [$this, 'itip_attend_response']);
         }
         else if ($this->rc->action == 'feed' && !empty($_REQUEST['_cal'])) {
             $this->add_hook('startup', [$this, 'ical_feed_export']);
         }
         else if ($this->rc->task != 'login') {
             // default startup routine
             $this->add_hook('startup', [$this, 'startup']);
         }
 
         $this->add_hook('user_delete', [$this, 'user_delete']);
     }
 
     /**
      * Setup basic plugin environment and UI
      */
     protected function setup()
     {
         $this->require_plugin('libcalendaring');
         $this->require_plugin('libkolab');
 
         $this->lib             = libcalendaring::get_instance();
         $this->timezone        = $this->lib->timezone;
         $this->gmt_offset      = $this->lib->gmt_offset;
         $this->dst_active      = $this->lib->dst_active;
         $this->timezone_offset = $this->gmt_offset / 3600 - $this->dst_active;
 
         // load localizations
         $this->add_texts('localization/', $this->rc->task == 'calendar' && (!$this->rc->action || $this->rc->action == 'print'));
 
         require($this->home . '/lib/calendar_ui.php');
         $this->ui = new calendar_ui($this);
     }
 
     /**
      * Startup hook
      */
     public function startup($args)
     {
         // the calendar module can be enabled/disabled by the kolab_auth plugin
         if ($this->rc->config->get('calendar_disabled', false)
             || !$this->rc->config->get('calendar_enabled', true)
         ) {
             return;
         }
 
         $this->setup();
 
         // load Calendar user interface
         if (!$this->rc->output->ajax_call
             && (empty($this->rc->output->env['framed']) || $args['action'] == 'preview')
         ) {
             $this->ui->init();
 
             // settings are required in (almost) every GUI step
             if ($args['action'] != 'attend') {
                 $this->rc->output->set_env('calendar_settings', $this->load_settings());
             }
         }
 
         if ($args['task'] == 'calendar' && $args['action'] != 'save-pref') {
             if ($args['action'] != 'upload') {
                 $this->load_driver();
             }
 
             // register calendar actions
             $this->register_action('index', [$this, 'calendar_view']);
             $this->register_action('event', [$this, 'event_action']);
             $this->register_action('calendar', [$this, 'calendar_action']);
             $this->register_action('count', [$this, 'count_events']);
             $this->register_action('load_events', [$this, 'load_events']);
             $this->register_action('export_events', [$this, 'export_events']);
             $this->register_action('import_events', [$this, 'import_events']);
             $this->register_action('upload', [$this, 'attachment_upload']);
             $this->register_action('get-attachment', [$this, 'attachment_get']);
             $this->register_action('freebusy-status', [$this, 'freebusy_status']);
             $this->register_action('freebusy-times', [$this, 'freebusy_times']);
             $this->register_action('randomdata', [$this, 'generate_randomdata']);
             $this->register_action('print', [$this,'print_view']);
             $this->register_action('mailimportitip', [$this, 'mail_import_itip']);
             $this->register_action('mailimportattach', [$this, 'mail_import_attachment']);
             $this->register_action('dialog-ui', [$this, 'mail_message2event']);
             $this->register_action('check-recent', [$this, 'check_recent']);
             $this->register_action('itip-status', [$this, 'event_itip_status']);
             $this->register_action('itip-remove', [$this, 'event_itip_remove']);
             $this->register_action('itip-decline-reply', [$this, 'mail_itip_decline_reply']);
             $this->register_action('itip-delegate', [$this, 'mail_itip_delegate']);
             $this->register_action('resources-list', [$this, 'resources_list']);
             $this->register_action('resources-owner', [$this, 'resources_owner']);
             $this->register_action('resources-calendar', [$this, 'resources_calendar']);
             $this->register_action('resources-autocomplete', [$this, 'resources_autocomplete']);
             $this->add_hook('refresh', [$this, 'refresh']);
 
             // remove undo information...
             if (!empty($_SESSION['calendar_event_undo'])) {
                 $undo = $_SESSION['calendar_event_undo'];
                 // ...after timeout
                 $undo_time = $this->rc->config->get('undo_timeout', 0);
                 if ($undo['ts'] < time() - $undo_time) {
                     $this->rc->session->remove('calendar_event_undo');
                     // @TODO: do EXPUNGE on kolab objects?
                 }
             }
         }
         else if ($args['task'] == 'settings') {
             // add hooks for Calendar settings
             $this->add_hook('preferences_sections_list', [$this, 'preferences_sections_list']);
             $this->add_hook('preferences_list', [$this, 'preferences_list']);
             $this->add_hook('preferences_save', [$this, 'preferences_save']);
         }
         else if ($args['task'] == 'mail') {
             // hooks to catch event invitations on incoming mails
             if ($args['action'] == 'show' || $args['action'] == 'preview') {
                 $this->add_hook('template_object_messagebody', [$this, 'mail_messagebody_html']);
             }
 
             // add 'Create event' item to message menu
             if ($this->api->output->type == 'html' && (empty($_GET['_rel']) || $_GET['_rel'] != 'event')) {
                 $this->api->output->add_label('calendar.createfrommail');
                 $this->api->add_content(
                     html::tag('li', ['role' => 'menuitem'],
                         $this->api->output->button([
                             'command'  => 'calendar-create-from-mail',
                             'label'    => 'calendar.createfrommail',
                             'type'     => 'link',
                             'classact' => 'icon calendarlink active',
                             'class'    => 'icon calendarlink disabled',
                             'innerclass' => 'icon calendar',
                         ])
                     ),
                     'messagemenu'
                 );
             }
 
             $this->add_hook('messages_list', [$this, 'mail_messages_list']);
             $this->add_hook('message_compose', [$this, 'mail_message_compose']);
         }
         else if ($args['task'] == 'addressbook') {
             if ($this->rc->config->get('calendar_contact_birthdays')) {
                 $this->add_hook('contact_update', [$this, 'contact_update']);
                 $this->add_hook('contact_create', [$this, 'contact_update']);
             }
         }
 
         // add hooks to display alarms
         $this->add_hook('pending_alarms', [$this, 'pending_alarms']);
         $this->add_hook('dismiss_alarms', [$this, 'dismiss_alarms']);
     }
 
     /**
      * Helper method to load the backend driver according to local config
      */
     private function load_driver()
     {
         if (!empty($this->driver)) {
             return;
         }
 
         $driver_name = $this->rc->config->get('calendar_driver', 'database');
         $driver_class = $driver_name . '_driver';
 
         require_once($this->home . '/drivers/calendar_driver.php');
         require_once($this->home . '/drivers/' . $driver_name . '/' . $driver_class . '.php');
 
         $this->driver = new $driver_class($this);
 
         if ($this->driver->undelete) {
             $this->driver->undelete = $this->rc->config->get('undo_timeout', 0) > 0;
         }
     }
 
     /**
      * Load iTIP functions
      */
     private function load_itip()
     {
         if (empty($this->itip)) {
             require_once($this->home . '/lib/calendar_itip.php');
             $this->itip = new calendar_itip($this);
 
             if ($this->rc->config->get('kolab_invitation_calendars')) {
                 $this->itip->set_rsvp_actions(['accepted','tentative','declined','delegated','needs-action']);
             }
         }
 
         return $this->itip;
     }
 
     /**
      * Load iCalendar functions
      */
     public function get_ical()
     {
         if (empty($this->ical)) {
             $this->ical = libcalendaring::get_ical();
         }
 
         return $this->ical;
     }
 
     /**
      * Get properties of the calendar this user has specified as default
      */
     public function get_default_calendar($sensitivity = null, $calendars = null)
     {
         if ($calendars === null) {
             $filter    = calendar_driver::FILTER_PERSONAL | calendar_driver::FILTER_WRITEABLE;
             $calendars = $this->driver->list_calendars($filter);
         }
 
         $default_id = $this->rc->config->get('calendar_default_calendar');
         $calendar   = !empty($calendars[$default_id]) ? $calendars[$default_id] : null;
         $first      = null;
 
         if (!$calendar || $sensitivity) {
             foreach ($calendars as $cal) {
                 if ($sensitivity && !empty($cal['subtype']) && $cal['subtype'] == $sensitivity) {
                     $calendar = $cal;
                     break;
                 }
                 if (!empty($cal['default']) && $cal['editable']) {
                     $calendar = $cal;
                 }
                 if ($cal['editable']) {
                     $first = $cal;
                 }
             }
         }
 
         return $calendar ?: $first;
     }
 
     /**
      * Render the main calendar view from skin template
      */
     function calendar_view()
     {
         $this->rc->output->set_pagetitle($this->gettext('calendar'));
 
         // Add JS files to the page header
         $this->ui->addJS();
 
         $this->ui->init_templates();
         $this->rc->output->add_label('lowest','low','normal','high','highest','delete',
             'cancel','uploading','noemailwarning','close'
         );
 
         // initialize attendees autocompletion
         $this->rc->autocomplete_init();
 
         $this->rc->output->set_env('timezone', $this->timezone->getName());
         $this->rc->output->set_env('calendar_driver', $this->rc->config->get('calendar_driver'), false);
         $this->rc->output->set_env('calendar_resources', (bool)$this->rc->config->get('calendar_resources_driver'));
         $this->rc->output->set_env('identities-selector', $this->ui->identity_select([
                 'id'         => 'edit-identities-list',
                 'aria-label' => $this->gettext('roleorganizer'),
                 'class'      => 'form-control custom-select',
         ]));
 
         $view = rcube_utils::get_input_value('view', rcube_utils::INPUT_GPC);
         if (in_array($view, ['agendaWeek', 'agendaDay', 'month', 'list'])) {
             $this->rc->output->set_env('view', $view);
         }
 
         if ($date = rcube_utils::get_input_value('date', rcube_utils::INPUT_GPC)) {
             $this->rc->output->set_env('date', $date);
         }
 
         if ($msgref = rcube_utils::get_input_value('itip', rcube_utils::INPUT_GPC)) {
             $this->rc->output->set_env('itip_events', $this->itip_events($msgref));
         }
 
         $this->rc->output->send('calendar.calendar');
     }
 
     /**
      * Handler for preferences_sections_list hook.
      * Adds Calendar settings sections into preferences sections list.
      *
      * @param array Original parameters
      *
      * @return array Modified parameters
      */
     function preferences_sections_list($p)
     {
         $p['list']['calendar'] = [
             'id'      => 'calendar',
             'section' => $this->gettext('calendar'),
         ];
 
         return $p;
     }
 
     /**
      * Handler for preferences_list hook.
      * Adds options blocks into Calendar settings sections in Preferences.
      *
      * @param array Original parameters
      *
      * @return array Modified parameters
      */
     function preferences_list($p)
     {
         if ($p['section'] != 'calendar') {
             return $p;
         }
 
         $no_override = array_flip((array) $this->rc->config->get('dont_override'));
 
         $p['blocks']['view']['name'] = $this->gettext('mainoptions');
 
         if (!isset($no_override['calendar_default_view'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             $field_id = 'rcmfd_default_view';
             $view = $this->rc->config->get('calendar_default_view', $this->defaults['calendar_default_view']);
 
             $select = new html_select(['name' => '_default_view', 'id' => $field_id]);
             $select->add($this->gettext('day'), "agendaDay");
             $select->add($this->gettext('week'), "agendaWeek");
             $select->add($this->gettext('month'), "month");
             $select->add($this->gettext('agenda'), "list");
 
             $p['blocks']['view']['options']['default_view'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('default_view'))),
                 'content' => $select->show($view == 'table' ? 'list' : $view),
             ];
         }
 
         if (!isset($no_override['calendar_timeslots'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             $field_id  = 'rcmfd_timeslot';
             $choices   = ['1', '2', '3', '4', '6'];
             $timeslots = $this->rc->config->get('calendar_timeslots', $this->defaults['calendar_timeslots']);
 
             $select = new html_select(['name' => '_timeslots', 'id' => $field_id]);
             $select->add($choices);
 
             $p['blocks']['view']['options']['timeslots'] = [
                 'title' => html::label($field_id, rcube::Q($this->gettext('timeslots'))),
                 'content' => $select->show(strval($timeslots)),
             ];
         }
 
         if (!isset($no_override['calendar_first_day'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             $field_id  = 'rcmfd_firstday';
             $first_day = $this->rc->config->get('calendar_first_day', $this->defaults['calendar_first_day']);
 
             $select = new html_select(['name' => '_first_day', 'id' => $field_id]);
             $select->add($this->gettext('sunday'), '0');
             $select->add($this->gettext('monday'), '1');
             $select->add($this->gettext('tuesday'), '2');
             $select->add($this->gettext('wednesday'), '3');
             $select->add($this->gettext('thursday'), '4');
             $select->add($this->gettext('friday'), '5');
             $select->add($this->gettext('saturday'), '6');
 
             $p['blocks']['view']['options']['first_day'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('first_day'))),
                 'content' => $select->show(strval($first_day)),
             ];
         }
 
         if (!isset($no_override['calendar_first_hour'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             $first_hour  = $this->rc->config->get('calendar_first_hour', $this->defaults['calendar_first_hour']);
             $time_format = $this->rc->config->get('calendar_time_format', $this->defaults['calendar_time_format']);
             $time_format = $this->rc->config->get('time_format', libcalendaring::to_php_date_format($time_format));
             $field_id    = 'rcmfd_firsthour';
 
             $select_hours = new html_select(['name' => '_first_hour', 'id' => $field_id]);
             for ($h = 0; $h < 24; $h++) {
                 $select_hours->add(date($time_format, mktime($h, 0, 0)), $h);
             }
 
             $p['blocks']['view']['options']['first_hour'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('first_hour'))),
                 'content' => $select_hours->show($first_hour),
             ];
         }
 
         if (!isset($no_override['calendar_work_start'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             $field_id   = 'rcmfd_workstart';
             $work_start = $this->rc->config->get('calendar_work_start', $this->defaults['calendar_work_start']);
             $work_end   = $this->rc->config->get('calendar_work_end', $this->defaults['calendar_work_end']);
 
             $p['blocks']['view']['options']['workinghours'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('workinghours'))),
                 'content' => html::div('input-group',
                     $select_hours->show($work_start, ['name' => '_work_start', 'id' => $field_id])
                     . html::span('input-group-append input-group-prepend', html::span('input-group-text',' &mdash; '))
                     . $select_hours->show($work_end, ['name' => '_work_end', 'id' => $field_id])
                 )
             ];
         }
 
         if (!isset($no_override['calendar_event_coloring'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             $field_id = 'rcmfd_coloring';
             $mode     = $this->rc->config->get('calendar_event_coloring', $this->defaults['calendar_event_coloring']);
 
             $select_colors = new html_select(['name' => '_event_coloring', 'id' => $field_id]);
             $select_colors->add($this->gettext('coloringmode0'), 0);
             $select_colors->add($this->gettext('coloringmode1'), 1);
             $select_colors->add($this->gettext('coloringmode2'), 2);
             $select_colors->add($this->gettext('coloringmode3'), 3);
 
             $p['blocks']['view']['options']['eventcolors'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('eventcoloring'))),
                 'content' => $select_colors->show($mode),
             ];
         }
 
         // loading driver is expensive, don't do it if not needed
         $this->load_driver();
 
         if (!isset($no_override['calendar_default_alarm_type']) || !isset($no_override['calendar_default_alarm_offset'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             $alarm_type = $alarm_offset = '';
 
             if (!isset($no_override['calendar_default_alarm_type'])) {
                 $field_id    = 'rcmfd_alarm';
                 $select_type = new html_select(['name' => '_alarm_type', 'id' => $field_id]);
                 $select_type->add($this->gettext('none'), '');
 
                 foreach ($this->driver->alarm_types as $type) {
                     $select_type->add($this->rc->gettext(strtolower("alarm{$type}option"), 'libcalendaring'), $type);
                 }
 
                 $alarm_type = $select_type->show($this->rc->config->get('calendar_default_alarm_type', ''));
             }
 
             if (!isset($no_override['calendar_default_alarm_offset'])) {
                 $field_id      = 'rcmfd_alarm';
                 $input_value   = new html_inputfield(['name' => '_alarm_value', 'id' => $field_id . 'value', 'size' => 3]);
                 $select_offset = new html_select(['name' => '_alarm_offset', 'id' => $field_id . 'offset']);
 
                 foreach (['-M','-H','-D','+M','+H','+D'] as $trigger) {
                     $select_offset->add($this->rc->gettext('trigger' . $trigger, 'libcalendaring'), $trigger);
                 }
 
                 $preset = libcalendaring::parse_alarm_value($this->rc->config->get('calendar_default_alarm_offset', '-15M'));
                 $alarm_offset = $input_value->show($preset[0]) . ' ' . $select_offset->show($preset[1]);
             }
 
             $p['blocks']['view']['options']['alarmtype'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('defaultalarmtype'))),
                 'content' => html::div('input-group', $alarm_type . ' ' . $alarm_offset),
             ];
         }
 
         if (!isset($no_override['calendar_default_calendar'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             // default calendar selection
             $field_id   = 'rcmfd_default_calendar';
             $filter     = calendar_driver::FILTER_PERSONAL | calendar_driver::FILTER_ACTIVE | calendar_driver::FILTER_INSERTABLE;
             $select_cal = new html_select(['name' => '_default_calendar', 'id' => $field_id, 'is_escaped' => true]);
 
             $default_calendar = null;
             foreach ((array) $this->driver->list_calendars($filter) as $id => $prop) {
                 $select_cal->add($prop['name'], strval($id));
                 if (!empty($prop['default'])) {
                     $default_calendar = $id;
                 }
             }
 
             $p['blocks']['view']['options']['defaultcalendar'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('defaultcalendar'))),
                 'content' => $select_cal->show($this->rc->config->get('calendar_default_calendar', $default_calendar)),
             ];
         }
 
         if (!isset($no_override['calendar_show_weekno'])) {
             if (empty($p['current'])) {
                 $p['blocks']['view']['content'] = true;
                 return $p;
             }
 
             $field_id   = 'rcmfd_show_weekno';
             $select = new html_select(['name' => '_show_weekno', 'id' => $field_id]);
             $select->add($this->gettext('weeknonone'), -1);
             $select->add($this->gettext('weeknodatepicker'), 0);
             $select->add($this->gettext('weeknoall'), 1);
 
             $p['blocks']['view']['options']['show_weekno'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('showweekno'))),
                 'content' => $select->show(intval($this->rc->config->get('calendar_show_weekno'))),
             ];
         }
 
         $p['blocks']['itip']['name'] = $this->gettext('itipoptions');
 
         // Invitations handling
         if (!isset($no_override['calendar_itip_after_action'])) {
             if (empty($p['current'])) {
                 $p['blocks']['itip']['content'] = true;
                 return $p;
             }
 
             $field_id = 'rcmfd_after_action';
             $select   = new html_select([
                     'name'     => '_after_action',
                     'id'       => $field_id,
                     'onchange' => "\$('#{$field_id}_select')[this.value == 4 ? 'show' : 'hide']()"
             ]);
 
             $select->add($this->gettext('afternothing'), '');
             $select->add($this->gettext('aftertrash'), 1);
             $select->add($this->gettext('afterdelete'), 2);
             $select->add($this->gettext('afterflagdeleted'), 3);
             $select->add($this->gettext('aftermoveto'), 4);
 
             $val    = $this->rc->config->get('calendar_itip_after_action', $this->defaults['calendar_itip_after_action']);
             $folder = null;
 
             if ($val !== null && $val !== '' && !is_int($val)) {
                 $folder = $val;
                 $val    = 4;
             }
 
             $folders = $this->rc->folder_selector([
                     'id'            => $field_id . '_select',
                     'name'          => '_after_action_folder',
                     'maxlength'     => 30,
                     'folder_filter' => 'mail',
                     'folder_rights' => 'w',
                     'style'         => $val !== 4 ? 'display:none' : '',
             ]);
 
             $p['blocks']['itip']['options']['after_action'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('afteraction'))),
                 'content' => html::div(
                     'input-group input-group-combo',
                     $select->show($val) . $folders->show($folder)
                 ),
             ];
         }
 
         // category definitions
         if (empty($this->driver->nocategories) && !isset($no_override['calendar_categories'])) {
             $p['blocks']['categories']['name'] = $this->gettext('categories');
 
             if (empty($p['current'])) {
                 $p['blocks']['categories']['content'] = true;
                 return $p;
             }
 
             $categories      = (array) $this->driver->list_categories();
             $categories_list = '';
 
             foreach ($categories as $name => $color) {
                 $key = md5($name);
                 $field_class = 'rcmfd_category_' . str_replace(' ', '_', $name);
                 $category_remove = html::span('input-group-append',
                     html::a([
                             'class'   => 'button icon delete input-group-text',
                             'onclick' => '$(this).parent().parent().remove()',
                             'title'   => $this->gettext('remove_category'),
                             'href'    => '#rcmfd_new_category',
                         ],
                         html::span('inner', $this->gettext('delete'))
                     )
                 );
 
                 $category_name  = new html_inputfield(array('name' => "_categories[$key]", 'class' => $field_class, 'size' => 30, 'disabled' => $this->driver->categoriesimmutable));
                 $category_color = new html_inputfield(array('name' => "_colors[$key]", 'class' => "$field_class colors", 'size' => 6));
                 $hidden         = '';
 
                 if (!empty($this->driver->categoriesimmutable)) {
                     $hidden =  html::tag('input', ['type' => 'hidden', 'name' => "_categories[$key]", 'value' => $name]);
                 }
 
                 $categories_list .= $hidden
                     . html::div('input-group', $category_name->show($name) . $category_color->show($color) . $category_remove);
             }
 
             $p['blocks']['categories']['options']['category_' . $name] = [
                 'content' => html::div(['id' => 'calendarcategories'], $categories_list),
             ];
 
             $field_id = 'rcmfd_new_category';
             $new_category = new html_inputfield(['name' => '_new_category', 'id' => $field_id, 'size' => 30]);
             $add_category = html::span('input-group-append',
                 html::a(
                     [
                         'type'    => 'button',
                         'class'   => 'button create input-group-text',
                         'title'   => $this->gettext('add_category'),
                         'onclick' => 'rcube_calendar_add_category()',
                         'href'    => '#rcmfd_new_category',
                     ],
                     html::span('inner', $this->gettext('add_category'))
                 )
             );
 
             $p['blocks']['categories']['options']['categories'] = [
                 'content' => html::div('input-group', $new_category->show('') . $add_category),
             ];
 
             $this->rc->output->add_label('delete', 'calendar.remove_category');
             $this->rc->output->add_script('
 function rcube_calendar_add_category() {
     var name = $("#rcmfd_new_category").val();
     if (name.length) {
         var button_label = rcmail.gettext("calendar.remove_category");
         var input = $("<input>").attr({type: "text", name: "_categories[]", size: 30, "class": "form-control"}).val(name);
         var color = $("<input>").attr({type: "text", name: "_colors[]", size: 6, "class": "colors form-control"}).val("000000");
         var button = $("<a>").attr({"class": "button icon delete input-group-text", title: button_label, href: "#rcmfd_new_category"})
             .click(function() { $(this).parent().parent().remove(); })
             .append($("<span>").addClass("inner").text(rcmail.gettext("delete")));
 
         $("<div>").addClass("input-group").append(input).append(color).append($("<span class=\'input-group-append\'>").append(button))
             .appendTo("#calendarcategories");
         color.minicolors(rcmail.env.minicolors_config || {});
         $("#rcmfd_new_category").val("");
     }
 }',
                 'foot'
             );
 
             $this->rc->output->add_script('
 $("#rcmfd_new_category").keypress(function(event) {
     if (event.which == 13) {
         rcube_calendar_add_category();
         event.preventDefault();
     }
 });',
                 'docready'
             );
 
             // load miniColors js/css files
             jqueryui::miniColors();
         }
 
         // virtual birthdays calendar
         if (!isset($no_override['calendar_contact_birthdays'])) {
             $p['blocks']['birthdays']['name'] = $this->gettext('birthdayscalendar');
 
             if (empty($p['current'])) {
                 $p['blocks']['birthdays']['content'] = true;
                 return $p;
             }
 
             $field_id = 'rcmfd_contact_birthdays';
             $input    = new html_checkbox([
                     'name'    => '_contact_birthdays',
                     'id'      => $field_id,
                     'value'   => 1,
                     'onclick' => '$(".calendar_birthday_props").prop("disabled",!this.checked)'
             ]);
 
             $p['blocks']['birthdays']['options']['contact_birthdays'] = [
                 'title'   => html::label($field_id, $this->gettext('displaybirthdayscalendar')),
                 'content' => $input->show($this->rc->config->get('calendar_contact_birthdays') ? 1 : 0),
             ];
 
             $input_attrib = [
                 'class'    => 'calendar_birthday_props',
                 'disabled' => !$this->rc->config->get('calendar_contact_birthdays'),
             ];
 
             $sources  = [];
             $checkbox = new html_checkbox(['name' => '_birthday_adressbooks[]'] + $input_attrib);
 
             foreach ($this->rc->get_address_sources(false, true) as $source) {
                 $active = in_array($source['id'], (array) $this->rc->config->get('calendar_birthday_adressbooks')) ? $source['id'] : '';
                 $sources[] = html::tag('li', null,
                     html::label(null,
                         $checkbox->show($active, ['value' => $source['id']])
                         . rcube::Q(!empty($source['realname']) ? $source['realname'] : $source['name'])
                     )
                 );
             }
 
             $p['blocks']['birthdays']['options']['birthday_adressbooks'] = [
                 'title'   => rcube::Q($this->gettext('birthdayscalendarsources')),
                 'content' => html::tag('ul', 'proplist', implode("\n", $sources)),
             ];
 
             $field_id = 'rcmfd_birthdays_alarm';
             $select_type = new html_select(['name' => '_birthdays_alarm_type', 'id' => $field_id] + $input_attrib);
             $select_type->add($this->gettext('none'), '');
 
             foreach ($this->driver->alarm_types as $type) {
                 $select_type->add($this->rc->gettext(strtolower("alarm{$type}option"), 'libcalendaring'), $type);
             }
 
             $input_value   = new html_inputfield(['name' => '_birthdays_alarm_value', 'id' => $field_id . 'value', 'size' => 3] + $input_attrib);
             $select_offset = new html_select(['name' => '_birthdays_alarm_offset', 'id' => $field_id . 'offset'] + $input_attrib);
 
             foreach (['-M','-H','-D'] as $trigger) {
                 $select_offset->add($this->rc->gettext('trigger' . $trigger, 'libcalendaring'), $trigger);
             }
 
             $preset      = libcalendaring::parse_alarm_value($this->rc->config->get('calendar_birthdays_alarm_offset', '-1D'));
             $preset_type = $this->rc->config->get('calendar_birthdays_alarm_type', '');
 
             $p['blocks']['birthdays']['options']['birthdays_alarmoffset'] = [
                 'title'   => html::label($field_id, rcube::Q($this->gettext('showalarms'))),
                 'content' => html::div('input-group',
                     $select_type->show($preset_type)
                     . $input_value->show($preset[0]) . ' ' . $select_offset->show($preset[1])
                 ),
             ];
         }
 
         return $p;
     }
 
     /**
      * Handler for preferences_save hook.
      * Executed on Calendar settings form submit.
      *
      * @param array Original parameters
      *
      * @return array Modified parameters
      */
     function preferences_save($p)
     {
         if ($p['section'] == 'calendar') {
             $this->load_driver();
 
             // compose default alarm preset value
             $alarm_offset  = rcube_utils::get_input_value('_alarm_offset', rcube_utils::INPUT_POST);
             $alarm_value   = rcube_utils::get_input_value('_alarm_value', rcube_utils::INPUT_POST);
             $default_alarm = $alarm_offset[0] . intval($alarm_value) . $alarm_offset[1];
 
             $birthdays_alarm_offset = rcube_utils::get_input_value('_birthdays_alarm_offset', rcube_utils::INPUT_POST);
             $birthdays_alarm_value  = rcube_utils::get_input_value('_birthdays_alarm_value', rcube_utils::INPUT_POST);
             $birthdays_alarm_value  = $birthdays_alarm_offset[0] . intval($birthdays_alarm_value) . $birthdays_alarm_offset[1];
 
             $p['prefs'] = [
                 'calendar_default_view' => rcube_utils::get_input_value('_default_view', rcube_utils::INPUT_POST),
                 'calendar_timeslots'    => intval(rcube_utils::get_input_value('_timeslots', rcube_utils::INPUT_POST)),
                 'calendar_first_day'    => intval(rcube_utils::get_input_value('_first_day', rcube_utils::INPUT_POST)),
                 'calendar_first_hour'   => intval(rcube_utils::get_input_value('_first_hour', rcube_utils::INPUT_POST)),
                 'calendar_work_start'   => intval(rcube_utils::get_input_value('_work_start', rcube_utils::INPUT_POST)),
                 'calendar_work_end'     => intval(rcube_utils::get_input_value('_work_end', rcube_utils::INPUT_POST)),
                 'calendar_show_weekno'  => intval(rcube_utils::get_input_value('_show_weekno', rcube_utils::INPUT_POST)),
                 'calendar_event_coloring'       => intval(rcube_utils::get_input_value('_event_coloring', rcube_utils::INPUT_POST)),
                 'calendar_default_alarm_type'   => rcube_utils::get_input_value('_alarm_type', rcube_utils::INPUT_POST),
                 'calendar_default_alarm_offset' => $default_alarm,
                 'calendar_default_calendar'     => rcube_utils::get_input_value('_default_calendar', rcube_utils::INPUT_POST),
                 'calendar_date_format'          => null,  // clear previously saved values
                 'calendar_time_format'          => null,
                 'calendar_contact_birthdays'      => (bool) rcube_utils::get_input_value('_contact_birthdays', rcube_utils::INPUT_POST),
                 'calendar_birthday_adressbooks'   => (array) rcube_utils::get_input_value('_birthday_adressbooks', rcube_utils::INPUT_POST),
                 'calendar_birthdays_alarm_type'   => rcube_utils::get_input_value('_birthdays_alarm_type', rcube_utils::INPUT_POST),
                 'calendar_birthdays_alarm_offset' => $birthdays_alarm_value ?: null,
                 'calendar_itip_after_action'      => intval(rcube_utils::get_input_value('_after_action', rcube_utils::INPUT_POST)),
             ];
 
             if ($p['prefs']['calendar_itip_after_action'] == 4) {
                 $p['prefs']['calendar_itip_after_action'] = rcube_utils::get_input_value('_after_action_folder', rcube_utils::INPUT_POST, true);
             }
 
             // categories
             if (empty($this->driver->nocategories)) {
                 $old_categories = $new_categories = [];
 
                 foreach ($this->driver->list_categories() as $name => $color) {
                     $old_categories[md5($name)] = $name;
                 }
 
                 $categories = (array) rcube_utils::get_input_value('_categories', rcube_utils::INPUT_POST);
                 $colors     = (array) rcube_utils::get_input_value('_colors', rcube_utils::INPUT_POST);
 
                 foreach ($categories as $key => $name) {
                     if (!isset($colors[$key])) {
                         continue;
                     }
 
                     $color = preg_replace('/^#/', '', strval($colors[$key]));
 
                     // rename categories in existing events -> driver's job
                     if (!empty($old_categories[$key])) {
                         $oldname = $old_categories[$key];
                         $this->driver->replace_category($oldname, $name, $color);
                         unset($old_categories[$key]);
                     }
                     else {
                         $this->driver->add_category($name, $color);
                     }
 
                     $new_categories[$name] = $color;
                 }
 
                 // these old categories have been removed, alter events accordingly -> driver's job
                 foreach ((array) $old_categories as $key => $name) {
                     $this->driver->remove_category($name);
                 }
 
                 $p['prefs']['calendar_categories'] = $new_categories;
             }
         }
 
         return $p;
     }
 
     /**
      * Dispatcher for calendar actions initiated by the client
      */
     function calendar_action()
     {
         $action  = rcube_utils::get_input_value('action', rcube_utils::INPUT_GPC);
         $cal     = rcube_utils::get_input_value('c', rcube_utils::INPUT_GPC);
         $success = false;
         $reload  = false;
 
         if (isset($cal['showalarms'])) {
             $cal['showalarms'] = intval($cal['showalarms']);
         }
 
         switch ($action) {
         case "form-new":
         case "form-edit":
             echo $this->ui->calendar_editform($action, $cal);
             exit;
 
         case "new":
             $success = $this->driver->create_calendar($cal);
             $reload  = true;
             break;
 
         case "edit":
             $success = $this->driver->edit_calendar($cal);
             $reload  = true;
             break;
 
         case "delete":
             if ($success = $this->driver->delete_calendar($cal)) {
                 $this->rc->output->command('plugin.destroy_source', ['id' => $cal['id']]);
             }
             break;
 
         case "subscribe":
             if (!$this->driver->subscribe_calendar($cal)) {
                 $this->rc->output->show_message($this->gettext('errorsaving'), 'error');
             }
             else {
                 $calendars = $this->driver->list_calendars();
                 $calendar  = !empty($calendars[$cal['id']]) ? $calendars[$cal['id']] : null;
 
                 // find parent folder and check if it's a "user calendar"
                 // if it's also activated we need to refresh it (#5340)
                 while (!empty($calendar['parent'])) {
                     if (isset($calendars[$calendar['parent']])) {
                         $calendar = $calendars[$calendar['parent']];
                     }
                     else {
                         break;
                     }
                 }
 
                 if ($calendar && $calendar['id'] != $cal['id']
                     && !empty($calendar['active'])
                     && $calendar['group'] == "other user"
                 ) {
                     $this->rc->output->command('plugin.refresh_source', $calendar['id']);
                 }
             }
             return;
 
         case "search":
             $results    = [];
             $color_mode = $this->rc->config->get('calendar_event_coloring', $this->defaults['calendar_event_coloring']);
             $query      = rcube_utils::get_input_value('q', rcube_utils::INPUT_GPC);
             $source     = rcube_utils::get_input_value('source', rcube_utils::INPUT_GPC);
 
             foreach ((array) $this->driver->search_calendars($query, $source) as $id => $prop) {
                 $editname = $prop['editname'];
                 unset($prop['editname']);  // force full name to be displayed
                 $prop['active'] = false;
 
                 // let the UI generate HTML and CSS representation for this calendar
                 $html = $this->ui->calendar_list_item($id, $prop, $jsenv);
                 $cal  = $jsenv[$id];
                 $cal['editname'] = $editname;
                 $cal['html']     = $html;
 
                 if (!empty($prop['color'])) {
                     $cal['css'] = $this->ui->calendar_css_classes($id, $prop, $color_mode);
                 }
 
                 $results[] = $cal;
             }
 
             // report more results available
             if (!empty($this->driver->search_more_results)) {
                 $this->rc->output->show_message('autocompletemore', 'notice');
             }
 
             $reqid = rcube_utils::get_input_value('_reqid', rcube_utils::INPUT_GPC);
             $this->rc->output->command('multi_thread_http_response', $results, $reqid);
             return;
         }
 
         if ($success) {
             $this->rc->output->show_message('successfullysaved', 'confirmation');
         }
         else {
             $error_msg = $this->gettext('errorsaving');
             if (!empty($this->driver->last_error)) {
                 $error_msg .= ': ' . $this->driver->last_error;
             }
             $this->rc->output->show_message($error_msg, 'error');
         }
 
         $this->rc->output->command('plugin.unlock_saving');
 
         if ($success && $reload) {
             $this->rc->output->command('plugin.reload_view');
         }
     }
 
     /**
      * Dispatcher for event actions initiated by the client
      */
     function event_action()
     {
         $action  = rcube_utils::get_input_value('action', rcube_utils::INPUT_GPC);
         $event   = rcube_utils::get_input_value('e', rcube_utils::INPUT_POST, true);
         $success = $reload = $got_msg = false;
         $old     = null;
 
         // read old event data in order to find changes
         if ((!empty($event['_notify']) || !empty($event['_decline'])) && $action != 'new') {
             $old = $this->driver->get_event($event);
 
             // load main event if savemode is 'all' or if deleting 'future' events
             if (($event['_savemode'] == 'all' || ($event['_savemode'] == 'future' && $action == 'remove' && empty($event['_decline'])))
                 && !empty($old['recurrence_id'])
             ) {
                 $old['id'] = $old['recurrence_id'];
                 $old = $this->driver->get_event($old);
             }
         }
 
         switch ($action) {
         case "new":
             // create UID for new event
             $event['uid'] = $this->generate_uid();
             if (!$this->write_preprocess($event, $action)) {
                 $got_msg = true;
             }
             else if ($success = $this->driver->new_event($event)) {
                 $event['id']        = $event['uid'];
                 $event['_savemode'] = 'all';
 
                 $this->cleanup_event($event);
                 $this->event_save_success($event, null, $action, true);
             }
 
             $reload = $success && !empty($event['recurrence']) ? 2 : 1;
             break;
 
         case "edit":
             if (!$this->write_preprocess($event, $action)) {
                 $got_msg = true;
             }
             else if ($success = $this->driver->edit_event($event)) {
                 $this->cleanup_event($event);
                 $this->event_save_success($event, $old, $action, $success);
             }
 
             $reload = $success && (!empty($event['recurrence']) || !empty($event['_savemode']) || !empty($event['_fromcalendar'])) ? 2 : 1;
             break;
 
         case "resize":
             if (!$this->write_preprocess($event, $action)) {
                 $got_msg = true;
             }
             else if ($success = $this->driver->resize_event($event)) {
                 $this->event_save_success($event, $old, $action, $success);
             }
 
             $reload = !empty($event['_savemode']) ? 2 : 1;
             break;
 
         case "move":
             if (!$this->write_preprocess($event, $action)) {
                 $got_msg = true;
             }
             else if ($success = $this->driver->move_event($event)) {
                 $this->event_save_success($event, $old, $action, $success);
             }
 
             $reload = $success && !empty($event['_savemode']) ? 2 : 1;
             break;
 
         case "remove":
             // remove previous deletes
             $undo_time = $this->driver->undelete ? $this->rc->config->get('undo_timeout', 0) : 0;
 
             // search for event if only UID is given
             if (!isset($event['calendar']) && !empty($event['uid'])) {
                 if (!($event = $this->driver->get_event($event, calendar_driver::FILTER_WRITEABLE))) {
                     break;
                 }
                 $undo_time = 0;
             }
 
             // Note: the driver is responsible for setting $_SESSION['calendar_event_undo']
             //       containing 'ts' and 'data' elements
             $success = $this->driver->remove_event($event, $undo_time < 1);
             $reload = (!$success || !empty($event['_savemode'])) ? 2 : 1;
 
             if ($undo_time > 0 && $success) {
                 // display message with Undo link.
                 $onclick = sprintf("%s.http_request('event', 'action=undo', %s.display_message('', 'loading'))",
                     rcmail_output::JS_OBJECT_NAME,
                     rcmail_output::JS_OBJECT_NAME
                 );
                 $msg = html::span(null, $this->gettext('successremoval'))
                     . ' ' . html::a(['onclick' => $onclick], $this->gettext('undo'));
 
                 $this->rc->output->show_message($msg, 'confirmation', null, true, $undo_time);
                 $got_msg = true;
             }
             else if ($success) {
                 $this->rc->output->show_message('calendar.successremoval', 'confirmation');
                 $got_msg = true;
             }
 
             // send cancellation for the main event
             if ($event['_savemode'] == 'all') {
                 unset($old['_instance'], $old['recurrence_date'], $old['recurrence_id']);
             }
             // send an update for the main event's recurrence rule instead of a cancellation message
             else if ($event['_savemode'] == 'future' && $success !== false && $success !== true) {
                 $event['_savemode'] = 'all';  // force event_save_success() to load master event
                 $action  = 'edit';
                 $success = true;
             }
 
             // send iTIP reply that participant has declined the event
             if ($success && !empty($event['_decline'])) {
                 $emails    = $this->get_user_emails();
                 $organizer = null;
 
                 foreach ($old['attendees'] as $i => $attendee) {
                     if ($attendee['role'] == 'ORGANIZER') {
                         $organizer = $attendee;
                     }
                     else if (!empty($attendee['email']) && in_array(strtolower($attendee['email']), $emails)) {
                         $old['attendees'][$i]['status'] = 'DECLINED';
                         $reply_sender = $attendee['email'];
                     }
                 }
 
                 if ($event['_savemode'] == 'future' && $event['id'] != $old['id']) {
                     $old['thisandfuture'] = true;
                 }
 
                 $itip = $this->load_itip();
                 $itip->set_sender_email($reply_sender);
 
                 if ($organizer && $itip->send_itip_message($old, 'REPLY', $organizer, 'itipsubjectdeclined', 'itipmailbodydeclined')) {
                     $mailto = !empty($organizer['name']) ? $organizer['name'] : $organizer['email'];
                     $msg    = $this->gettext(['name' => 'sentresponseto', 'vars' => ['mailto' => $mailto]]);
 
                     $this->rc->output->command('display_message', $msg, 'confirmation');
                 }
                 else {
                     $this->rc->output->command('display_message', $this->gettext('itipresponseerror'), 'error');
                 }
             }
             else if ($success) {
                 $this->event_save_success($event, $old, $action, $success);
             }
 
             break;
 
         case "undo":
             // Restore deleted event
             if (!empty($_SESSION['calendar_event_undo']['data'])) {
                 $event   = $_SESSION['calendar_event_undo']['data'];
                 $success = $this->driver->restore_event($event);
             }
 
             if ($success) {
                 $this->rc->session->remove('calendar_event_undo');
                 $this->rc->output->show_message('calendar.successrestore', 'confirmation');
                 $got_msg = true;
                 $reload  = 2;
             }
 
             break;
 
         case "rsvp":
             $itip_sending  = $this->rc->config->get('calendar_itip_send_option', $this->defaults['calendar_itip_send_option']);
             $status        = rcube_utils::get_input_value('status', rcube_utils::INPUT_POST);
             $attendees     = rcube_utils::get_input_value('attendees', rcube_utils::INPUT_POST);
             $reply_comment = $event['comment'];
 
             $this->write_preprocess($event, 'edit');
             $ev = $this->driver->get_event($event);
             $ev['attendees'] = $event['attendees'];
             $ev['free_busy'] = $event['free_busy'];
             $ev['_savemode'] = $event['_savemode'];
             $ev['comment']   = $reply_comment;
 
             // send invitation to delegatee + add it as attendee
             if ($status == 'delegated' && !empty($event['to'])) {
                 $itip = $this->load_itip();
                 if ($itip->delegate_to($ev, $event['to'], !empty($event['rsvp']), $attendees)) {
                     $this->rc->output->show_message('calendar.itipsendsuccess', 'confirmation');
                     $noreply = false;
                 }
             }
 
             $event = $ev;
 
             // compose a list of attendees affected by this change
             $updated_attendees = array_filter(array_map(function($j) use ($event) {
                     return $event['attendees'][$j];
                 },
                 $attendees
             ));
 
             if ($success = $this->driver->edit_rsvp($event, $status, $updated_attendees)) {
                 $noreply = rcube_utils::get_input_value('noreply', rcube_utils::INPUT_GPC);
                 $noreply = intval($noreply) || $status == 'needs-action' || $itip_sending === 0;
                 $reload  = $event['calendar'] != $ev['calendar'] || !empty($event['recurrence']) ? 2 : 1;
                 $emails  = $this->get_user_emails();
+                $ownedResourceEmails  = $this->owned_resources_emails($emails);
                 $organizer = null;
+                $resourceConfirmation = false;
 
                 foreach ($event['attendees'] as $i => $attendee) {
                     if ($attendee['role'] == 'ORGANIZER') {
                         $organizer = $attendee;
                     }
-                    else if (!empty($attendee['email']) && in_array(strtolower($attendee['email']), $emails)) {
+                    else if (!empty($attendee['email']) && in_array_nocase($attendee['email'], $emails)) {
                         $reply_sender = $attendee['email'];
                     }
+                    else if (!empty($attendee['cutype']) && $attendee['cutype'] == 'RESOURCE' && !empty($attendee['email']) && in_array_nocase($attendee['email'], $ownedResourceEmails)) {
+                        $resourceConfirmation = true;
+                        // Note on behalf of which resource this update is going to be sent out
+                        $event['_resource'] = $attendee['email'];
+                    }
                 }
 
                 if (!$noreply) {
                     $itip = $this->load_itip();
                     $itip->set_sender_email($reply_sender);
                     $event['thisandfuture'] = $event['_savemode'] == 'future';
+                    $bodytextprefix = $resourceConfirmation ? 'itipmailbodyresource' : 'itipmailbody';
 
-                    if ($organizer && $itip->send_itip_message($event, 'REPLY', $organizer, 'itipsubject' . $status, 'itipmailbody' . $status)) {
+                    if ($organizer && $itip->send_itip_message($event, 'REPLY', $organizer, 'itipsubject' . $status, $bodytextprefix . $status)) {
                         $mailto = !empty($organizer['name']) ? $organizer['name'] : $organizer['email'];
                         $msg    = $this->gettext(['name' => 'sentresponseto', 'vars' => ['mailto' => $mailto]]);
 
                         $this->rc->output->command('display_message', $msg, 'confirmation');
                     }
                     else {
                         $this->rc->output->command('display_message', $this->gettext('itipresponseerror'), 'error');
                     }
                 }
 
                 // refresh all calendars
                 if ($event['calendar'] != $ev['calendar']) {
                     $this->rc->output->command('plugin.refresh_calendar', ['source' => null, 'refetch' => true]);
                     $reload = 0;
                 }
             }
 
             break;
 
         case "dismiss":
             $event['ids'] = explode(',', $event['id']);
             $plugin  = $this->rc->plugins->exec_hook('dismiss_alarms', $event);
             $success = $plugin['success'];
 
             foreach ($event['ids'] as $id) {
                 if (strpos($id, 'cal:') === 0) {
                     $success |= $this->driver->dismiss_alarm(substr($id, 4), $event['snooze']);
                 }
             }
 
             break;
 
         case "changelog":
             $data = $this->driver->get_event_changelog($event);
             if (is_array($data) && !empty($data)) {
                 $lib = $this->lib;
                 $dtformat = $this->rc->config->get('date_format') . ' ' . $this->rc->config->get('time_format');
                 array_walk($data, function(&$change) use ($lib, $dtformat) {
                     if (!empty($change['date'])) {
                         $dt = $lib->adjust_timezone($change['date']);
 
                         if ($dt instanceof DateTime) {
                             $change['date'] = $this->rc->format_date($dt, $dtformat, false);
                         }
                     }
                 });
 
                 $this->rc->output->command('plugin.render_event_changelog', $data);
             }
             else {
                 $this->rc->output->command('plugin.render_event_changelog', false);
             }
 
             $got_msg = true;
             $reload  = false;
 
             break;
 
         case "diff":
             $data = $this->driver->get_event_diff($event, $event['rev1'], $event['rev2']);
             if (is_array($data)) {
                 // convert some properties, similar to self::_client_event()
                 $lib = $this->lib;
                 array_walk($data['changes'], function(&$change, $i) use ($event, $lib) {
                     // convert date cols
                     foreach (['start', 'end', 'created', 'changed'] as $col) {
                         if ($change['property'] == $col) {
                             $change['old'] = $lib->adjust_timezone($change['old'], strlen($change['old']) == 10)->format('c');
                             $change['new'] = $lib->adjust_timezone($change['new'], strlen($change['new']) == 10)->format('c');
                         }
                     }
                     // create textual representation for alarms and recurrence
                     if ($change['property'] == 'alarms') {
                         if (is_array($change['old'])) {
                             $change['old_'] = libcalendaring::alarm_text($change['old']);
                         }
                         if (is_array($change['new'])) {
                             $change['new_'] = libcalendaring::alarm_text(array_merge((array)$change['old'], $change['new']));
                         }
                     }
                     if ($change['property'] == 'recurrence') {
                         if (is_array($change['old'])) {
                             $change['old_'] = $lib->recurrence_text($change['old']);
                         }
                         if (is_array($change['new'])) {
                             $change['new_'] = $lib->recurrence_text(array_merge((array)$change['old'], $change['new']));
                         }
                     }
                     if ($change['property'] == 'attachments') {
                         if (is_array($change['old'])) {
                             $change['old']['classname'] = rcube_utils::file2class($change['old']['mimetype'], $change['old']['name']);
                         }
                         if (is_array($change['new'])) {
                             $change['new']['classname'] = rcube_utils::file2class($change['new']['mimetype'], $change['new']['name']);
                         }
                     }
                     // compute a nice diff of description texts
                     if ($change['property'] == 'description') {
                         $change['diff_'] = libkolab::html_diff($change['old'], $change['new']);
                     }
                 });
 
                 $this->rc->output->command('plugin.event_show_diff', $data);
             }
             else {
                 $this->rc->output->command('display_message', $this->gettext('objectdiffnotavailable'), 'error');
             }
 
             $got_msg = true;
             $reload  = false;
 
             break;
 
         case "show":
             if ($event = $this->driver->get_event_revison($event, $event['rev'])) {
                 $this->rc->output->command('plugin.event_show_revision', $this->_client_event($event));
             }
             else {
                 $this->rc->output->command('display_message', $this->gettext('objectnotfound'), 'error');
             }
 
             $got_msg = true;
             $reload  = false;
             break;
 
         case "restore":
             if ($success = $this->driver->restore_event_revision($event, $event['rev'])) {
                 $_event = $this->driver->get_event($event);
                 $reload = $_event['recurrence'] ? 2 : 1;
                 $msg = $this->gettext(['name' => 'objectrestoresuccess', 'vars' => ['rev' => $event['rev']]]);
                 $this->rc->output->command('display_message', $msg, 'confirmation');
                 $this->rc->output->command('plugin.close_history_dialog');
             }
             else {
                 $this->rc->output->command('display_message', $this->gettext('objectrestoreerror'), 'error');
                 $reload = 0;
             }
 
             $got_msg = true;
             break;
         }
 
         // show confirmation/error message
         if (!$got_msg) {
             if ($success) {
                 $this->rc->output->show_message('successfullysaved', 'confirmation');
             }
             else {
                 $this->rc->output->show_message('calendar.errorsaving', 'error');
             }
         }
 
         // unlock client
         $this->rc->output->command('plugin.unlock_saving', $success);
 
         // update event object on the client or trigger a complete refresh if too complicated
         if ($reload && empty($_REQUEST['_framed'])) {
             $args = ['source' => $event['calendar']];
             if ($reload > 1) {
                 $args['refetch'] = true;
             }
             else if ($success && $action != 'remove') {
                 $args['update'] = $this->_client_event($this->driver->get_event($event), true);
             }
             $this->rc->output->command('plugin.refresh_calendar', $args);
         }
     }
 
     /**
      * Helper method sending iTip notifications after successful event updates
      */
     private function event_save_success(&$event, $old, $action, $success)
     {
         // $success is a new event ID
         if ($success !== true) {
             // send update notification on the main event
             if ($event['_savemode'] == 'future' && !empty($event['_notify'])
                 && !empty($old['attendees']) && !empty($old['recurrence_id'])
             ) {
                 $master = $this->driver->get_event(['id' => $old['recurrence_id'], 'calendar' => $old['calendar']], 0, true);
                 unset($master['_instance'], $master['recurrence_date']);
 
                 $sent = $this->notify_attendees($master, null, $action, $event['_comment'], false);
                 if ($sent < 0) {
                     $this->rc->output->show_message('calendar.errornotifying', 'error');
                 }
 
                 $event['attendees'] = $master['attendees'];  // this tricks us into the next if clause
             }
 
             // delete old reference if saved as new
             if ($event['_savemode'] == 'future' || $event['_savemode'] == 'new') {
                 $old = null;
             }
 
             $event['id']        = $success;
             $event['_savemode'] = 'all';
         }
 
         // send out notifications
         if (!empty($event['_notify']) && (!empty($event['attendees']) || !empty($old['attendees']))) {
             $_savemode = $event['_savemode'];
 
             // send notification for the main event when savemode is 'all'
             if ($action != 'remove' && $_savemode == 'all'
                 && (!empty($event['recurrence_id']) || !empty($old['recurrence_id']) || ($old && $old['id'] != $event['id']))
             ) {
                 if (!empty($event['recurrence_id'])) {
                     $event['id'] = $event['recurrence_id'];
                 }
                 else if (!empty($old['recurrence_id'])) {
                     $event['id'] = $old['recurrence_id'];
                 }
                 else {
                     $event['id'] = $old['id'];
                 }
                 $event = $this->driver->get_event($event, 0, true);
                 unset($event['_instance'], $event['recurrence_date']);
             }
             else {
                 // make sure we have the complete record
                 $event = $action == 'remove' ? $old : $this->driver->get_event($event, 0, true);
             }
 
             $event['_savemode'] = $_savemode;
 
             if ($old) {
                 $old['thisandfuture'] = $_savemode == 'future';
             }
 
             // only notify if data really changed (TODO: do diff check on client already)
             if (!$old || $action == 'remove' || self::event_diff($event, $old)) {
                 $comment = isset($event['_comment']) ? $event['_comment'] : null;
                 $sent    = $this->notify_attendees($event, $old, $action, $comment);
 
                 if ($sent > 0) {
                     $this->rc->output->show_message('calendar.itipsendsuccess', 'confirmation');
                 }
                 else if ($sent < 0) {
                     $this->rc->output->show_message('calendar.errornotifying', 'error');
                 }
             }
         }
     }
 
     /**
      * Handler for load-requests from fullcalendar
      * This will return pure JSON formatted output
      */
     function load_events()
     {
         $start  = $this->input_timestamp('start', rcube_utils::INPUT_GET);
         $end    = $this->input_timestamp('end', rcube_utils::INPUT_GET);
         $query  = rcube_utils::get_input_value('q', rcube_utils::INPUT_GET);
         $source = rcube_utils::get_input_value('source', rcube_utils::INPUT_GET);
 
         $events = $this->driver->load_events($start, $end, $query, $source);
         echo $this->encode($events, !empty($query));
         exit;
     }
 
     /**
      * Handler for requests fetching event counts for calendars
      */
     public function count_events()
     {
         // don't update session on these requests (avoiding race conditions)
         $this->rc->session->nowrite = true;
 
         $start  = rcube_utils::get_input_value('start', rcube_utils::INPUT_GET);
         $source = rcube_utils::get_input_value('source', rcube_utils::INPUT_GET);
         $end    = rcube_utils::get_input_value('end', rcube_utils::INPUT_GET);
 
         if (!$start) {
             $start = new DateTime('today 00:00:00', $this->timezone);
             $start = $start->format('U');
         }
 
         $counts = $this->driver->count_events($source, $start, $end);
 
         $this->rc->output->command('plugin.update_counts', ['counts' => $counts]);
     }
 
     /**
      * Load event data from an iTip message attachment
      */
     public function itip_events($msgref)
     {
         $path = explode('/', $msgref);
         $msg  = array_pop($path);
         $mbox = join('/', $path);
         list($uid, $mime_id) = explode('#', $msg);
         $events = [];
 
         if ($event = $this->lib->mail_get_itip_object($mbox, $uid, $mime_id, 'event')) {
             $partstat = 'NEEDS-ACTION';
 
             $event['id']        = $event['uid'];
             $event['temporary'] = true;
             $event['readonly']  = true;
             $event['calendar']  = '--invitation--itip';
             $event['className'] = 'fc-invitation-' . strtolower($partstat);
             $event['_mbox']     = $mbox;
             $event['_uid']      = $uid;
             $event['_part']     = $mime_id;
 
             $events[] = $this->_client_event($event, true);
 
             // add recurring instances
             if (!empty($event['recurrence'])) {
                 // Some installations can't handle all occurrences (aborting the request w/o an error in log)
                 $freq = !empty($event['recurrence']['FREQ']) ? $event['recurrence']['FREQ'] : null;
                 $end  = clone $event['start'];
                 $end->add(new DateInterval($freq == 'DAILY' ? 'P1Y' : 'P10Y'));
 
                 foreach ($this->driver->get_recurring_events($event, $event['start'], $end) as $recurring) {
                     $recurring['temporary'] = true;
                     $recurring['readonly']  = true;
                     $recurring['calendar']  = '--invitation--itip';
 
                     $events[] = $this->_client_event($recurring, true);
                 }
             }
         }
 
         return $events;
     }
 
     /**
      * Handler for keep-alive requests
      * This will check for updated data in active calendars and sync them to the client
      */
     public function refresh($attr)
     {
         // refresh the entire calendar every 10th time to also sync deleted events
         if (rand(0, 10) == 10) {
             $this->rc->output->command('plugin.refresh_calendar', ['refetch' => true]);
             return;
         }
 
         $counts = [];
 
         foreach ($this->driver->list_calendars(calendar_driver::FILTER_ACTIVE) as $cal) {
             $events = $this->driver->load_events(
                 rcube_utils::get_input_value('start', rcube_utils::INPUT_GPC),
                 rcube_utils::get_input_value('end', rcube_utils::INPUT_GPC),
                 rcube_utils::get_input_value('q', rcube_utils::INPUT_GPC),
                 $cal['id'],
                 1,
                 $attr['last']
             );
 
             foreach ($events as $event) {
                 $this->rc->output->command(
                     'plugin.refresh_calendar',
                     ['source' => $cal['id'], 'update' => $this->_client_event($event)]
                 );
             }
 
             // refresh count for this calendar
             if (!empty($cal['counts'])) {
                 $today = new DateTime('today 00:00:00', $this->timezone);
                 $counts += $this->driver->count_events($cal['id'], $today->format('U'));
             }
         }
 
         if (!empty($counts)) {
             $this->rc->output->command('plugin.update_counts', ['counts' => $counts]);
         }
     }
 
     /**
      * Handler for pending_alarms plugin hook triggered by the calendar module on keep-alive requests.
      * This will check for pending notifications and pass them to the client
      */
     public function pending_alarms($p)
     {
         $this->load_driver();
 
         $time = !empty($p['time']) ? $p['time'] : time();
 
         if ($alarms = $this->driver->pending_alarms($time)) {
             foreach ($alarms as $alarm) {
                 $alarm['id'] = 'cal:' . $alarm['id'];  // prefix ID with cal:
                 $p['alarms'][] = $alarm;
             }
         }
 
         // get alarms for birthdays calendar
         if (
             $this->rc->config->get('calendar_contact_birthdays')
             && $this->rc->config->get('calendar_birthdays_alarm_type') == 'DISPLAY'
         ) {
             $cache = $this->rc->get_cache('calendar.birthdayalarms', 'db');
 
             foreach ($this->driver->load_birthday_events($time, $time + 86400 * 60) as $e) {
                 $alarm = libcalendaring::get_next_alarm($e);
 
                 // overwrite alarm time with snooze value (or null if dismissed)
                 if ($dismissed = $cache->get($e['id'])) {
                     $alarm['time'] = $dismissed['notifyat'];
                 }
 
                 // add to list if alarm is set
                 if ($alarm && !empty($alarm['time']) && $alarm['time'] <= $time) {
                     $e['id']       = 'cal:bday:' . $e['id'];
                     $e['notifyat'] = $alarm['time'];
                     $p['alarms'][] = $e;
                 }
             }
         }
 
         return $p;
     }
 
     /**
      * Handler for alarm dismiss hook triggered by libcalendaring
      */
     public function dismiss_alarms($p)
     {
         $this->load_driver();
 
         foreach ((array) $p['ids'] as $id) {
             if (strpos($id, 'cal:bday:') === 0) {
                 $p['success'] |= $this->driver->dismiss_birthday_alarm(substr($id, 9), $p['snooze']);
             }
             else if (strpos($id, 'cal:') === 0) {
                 $p['success'] |= $this->driver->dismiss_alarm(substr($id, 4), $p['snooze']);
             }
         }
 
         return $p;
     }
 
     /**
      * Handler for check-recent requests which are accidentally sent to calendar
      */
     function check_recent()
     {
         // NOP
         $this->rc->output->send();
     }
 
     /**
      * Hook triggered when a contact is saved
      */
     function contact_update($p)
     {
         // clear birthdays calendar cache
         if (!empty($p['record']['birthday'])) {
             $cache = $this->rc->get_cache('calendar.birthdays', 'db');
             $cache->remove();
         }
     }
 
     /**
      *
      */
     function import_events()
     {
         // Upload progress update
         if (!empty($_GET['_progress'])) {
             $this->rc->upload_progress();
         }
 
         @set_time_limit(0);
 
         // process uploaded file if there is no error
         $err = $_FILES['_data']['error'];
 
         if (!$err && !empty($_FILES['_data']['tmp_name'])) {
             $calendar   = rcube_utils::get_input_value('calendar', rcube_utils::INPUT_GPC);
             $rangestart = !empty($_REQUEST['_range']) ? date_create("now -" . intval($_REQUEST['_range']) . " months") : 0;
 
             // extract zip file
             if ($_FILES['_data']['type'] == 'application/zip') {
                 $count = 0;
                 if (class_exists('ZipArchive', false)) {
                     $zip = new ZipArchive();
                     if ($zip->open($_FILES['_data']['tmp_name'])) {
                         $randname = uniqid('zip-' . session_id(), true);
                         $tmpdir = slashify($this->rc->config->get('temp_dir', sys_get_temp_dir())) . $randname;
                         mkdir($tmpdir, 0700);
 
                         // extract each ical file from the archive and import it
                         for ($i = 0; $i < $zip->numFiles; $i++) {
                             $filename = $zip->getNameIndex($i);
                             if (preg_match('/\.ics$/i', $filename)) {
                                 $tmpfile = $tmpdir . '/' . basename($filename);
                                 if (copy('zip://' . $_FILES['_data']['tmp_name'] . '#'.$filename, $tmpfile)) {
                                     $count += $this->import_from_file($tmpfile, $calendar, $rangestart, $errors);
                                     unlink($tmpfile);
                                 }
                             }
                         }
 
                         rmdir($tmpdir);
                         $zip->close();
                     }
                     else {
                         $errors = 1;
                         $msg = 'Failed to open zip file.';
                     }
                 }
                 else {
                     $errors = 1;
                     $msg = 'Zip files are not supported for import.';
                 }
             }
             else {
                 // attempt to import teh uploaded file directly
                 $count = $this->import_from_file($_FILES['_data']['tmp_name'], $calendar, $rangestart, $errors);
             }
 
             if ($count) {
                 $this->rc->output->command('display_message', $this->gettext(['name' => 'importsuccess', 'vars' => ['nr' => $count]]), 'confirmation');
                 $this->rc->output->command('plugin.import_success', ['source' => $calendar, 'refetch' => true]);
             }
             else if (!$errors) {
                 $this->rc->output->command('display_message', $this->gettext('importnone'), 'notice');
                 $this->rc->output->command('plugin.import_success', ['source' => $calendar]);
             }
             else {
                 $this->rc->output->command('plugin.import_error', ['message' => $this->gettext('importerror') . ($msg ? ': ' . $msg : '')]);
             }
         }
         else {
             if ($err == UPLOAD_ERR_INI_SIZE || $err == UPLOAD_ERR_FORM_SIZE) {
                 $max = $this->rc->show_bytes(parse_bytes(ini_get('upload_max_filesize')));
                 $msg = $this->rc->gettext(['name' => 'filesizeerror', 'vars' => ['size' => $max]]);
             }
             else {
                 $msg = $this->rc->gettext('fileuploaderror');
             }
 
             $this->rc->output->command('plugin.import_error', ['message' => $msg]);
         }
 
         $this->rc->output->send('iframe');
     }
 
     /**
      * Helper function to parse and import a single .ics file
      */
     private function import_from_file($filepath, $calendar, $rangestart, &$errors)
     {
         $user_email = $this->rc->user->get_username();
         $ical       = $this->get_ical();
         $errors     = !$ical->fopen($filepath);
 
         $count = $i = 0;
 
         foreach ($ical as $event) {
             // keep the browser connection alive on long import jobs
             if (++$i > 100 && $i % 100 == 0) {
                 echo "<!-- -->";
                 ob_flush();
             }
 
             // TODO: correctly handle recurring events which start before $rangestart
             if ($rangestart && $event['end'] < $rangestart
                 && (empty($event['recurrence']) || (!empty($event['recurrence']['until']) && $event['recurrence']['until'] < $rangestart))
             ) {
                 continue;
             }
 
             $event['_owner']   = $user_email;
             $event['calendar'] = $calendar;
 
             if ($this->driver->new_event($event)) {
                 $count++;
             }
             else {
                 $errors++;
             }
         }
 
         return $count;
     }
 
     /**
      * Construct the ics file for exporting events to iCalendar format;
      */
     function export_events($terminate = true)
     {
         $start       = rcube_utils::get_input_value('start', rcube_utils::INPUT_GET);
         $end         = rcube_utils::get_input_value('end', rcube_utils::INPUT_GET);
         $event_id    = rcube_utils::get_input_value('id', rcube_utils::INPUT_GET);
         $attachments = rcube_utils::get_input_value('attachments', rcube_utils::INPUT_GET);
         $calid       = rcube_utils::get_input_value('source', rcube_utils::INPUT_GET);
 
         if (!isset($start)) {
             $start = 'today -1 year';
         }
         if (!is_numeric($start)) {
             $start = strtotime($start . ' 00:00:00');
         }
         if (!$end) {
             $end = 'today +10 years';
         }
         if (!is_numeric($end)) {
             $end = strtotime($end . ' 23:59:59');
         }
 
         $filename  = $calid;
         $calendars = $this->driver->list_calendars();
         $events    = [];
 
         if (!empty($calendars[$calid])) {
             $filename = !empty($calendars[$calid]['name']) ? $calendars[$calid]['name'] : $calid;
             $filename = asciiwords(html_entity_decode($filename));  // to 7bit ascii
 
             if (!empty($event_id)) {
                 if ($event = $this->driver->get_event(['calendar' => $calid, 'id' => $event_id], 0, true)) {
                     if (!empty($event['recurrence_id'])) {
                         $event = $this->driver->get_event(['calendar' => $calid, 'id' => $event['recurrence_id']], 0, true);
                     }
 
                     $events   = [$event];
                     $filename = asciiwords($event['title']);
 
                     if (empty($filename)) {
                         $filename = 'event';
                     }
                 }
             }
             else {
                 $events = $this->driver->load_events($start, $end, null, $calid, 0);
                 if (empty($filename)) {
                     $filename = $calid;
                 }
             }
         }
 
         header("Content-Type: text/calendar");
         header("Content-Disposition: inline; filename=".$filename.'.ics');
 
         $this->get_ical()->export($events, '', true, $attachments ? [$this->driver, 'get_attachment_body'] : null);
 
         if ($terminate) {
             exit;
         }
     }
 
     /**
      * Handler for iCal feed requests
      */
     function ical_feed_export()
     {
         $session_exists = !empty($_SESSION['user_id']);
 
         // process HTTP auth info
         if (!empty($_SERVER['PHP_AUTH_USER']) && isset($_SERVER['PHP_AUTH_PW'])) {
             $_POST['_user'] = $_SERVER['PHP_AUTH_USER']; // used for rcmail::autoselect_host()
             $auth = $this->rc->plugins->exec_hook('authenticate', [
                 'host' => $this->rc->autoselect_host(),
                 'user' => trim($_SERVER['PHP_AUTH_USER']),
                 'pass' => $_SERVER['PHP_AUTH_PW'],
                 'cookiecheck' => true,
                 'valid'       => true,
             ]);
 
             if ($auth['valid'] && !$auth['abort']) {
                 $this->rc->login($auth['user'], $auth['pass'], $auth['host']);
             }
         }
 
         // require HTTP auth
         if (empty($_SESSION['user_id'])) {
             header('WWW-Authenticate: Basic realm="Kolab Calendar"');
             header('HTTP/1.0 401 Unauthorized');
             exit;
         }
 
         // decode calendar feed hash
         $format  = 'ics';
         $calhash = rcube_utils::get_input_value('_cal', rcube_utils::INPUT_GET);
 
         if (preg_match(($suff_regex = '/\.([a-z0-9]{3,5})$/i'), $calhash, $m)) {
             $format  = strtolower($m[1]);
             $calhash = preg_replace($suff_regex, '', $calhash);
         }
 
         if (!strpos($calhash, ':')) {
             $calhash = base64_decode($calhash);
         }
 
         list($user, $_GET['source']) = explode(':', $calhash, 2);
 
         // sanity check user
         if ($this->rc->user->get_username() == $user) {
             $this->setup();
             $this->load_driver();
             $this->export_events(false);
         }
         else {
             header('HTTP/1.0 404 Not Found');
         }
 
         // don't save session data
         if (!$session_exists) {
             session_destroy();
         }
 
         exit;
     }
 
     /**
      *
      */
     function load_settings()
     {
         $this->lib->load_settings();
         $this->defaults += $this->lib->defaults;
 
         $settings = [];
 
         // configuration
         $settings['default_view']     = (string) $this->rc->config->get('calendar_default_view', $this->defaults['calendar_default_view']);
         $settings['timeslots']        = (int) $this->rc->config->get('calendar_timeslots', $this->defaults['calendar_timeslots']);
         $settings['first_day']        = (int) $this->rc->config->get('calendar_first_day', $this->defaults['calendar_first_day']);
         $settings['first_hour']       = (int) $this->rc->config->get('calendar_first_hour', $this->defaults['calendar_first_hour']);
         $settings['work_start']       = (int) $this->rc->config->get('calendar_work_start', $this->defaults['calendar_work_start']);
         $settings['work_end']         = (int) $this->rc->config->get('calendar_work_end', $this->defaults['calendar_work_end']);
         $settings['agenda_range']     = (int) $this->rc->config->get('calendar_agenda_range', $this->defaults['calendar_agenda_range']);
         $settings['event_coloring']   = (int) $this->rc->config->get('calendar_event_coloring', $this->defaults['calendar_event_coloring']);
         $settings['time_indicator']   = (int) $this->rc->config->get('calendar_time_indicator', $this->defaults['calendar_time_indicator']);
         $settings['invite_shared']    = (int) $this->rc->config->get('calendar_allow_invite_shared', $this->defaults['calendar_allow_invite_shared']);
         $settings['itip_notify']      = (int) $this->rc->config->get('calendar_itip_send_option', $this->defaults['calendar_itip_send_option']);
         $settings['show_weekno']      = (int) $this->rc->config->get('calendar_show_weekno', $this->defaults['calendar_show_weekno']);
         $settings['default_calendar'] = $this->rc->config->get('calendar_default_calendar');
         $settings['invitation_calendars'] = (bool) $this->rc->config->get('kolab_invitation_calendars', false);
 
         // 'table' view has been replaced by 'list' view
         if ($settings['default_view'] == 'table') {
             $settings['default_view'] = 'list';
         }
 
         // get user identity to create default attendee
         if ($this->ui->screen == 'calendar') {
             foreach ($this->rc->user->list_emails() as $rec) {
                 if (empty($identity)) {
                     $identity = $rec;
                 }
 
                 $identity['emails'][] = $rec['email'];
                 $settings['identities'][$rec['identity_id']] = $rec['email'];
             }
 
             $identity['emails'][] = $this->rc->user->get_username();
+            $identity['ownedResources'] = $this->owned_resources_emails($identity['emails']);
             $settings['identity'] = [
                 'name'   => $identity['name'],
                 'email'  => strtolower($identity['email']),
-                'emails' => ';' . strtolower(join(';', $identity['emails']))
+                'emails' => ';' . strtolower(join(';', $identity['emails'])),
+                'ownedResources' => ';' . strtolower(join(';', $identity['ownedResources']))
             ];
         }
 
         // freebusy token authentication URL
         if (($url = $this->rc->config->get('calendar_freebusy_session_auth_url'))
             && ($uniqueid = $this->rc->config->get('kolab_uniqueid'))
         ) {
             if ($url === true) {
                 $url = '/freebusy';
             }
             $url = rtrim(rcube_utils::resolve_url($url), '/ ');
             $url .= '/' . urlencode($this->rc->get_user_name());
             $url .= '/' . urlencode($uniqueid);
 
             $settings['freebusy_url'] = $url;
         }
 
         return $settings;
     }
 
     /**
      * Encode events as JSON
      *
      * @param array Events as array
      * @param bool  Add CSS class names according to calendar and categories
      *
      * @return string JSON encoded events
      */
     function encode($events, $addcss = false)
     {
         $json = [];
         foreach ($events as $event) {
             $json[] = $this->_client_event($event, $addcss);
         }
         return rcube_output::json_serialize($json);
     }
 
     /**
      * Convert an event object to be used on the client
      */
     private function _client_event($event, $addcss = false)
     {
         // compose a human readable strings for alarms_text and recurrence_text
         if (!empty($event['valarms'])) {
             $event['alarms_text'] = libcalendaring::alarms_text($event['valarms']);
             $event['valarms'] = libcalendaring::to_client_alarms($event['valarms']);
         }
 
         if (!empty($event['recurrence'])) {
             $event['recurrence_text'] = $this->lib->recurrence_text($event['recurrence']);
             $event['recurrence'] = $this->lib->to_client_recurrence($event['recurrence'], $event['allday']);
             unset($event['recurrence_date']);
         }
 
         if (!empty($event['attachments'])) {
             foreach ($event['attachments'] as $k => $attachment) {
                 $event['attachments'][$k]['classname'] = rcube_utils::file2class($attachment['mimetype'], $attachment['name']);
 
                 unset($event['attachments'][$k]['data'], $event['attachments'][$k]['content']);
 
                 if (empty($attachment['id'])) {
                     $event['attachments'][$k]['id'] = $k;
                 }
             }
         }
 
         // convert link URIs references into structs
         if (array_key_exists('links', $event)) {
             foreach ((array) $event['links'] as $i => $link) {
                 if (strpos($link, 'imap://') === 0 && ($msgref = $this->driver->get_message_reference($link))) {
                     $event['links'][$i] = $msgref;
                 }
             }
         }
 
         // check for organizer in attendees list
         $organizer = null;
         foreach ((array) $event['attendees'] as $i => $attendee) {
             if ($attendee['role'] == 'ORGANIZER') {
                 $organizer = $attendee;
             }
             if (!empty($attendee['status']) && $attendee['status'] == 'DELEGATED' && empty($attendee['rsvp'])) {
                 $event['attendees'][$i]['noreply'] = true;
             }
             else {
                 unset($event['attendees'][$i]['noreply']);
             }
         }
 
         if ($organizer === null && !empty($event['organizer'])) {
             $organizer = $event['organizer'];
             $organizer['role'] = 'ORGANIZER';
             if (!is_array($event['attendees'])) {
                 $event['attendees'] = [$organizer];
             }
         }
 
         // Convert HTML description into plain text
         if ($this->is_html($event)) {
             $h2t = new rcube_html2text($event['description'], false, true, 0);
             $event['description'] = trim($h2t->get_text());
         }
 
         // mapping url => vurl, allday => allDay because of the fullcalendar client script
         $event['vurl']   = $event['url'];
         $event['allDay'] = !empty($event['allday']);
         unset($event['url']);
         unset($event['allday']);
 
         $event['className'] = !empty($event['className']) ? explode(' ', $event['className']) : [];
 
         if ($event['allDay']) {
             $event['end'] = $event['end']->add(new DateInterval('P1D'));
         }
 
         if (!empty($_GET['mode']) && $_GET['mode'] == 'print') {
             $event['editable'] = false;
         }
 
         return [
             '_id'     => $event['calendar'] . ':' . $event['id'],  // unique identifier for fullcalendar
             'start'   => $this->lib->adjust_timezone($event['start'], $event['allDay'])->format('c'),
             'end'     => $this->lib->adjust_timezone($event['end'], $event['allDay'])->format('c'),
             // 'changed' might be empty for event recurrences (Bug #2185)
             'changed' => !empty($event['changed']) ? $this->lib->adjust_timezone($event['changed'])->format('c') : null,
             'created' => !empty($event['created']) ? $this->lib->adjust_timezone($event['created'])->format('c') : null,
             'title'       => strval($event['title']),
             'description' => strval($event['description']),
             'location'    => strval($event['location']),
         ] + $event;
     }
 
     /**
      * Generate a unique identifier for an event
      */
     public function generate_uid()
     {
         return strtoupper(md5(time() . uniqid(rand())) . '-' . substr(md5($this->rc->user->get_username()), 0, 16));
     }
 
     /**
      * TEMPORARY: generate random event data for testing
      * Create events by opening http://<roundcubeurl>/?_task=calendar&_action=randomdata&_num=500&_date=2014-08-01&_dev=120
      */
     public function generate_randomdata()
     {
         @set_time_limit(0);
 
         $num   = !empty($_REQUEST['_num']) ? intval($_REQUEST['_num']) : 100;
         $date  = !empty($_REQUEST['_date']) ? $_REQUEST['_date'] : 'now';
         $dev   = !empty($_REQUEST['_dev']) ? $_REQUEST['_dev'] : 30;
         $cats  = array_keys($this->driver->list_categories());
         $cals  = $this->driver->list_calendars(calendar_driver::FILTER_ACTIVE);
         $count = 0;
 
         while ($count++ < $num) {
             $spread   = intval($dev) * 86400; // days
             $refdate  = strtotime($date);
             $start    = round(($refdate + rand(-$spread, $spread)) / 600) * 600;
             $duration = round(rand(30, 360) / 30) * 30 * 60;
             $allday   = rand(0,20) > 18;
             $alarm    = rand(-30,12) * 5;
             $fb       = rand(0,2);
 
             if (date('G', $start) > 23) {
                 $start -= 3600;
             }
 
             if ($allday) {
                 $start    = strtotime(date('Y-m-d 00:00:00', $start));
                 $duration = 86399;
             }
 
             $title = '';
             $len = rand(2, 12);
             $words = explode(" ", "The Hough transform is named after Paul Hough who patented the method in 1962."
                 . " It is a technique which can be used to isolate features of a particular shape within an image."
                 . " Because it requires that the desired features be specified in some parametric form, the classical"
                 . " Hough transform is most commonly used for the de- tection of regular curves such as lines, circles,"
                 . " ellipses, etc. A generalized Hough transform can be employed in applications where a simple"
                 . " analytic description of a feature(s) is not possible. Due to the computational complexity of"
                 . " the generalized Hough algorithm, we restrict the main focus of this discussion to the classical"
                 . " Hough transform. Despite its domain restrictions, the classical Hough transform (hereafter"
                 . " referred to without the classical prefix ) retains many applications, as most manufac- tured"
                 . " parts (and many anatomical parts investigated in medical imagery) contain feature boundaries"
                 . " which can be described by regular curves. The main advantage of the Hough transform technique"
                 . " is that it is tolerant of gaps in feature boundary descriptions and is relatively unaffected"
                 . " by image noise.");
             // $chars = "!# abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ 1234567890";
             for ($i = 0; $i < $len; $i++) {
                 $title .= $words[rand(0,count($words)-1)] . " ";
             }
 
             $this->driver->new_event([
                 'uid'        => $this->generate_uid(),
                 'start'      => new DateTime('@'.$start),
                 'end'        => new DateTime('@'.($start + $duration)),
                 'allday'     => $allday,
                 'title'      => rtrim($title),
                 'free_busy'  => $fb == 2 ? 'outofoffice' : ($fb ? 'busy' : 'free'),
                 'categories' => $cats[array_rand($cats)],
                 'calendar'   => array_rand($cals),
                 'alarms'     => $alarm > 0 ? "-{$alarm}M:DISPLAY" : '',
                 'priority'   => rand(0,9),
             ]);
         }
 
         $this->rc->output->redirect('');
     }
 
     /**
      * Handler for attachments upload
      */
     public function attachment_upload()
     {
         $handler = new kolab_attachments_handler();
         $handler->attachment_upload(self::SESSION_KEY, 'cal-');
     }
 
     /**
      * Handler for attachments download/displaying
      */
     public function attachment_get()
     {
         $handler = new kolab_attachments_handler();
 
         // show loading page
         if (!empty($_GET['_preload'])) {
             return $handler->attachment_loading_page();
         }
 
         $event_id = rcube_utils::get_input_value('_event', rcube_utils::INPUT_GPC);
         $calendar = rcube_utils::get_input_value('_cal', rcube_utils::INPUT_GPC);
         $id       = rcube_utils::get_input_value('_id', rcube_utils::INPUT_GPC);
         $rev      = rcube_utils::get_input_value('_rev', rcube_utils::INPUT_GPC);
 
         $event = ['id' => $event_id, 'calendar' => $calendar, 'rev' => $rev];
 
         if ($calendar == '--invitation--itip') {
             $uid  = rcube_utils::get_input_value('_uid', rcube_utils::INPUT_GPC);
             $part = rcube_utils::get_input_value('_part', rcube_utils::INPUT_GPC);
             $mbox = rcube_utils::get_input_value('_mbox', rcube_utils::INPUT_GPC);
 
             $event      = $this->lib->mail_get_itip_object($mbox, $uid, $part, 'event');
             $attachment = $event['attachments'][$id];
             $attachment['body'] = &$attachment['data'];
         }
         else {
             $attachment = $this->driver->get_attachment($id, $event);
         }
 
         // show part page
         if (!empty($_GET['_frame'])) {
             $handler->attachment_page($attachment);
         }
         // deliver attachment content
         else if ($attachment) {
             if ($calendar != '--invitation--itip') {
                 $attachment['body'] = $this->driver->get_attachment_body($id, $event);
             }
 
             $handler->attachment_get($attachment);
         }
 
         // if we arrive here, the requested part was not found
         header('HTTP/1.1 404 Not Found');
         exit;
     }
 
     /**
      * Determine whether the given event description is HTML formatted
      */
     private function is_html($event)
     {
           // check for opening and closing <html> or <body> tags
         return preg_match('/<(html|body)(\s+[a-z]|>)/', $event['description'], $m)
             && strpos($event['description'], '</'.$m[1].'>') > 0;
     }
 
     /**
      * Prepares new/edited event properties before save
      */
     private function write_preprocess(&$event, $action)
     {
         // Remove double timezone specification (T2313)
         $event['start'] = preg_replace('/\s*\(.*\)/', '', $event['start']);
         $event['end']   = preg_replace('/\s*\(.*\)/', '', $event['end']);
 
         // convert dates into DateTime objects in user's current timezone
         $event['start']  = new DateTime($event['start'], $this->timezone);
         $event['end']    = new DateTime($event['end'], $this->timezone);
         $event['allday'] = !empty($event['allDay']);
         unset($event['allDay']);
 
         // start/end is all we need for 'move' action (#1480)
         if ($action == 'move') {
             return true;
         }
 
         // convert the submitted recurrence settings
         if (!empty($event['recurrence'])) {
             $event['recurrence'] = $this->lib->from_client_recurrence($event['recurrence'], $event['start']);
 
             // align start date with the first occurrence
             if (!empty($event['recurrence']) && !empty($event['syncstart'])
                 && (empty($event['_savemode']) || $event['_savemode'] == 'all')
             ) {
                 $next = $this->find_first_occurrence($event);
 
                 if (!$next) {
                     $this->rc->output->show_message('calendar.recurrenceerror', 'error');
                     return false;
                 }
                 else if ($event['start'] != $next) {
                     $diff = $event['start']->diff($event['end'], true);
 
                     $event['start'] = $next;
                     $event['end']   = clone $next;
                     $event['end']->add($diff);
                 }
             }
         }
 
         // convert the submitted alarm values
         if (!empty($event['valarms'])) {
             $event['valarms'] = libcalendaring::from_client_alarms($event['valarms']);
         }
 
         $attachments = [];
         $eventid     = 'cal-' . (!empty($event['id']) ? $event['id'] : 'new-event');
 
         if (!empty($_SESSION[self::SESSION_KEY]) && $_SESSION[self::SESSION_KEY]['id'] == $eventid) {
             if (!empty($_SESSION[self::SESSION_KEY]['attachments'])) {
                 foreach ($_SESSION[self::SESSION_KEY]['attachments'] as $id => $attachment) {
                     if (!empty($event['attachments']) && in_array($id, $event['attachments'])) {
                         $attachments[$id] = $this->rc->plugins->exec_hook('attachment_get', $attachment);
                     }
                 }
             }
         }
 
         $event['attachments'] = $attachments;
 
         // convert link references into simple URIs
         if (array_key_exists('links', $event)) {
             $event['links'] = array_map(function($link) {
                     return is_array($link) ? $link['uri'] : strval($link);
                 },
                 (array) $event['links']
             );
         }
 
         // check for organizer in attendees
         if ($action == 'new' || $action == 'edit') {
             if (empty($event['attendees'])) {
                 $event['attendees'] = [];
             }
 
             $emails = $this->get_user_emails();
             $organizer = $owner = false;
 
             foreach ((array) $event['attendees'] as $i => $attendee) {
                 if ($attendee['role'] == 'ORGANIZER') {
                     $organizer = $i;
                 }
                 if (!empty($attendee['email']) && in_array(strtolower($attendee['email']), $emails)) {
                     $owner = $i;
                 }
                 if (!isset($attendee['rsvp'])) {
                     $event['attendees'][$i]['rsvp'] = true;
                 }
                 else if (is_string($attendee['rsvp'])) {
                     $event['attendees'][$i]['rsvp'] = $attendee['rsvp'] == 'true' || $attendee['rsvp'] == '1';
                 }
             }
 
             if (!empty($event['_identity'])) {
                 $identity = $this->rc->user->get_identity($event['_identity']);
             }
 
             // set new organizer identity
             if ($organizer !== false && !empty($identity)) {
                 $event['attendees'][$organizer]['name']  = $identity['name'];
                 $event['attendees'][$organizer]['email'] = $identity['email'];
             }
             // set owner as organizer if yet missing
             else if ($organizer === false && $owner !== false) {
                 $event['attendees'][$owner]['role'] = 'ORGANIZER';
                 unset($event['attendees'][$owner]['rsvp']);
             }
             // fallback to the selected identity
             else if ($organizer === false && !empty($identity)) {
                 $event['attendees'][] = [
                     'role'  => 'ORGANIZER',
                     'name'  => $identity['name'],
                     'email' => $identity['email'],
                 ];
             }
         }
 
         // mapping url => vurl because of the fullcalendar client script
         if (array_key_exists('vurl', $event)) {
             $event['url'] = $event['vurl'];
             unset($event['vurl']);
         }
 
         return true;
     }
 
     /**
      * Releases some resources after successful event save
      */
     private function cleanup_event(&$event)
     {
         // remove temp. attachment files
         if (!empty($_SESSION[self::SESSION_KEY]) && ($eventid = $_SESSION[self::SESSION_KEY]['id'])) {
             $this->rc->plugins->exec_hook('attachments_cleanup', ['group' => $eventid]);
             $this->rc->session->remove(self::SESSION_KEY);
         }
     }
 
     /**
      * Send out an invitation/notification to all event attendees
      */
     private function notify_attendees($event, $old, $action = 'edit', $comment = null, $rsvp = null)
     {
         $is_cancelled = false;
         if ($action == 'remove' || ($event['status'] == 'CANCELLED' && $old['status'] != $event['status'])) {
             $event['cancelled'] = true;
             $is_cancelled = true;
         }
 
         if ($rsvp === null) {
             $rsvp = !$old || $event['sequence'] > $old['sequence'];
         }
 
         $itip        = $this->load_itip();
         $emails      = $this->get_user_emails();
         $itip_notify = (int) $this->rc->config->get('calendar_itip_send_option', $this->defaults['calendar_itip_send_option']);
 
         // add comment to the iTip attachment
         $event['comment'] = $comment;
 
         // set a valid recurrence-id if this is a recurrence instance
         libcalendaring::identify_recurrence_instance($event);
 
         // compose multipart message using PEAR:Mail_Mime
         $method  = $action == 'remove' ? 'CANCEL' : 'REQUEST';
         $message = $itip->compose_itip_message($event, $method, $rsvp);
 
         // list existing attendees from $old event
         $old_attendees = [];
         if (!empty($old['attendees'])) {
             foreach ((array) $old['attendees'] as $attendee) {
                 $old_attendees[] = $attendee['email'];
             }
         }
 
         // send to every attendee
         $sent    = 0;
         $current = [];
         foreach ((array) $event['attendees'] as $attendee) {
             // skip myself for obvious reasons
             if (empty($attendee['email']) || in_array(strtolower($attendee['email']), $emails)) {
                 continue;
             }
 
             $current[] = strtolower($attendee['email']);
 
             // skip if notification is disabled for this attendee
             if (!empty($attendee['noreply']) && $itip_notify & 2) {
                 continue;
             }
 
             // skip if this attendee has delegated and set RSVP=FALSE
             if ($attendee['status'] == 'DELEGATED' && $attendee['rsvp'] === false) {
                 continue;
             }
 
             // which template to use for mail text
             $is_new   = !in_array($attendee['email'], $old_attendees);
             $is_rsvp  = $is_new || $event['sequence'] > $old['sequence'];
             $bodytext = $is_cancelled ? 'eventcancelmailbody' : ($is_new ? 'invitationmailbody' : 'eventupdatemailbody');
             $subject  = $is_cancelled ? 'eventcancelsubject'  : ($is_new ? 'invitationsubject' : ($event['title'] ? 'eventupdatesubject' : 'eventupdatesubjectempty'));
 
             $event['comment'] = $comment;
 
             // finally send the message
             if ($itip->send_itip_message($event, $method, $attendee, $subject, $bodytext, $message, $is_rsvp)) {
                 $sent++;
             }
             else {
                 $sent = -100;
             }
         }
 
         // TODO: on change of a recurring (main) event, also send updates to differing attendess of recurrence exceptions
 
         // send CANCEL message to removed attendees
         if (!empty($old['attendees'])) {
             foreach ($old['attendees'] as $attendee) {
                 if ($attendee['role'] == 'ORGANIZER'
                     || empty($attendee['email'])
                     || in_array(strtolower($attendee['email']), $current)
                 ) {
                     continue;
                 }
 
                 $vevent = $old;
                 $vevent['cancelled'] = $is_cancelled;
                 $vevent['attendees'] = [$attendee];
                 $vevent['comment']   = $comment;
 
                 if ($itip->send_itip_message($vevent, 'CANCEL', $attendee, 'eventcancelsubject', 'eventcancelmailbody')) {
                     $sent++;
                 }
                 else {
                     $sent = -100;
                 }
             }
         }
 
         return $sent;
     }
 
     /**
      * Echo simple free/busy status text for the given user and time range
      */
     public function freebusy_status()
     {
         $email = rcube_utils::get_input_value('email', rcube_utils::INPUT_GPC);
         $start = $this->input_timestamp('start', rcube_utils::INPUT_GPC);
         $end   = $this->input_timestamp('end', rcube_utils::INPUT_GPC);
 
         if (!$start) $start = time();
         if (!$end) $end = $start + 3600;
 
         $status = 'UNKNOWN';
         $fbtypemap = [
             calendar::FREEBUSY_UNKNOWN   => 'UNKNOWN',
             calendar::FREEBUSY_FREE      => 'FREE',
             calendar::FREEBUSY_BUSY      => 'BUSY',
             calendar::FREEBUSY_TENTATIVE => 'TENTATIVE',
             calendar::FREEBUSY_OOF       => 'OUT-OF-OFFICE'
         ];
 
         // if the backend has free-busy information
         $fblist = $this->driver->get_freebusy_list($email, $start, $end);
 
         if (is_array($fblist)) {
             $status = 'FREE';
 
             foreach ($fblist as $slot) {
                 list($from, $to, $type) = $slot;
                 if ($from < $end && $to > $start) {
                     $status = isset($type) && !empty($fbtypemap[$type]) ? $fbtypemap[$type] : 'BUSY';
                     break;
                 }
             }
         }
 
         // let this information be cached for 5min
         $this->rc->output->future_expire_header(300);
 
         echo $status;
         exit;
     }
 
     /**
      * Return a list of free/busy time slots within the given period
      * Echo data in JSON encoding
      */
     public function freebusy_times()
     {
         $email = rcube_utils::get_input_value('email', rcube_utils::INPUT_GPC);
         $start = $this->input_timestamp('start', rcube_utils::INPUT_GPC);
         $end   = $this->input_timestamp('end', rcube_utils::INPUT_GPC);
         $interval  = intval(rcube_utils::get_input_value('interval', rcube_utils::INPUT_GPC));
         $strformat = $interval > 60 ? 'Ymd' : 'YmdHis';
 
         if (!$start) $start = time();
         if (!$end)   $end = $start + 86400 * 30;
         if (!$interval) $interval = 60;  // 1 hour
 
         if (!$dte) {
             $dts = new DateTime('@'.$start);
             $dts->setTimezone($this->timezone);
         }
 
         $fblist = $this->driver->get_freebusy_list($email, $start, $end);
         $slots  = '';
 
         // prepare freebusy list before use (for better performance)
         if (is_array($fblist)) {
             foreach ($fblist as $idx => $slot) {
                 list($from, $to, ) = $slot;
 
                 // check for possible all-day times
                 if (gmdate('His', $from) == '000000' && gmdate('His', $to) == '235959') {
                     // shift into the user's timezone for sane matching
                     $fblist[$idx][0] -= $this->gmt_offset;
                     $fblist[$idx][1] -= $this->gmt_offset;
                 }
             }
         }
 
         // build a list from $start till $end with blocks representing the fb-status
         for ($s = 0, $t = $start; $t <= $end; $s++) {
             $t_end = $t + $interval * 60;
             $dt = new DateTime('@'.$t);
             $dt->setTimezone($this->timezone);
 
             // determine attendee's status
             if (is_array($fblist)) {
                 $status = self::FREEBUSY_FREE;
 
                 foreach ($fblist as $slot) {
                     list($from, $to, $type) = $slot;
 
                     if ($from < $t_end && $to > $t) {
                         $status = isset($type) ? $type : self::FREEBUSY_BUSY;
                         if ($status == self::FREEBUSY_BUSY) {
                             // can't get any worse :-)
                             break;
                         }
                     }
                 }
             }
             else {
                 $status = self::FREEBUSY_UNKNOWN;
             }
 
             // use most compact format, assume $status is one digit/character
             $slots .= $status;
             $t = $t_end;
         }
 
         $dte = new DateTime('@'.$t_end);
         $dte->setTimezone($this->timezone);
 
         // let this information be cached for 5min
         $this->rc->output->future_expire_header(300);
 
         echo rcube_output::json_serialize([
             'email' => $email,
             'start' => $dts->format('c'),
             'end'   => $dte->format('c'),
             'interval' => $interval,
             'slots' => $slots,
         ]);
         exit;
     }
 
     /**
      * Handler for printing calendars
      */
     public function print_view()
     {
         $title = $this->gettext('print');
 
         $view = rcube_utils::get_input_value('view', rcube_utils::INPUT_GPC);
         if (!in_array($view, ['agendaWeek', 'agendaDay', 'month', 'list'])) {
             $view = 'agendaDay';
         }
 
         $this->rc->output->set_env('view', $view);
 
         if ($date = rcube_utils::get_input_value('date', rcube_utils::INPUT_GPC)) {
             $this->rc->output->set_env('date', $date);
         }
 
         if ($range = rcube_utils::get_input_value('range', rcube_utils::INPUT_GPC)) {
             $this->rc->output->set_env('listRange', intval($range));
         }
 
         if ($search = rcube_utils::get_input_value('search', rcube_utils::INPUT_GPC)) {
             $this->rc->output->set_env('search', $search);
             $title .= ' "' . $search . '"';
         }
 
         // Add JS to the page
         $this->ui->addJS();
 
         $this->register_handler('plugin.calendar_css', [$this->ui, 'calendar_css']);
         $this->register_handler('plugin.calendar_list', [$this->ui, 'calendar_list']);
 
         $this->rc->output->set_pagetitle($title);
         $this->rc->output->send('calendar.print');
     }
 
     /**
      * Compare two event objects and return differing properties
      *
      * @param array Event A
      * @param array Event B
      *
      * @return array List of differing event properties
      */
     public static function event_diff($a, $b)
     {
         $diff   = [];
         $ignore = ['changed' => 1, 'attachments' => 1];
 
         foreach (array_unique(array_merge(array_keys($a), array_keys($b))) as $key) {
             if (empty($ignore[$key]) && $key[0] != '_') {
                 $av = isset($a[$key]) ? $a[$key] : null;
                 $bv = isset($b[$key]) ? $b[$key] : null;
 
                 if ($av != $bv) {
                     $diff[] = $key;
                 }
             }
         }
 
         // only compare number of attachments
         $ac = !empty($a['attachments']) ? count($a['attachments']) : 0;
         $bc = !empty($b['attachments']) ? count($b['attachments']) : 0;
 
         if ($ac != $bc) {
             $diff[] = 'attachments';
         }
 
         return $diff;
     }
 
     /**
      * Update attendee properties on the given event object
      *
      * @param array The event object to be altered
      * @param array List of hash arrays each represeting an updated/added attendee
      */
     public static function merge_attendee_data(&$event, $attendees, $removed = null)
     {
         if (!empty($attendees) && !is_array($attendees[0])) {
             $attendees = [$attendees];
         }
 
         foreach ($attendees as $attendee) {
             $found = false;
 
             foreach ($event['attendees'] as $i => $candidate) {
                 if ($candidate['email'] == $attendee['email']) {
                     $event['attendees'][$i] = $attendee;
                     $found = true;
                     break;
                 }
             }
 
             if (!$found) {
                 $event['attendees'][] = $attendee;
             }
         }
 
         // filter out removed attendees
         if (!empty($removed)) {
             $event['attendees'] = array_filter($event['attendees'], function($attendee) use ($removed) {
                 return !in_array($attendee['email'], $removed);
             });
         }
     }
 
     /****  Resource management functions  ****/
 
     /**
      * Getter for the configured implementation of the resource directory interface
      */
     private function resources_directory()
     {
         if (!empty($this->resources_dir)) {
             return $this->resources_dir;
         }
 
         if ($driver_name = $this->rc->config->get('calendar_resources_driver')) {
             $driver_class = 'resources_driver_' . $driver_name;
 
             require_once($this->home . '/drivers/resources_driver.php');
             require_once($this->home . '/drivers/' . $driver_name . '/' . $driver_class . '.php');
 
             $this->resources_dir = new $driver_class($this);
         }
 
         return $this->resources_dir;
     }
 
     /**
      * Handler for resoruce autocompletion requests
      */
     public function resources_autocomplete()
     {
         $search  = rcube_utils::get_input_value('_search', rcube_utils::INPUT_GPC, true);
         $sid     = rcube_utils::get_input_value('_reqid', rcube_utils::INPUT_GPC);
         $maxnum  = (int)$this->rc->config->get('autocomplete_max', 15);
         $results = [];
 
         if ($directory = $this->resources_directory()) {
             foreach ($directory->load_resources($search, $maxnum) as $rec) {
                 $results[]  = [
                     'name'  => $rec['name'],
                     'email' => $rec['email'],
                     'type'  => $rec['_type'],
                 ];
             }
         }
 
         $this->rc->output->command('ksearch_query_results', $results, $search, $sid);
         $this->rc->output->send();
     }
 
     /**
      * Handler for load-requests for resource data
      */
     function resources_list()
     {
         $data = [];
 
         if ($directory = $this->resources_directory()) {
             foreach ($directory->load_resources() as $rec) {
                 $data[] = $rec;
             }
         }
 
         $this->rc->output->command('plugin.resource_data', $data);
         $this->rc->output->send();
     }
 
     /**
      * Handler for requests loading resource owner information
      */
     function resources_owner()
     {
         if ($directory = $this->resources_directory()) {
             $id   = rcube_utils::get_input_value('_id', rcube_utils::INPUT_GPC);
             $data = $directory->get_resource_owner($id);
         }
 
         $this->rc->output->command('plugin.resource_owner', $data);
         $this->rc->output->send();
     }
 
     /**
      * Deliver event data for a resource's calendar
      */
     function resources_calendar()
     {
         $events = [];
 
         if ($directory = $this->resources_directory()) {
             $id    = rcube_utils::get_input_value('_id', rcube_utils::INPUT_GPC);
             $start = $this->input_timestamp('start', rcube_utils::INPUT_GET);
             $end   = $this->input_timestamp('end', rcube_utils::INPUT_GET);
 
             $events = $directory->get_resource_calendar($id, $start, $end);
         }
 
         echo $this->encode($events);
         exit;
     }
 
+    /**
+     * List email addressed of owned resources
+     */
+    private function owned_resources_emails($identities)
+    {
+        $results = [];
+        if ($directory = $this->resources_directory()) {
+            foreach ($directory->load_owned_resources($identities) as $rec) {
+                $results[] = $rec['email'];
+            }
+        }
+        return $results;
+    }
+
+
     /****  Event invitation plugin hooks ****/
 
     /**
      * Find an event in user calendars
      */
     protected function find_event($event, &$mode)
     {
         $this->load_driver();
 
         // We search for writeable calendars in personal namespace by default
         $mode   = calendar_driver::FILTER_WRITEABLE | calendar_driver::FILTER_PERSONAL;
         $result = $this->driver->get_event($event, $mode);
         // ... now check shared folders if not found
         if (!$result) {
             $result = $this->driver->get_event($event, calendar_driver::FILTER_WRITEABLE | calendar_driver::FILTER_SHARED);
             if ($result) {
                 $mode |= calendar_driver::FILTER_SHARED;
             }
         }
 
         return $result;
     }
 
     /**
      * Handler for calendar/itip-status requests
      */
     function event_itip_status()
     {
         $data = rcube_utils::get_input_value('data', rcube_utils::INPUT_POST, true);
 
         $this->load_driver();
 
         // find local copy of the referenced event (in personal namespace)
         $existing  = $this->find_event($data, $mode);
         $is_shared = $mode & calendar_driver::FILTER_SHARED;
         $itip      = $this->load_itip();
         $response  = $itip->get_itip_status($data, $existing);
 
         // get a list of writeable calendars to save new events to
         if (
             (!$existing || $is_shared)
             && empty($data['nosave'])
             && ($response['action'] == 'rsvp' || $response['action'] == 'import')
         ) {
             $calendars       = $this->driver->list_calendars($mode);
             $calendar_select = new html_select([
                 'name'       => 'calendar',
                 'id'         => 'itip-saveto',
                 'is_escaped' => true,
                 'class'      => 'form-control custom-select'
             ]);
 
             $calendar_select->add('--', '');
             $numcals = 0;
             foreach ($calendars as $calendar) {
                 if (!empty($calendar['editable'])) {
                     $calendar_select->add($calendar['name'], $calendar['id']);
                     $numcals++;
                 }
             }
             if ($numcals < 1) {
                 $calendar_select = null;
             }
         }
 
         if (!empty($calendar_select)) {
             $default_calendar   = $this->get_default_calendar($data['sensitivity'], $calendars);
             $response['select'] = html::span('folder-select', $this->gettext('saveincalendar')
                 . '&nbsp;'
                 . $calendar_select->show($is_shared ? $existing['calendar'] : $default_calendar['id'])
             );
         }
         else if (!empty($data['nosave'])) {
             $response['select'] = html::tag('input', ['type' => 'hidden', 'name' => 'calendar', 'id' => 'itip-saveto', 'value' => '']);
         }
 
         // render small agenda view for the respective day
         if ($data['method'] == 'REQUEST' && !empty($data['date']) && $response['action'] == 'rsvp') {
             $event_start = rcube_utils::anytodatetime($data['date']);
             $day_start   = new Datetime(gmdate('Y-m-d 00:00', $data['date']), $this->lib->timezone);
             $day_end     = new Datetime(gmdate('Y-m-d 23:59', $data['date']), $this->lib->timezone);
 
             // get events on that day from the user's personal calendars
             $calendars = $this->driver->list_calendars(calendar_driver::FILTER_PERSONAL);
             $events    = $this->driver->load_events($day_start->format('U'), $day_end->format('U'), null, array_keys($calendars));
 
             usort($events, function($a, $b) { return $a['start'] > $b['start'] ? 1 : -1; });
 
             $before = $after = [];
             foreach ($events as $event) {
                 // TODO: skip events with free_busy == 'free' ?
                 if ($event['uid'] == $data['uid']
                     || $event['end'] < $day_start || $event['start'] > $day_end
                     || $event['status'] == 'CANCELLED'
                     || (!empty($event['className']) && strpos($event['className'], 'declined') !== false)
                 ) {
                     continue;
                 }
 
                 if ($event['start'] < $event_start) {
                     $before[] = $this->mail_agenda_event_row($event);
                 }
                 else {
                     $after[] = $this->mail_agenda_event_row($event);
                 }
             }
 
             $response['append'] = [
                 'selector' => '.calendar-agenda-preview',
                 'replacements' => [
                     '%before%' => !empty($before) ? join("\n", array_slice($before,  -3)) : html::div('event-row no-event', $this->gettext('noearlierevents')),
                     '%after%'  => !empty($after)  ? join("\n", array_slice($after, 0, 3)) : html::div('event-row no-event', $this->gettext('nolaterevents')),
                 ],
             ];
         }
 
         $this->rc->output->command('plugin.update_itip_object_status', $response);
     }
 
     /**
      * Handler for calendar/itip-remove requests
      */
     function event_itip_remove()
     {
         $uid      = rcube_utils::get_input_value('uid', rcube_utils::INPUT_POST);
         $instance = rcube_utils::get_input_value('_instance', rcube_utils::INPUT_POST);
         $savemode = rcube_utils::get_input_value('_savemode', rcube_utils::INPUT_POST);
         $listmode = calendar_driver::FILTER_WRITEABLE | calendar_driver::FILTER_PERSONAL;
         $success  = false;
 
         // search for event if only UID is given
         if ($event = $this->driver->get_event(['uid' => $uid, '_instance' => $instance], $listmode)) {
             $event['_savemode'] = $savemode;
             $success = $this->driver->remove_event($event, true);
         }
 
         if ($success) {
             $this->rc->output->show_message('calendar.successremoval', 'confirmation');
         }
         else {
             $this->rc->output->show_message('calendar.errorsaving', 'error');
         }
     }
 
     /**
      * Handler for URLs that allow an invitee to respond on his invitation mail
      */
     public function itip_attend_response($p)
     {
         $this->setup();
 
         if ($p['action'] == 'attend') {
             $this->ui->init();
 
             $this->rc->output->set_env('task', 'calendar');  // override some env vars
             $this->rc->output->set_env('refresh_interval', 0);
             $this->rc->output->set_pagetitle($this->gettext('calendar'));
 
             $itip  = $this->load_itip();
             $token = rcube_utils::get_input_value('_t', rcube_utils::INPUT_GPC);
 
             // read event info stored under the given token
             if ($invitation = $itip->get_invitation($token)) {
                 $this->token = $token;
                 $this->event = $invitation['event'];
 
                 // show message about cancellation
                 if (!empty($invitation['cancelled'])) {
                     $this->invitestatus = html::div('rsvp-status declined', $itip->gettext('eventcancelled'));
                 }
                 // save submitted RSVP status
                 else if (!empty($_POST['rsvp'])) {
                     $status = null;
                     foreach (['accepted', 'tentative', 'declined'] as $method) {
                         if ($_POST['rsvp'] == $itip->gettext('itip' . $method)) {
                             $status = $method;
                             break;
                         }
                     }
 
                     // send itip reply to organizer
                     $invitation['event']['comment'] = rcube_utils::get_input_value('_comment', rcube_utils::INPUT_POST);
                     if ($status && $itip->update_invitation($invitation, $invitation['attendee'], strtoupper($status))) {
                         $this->invitestatus = html::div('rsvp-status ' . strtolower($status), $itip->gettext('youhave'.strtolower($status)));
                     }
                     else {
                         $this->rc->output->command('display_message', $this->gettext('errorsaving'), 'error', -1);
                     }
 
                     // if user is logged in...
                     // FIXME: we should really consider removing this functionality
                     //        it's confusing that it creates/updates an event only for logged-in user
                     //        what if the logged-in user is not the same as the attendee?
                     if ($this->rc->user->ID) {
                         $this->load_driver();
 
                         $invitation = $itip->get_invitation($token);
                         $existing   = $this->driver->get_event($this->event);
 
                         // save the event to his/her default calendar if not yet present
                         if (!$existing && ($calendar = $this->get_default_calendar($invitation['event']['sensitivity']))) {
                             $invitation['event']['calendar'] = $calendar['id'];
                             if ($this->driver->new_event($invitation['event'])) {
                                 $msg = $this->gettext(['name' => 'importedsuccessfully', 'vars' => ['calendar' => $calendar['name']]]);
                                 $this->rc->output->command('display_message', $msg, 'confirmation');
                             }
                             else {
                                 $this->rc->output->command('display_message', $this->gettext('errorimportingevent'), 'error');
                             }
                         }
                         else if ($existing
                             && ($this->event['sequence'] >= $existing['sequence']
                                 || $this->event['changed'] >= $existing['changed'])
                             && ($calendar = $this->driver->get_calendar($existing['calendar']))
                         ) {
                             $this->event       = $invitation['event'];
                             $this->event['id'] = $existing['id'];
 
                             unset($this->event['comment']);
 
                             // merge attendees status
                             // e.g. preserve my participant status for regular updates
                             $this->lib->merge_attendees($this->event, $existing, $status);
 
                             // update attachments list
                             $event['deleted_attachments'] = true;
 
                             // show me as free when declined (#1670)
                             if ($status == 'declined') {
                                 $this->event['free_busy'] = 'free';
                             }
 
                             if ($this->driver->edit_event($this->event)) {
                                 $msg = $this->gettext(['name' => 'updatedsuccessfully', 'vars' => ['calendar' => $calendar->get_name()]]);
                                 $this->rc->output->command('display_message', $msg, 'confirmation');
                             }
                             else {
                                 $this->rc->output->command('display_message', $this->gettext('errorimportingevent'), 'error');
                             }
                         }
                     }
                 }
 
                 $this->register_handler('plugin.event_inviteform', [$this, 'itip_event_inviteform']);
                 $this->register_handler('plugin.event_invitebox', [$this->ui, 'event_invitebox']);
 
                 if (empty($this->invitestatus)) {
                     $this->itip->set_rsvp_actions(['accepted', 'tentative', 'declined']);
                     $this->register_handler('plugin.event_rsvp_buttons', [$this->ui, 'event_rsvp_buttons']);
                 }
 
                 $this->rc->output->set_pagetitle($itip->gettext('itipinvitation') . ' ' . $this->event['title']);
             }
             else {
                 $this->rc->output->command('display_message', $this->gettext('itipinvalidrequest'), 'error', -1);
             }
 
             $this->rc->output->send('calendar.itipattend');
         }
     }
 
     /**
      *
      */
     public function itip_event_inviteform($attrib)
     {
         $hidden = new html_hiddenfield(['name' => "_t", 'value' => $this->token]);
 
         return html::tag('form', [
                 'action' => $this->rc->url(['task' => 'calendar', 'action' => 'attend']),
                 'method' => 'post',
                 'noclose' => true
             ] + $attrib
         ) . $hidden->show();
     }
 
     /**
      *
      */
     private function mail_agenda_event_row($event, $class = '')
     {
         $time = !empty($event['allday']) ? $this->gettext('all-day') :
             $this->rc->format_date($event['start'], $this->rc->config->get('time_format'))
             . ' - ' .
             $this->rc->format_date($event['end'], $this->rc->config->get('time_format'));
 
         return html::div(rtrim('event-row ' . ($class ?: $event['className'])),
             html::span('event-date', $time)
             . html::span('event-title', rcube::Q($event['title']))
         );
     }
 
     /**
      *
      */
     public function mail_messages_list($p)
     {
         if (!empty($p['cols']) && in_array('attachment', (array) $p['cols']) && !empty($p['messages'])) {
             foreach ($p['messages'] as $header) {
                 $part = new StdClass;
                 $part->mimetype = $header->ctype;
 
                 if (libcalendaring::part_is_vcalendar($part)) {
                     $header->list_flags['attachmentClass'] = 'ical';
                 }
                 else if (in_array($header->ctype, ['multipart/alternative', 'multipart/mixed'])) {
                     // TODO: fetch bodystructure and search for ical parts. Maybe too expensive?
                     if (!empty($header->structure) && !empty($header->structure->parts)) {
                         foreach ($header->structure->parts as $part) {
                             if (libcalendaring::part_is_vcalendar($part)
                                 && !empty($part->ctype_parameters['method'])
                             ) {
                                 $header->list_flags['attachmentClass'] = 'ical';
                                 break;
                             }
                         }
                     }
                 }
             }
         }
     }
 
     /**
      * Add UI element to copy event invitations or updates to the calendar
      */
     public function mail_messagebody_html($p)
     {
         // load iCalendar functions (if necessary)
         if (!empty($this->lib->ical_parts)) {
             $this->get_ical();
             $this->load_itip();
         }
 
         $html = '';
         $has_events = false;
         $ical_objects = $this->lib->get_mail_ical_objects();
 
         // show a box for every event in the file
         foreach ($ical_objects as $idx => $event) {
             if ($event['_type'] != 'event') {
                 // skip non-event objects (#2928)
                 continue;
             }
 
             $has_events = true;
 
             // get prepared inline UI for this event object
             if ($ical_objects->method) {
                 $append   = '';
                 $date_str = $this->rc->format_date($event['start'], $this->rc->config->get('date_format'), empty($event['start']->_dateonly));
                 $date     = new DateTime($event['start']->format('Y-m-d') . ' 12:00:00', new DateTimeZone('UTC'));
 
                 // prepare a small agenda preview to be filled with actual event data on async request
                 if ($ical_objects->method == 'REQUEST') {
                     $append = html::div('calendar-agenda-preview',
                         html::tag('h3', 'preview-title', $this->gettext('agenda') . ' ' . html::span('date', $date_str))
                         . '%before%' . $this->mail_agenda_event_row($event, 'current') . '%after%'
                     );
                 }
 
                 $html .= html::div('calendar-invitebox invitebox boxinformation',
                     $this->itip->mail_itip_inline_ui(
                         $event,
                         $ical_objects->method,
                         $ical_objects->mime_id . ':' . $idx,
                         'calendar',
                         rcube_utils::anytodatetime($ical_objects->message_date),
                         $this->rc->url(['task' => 'calendar']) . '&view=agendaDay&date=' . $date->format('U')
                     ) . $append
                 );
             }
 
             // limit listing
             if ($idx >= 3) {
                 break;
             }
         }
 
         // prepend event boxes to message body
         if ($html) {
             $this->ui->init();
             $p['content'] = $html . $p['content'];
             $this->rc->output->add_label('calendar.savingdata','calendar.deleteventconfirm','calendar.declinedeleteconfirm');
         }
 
         // add "Save to calendar" button into attachment menu
         if ($has_events) {
             $this->add_button([
                     'id'         => 'attachmentsavecal',
                     'name'       => 'attachmentsavecal',
                     'type'       => 'link',
                     'wrapper'    => 'li',
                     'command'    => 'attachment-save-calendar',
                     'class'      => 'icon calendarlink disabled',
                     'classact'   => 'icon calendarlink active',
                     'innerclass' => 'icon calendar',
                     'label'      => 'calendar.savetocalendar',
                 ],
                 'attachmentmenu'
             );
         }
 
         return $p;
     }
 
     /**
      * Handler for POST request to import an event attached to a mail message
      */
     public function mail_import_itip()
     {
         $itip_sending = $this->rc->config->get('calendar_itip_send_option', $this->defaults['calendar_itip_send_option']);
 
         $uid     = rcube_utils::get_input_value('_uid', rcube_utils::INPUT_POST);
         $mbox    = rcube_utils::get_input_value('_mbox', rcube_utils::INPUT_POST);
         $mime_id = rcube_utils::get_input_value('_part', rcube_utils::INPUT_POST);
         $status  = rcube_utils::get_input_value('_status', rcube_utils::INPUT_POST);
         $delete  = intval(rcube_utils::get_input_value('_del', rcube_utils::INPUT_POST));
         $noreply = intval(rcube_utils::get_input_value('_noreply', rcube_utils::INPUT_POST));
         $noreply = $noreply || $status == 'needs-action' || $itip_sending === 0;
         $instance = rcube_utils::get_input_value('_instance', rcube_utils::INPUT_POST);
         $savemode = rcube_utils::get_input_value('_savemode', rcube_utils::INPUT_POST);
         $comment  = rcube_utils::get_input_value('_comment', rcube_utils::INPUT_POST);
 
         $error_msg = $this->gettext('errorimportingevent');
         $success   = false;
         $deleted   = false;
 
         if ($status == 'delegated') {
             $to = rcube_utils::get_input_value('_to', rcube_utils::INPUT_POST, true);
             $delegates = rcube_mime::decode_address_list($to, 1, false);
             $delegate  = reset($delegates);
 
             if (empty($delegate) || empty($delegate['mailto'])) {
                 $this->rc->output->command('display_message', $this->rc->gettext('libcalendaring.delegateinvalidaddress'), 'error');
                 return;
             }
         }
 
         // successfully parsed events?
         if ($event = $this->lib->mail_get_itip_object($mbox, $uid, $mime_id, 'event')) {
             // forward iTip request to delegatee
             if (!empty($delegate)) {
                 $rsvpme = rcube_utils::get_input_value('_rsvp', rcube_utils::INPUT_POST);
                 $itip   = $this->load_itip();
 
                 $event['comment'] = $comment;
 
                 if ($itip->delegate_to($event, $delegate, !empty($rsvpme))) {
                     $this->rc->output->show_message('calendar.itipsendsuccess', 'confirmation');
                 }
                 else {
                     $this->rc->output->command('display_message', $this->gettext('itipresponseerror'), 'error');
                 }
 
                 unset($event['comment']);
 
                 // the delegator is set to non-participant, thus save as non-blocking
                 $event['free_busy'] = 'free';
             }
 
             $mode = calendar_driver::FILTER_PERSONAL
                 | calendar_driver::FILTER_SHARED
                 | calendar_driver::FILTER_WRITEABLE;
 
             // find writeable calendar to store event
             $cal_id    = rcube_utils::get_input_value('_folder', rcube_utils::INPUT_POST);
             $dontsave  = $cal_id === '' && $event['_method'] == 'REQUEST';
             $calendars = $this->driver->list_calendars($mode);
             $calendar  = isset($calendars[$cal_id]) ? $calendars[$cal_id] : null;
 
             // select default calendar except user explicitly selected 'none'
             if (!$calendar && !$dontsave) {
                 $calendar = $this->get_default_calendar($event['sensitivity'], $calendars);
             }
 
             $metadata = [
                 'uid'       => $event['uid'],
                 '_instance' => isset($event['_instance']) ? $event['_instance'] : null,
                 'changed'   => is_object($event['changed']) ? $event['changed']->format('U') : 0,
                 'sequence'  => intval($event['sequence']),
                 'fallback'  => strtoupper($status),
                 'method'    => $event['_method'],
                 'task'      => 'calendar',
             ];
 
             // update my attendee status according to submitted method
             if (!empty($status)) {
                 $organizer = null;
                 $emails = $this->get_user_emails();
                 foreach ($event['attendees'] as $i => $attendee) {
                     if ($attendee['role'] == 'ORGANIZER') {
                         $organizer = $attendee;
                     }
                     else if (!empty($attendee['email']) && in_array(strtolower($attendee['email']), $emails)) {
                         $event['attendees'][$i]['status'] = strtoupper($status);
                         if (!in_array($event['attendees'][$i]['status'], ['NEEDS-ACTION', 'DELEGATED'])) {
                             $event['attendees'][$i]['rsvp'] = false;  // unset RSVP attribute
                         }
 
                         $metadata['attendee'] = $attendee['email'];
                         $metadata['rsvp']     = $attendee['role'] != 'NON-PARTICIPANT';
 
                         $reply_sender   = $attendee['email'];
                         $event_attendee = $attendee;
                     }
                 }
 
                 // add attendee with this user's default identity if not listed
                 if (!$reply_sender) {
                     $sender_identity = $this->rc->user->list_emails(true);
                     $event['attendees'][] = [
                         'name'   => $sender_identity['name'],
                         'email'  => $sender_identity['email'],
                         'role'   => 'OPT-PARTICIPANT',
                         'status' => strtoupper($status),
                     ];
                     $metadata['attendee'] = $sender_identity['email'];
                 }
             }
 
             // save to calendar
             if ($calendar && !empty($calendar['editable'])) {
                 // check for existing event with the same UID
                 $existing = $this->find_event($event, $mode);
 
                 // we'll create a new copy if user decided to change the calendar
                 if ($existing && $cal_id && $calendar && $calendar['id'] != $existing['calendar']) {
                     $existing = null;
                 }
 
                 if ($existing) {
                     $calendar = $calendars[$existing['calendar']];
 
                     // forward savemode for correct updates of recurring events
                     $existing['_savemode'] = $savemode ?: (!empty($event['_savemode']) ? $event['_savemode'] : null);
 
                     // only update attendee status
                     if ($event['_method'] == 'REPLY') {
                         // try to identify the attendee using the email sender address
                         $existing_attendee        = -1;
                         $existing_attendee_emails = [];
 
                         foreach ($existing['attendees'] as $i => $attendee) {
                             $existing_attendee_emails[] = $attendee['email'];
                             if ($this->itip->compare_email($attendee['email'], $event['_sender'], $event['_sender_utf'])) {
                                 $existing_attendee = $i;
                             }
                         }
 
                         $event_attendee   = null;
                         $update_attendees = [];
 
                         foreach ($event['attendees'] as $attendee) {
                             if ($this->itip->compare_email($attendee['email'], $event['_sender'], $event['_sender_utf'])) {
                                 $event_attendee       = $attendee;
                                 $update_attendees[]   = $attendee;
                                 $metadata['fallback'] = $attendee['status'];
                                 $metadata['attendee'] = $attendee['email'];
                                 $metadata['rsvp']     = !empty($attendee['rsvp']) || $attendee['role'] != 'NON-PARTICIPANT';
 
                                 if ($attendee['status'] != 'DELEGATED') {
                                     break;
                                 }
                             }
                             // also copy delegate attendee
                             else if (!empty($attendee['delegated-from'])
                                 && $this->itip->compare_email($attendee['delegated-from'], $event['_sender'], $event['_sender_utf'])
                             ) {
                                 $update_attendees[] = $attendee;
                                 if (!in_array_nocase($attendee['email'], $existing_attendee_emails)) {
                                     $existing['attendees'][] = $attendee;
                                 }
                             }
                         }
 
                         // if delegatee has declined, set delegator's RSVP=True
                         if ($event_attendee
                             && $event_attendee['status'] == 'DECLINED'
                             && !empty($event_attendee['delegated-from'])
                         ) {
                             foreach ($existing['attendees'] as $i => $attendee) {
                                 if ($attendee['email'] == $event_attendee['delegated-from']) {
                                     $existing['attendees'][$i]['rsvp'] = true;
                                     break;
                                 }
                             }
                         }
 
                         // Accept sender as a new participant (different email in From: and the iTip)
                         // Use ATTENDEE entry from the iTip with replaced email address
                         if (!$event_attendee) {
                             // remove the organizer
                             $itip_attendees = array_filter(
                                 $event['attendees'],
                                 function($item) { return $item['role'] != 'ORGANIZER'; }
                             );
 
                             // there must be only one attendee
                             if (is_array($itip_attendees) && count($itip_attendees) == 1) {
                                 $event_attendee          = $itip_attendees[key($itip_attendees)];
                                 $event_attendee['email'] = $event['_sender'];
                                 $update_attendees[]      = $event_attendee;
                                 $metadata['fallback']    = $event_attendee['status'];
                                 $metadata['attendee']    = $event_attendee['email'];
                                 $metadata['rsvp']        = !empty($event_attendee['rsvp']) || $event_attendee['role'] != 'NON-PARTICIPANT';
                             }
                         }
 
                         // found matching attendee entry in both existing and new events
                         if ($existing_attendee >= 0 && $event_attendee) {
                             $existing['attendees'][$existing_attendee] = $event_attendee;
                             $success = $this->driver->update_attendees($existing, $update_attendees);
                         }
                         // update the entire attendees block
                         else if (
                             ($event['sequence'] >= $existing['sequence'] || $event['changed'] >= $existing['changed'])
                             && $event_attendee
                         ) {
                             $existing['attendees'][] = $event_attendee;
                             $success = $this->driver->update_attendees($existing, $update_attendees);
                         }
                         else if (!$event_attendee) {
                             $error_msg = $this->gettext('errorunknownattendee');
                         }
                         else {
                             $error_msg = $this->gettext('newerversionexists');
                         }
                     }
                     // delete the event when declined (#1670)
                     else if ($status == 'declined' && $delete) {
                         $deleted = $this->driver->remove_event($existing, true);
                         $success = true;
                     }
                     // import the (newer) event
                     else if ($event['sequence'] >= $existing['sequence'] || $event['changed'] >= $existing['changed']) {
                         $event['id']       = $existing['id'];
                         $event['calendar'] = $existing['calendar'];
 
                         // merge attendees status
                         // e.g. preserve my participant status for regular updates
                         $this->lib->merge_attendees($event, $existing, $status);
 
                         // set status=CANCELLED on CANCEL messages
                         if ($event['_method'] == 'CANCEL') {
                             $event['status'] = 'CANCELLED';
                         }
 
                         // update attachments list, allow attachments update only on REQUEST (#5342)
                         if ($event['_method'] == 'REQUEST') {
                             $event['deleted_attachments'] = true;
                         }
                         else {
                             unset($event['attachments']);
                         }
 
                         // show me as free when declined (#1670)
                         if ($status == 'declined'
                             || (!empty($event['status']) && $event['status'] == 'CANCELLED')
                             || $event_attendee['role'] == 'NON-PARTICIPANT'
                         ) {
                             $event['free_busy'] = 'free';
                         }
 
                         $success = $this->driver->edit_event($event);
                     }
                     else if (!empty($status)) {
                         $existing['attendees'] = $event['attendees'];
                         if ($status == 'declined' || $event_attendee['role'] == 'NON-PARTICIPANT') {
                             // show me as free when declined (#1670)
                             $existing['free_busy'] = 'free';
                         }
                         $success = $this->driver->edit_event($existing);
                     }
                     else {
                         $error_msg = $this->gettext('newerversionexists');
                     }
                 }
                 else if (!$existing && ($status != 'declined' || $this->rc->config->get('kolab_invitation_calendars'))) {
                     if ($status == 'declined'
                         || $event['status'] == 'CANCELLED'
                         || $event_attendee['role'] == 'NON-PARTICIPANT'
                     ) {
                         $event['free_busy'] = 'free';
                     }
 
                     // if the RSVP reply only refers to a single instance:
                     // store unmodified master event with current instance as exception
                     if (!empty($instance) && !empty($savemode) && $savemode != 'all') {
                         $master = $this->lib->mail_get_itip_object($mbox, $uid, $mime_id, 'event');
                         if ($master['recurrence'] && empty($master['_instance'])) {
                             // compute recurring events until this instance's date
                             if ($recurrence_date = rcube_utils::anytodatetime($instance, $master['start']->getTimezone())) {
                                 $recurrence_date->setTime(23,59,59);
 
                                 foreach ($this->driver->get_recurring_events($master, $master['start'], $recurrence_date) as $recurring) {
                                     if ($recurring['_instance'] == $instance) {
                                         // copy attendees block with my partstat to exception
                                         $recurring['attendees'] = $event['attendees'];
                                         $master['recurrence']['EXCEPTIONS'][] = $recurring;
                                         $event = $recurring;  // set reference for iTip reply
                                         break;
                                     }
                                 }
 
                                 $master['calendar'] = $event['calendar'] = $calendar['id'];
                                 $success = $this->driver->new_event($master);
                             }
                             else {
                                 $master = null;
                             }
                         }
                         else {
                             $master = null;
                         }
                     }
 
                     // save to the selected/default calendar
                     if (!$master) {
                         $event['calendar'] = $calendar['id'];
                         $success = $this->driver->new_event($event);
                     }
                 }
                 else if ($status == 'declined') {
                     $error_msg = null;
                 }
             }
             else if ($status == 'declined' || $dontsave) {
                 $error_msg = null;
             }
             else {
                 $error_msg = $this->gettext('nowritecalendarfound');
             }
         }
 
         if ($success) {
             if ($event['_method'] == 'REPLY') {
                 $message = 'attendeupdateesuccess';
             }
             else {
                 $message = $deleted ? 'successremoval' : ($existing ? 'updatedsuccessfully' : 'importedsuccessfully');
             }
 
             $msg = $this->gettext(['name' => $message, 'vars' => ['calendar' => $calendar['name']]]);
             $this->rc->output->command('display_message', $msg, 'confirmation');
         }
 
         if ($success || $dontsave) {
             $metadata['calendar'] = isset($event['calendar']) ? $event['calendar'] : null;
             $metadata['nosave']   = $dontsave;
             $metadata['rsvp']     = !empty($metadata['rsvp']);
 
             $metadata['after_action'] = $this->rc->config->get('calendar_itip_after_action', $this->defaults['calendar_itip_after_action']);
             $this->rc->output->command('plugin.itip_message_processed', $metadata);
             $error_msg = null;
         }
         else if ($error_msg) {
             $this->rc->output->command('display_message', $error_msg, 'error');
         }
 
         // send iTip reply
         if ($event['_method'] == 'REQUEST' && !empty($organizer) && !$noreply
             && !in_array(strtolower($organizer['email']), $emails) && !$error_msg
         ) {
             $event['comment'] = $comment;
             $itip = $this->load_itip();
             $itip->set_sender_email($reply_sender);
 
             if ($itip->send_itip_message($event, 'REPLY', $organizer, 'itipsubject' . $status, 'itipmailbody' . $status)) {
                 $mailto = $organizer['name'] ? $organizer['name'] : $organizer['email'];
                 $msg    = $this->gettext(['name' => 'sentresponseto', 'vars' => ['mailto' => $mailto]]);
                 $this->rc->output->command('display_message', $msg, 'confirmation');
             }
             else {
                 $this->rc->output->command('display_message', $this->gettext('itipresponseerror'), 'error');
             }
         }
 
         $this->rc->output->send();
     }
 
     /**
      * Handler for calendar/itip-remove requests
      */
     function mail_itip_decline_reply()
     {
         $uid     = rcube_utils::get_input_value('_uid', rcube_utils::INPUT_POST);
         $mbox    = rcube_utils::get_input_value('_mbox', rcube_utils::INPUT_POST);
         $mime_id = rcube_utils::get_input_value('_part', rcube_utils::INPUT_POST);
 
         if (($event = $this->lib->mail_get_itip_object($mbox, $uid, $mime_id, 'event'))
             && $event['_method'] == 'REPLY'
         ) {
             $event['comment'] = rcube_utils::get_input_value('_comment', rcube_utils::INPUT_POST);
 
             foreach ($event['attendees'] as $_attendee) {
                 if ($_attendee['role'] != 'ORGANIZER') {
                     $attendee = $_attendee;
                     break;
                 }
             }
 
             $itip = $this->load_itip();
 
             if ($itip->send_itip_message($event, 'CANCEL', $attendee, 'itipsubjectcancel', 'itipmailbodycancel')) {
                 $mailto = !empty($attendee['name']) ? $attendee['name'] : $attendee['email'];
                 $msg    = $this->gettext(['name' => 'sentresponseto', 'vars' => ['mailto' => $mailto]]);
                 $this->rc->output->command('display_message', $msg, 'confirmation');
             }
             else {
                 $this->rc->output->command('display_message', $this->gettext('itipresponseerror'), 'error');
             }
         }
         else {
             $this->rc->output->command('display_message', $this->gettext('itipresponseerror'), 'error');
         }
     }
 
     /**
      * Handler for calendar/itip-delegate requests
      */
     function mail_itip_delegate()
     {
         // forward request to mail_import_itip() with the right status
         $_POST['_status'] = $_REQUEST['_status'] = 'delegated';
         $this->mail_import_itip();
     }
 
     /**
      * Import the full payload from a mail message attachment
      */
     public function mail_import_attachment()
     {
         $uid     = rcube_utils::get_input_value('_uid', rcube_utils::INPUT_POST);
         $mbox    = rcube_utils::get_input_value('_mbox', rcube_utils::INPUT_POST);
         $mime_id = rcube_utils::get_input_value('_part', rcube_utils::INPUT_POST);
         $charset = RCUBE_CHARSET;
 
         // establish imap connection
         $imap = $this->rc->get_storage();
         $imap->set_folder($mbox);
 
         if ($uid && $mime_id) {
             $part = $imap->get_message_part($uid, $mime_id);
             // $headers = $imap->get_message_headers($uid);
 
             if ($part) {
                 if (!empty($part->ctype_parameters['charset'])) {
                     $charset = $part->ctype_parameters['charset'];
                 }
                 $events = $this->get_ical()->import($part, $charset);
             }
         }
 
         $success = $existing = 0;
 
         if (!empty($events)) {
             // find writeable calendar to store event
             $cal_id = !empty($_REQUEST['_calendar']) ? rcube_utils::get_input_value('_calendar', rcube_utils::INPUT_POST) : null;
             $calendars = $this->driver->list_calendars(calendar_driver::FILTER_PERSONAL);
 
             foreach ($events as $event) {
                 // save to calendar
                 $calendar = !empty($calendars[$cal_id]) ? $calendars[$cal_id] : $this->get_default_calendar($event['sensitivity']);
                 if ($calendar && $calendar['editable'] && $event['_type'] == 'event') {
                     $event['calendar'] = $calendar['id'];
 
                     if (!$this->driver->get_event($event['uid'], calendar_driver::FILTER_WRITEABLE)) {
                         $success += (bool)$this->driver->new_event($event);
                     }
                     else {
                         $existing++;
                     }
                 }
             }
         }
 
         if ($success) {
             $msg = $this->gettext(['name' => 'importsuccess', 'vars' => ['nr' => $success]]);
             $this->rc->output->command('display_message', $msg, 'confirmation');
         }
         else if ($existing) {
             $this->rc->output->command('display_message', $this->gettext('importwarningexists'), 'warning');
         }
         else {
             $this->rc->output->command('display_message', $this->gettext('errorimportingevent'), 'error');
         }
     }
 
     /**
      * Read email message and return contents for a new event based on that message
      */
     public function mail_message2event()
     {
         $this->ui->init();
         $this->ui->addJS();
         $this->ui->init_templates();
         $this->ui->calendar_list([], true); // set env['calendars']
 
         $uid   = rcube_utils::get_input_value('_uid', rcube_utils::INPUT_GET);
         $mbox  = rcube_utils::get_input_value('_mbox', rcube_utils::INPUT_GET);
         $event = [];
 
         // establish imap connection
         $imap    = $this->rc->get_storage();
         $message = new rcube_message($uid, $mbox);
 
         if ($message->headers) {
             $event['title']       = trim($message->subject);
             $event['description'] = trim($message->first_text_part());
 
             $this->load_driver();
 
             // add a reference to the email message
             if ($msgref = $this->driver->get_message_reference($message->headers, $mbox)) {
                 $event['links'] = [$msgref];
             }
             // copy mail attachments to event
             else if ($message->attachments) {
                 $eventid = 'cal-';
                 if (empty($_SESSION[self::SESSION_KEY]) || $_SESSION[self::SESSION_KEY]['id'] != $eventid) {
                     $_SESSION[self::SESSION_KEY] = [
                         'id'          => $eventid,
                         'attachments' => [],
                     ];
                 }
 
                 foreach ((array) $message->attachments as $part) {
                     $attachment = [
                         'data' => $imap->get_message_part($uid, $part->mime_id, $part),
                         'size' => $part->size,
                         'name' => $part->filename,
                         'mimetype' => $part->mimetype,
                         'group' => $eventid,
                     ];
 
                     $attachment = $this->rc->plugins->exec_hook('attachment_save', $attachment);
 
                     if (!empty($attachment['status']) && !$attachment['abort']) {
                         $id = $attachment['id'];
                         $attachment['classname'] = rcube_utils::file2class($attachment['mimetype'], $attachment['name']);
 
                         // store new attachment in session
                         unset($attachment['status'], $attachment['abort'], $attachment['data']);
                         $_SESSION[self::SESSION_KEY]['attachments'][$id] = $attachment;
 
                         $attachment['id'] = 'rcmfile' . $attachment['id'];  // add prefix to consider it 'new'
                         $event['attachments'][] = $attachment;
                     }
                 }
             }
 
             $this->rc->output->set_env('event_prop', $event);
         }
         else {
             $this->rc->output->command('display_message', $this->gettext('messageopenerror'), 'error');
         }
 
         $this->rc->output->send('calendar.dialog');
     }
 
     /**
      * Handler for the 'message_compose' plugin hook. This will check for
      * a compose parameter 'calendar_event' and create an attachment with the
      * referenced event in iCal format
      */
     public function mail_message_compose($args)
     {
         // set the submitted event ID as attachment
         if (!empty($args['param']['calendar_event'])) {
             $this->load_driver();
 
             list($cal, $id) = explode(':', $args['param']['calendar_event'], 2);
 
             if ($event = $this->driver->get_event(['id' => $id, 'calendar' => $cal])) {
                 $filename = asciiwords($event['title']);
                 if (empty($filename)) {
                     $filename = 'event';
                 }
 
                 // save ics to a temp file and register as attachment
                 $tmp_path = tempnam($this->rc->config->get('temp_dir'), 'rcmAttmntCal');
                 $export   = $this->get_ical()->export([$event], '', false, [$this->driver, 'get_attachment_body']);
 
                 file_put_contents($tmp_path, $export);
 
                 $args['attachments'][] = [
                     'path'     => $tmp_path,
                     'name'     => $filename . '.ics',
                     'mimetype' => 'text/calendar',
                     'size'     => filesize($tmp_path),
                 ];
                 $args['param']['subject'] = $event['title'];
             }
         }
 
         return $args;
     }
 
     /**
      * Get a list of email addresses of the current user (from login and identities)
      */
     public function get_user_emails()
     {
         return $this->lib->get_user_emails();
     }
 
     /**
      * Build an absolute URL with the given parameters
      */
     public function get_url($param = [])
     {
         $param += ['task' => 'calendar'];
         return $this->rc->url($param, true, true);
     }
 
     public function ical_feed_hash($source)
     {
         return base64_encode($this->rc->user->get_username() . ':' . $source);
     }
 
     /**
      * Handler for user_delete plugin hook
      */
     public function user_delete($args)
     {
          // delete itipinvitations entries related to this user
          $db = $this->rc->get_dbh();
          $table_itipinvitations = $db->table_name('itipinvitations', true);
 
          $db->query("DELETE FROM $table_itipinvitations WHERE `user_id` = ?", $args['user']->ID);
 
         $this->setup();
         $this->load_driver();
 
         return $this->driver->user_delete($args);
     }
 
     /**
      * Find first occurrence of a recurring event excluding start date
      *
      * @param array $event Event data (with 'start' and 'recurrence')
      *
      * @return DateTime Date of the first occurrence
      */
     public function find_first_occurrence($event)
     {
         // Make sure libkolab plugin is loaded in case of Kolab driver
         $this->load_driver();
 
         // Use libkolab to compute recurring events (and libkolab plugin)
         // Horde-based fallback has many bugs
         if (class_exists('kolabformat') && class_exists('kolabcalendaring') && class_exists('kolab_date_recurrence')) {
             $object = kolab_format::factory('event', 3.0);
             $object->set($event);
 
             $recurrence = new kolab_date_recurrence($object);
         }
         else {
             // fallback to libcalendaring (Horde-based) recurrence implementation
             require_once(__DIR__ . '/lib/calendar_recurrence.php');
             $recurrence = new calendar_recurrence($this, $event);
         }
 
         return $recurrence->first_occurrence();
     }
 
     /**
      * Get date-time input from UI and convert to unix timestamp
      */
     protected function input_timestamp($name, $type)
     {
         $ts = rcube_utils::get_input_value($name, $type);
 
         if ($ts && (!is_numeric($ts) || strpos($ts, 'T'))) {
             $ts = new DateTime($ts, $this->timezone);
             $ts = $ts->getTimestamp();
         }
 
         return $ts;
     }
 
     /**
      * Magic getter for public access to protected members
      */
     public function __get($name)
     {
         switch ($name) {
         case 'ical':
             return $this->get_ical();
 
         case 'itip':
             return $this->load_itip();
 
         case 'driver':
             $this->load_driver();
             return $this->driver;
         }
 
         return null;
     }
 }
diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index e1f46fd5..9cee7279 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -1,4315 +1,4324 @@
 /**
  * Client UI Javascript for the Calendar plugin
  *
  * @author Lazlo Westerhof <hello@lazlo.me>
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * @licstart  The following is the entire license notice for the
  * JavaScript code in this file.
  *
  * Copyright (C) 2010, Lazlo Westerhof <hello@lazlo.me>
  * Copyright (C) 2014-2015, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  *
  * @licend  The above is the entire license notice
  * for the JavaScript code in this file.
  */
 
 // Roundcube calendar UI client class
 function rcube_calendar_ui(settings)
 {
     // extend base class
     rcube_calendar.call(this, settings);
 
     /***  member vars  ***/
     this.is_loading = false;
     this.selected_event = null;
     this.selected_calendar = null;
     this.search_request = null;
     this.saving_lock = null;
     this.calendars = {};
     this.quickview_sources = [];
 
 
     /***  private vars  ***/
     var DAY_MS = 86400000;
     var HOUR_MS = 3600000;
     var me = this;
     var day_clicked = day_clicked_ts = 0;
     var ignore_click = false;
     var event_defaults = { free_busy:'busy', alarms:'' };
     var event_attendees = [];
     var calendars_list;
     var calenders_search_list;
     var calenders_search_container;
     var search_calendars = {};
     var attendees_list;
     var resources_list;
     var resources_treelist;
     var resources_data = {};
     var resources_index = [];
     var resource_owners = {};
     var resources_events_source = { url:null, editable:false };
     var freebusy_ui = { workinhoursonly:false, needsupdate:false };
     var freebusy_data = {};
     var current_view = null;
     var count_sources = [];
     var event_sources = [];
     var exec_deferred = 1;
     var sensitivitylabels = { 'public':rcmail.gettext('public','calendar'), 'private':rcmail.gettext('private','calendar'), 'confidential':rcmail.gettext('confidential','calendar') };
     var ui_loading = rcmail.set_busy(true, 'loading');
 
     // global fullcalendar settings
     var fullcalendar_defaults = {
       theme: false,
       aspectRatio: 1,
       timezone: false,  // will treat the given date strings as in local (browser's) timezone
       monthNames: settings.months,
       monthNamesShort: settings.months_short,
       dayNames: settings.days,
       dayNamesShort: settings.days_short,
       weekNumbers: settings.show_weekno > 0,
       weekNumberTitle: rcmail.gettext('weekshort', 'calendar') + ' ',
       weekNumberCalculation: 'ISO',
       firstDay: settings.first_day,
       firstHour: settings.first_hour,
       slotDuration: {minutes: 60/settings.timeslots},
       businessHours: {
         start: settings.work_start + ':00',
         end: settings.work_end + ':00'
       },
       scrollTime: settings.work_start + ':00',
       views: {
         list: {
           titleFormat: settings.dates_long,
           listDayFormat: settings.date_long,
           visibleRange: function(currentDate) {
             return {
               start: currentDate.clone(),
               end: currentDate.clone().add(settings.agenda_range, 'days')
             }
           }
         },
         month: {
           columnFormat: 'ddd', // Mon
           titleFormat: 'MMMM YYYY',
           eventLimit: 4
         },
         week: {
           columnFormat: 'ddd ' + settings.date_short, // Mon 9/7
           titleFormat: settings.dates_long
         },
         day: {
           columnFormat: 'dddd ' + settings.date_short,  // Monday 9/7
           titleFormat: 'dddd ' + settings.date_long
         }
       },
       timeFormat: settings.time_format,
       slotLabelFormat: settings.time_format,
       defaultView: rcmail.env.view || settings.default_view,
       allDayText: rcmail.gettext('all-day', 'calendar'),
       buttonText: {
         today: settings['today'],
         day: rcmail.gettext('day', 'calendar'),
         week: rcmail.gettext('week', 'calendar'),
         month: rcmail.gettext('month', 'calendar'),
         list: rcmail.gettext('agenda', 'calendar')
       },
       buttonIcons: {
        prev: 'left-single-arrow',
        next: 'right-single-arrow'
       },
       nowIndicator: settings.time_indicator,
       eventLimitText: function(num) {
         return rcmail.gettext('andnmore', 'calendar').replace('$nr', num);
       },
       // event rendering
       eventRender: function(event, element, view) {
         if (view.name != 'list') {
           var prefix = event.sensitivity && event.sensitivity != 'public' ? String(sensitivitylabels[event.sensitivity]).toUpperCase()+': ' : '';
           element.attr('title', prefix + event.title);
         }
         if (view.name != 'month') {
           if (view.name == 'list') {
             var loc = $('<td>').attr('class', 'fc-event-location');
             if (event.location)
               loc.text(event.location);
             element.find('.fc-list-item-title').after(loc);
           }
           else if (event.location) {
             element.find('div.fc-title').after($('<div class="fc-event-location">').html('@&nbsp;' + Q(event.location)));
           }
           var time_element = element.find('div.fc-time');
           if (event.sensitivity && event.sensitivity != 'public')
             time_element.append('<i class="fc-icon-sensitive"></i>');
           if (event.recurrence)
             time_element.append('<i class="fc-icon-recurring"></i>');
           if (event.alarms || (event.valarms && event.valarms.length))
             time_element.append('<i class="fc-icon-alarms"></i>');
         }
         if (event.status) {
           element.addClass('cal-event-status-' + String(event.status).toLowerCase());
         }
 
         set_event_colors(element, event, view.name);
         element.attr('aria-label', event.title + ', ' + me.event_date_text(event, true));
       },
       // callback when a specific event is clicked
       eventClick: function(event, ev, view) {
         if (!event.temp && (!event.className || event.className.indexOf('fc-type-freebusy') < 0))
           event_show_dialog(event, ev);
       }
     };
 
     /***  imports  ***/
     var Q = this.quote_html;
     var text2html = this.text2html;
     var event_date_text = this.event_date_text;
     var date2unixtime = this.date2unixtime;
     var fromunixtime = this.fromunixtime;
     var parseISO8601 = this.parseISO8601;
     var date2servertime = this.date2ISO8601;
     var render_message_links = this.render_message_links;
 
 
     /***  private methods  ***/
 
     // same as str.split(delimiter) but it ignores delimiters within quoted strings
     var explode_quoted_string = function(str, delimiter)
     {
       var result = [],
         strlen = str.length,
         q, p, i, chr, last;
 
       for (q = p = i = 0; i < strlen; i++) {
         chr = str.charAt(i);
         if (chr == '"' && last != '\\') {
           q = !q;
         }
         else if (!q && chr == delimiter) {
           result.push(str.substring(p, i));
           p = i + 1;
         }
         last = chr;
       }
 
       result.push(str.substr(p));
       return result;
     };
 
     // Change the first charcter to uppercase
     var ucfirst = function(str)
     {
         return str.charAt(0).toUpperCase() + str.substr(1);
     };
 
     // clone the given date object and optionally adjust time
     var clone_date = function(date, adjust)
     {
       var d = 'toDate' in date ? date.toDate() : new Date(date.getTime());
 
       // set time to 00:00
       if (adjust == 1) {
         d.setHours(0);
         d.setMinutes(0);
       }
       // set time to 23:59
       else if (adjust == 2) {
         d.setHours(23);
         d.setMinutes(59);
       }
 
       return d;
     };
 
     // fix date if jumped over a DST change
     var fix_date = function(date)
     {
       if (date.getHours() == 23)
         date.setTime(date.getTime() + HOUR_MS);
       else if (date.getHours() > 0)
         date.setHours(0);
     };
 
     var date2timestring = function(date, dateonly)
     {
       return date2servertime(date).replace(/[^0-9]/g, '').substr(0, (dateonly ? 8 : 14));
     }
 
     var format_date = function(date, format)
     {
       return $.fullCalendar.formatDate('toDate' in date ? date : moment(date), format);
     };
 
     var format_datetime = function(date, mode, voice)
     {
       return me.format_datetime(date, mode, voice);
     }
 
     var render_link = function(url)
     {
       var islink = false, href = url;
       if (url.match(/^[fhtpsmailo]+?:\/\//i)) {
         islink = true;
       }
       else if (url.match(/^[a-z0-9.-:]+(\/|$)/i)) {
         islink = true;
         href = 'http://' + url;
       }
       return islink ? '<a href="' + Q(href) + '" target="_blank">' + Q(url) + '</a>' : Q(url);
     }
 
     // determine whether the given date is on a weekend
     var is_weekend = function(date)
     {
       return date.getDay() == 0 || date.getDay() == 6;
     };
 
     var is_workinghour = function(date)
     {
       if (settings['work_start'] > settings['work_end'])
         return date.getHours() >= settings['work_start'] || date.getHours() < settings['work_end'];
       else
         return date.getHours() >= settings['work_start'] && date.getHours() < settings['work_end'];
     };
 
     var set_event_colors = function(element, event, mode)
     {
       var bg_color = '', border_color = '',
         cat = String(event.categories),
         color = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar].color : '',
         cat_color = rcmail.env.calendar_categories[cat] ? rcmail.env.calendar_categories[cat] : color;
 
       switch (settings.event_coloring) {
         case 1:
           bg_color = border_color = cat_color;
           break;
         case 2:
           border_color = color;
           bg_color = cat_color;
           break;
         case 3:
           border_color = cat_color;
           bg_color = color;
           break;
         default:
           bg_color = border_color = color;
           break;
       }
 
       var css = {
         'border-color': border_color,
         'background-color': bg_color,
         'color': me.text_color(bg_color)
       };
 
       if (String(css['border-color']).match(/^#?f+$/i))
         delete css['border-color'];
 
       $.each(css, function(i, v) { if (!v) delete css[i]; else if (v.charAt(0) != '#') css[i] = '#' + v; });
 
       if (mode == 'list') {
         bg_color = css['background-color'];
         if (bg_color && !bg_color.match(/^#?f+$/i))
           $(element).find('.fc-event-dot').css('background-color', bg_color);
       }
       else
         $(element).css(css);
     };
 
     var load_attachment = function(data)
     {
       var event = data.record,
         query = {_id: data.attachment.id, _event: event.recurrence_id || event.id, _cal: event.calendar};
 
       if (event.rev)
         query._rev = event.rev;
 
       if (event.calendar == "--invitation--itip")
         $.extend(query, {_uid: event._uid, _part: event._part, _mbox: event._mbox});
 
       libkolab.load_attachment(query, data.attachment);
     };
 
     // build event attachments list
     var event_show_attachments = function(list, container, event, edit)
     {
       libkolab.list_attachments(list, container, edit, event,
         function(id) { remove_attachment(id); },
         function(data) { load_attachment(data); }
       );
     };
 
     var remove_attachment = function(id)
     {
       rcmail.env.deleted_attachments.push(id);
     };
 
     // event details dialog (show only)
     var event_show_dialog = function(event, ev, temp)
     {
       var $dialog = $("#eventshow");
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { editable:false, rights:'lrs' };
 
       if (!temp)
         me.selected_event = event;
 
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
 
       // remove status-* and sensitivity-* classes
       $dialog.removeClass(function(i, oldclass) {
           var oldies = String(oldclass).split(' ');
           return $.grep(oldies, function(cls) { return cls.indexOf('status-') === 0 || cls.indexOf('sensitivity-') === 0 }).join(' ');
       });
 
       // convert start/end dates if not done yet by fullcalendar
       if (typeof event.start == 'string')
         event.start = parseISO8601(event.start);
       if (typeof event.end == 'string')
         event.end = parseISO8601(event.end);
 
       // allow other plugins to do actions when event form is opened
       rcmail.triggerEvent('calendar-event-init', {o: event});
 
       $dialog.find('div.event-section, div.event-line, .form-group').hide();
       $('#event-title').html(Q(event.title)).show();
 
       if (event.location)
         $('#event-location').html('@ ' + text2html(event.location)).show();
       if (event.description)
         $('#event-description').show().find('.event-text').html(text2html(event.description, 300, 6));
       if (event.vurl)
         $('#event-url').show().find('.event-text').html(render_link(event.vurl));
       if (event.recurrence && event.recurrence_text)
         $('#event-repeat').show().find('.event-text').html(Q(event.recurrence_text));
       if (event.valarms && event.alarms_text)
         $('#event-alarm').show().find('.event-text').html(Q(event.alarms_text).replace(',', ',<br>'));
       if (calendar.name)
         $('#event-calendar').show().find('.event-text').html(Q(calendar.name)).addClass('cal-'+calendar.id);
       if (event.categories)
         $('#event-category').show().find('.event-text').text(event.categories).addClass('cat-'+String(event.categories).toLowerCase().replace(rcmail.identifier_expr, ''));
       if (event.free_busy)
         $('#event-free-busy').show().find('.event-text').text(rcmail.gettext(event.free_busy, 'calendar'));
       if (event.priority > 0) {
         var priolabels = [ '', rcmail.gettext('highest'), rcmail.gettext('high'), '', '', rcmail.gettext('normal'), '', '', rcmail.gettext('low'), rcmail.gettext('lowest') ];
         $('#event-priority').show().find('.event-text').text(event.priority+' '+priolabels[event.priority]);
       }
 
       if (event.status) {
         var status_lc = String(event.status).toLowerCase();
         $('#event-status').show().find('.event-text').text(rcmail.gettext('status-'+status_lc,'calendar'));
         $('#event-status-badge > span').text(rcmail.gettext('status-'+status_lc,'calendar'));
         $dialog.addClass('status-'+status_lc);
       }
       if (event.sensitivity && event.sensitivity != 'public') {
         $('#event-sensitivity').show().find('.event-text').text(sensitivitylabels[event.sensitivity]);
         $('#event-status-badge > span').text(sensitivitylabels[event.sensitivity]);
         $dialog.addClass('sensitivity-'+event.sensitivity);
       }
       if (event.created || event.changed) {
         var created = parseISO8601(event.created),
           changed = parseISO8601(event.changed);
         $('.event-created', $dialog).text(created ? format_datetime(created) : rcmail.gettext('unknown','calendar'));
         $('.event-changed', $dialog).text(changed ? format_datetime(changed) : rcmail.gettext('unknown','calendar'));
         $('#event-created,#event-changed,#event-created-changed').show()
       }
 
       // create attachments list
       if ($.isArray(event.attachments)) {
         event_show_attachments(event.attachments, $('#event-attachments').find('.event-text'), event);
         if (event.attachments.length > 0) {
           $('#event-attachments').show();
         }
       }
       else if (calendar.attachments) {
         // fetch attachments, some drivers doesn't set 'attachments' prop of the event?
       }
 
       // build attachments list
       $('#event-links').hide();
       if ($.isArray(event.links) && event.links.length) {
           render_message_links(event.links || [], $('#event-links').find('.event-text'), false, 'calendar');
           $('#event-links').show();
       }
 
       // list event attendees
       if (calendar.attendees && event.attendees) {
         // sort resources to the end
         event.attendees.sort(function(a,b) {
           var j = a.cutype == 'RESOURCE' ? 1 : 0,
               k = b.cutype == 'RESOURCE' ? 1 : 0;
           return (j - k);
         });
 
         var data, mystatus = null, rsvp, line, morelink, html = '', overflow = '',
           organizer = me.is_organizer(event), num_attendees = event.attendees.length;
 
         for (var j=0; j < num_attendees; j++) {
           data = event.attendees[j];
           if (data.email) {
-            if (data.role != 'ORGANIZER' && settings.identity.emails.indexOf(';'+data.email) >= 0) {
+            if (data.role != 'ORGANIZER' && is_this_me(data.email)) {
               mystatus = (data.status || 'UNKNOWN').toLowerCase();
               if (data.status == 'NEEDS-ACTION' || data.status == 'TENTATIVE' || data.rsvp)
                 rsvp = mystatus;
             }
           }
 
           line = rcube_libcalendaring.attendee_html(data);
 
           if (morelink)
             overflow += ' ' + line;
           else
             html += ' ' + line;
 
           // stop listing attendees
           if (j == 7 && num_attendees > 8) {
             morelink = $('<a href="#more" class="morelink"></a>').html(rcmail.gettext('andnmore', 'calendar').replace('$nr', num_attendees - j - 1));
           }
         }
 
         if (html && (num_attendees > 1 || !organizer)) {
           $('#event-attendees').show()
             .find('.event-text')
             .html(html)
             .find('a.mailtolink').click(event_attendee_click);
 
           // display all attendees in a popup when clicking the "more" link
           if (morelink) {
             $('#event-attendees .event-text').append(morelink);
             morelink.click(function(e){
               rcmail.simple_dialog(
                 '<div id="all-event-attendees" class="event-attendees">' + html + overflow + '</div>',
                 rcmail.gettext('tabattendees','calendar'),
                 null,
                 {width: 450, cancel_button: 'close'});
               $('#all-event-attendees a.mailtolink').click(event_attendee_click);
               return false;
             });
           }
         }
 
         if (mystatus && !rsvp) {
           $('#event-partstat').show().find('.changersvp, .event-text')
             .removeClass('accepted tentative declined delegated needs-action unknown')
             .addClass(mystatus);
           $('#event-partstat').find('.event-text')
             .text(rcmail.gettext('status' + mystatus, 'libcalendaring'));
         }
 
         var show_rsvp = rsvp && !organizer && event.status != 'CANCELLED' && me.has_permission(calendar, 'v');
         $('#event-rsvp')[(show_rsvp ? 'show' : 'hide')]();
         $('#event-rsvp .rsvp-buttons input').prop('disabled', false).filter('input[rel="'+(mystatus || '')+'"]').prop('disabled', true);
 
         if (show_rsvp && event.comment)
           $('#event-rsvp-comment').show().find('.event-text').html(Q(event.comment));
 
         $('#event-rsvp a.reply-comment-toggle').show();
         $('#event-rsvp .itip-reply-comment textarea').hide().val('');
 
         if (event.recurrence && event.id) {
           var sel = event._savemode || (event.thisandfuture ? 'future' : (event.isexception ? 'current' : 'all'));
           $('#event-rsvp .rsvp-buttons').addClass('recurring');
         }
         else {
           $('#event-rsvp .rsvp-buttons').removeClass('recurring');
         }
       }
 
       var buttons = [], is_removable_event = function(event, calendar) {
           // for invitation calendars check permissions of the original folder
           if (event._folder_id)
             calendar = me.calendars[event._folder_id];
           return calendar && me.has_permission(calendar, 'td');
         };
 
       if (!temp && calendar.editable && event.editable !== false) {
         buttons.push({
           text: rcmail.gettext('edit', 'calendar'),
           'class': 'edit mainaction',
           click: function() {
             event_edit_dialog('edit', event);
           }
         });
       }
 
       if (!temp && is_removable_event(event, calendar) && event.editable !== false) {
         buttons.push({
           text: rcmail.gettext('delete', 'calendar'),
           'class': 'delete',
           click: function() {
             me.delete_event(event);
             $dialog.dialog('close');
           }
         });
       }
 
       buttons.push({
         text: rcmail.gettext('close', 'calendar'),
         'class': 'cancel',
         click: function() {
           $dialog.dialog('close');
         }
       });
 
       var close_func = function(e) {
           rcmail.command('menu-close', 'eventoptionsmenu', null, e);
           $('.libcal-rsvp-replymode').hide();
         };
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: true,
         closeOnEscape: true,
         title: me.event_date_text(event),
         open: function() {
           $dialog.attr('aria-hidden', 'false');
           setTimeout(function(){
             $dialog.parent().find('button:not(.ui-dialog-titlebar-close,.delete)').first().focus();
           }, 5);
         },
         close: function(e) {
           close_func(e);
           $dialog.dialog('close');
         },
         dragStart: close_func,
         resizeStart: close_func,
         buttons: buttons,
         minWidth: 320,
         width: 420
       }).show();
 
       // remember opener element (to be focused on close)
       $dialog.data('opener', ev && rcube_event.is_keyboard(ev) ? ev.target : null);
 
       // set voice title on dialog widget
       $dialog.dialog('widget').removeAttr('aria-labelledby')
         .attr('aria-label', me.event_date_text(event, true) + ', ', event.title);
 
       // set dialog size according to content
       me.dialog_resize($dialog.get(0), $dialog.height(), 420);
 
       // add link for "more options" drop-down
       if (!temp && !event.temporary && event.calendar != '_resource') {
         $('<a>')
           .attr({href: '#', 'class': 'dropdown-link btn btn-link options', 'data-popup-pos': 'top'})
           .text(rcmail.gettext('eventoptions','calendar'))
           .click(function(e) {
             return rcmail.command('menu-open','eventoptionsmenu', this, e);
           })
           .appendTo($dialog.parent().find('.ui-dialog-buttonset'));
       }
 
       rcmail.enable_command('event-history', calendar.history);
 
       rcmail.triggerEvent('calendar-event-dialog', {dialog: $dialog});
     };
 
     // event handler for clicks on an attendee link
     var event_attendee_click = function(e)
     {
       var cutype = $(this).attr('data-cutype'),
         mailto = this.href.substr(7);
 
       if (rcmail.env.calendar_resources && cutype == 'RESOURCE') {
         event_resources_dialog(mailto);
       }
       else {
         rcmail.command('compose', mailto, e ? e.target : null, e);
       }
 
       return false;
     };
 
     // bring up the event dialog (jquery-ui popup)
     var event_edit_dialog = function(action, event)
     {
       // copy opener element from show dialog
       var op_elem = $("#eventshow:ui-dialog").data('opener');
 
       // close show dialog first
       $("#eventshow:ui-dialog").data('opener', null).dialog('close');
 
       var $dialog = $('<div>');
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { editable:true, rights: action=='new' ? 'lrwitd' : 'lrs' };
       me.selected_event = $.extend($.extend({}, event_defaults), event);  // clone event object (with defaults)
       event = me.selected_event; // change reference to clone
       freebusy_ui.needsupdate = false;
 
       if (rcmail.env.action == 'dialog-ui')
         calendar.attendees = false; // TODO: allow Attendees tab in Save-as-event dialog
 
       // reset dialog first
       $('#eventedit form').trigger('reset');
       $('#event-panel-recurrence input, #event-panel-recurrence select, #event-panel-attachments input').prop('disabled', false);
       $('#event-panel-recurrence, #event-panel-attachments').removeClass('disabled');
 
       // allow other plugins to do actions when event form is opened
       rcmail.triggerEvent('calendar-event-init', {o: event});
 
       // event details
       var title = $('#edit-title').val(event.title || '');
       var location = $('#edit-location').val(event.location || '');
       var description = $('#edit-description').text(event.description || '');
       var vurl = $('#edit-url').val(event.vurl || '');
       var categories = $('#edit-categories').val(event.categories);
       var calendars = $('#edit-calendar').val(event.calendar);
       var eventstatus = $('#edit-event-status').val(event.status);
       var freebusy = $('#edit-free-busy').val(event.free_busy);
       var priority = $('#edit-priority').val(event.priority);
       var sensitivity = $('#edit-sensitivity').val(event.sensitivity);
       var syncstart = $('#edit-recurrence-syncstart input');
       var end = 'toDate' in event.end ? event.end : moment(event.end);
       var start = 'toDate' in event.start ? event.start : moment(event.start);
       var duration = Math.round((end.format('x') - start.format('x')) / 1000);
 
       // Correct the fullCalendar end date for all-day events
       if (!end.hasTime()) {
         end.subtract(1, 'days');
       }
 
       var startdate = $('#edit-startdate').val(format_date(start, settings.date_format)).data('duration', duration);
       var starttime = $('#edit-starttime').val(format_date(start, settings.time_format)).show();
       var enddate = $('#edit-enddate').val(format_date(end, settings.date_format));
       var endtime = $('#edit-endtime').val(format_date(end, settings.time_format)).show();
       var allday = $('#edit-allday').get(0);
       var notify = $('#edit-attendees-donotify').get(0);
       var invite = $('#edit-attendees-invite').get(0);
       var comment = $('#edit-attendees-comment');
 
       // make sure any calendar is selected
       if (!calendars.val())
         calendars.val($('option:first', calendars).attr('value'));
 
       invite.checked = settings.itip_notify & 1 > 0;
       notify.checked = me.has_attendees(event) && invite.checked;
 
       if (event.allDay) {
         starttime.val("12:00").hide();
         endtime.val("13:00").hide();
         allday.checked = true;
       }
       else {
         allday.checked = false;
       }
 
       // set calendar selection according to permissions
       calendars.find('option').each(function(i, opt) {
         var cal = me.calendars[opt.value] || {};
         $(opt).prop('disabled', !(cal.editable || (action == 'new' && me.has_permission(cal, 'i'))))
       });
 
       // set alarm(s)
       me.set_alarms_edit('#edit-alarms', action != 'new' && event.valarms && calendar.alarms ? event.valarms : []);
 
       // enable/disable alarm property according to backend support
       $('#edit-alarms')[(calendar.alarms ? 'show' : 'hide')]();
 
       // check categories drop-down: add value if not exists
       if (event.categories && !categories.find("option[value='"+event.categories+"']").length) {
         $('<option>').attr('value', event.categories).text(event.categories).appendTo(categories).prop('selected', true);
       }
 
       if ($.isArray(event.links) && event.links.length) {
           render_message_links(event.links, $('#edit-event-links .event-text'), true, 'calendar');
           $('#edit-event-links').show();
       }
       else {
           $('#edit-event-links').hide();
       }
 
       // show warning if editing a recurring event
       if (event.id && event.recurrence) {
         var sel = event._savemode || (event.thisandfuture ? 'future' : (event.isexception ? 'current' : 'all'));
         $('#edit-recurring-warning').show();
         $('input.edit-recurring-savemode[value="'+sel+'"]').prop('checked', true).change();
       }
       else
         $('#edit-recurring-warning').hide();
 
       // init attendees tab
       var organizer = !event.attendees || me.is_organizer(event),
         allow_invitations = organizer || (calendar.owner && calendar.owner == 'anonymous') || settings.invite_shared;
       event_attendees = [];
       attendees_list = $('#edit-attendees-table > tbody').html('');
       resources_list = $('#edit-resources-table > tbody').html('');
       $('#edit-attendees-notify')[(action != 'new' && allow_invitations && me.has_attendees(event) && (settings.itip_notify & 2) ? 'show' : 'hide')]();
       $('#edit-localchanges-warning')[(action != 'new' && me.has_attendees(event) && !(allow_invitations || (calendar.owner && me.is_organizer(event, calendar.owner))) ? 'show' : 'hide')]();
 
       var load_attendees_tab = function()
       {
         var j, data, organizer_attendee, reply_selected = 0;
         if (event.attendees) {
           for (j=0; j < event.attendees.length; j++) {
             data = event.attendees[j];
             // reset attendee status
             if (event._savemode == 'new' && data.role != 'ORGANIZER') {
               data.status = 'NEEDS-ACTION';
               delete data.noreply;
             }
             add_attendee(data, !allow_invitations);
             if (allow_invitations && data.role != 'ORGANIZER' && !data.noreply)
               reply_selected++;
 
             if (data.role == 'ORGANIZER')
               organizer_attendee = data;
           }
         }
 
         // make sure comment box is visible if at least one attendee has reply enabled
         // or global "send invitations" checkbox is checked
         $('#eventedit .attendees-commentbox')[(reply_selected || invite.checked ? 'show' : 'hide')]();
 
         // select the correct organizer identity
         var identity_id = 0;
         $.each(settings.identities, function(i,v){
           if (organizer && typeof organizer == 'object' && v == organizer.email) {
             identity_id = i;
             return false;
           }
         });
 
         // In case the user is not the (shared) event organizer we'll add the organizer to the selection list
         if (!identity_id && !organizer && organizer_attendee) {
           var organizer_name = organizer_attendee.email;
           if (organizer_attendee.name)
             organizer_name = '"' + organizer_attendee.name + '" <' + organizer_name + '>';
           $('#edit-identities-list').append($('<option value="0">').text(organizer_name));
         }
 
         $('#edit-identities-list').val(identity_id);
         $('#edit-attendees-form')[(allow_invitations?'show':'hide')]();
         $('#edit-attendee-schedule')[(calendar.freebusy?'show':'hide')]();
       };
 
       // attachments
       var load_attachments_tab = function()
       {
         rcmail.enable_command('remove-attachment', 'upload-file', calendar.editable && !event.recurrence_id);
         rcmail.env.deleted_attachments = [];
         // we're sharing some code for uploads handling with app.js
         rcmail.env.attachments = [];
         rcmail.env.compose_id = event.id; // for rcmail.async_upload_form()
 
         if ($.isArray(event.attachments)) {
           event_show_attachments(event.attachments, $('#edit-attachments'), event, true);
         }
         else {
           $('#edit-attachments > ul').empty();
           // fetch attachments, some drivers doesn't set 'attachments' array for event?
         }
       };
 
       // init dialog buttons
       var buttons = [],
         save_func = function() {
           var start = allday.checked ? '12:00' : $.trim(starttime.val()),
             end = allday.checked ? '13:00' : $.trim(endtime.val()),
             re = /^((0?[0-9])|(1[0-9])|(2[0-3])):([0-5][0-9])(\s*[ap]\.?m\.?)?$/i;
 
           if (!re.test(start) || !re.test(end)) {
             rcmail.alert_dialog(rcmail.gettext('invalideventdates', 'calendar'));
             return false;
           }
 
           start = me.parse_datetime(start, startdate.val());
           end   = me.parse_datetime(end, enddate.val());
 
           if (!title.val()) {
             rcmail.alert_dialog(rcmail.gettext('emptyeventtitle', 'calendar'));
             return false;
           }
 
           if (start.getTime() > end.getTime()) {
             rcmail.alert_dialog(rcmail.gettext('invalideventdates', 'calendar'));
             return false;
           }
 
           // post data to server
           var data = {
             calendar: event.calendar,
             start: date2servertime(start),
             end: date2servertime(end),
             allDay: allday.checked?1:0,
             title: title.val(),
             description: description.val(),
             location: location.val(),
             categories: categories.val(),
             vurl: vurl.val(),
             free_busy: freebusy.val(),
             priority: priority.val(),
             sensitivity: sensitivity.val(),
             status: eventstatus.val(),
             recurrence: me.serialize_recurrence(endtime.val()),
             valarms: me.serialize_alarms('#edit-alarms'),
             attendees: event_attendees,
             links: me.selected_event.links,
             deleted_attachments: rcmail.env.deleted_attachments,
             attachments: []
           };
 
           // uploaded attachments list
           for (var i in rcmail.env.attachments)
             if (i.match(/^rcmfile(.+)/))
               data.attachments.push(RegExp.$1);
 
           // read attendee roles
           $('select.edit-attendee-role').each(function(i, elem){
             if (data.attendees[i])
               data.attendees[i].role = $(elem).val();
           });
 
           if (organizer)
             data._identity = $('#edit-identities-list option:selected').val();
 
           // per-attendee notification suppression
           var need_invitation = false;
           if (allow_invitations) {
             $.each(data.attendees, function (i, v) {
               if (v.role != 'ORGANIZER') {
                 if ($('input.edit-attendee-reply[value="' + v.email + '"]').prop('checked') || v.cutype == 'RESOURCE') {
                   need_invitation = true;
                   delete data.attendees[i]['noreply'];
                 }
                 else if (settings.itip_notify > 0) {
                   data.attendees[i].noreply = 1;
                 }
               }
             });
           }
 
           // tell server to send notifications
           if ((data.attendees.length || (event.id && event.attendees.length)) && allow_invitations && (notify.checked || invite.checked || need_invitation)) {
             data._notify = settings.itip_notify;
             data._comment = comment.val();
           }
 
           data.calendar = calendars.val();
 
           if (event.id) {
             data.id = event.id;
             if (event.recurrence)
               data._savemode = $('input.edit-recurring-savemode:checked').val();
             if (data.calendar && data.calendar != event.calendar)
               data._fromcalendar = event.calendar;
           }
 
           if (data.recurrence && syncstart.is(':checked'))
             data.syncstart = 1;
 
           update_event(action, data);
 
           if (rcmail.env.action != 'dialog-ui')
             $dialog.dialog("close");
         };
 
       rcmail.env.event_save_func = save_func;
 
       // save action
       buttons.push({
         text: rcmail.gettext('save', 'calendar'),
         'class': 'save mainaction',
         click: save_func
       });
 
       buttons.push({
         text: rcmail.gettext('cancel', 'calendar'),
         'class': 'cancel',
         click: function() {
           $dialog.dialog("close");
         }
       });
 
       // show/hide tabs according to calendar's feature support and activate first tab (Larry)
       $('#edit-tab-attendees')[(calendar.attendees?'show':'hide')]();
       $('#edit-tab-resources')[(rcmail.env.calendar_resources?'show':'hide')]();
       $('#edit-tab-attachments')[(calendar.attachments?'show':'hide')]();
       $('#eventedit:not([data-notabs])').tabs('option', 'active', 0); // Larry
 
       // show/hide tabs according to calendar's feature support and activate first tab (Ellastic)
       $('li > a[href="#event-panel-attendees"]').parent()[(calendar.attendees?'show':'hide')]();
       $('li > a[href="#event-panel-resources"]').parent()[(rcmail.env.calendar_resources?'show':'hide')]();
       $('li > a[href="#event-panel-attachments"]').parent()[(calendar.attachments?'show':'hide')]();
       if ($('#eventedit').data('notabs'))
         $('#eventedit li.nav-item:first-child a').tab('show');
 
       // hack: set task to 'calendar' to make all dialog actions work correctly
       var comm_path_before = rcmail.env.comm_path;
       rcmail.env.comm_path = comm_path_before.replace(/_task=[a-z]+/, '_task=calendar');
 
       var editform = $("#eventedit");
 
       if (rcmail.env.action != 'dialog-ui') {
         // open jquery UI dialog
         $dialog.dialog({
           modal: true,
           resizable: true,
           closeOnEscape: false,
           title: rcmail.gettext((action == 'edit' ? 'edit_event' : 'new_event'), 'calendar'),
           open: function() {
             editform.attr('aria-hidden', 'false');
           },
           close: function() {
             editform.hide().attr('aria-hidden', 'true').appendTo(document.body);
             $dialog.dialog("destroy").remove();
             rcmail.ksearch_blur();
             freebusy_data = {};
             rcmail.env.comm_path = comm_path_before;  // restore comm_path
             if (op_elem)
               $(op_elem).focus();
           },
           buttons: buttons,
           minWidth: 500,
           width: 600
         }).append(editform.show());  // adding form content AFTERWARDS massively speeds up opening on IE6
 
         // set dialog size according to form content
         me.dialog_resize($dialog.get(0), editform.height() + (bw.ie ? 20 : 0), 550);
 
         rcmail.triggerEvent('calendar-event-dialog', {dialog: $dialog});
       }
 
       // init other tabs asynchronously
       window.setTimeout(function(){ me.set_recurrence_edit(event); }, exec_deferred);
       if (calendar.attendees)
         window.setTimeout(load_attendees_tab, exec_deferred);
       if (calendar.attachments)
         window.setTimeout(load_attachments_tab, exec_deferred);
 
       title.select();
     };
 
     // show event changelog in a dialog
     var event_history_dialog = function(event)
     {
       if (!event.id || !window.libkolab_audittrail)
         return false
 
       // render dialog
       var $dialog = libkolab_audittrail.object_history_dialog({
         module: 'calendar',
         container: '#eventhistory',
         title: rcmail.gettext('objectchangelog','calendar') + ' - ' + event.title + ', ' + me.event_date_text(event),
 
         // callback function for list actions
         listfunc: function(action, rev) {
           me.loading_lock = rcmail.set_busy(true, 'loading', me.loading_lock);
           rcmail.http_post('event', { action:action, e:{ id:event.id, calendar:event.calendar, rev: rev } }, me.loading_lock);
         },
 
         // callback function for comparing two object revisions
         comparefunc: function(rev1, rev2) {
           me.loading_lock = rcmail.set_busy(true, 'loading', me.loading_lock);
           rcmail.http_post('event', { action:'diff', e:{ id:event.id, calendar:event.calendar, rev1: rev1, rev2: rev2 } }, me.loading_lock);
         }
       });
 
       $dialog.data('event', event);
 
       // fetch changelog data
       me.loading_lock = rcmail.set_busy(true, 'loading', me.loading_lock);
       rcmail.http_post('event', { action:'changelog', e:{ id:event.id, calendar:event.calendar } }, me.loading_lock);
     };
 
     // callback from server with changelog data
     var render_event_changelog = function(data)
     {
       var $dialog = $('#eventhistory'),
         event = $dialog.data('event');
 
       if (data === false || !data.length || !event) {
         // display 'unavailable' message
         $('<div class="notfound-message dialog-message warning">' + rcmail.gettext('objectchangelognotavailable','calendar') + '</div>')
           .insertBefore($dialog.find('.changelog-table').hide());
         return;
       }
 
       data.module = 'calendar';
       libkolab_audittrail.render_changelog(data, event, me.calendars[event.calendar]);
 
       // set dialog size according to content
       me.dialog_resize($dialog.get(0), $dialog.height(), 600);
     };
 
     // callback from server with event diff data
     var event_show_diff = function(data)
     {
       var event = me.selected_event,
         $dialog = $("#eventdiff");
 
       $dialog.find('div.event-section, div.event-line, h1.event-title-new').hide().data('set', false).find('.index').html('');
       $dialog.find('div.event-section.clone, div.event-line.clone').remove();
 
       // always show event title and date
       $('.event-title', $dialog).text(event.title).removeClass('event-text-old').show();
       $('.event-date', $dialog).text(me.event_date_text(event)).show();
 
       // show each property change
       $.each(data.changes, function(i,change) {
         var prop = change.property, r2, html = false,
           row = $('div.event-' + prop, $dialog).first();
 
           // special case: title
           if (prop == 'title') {
             $('.event-title', $dialog).addClass('event-text-old').text(change['old'] || '--');
             $('.event-title-new', $dialog).text(change['new'] || '--').show();
           }
 
           // no display container for this property
           if (!row.length) {
             return true;
           }
 
           // clone row if already exists
           if (row.data('set')) {
             r2 = row.clone().addClass('clone').insertAfter(row);
             row = r2;
           }
 
           // format dates
           if (['start','end','changed'].indexOf(prop) >= 0) {
             if (change['old']) change.old_ = me.format_datetime(parseISO8601(change['old']));
             if (change['new']) change.new_ = me.format_datetime(parseISO8601(change['new']));
           }
           // render description text
           else if (prop == 'description') {
             // TODO: show real text diff
             if (!change.diff_ && change['old']) change.old_ = text2html(change['old']);
             if (!change.diff_ && change['new']) change.new_ = text2html(change['new']);
             html = true;
           }
           // format attendees struct
           else if (prop == 'attendees') {
             if (change['old']) change.old_ = rcube_libcalendaring.attendee_html(change['old']);
             if (change['new']) change.new_ = rcube_libcalendaring.attendee_html($.extend({}, change['old'] || {}, change['new']));
             html = true;
           }
           // localize priority values
           else if (prop == 'priority') {
             var priolabels = [ '', rcmail.gettext('highest'), rcmail.gettext('high'), '', '', rcmail.gettext('normal'), '', '', rcmail.gettext('low'), rcmail.gettext('lowest') ];
             if (change['old']) change.old_ = change['old'] + ' ' + (priolabels[change['old']] || '');
             if (change['new']) change.new_ = change['new'] + ' ' + (priolabels[change['new']] || '');
           }
           // localize status
           else if (prop == 'status') {
             var status_lc = String(event.status).toLowerCase();
             if (change['old']) change.old_ = rcmail.gettext(String(change['old']).toLowerCase(), 'calendar');
             if (change['new']) change.new_ = rcmail.gettext(String(change['new']).toLowerCase(), 'calendar');
           }
 
           // format attachments struct
           if (prop == 'attachments') {
             if (change['old']) event_show_attachments([change['old']], row.children('.event-text-old'), event, false);
             else            row.children('.event-text-old').text('--');
             if (change['new']) event_show_attachments([$.extend({}, change['old'] || {}, change['new'])], row.children('.event-text-new'), event, false);
             else            row.children('.event-text-new').text('--');
             // remove click handler as we're currentyl not able to display the according attachment contents
             $('.attachmentslist li a', row).unbind('click').removeAttr('href');
           }
           else if (change.diff_) {
             row.children('.event-text-diff').html(change.diff_);
             row.children('.event-text-old, .event-text-new').hide();
           }
           else {
             if (!html) {
               // escape HTML characters
               change.old_ = Q(change.old_ || change['old'] || '--')
               change.new_ = Q(change.new_ || change['new'] || '--')
             }
             row.children('.event-text-old').html(change.old_ || change['old'] || '--');
             row.children('.event-text-new').html(change.new_ || change['new'] || '--');
           }
 
           // display index number
           if (typeof change.index != 'undefined') {
             row.find('.index').html('(' + change.index + ')');
           }
 
           row.show().data('set', true);
 
           // hide event-date line
           if (prop == 'start' || prop == 'end')
             $('.event-date', $dialog).hide();
       });
 
       var buttons = [{
         text: rcmail.gettext('close', 'calendar'),
         'class': 'cancel',
         click: function() { $dialog.dialog('close'); }
       }];
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: false,
         resizable: true,
         closeOnEscape: true,
         title: rcmail.gettext('objectdiff','calendar').replace('$rev1', data.rev1).replace('$rev2', data.rev2) + ' - ' + event.title,
         open: function() {
           $dialog.attr('aria-hidden', 'false');
           setTimeout(function(){
             $dialog.parent().find('button:not(.ui-dialog-titlebar-close)').first().focus();
           }, 5);
         },
         close: function() {
           $dialog.dialog('destroy').attr('aria-hidden', 'true').hide();
         },
         buttons: buttons,
         minWidth: 320,
         width: 450
       }).show();
 
       // set dialog size according to content
       me.dialog_resize($dialog.get(0), $dialog.height(), 400);
     };
 
     // close the event history dialog
     var close_history_dialog = function()
     {
       $('#eventhistory, #eventdiff').each(function(i, elem) {
         var $dialog = $(elem);
         if ($dialog.is(':ui-dialog'))
           $dialog.dialog('close');
       });
     }
 
     // exports
     this.event_show_diff = event_show_diff;
     this.event_show_dialog = event_show_dialog;
     this.event_history_dialog = event_history_dialog;
     this.render_event_changelog = render_event_changelog;
     this.close_history_dialog = close_history_dialog;
 
     // open a dialog to display detailed free-busy information and to find free slots
     var event_freebusy_dialog = function()
     {
       var $dialog = $('#eventfreebusy'),
         event = me.selected_event;
       
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
       
       if (!event_attendees.length)
         return false;
       
       // set form elements
       var allday = $('#edit-allday').get(0);
       var end = 'toDate' in event.end ? event.end : moment(event.end);
       var start = 'toDate' in event.start ? event.start : moment(event.start);
       var duration = Math.round((end.format('x') - start.format('x')) / 1000);
 
       freebusy_ui.startdate = $('#schedule-startdate').val(format_date(start, settings.date_format)).data('duration', duration);
       freebusy_ui.starttime = $('#schedule-starttime').val(format_date(start, settings.time_format)).show();
       freebusy_ui.enddate = $('#schedule-enddate').val(format_date(end, settings.date_format));
       freebusy_ui.endtime = $('#schedule-endtime').val(format_date(end, settings.time_format)).show();
       
       if (allday.checked) {
         freebusy_ui.starttime.val("12:00").hide();
         freebusy_ui.endtime.val("13:00").hide();
         event.allDay = true;
       }
       
       // read attendee roles from drop-downs
       $('select.edit-attendee-role').each(function(i, elem){
         if (event_attendees[i])
           event_attendees[i].role = $(elem).val();
       });
       
       // render time slots
       var now = new Date(), fb_start = new Date(), fb_end = new Date();
       fb_start.setTime(event.start);
       fb_start.setHours(0); fb_start.setMinutes(0); fb_start.setSeconds(0); fb_start.setMilliseconds(0);
       fb_end.setTime(fb_start.getTime() + DAY_MS);
       
       freebusy_data = { required:{}, all:{} };
       freebusy_ui.loading = 1;  // prevent render_freebusy_grid() to load data yet
       freebusy_ui.numdays = Math.max(allday.checked ? 14 : 1, Math.ceil(duration * 2 / 86400));
       freebusy_ui.interval = allday.checked ? 1440 : (60 / (settings.timeslots || 1));
       freebusy_ui.start = fb_start;
       freebusy_ui.end = new Date(freebusy_ui.start.getTime() + DAY_MS * freebusy_ui.numdays);
       render_freebusy_grid(0);
       
       // render list of attendees
       freebusy_ui.attendees = {};
       var domid, dispname, data, role_html, list_html = '';
       for (var i=0; i < event_attendees.length; i++) {
         data = event_attendees[i];
         dispname = Q(data.name || data.email);
         domid = String(data.email).replace(rcmail.identifier_expr, '');
         role_html = '<a class="attendee-role-toggle" id="rcmlia' + domid + '" title="' + Q(rcmail.gettext('togglerole', 'calendar')) + '">&nbsp;</a>';
         list_html += '<div class="attendee ' + String(data.role).toLowerCase() + '" id="rcmli' + domid + '">' + role_html + dispname + '</div>';
         
         // clone attendees data for local modifications
         freebusy_ui.attendees[i] = freebusy_ui.attendees[domid] = $.extend({}, data);
       }
       
       // add total row
       list_html += '<div class="attendee spacer">&nbsp;</div>';
       list_html += '<div class="attendee total">' + rcmail.gettext('reqallattendees','calendar') + '</div>';
       
       $('#schedule-attendees-list').html(list_html)
         .unbind('click.roleicons')
         .bind('click.roleicons', function(e){
           // toggle attendee status upon click on icon
           if (e.target.id && e.target.id.match(/rcmlia(.+)/)) {
             var attendee, domid = RegExp.$1,
                 roles = [ 'REQ-PARTICIPANT', 'OPT-PARTICIPANT', 'NON-PARTICIPANT', 'CHAIR' ];
             if ((attendee = freebusy_ui.attendees[domid]) && attendee.role != 'ORGANIZER') {
               var req = attendee.role != 'OPT-PARTICIPANT' && attendee.role != 'NON-PARTICIPANT';
               var j = $.inArray(attendee.role, roles);
               j = (j+1) % roles.length;
               attendee.role = roles[j];
               $(e.target).parent().attr('class', 'attendee '+String(attendee.role).toLowerCase());
               
               // update total display if required-status changed
               if (req != (roles[j] != 'OPT-PARTICIPANT' && roles[j] != 'NON-PARTICIPANT')) {
                 compute_freebusy_totals();
                 update_freebusy_display(attendee.email);
               }
             }
           }
           
           return false;
         });
 
       // enable/disable buttons
       $('#schedule-find-prev').prop('disabled', fb_start.getTime() < now.getTime());
 
       // dialog buttons
       var buttons = [
         {
           text: rcmail.gettext('select', 'calendar'),
           'class': 'save mainaction',
           click: function() {
             $('#edit-startdate').val(freebusy_ui.startdate.val());
             $('#edit-starttime').val(freebusy_ui.starttime.val());
             $('#edit-enddate').val(freebusy_ui.enddate.val());
             $('#edit-endtime').val(freebusy_ui.endtime.val());
 
             // write role changes back to main dialog
             $('select.edit-attendee-role').each(function(i, elem){
               if (event_attendees[i] && freebusy_ui.attendees[i]) {
                 event_attendees[i].role = freebusy_ui.attendees[i].role;
                 $(elem).val(event_attendees[i].role);
               }
             });
 
             if (freebusy_ui.needsupdate)
               update_freebusy_status(me.selected_event);
             freebusy_ui.needsupdate = false;
             $dialog.dialog("close");
           }
         },
         {
           text: rcmail.gettext('cancel', 'calendar'),
           'class': 'cancel',
           click: function() { $dialog.dialog("close"); }
         }
       ];
 
       $dialog.dialog({
         modal: true,
         resizable: true,
         closeOnEscape: true,
         title: rcmail.gettext('scheduletime', 'calendar'),
         open: function() {
           rcmail.ksearch_blur();
           $dialog.attr('aria-hidden', 'false').find('#schedule-find-next, #schedule-find-prev').not(':disabled').first().focus();
         },
         close: function() {
           $dialog.dialog("destroy").attr('aria-hidden', 'true').hide();
           // TODO: focus opener button
         },
         resizeStop: function() {
           render_freebusy_overlay();
         },
         buttons: buttons,
         minWidth: 640,
         width: 850
       }).show();
       
       // adjust dialog size to fit grid without scrolling
       var gridw = $('#schedule-freebusy-times').width();
       var overflow = gridw - $('#attendees-freebusy-table td.times').width();
       me.dialog_resize($dialog.get(0), $dialog.height() + (bw.ie ? 20 : 0), 800 + Math.max(0, overflow));
       
       // fetch data from server
       freebusy_ui.loading = 0;
       load_freebusy_data(freebusy_ui.start, freebusy_ui.interval);
     };
 
     // render an HTML table showing free-busy status for all the event attendees
     var render_freebusy_grid = function(delta)
     {
       if (delta) {
         freebusy_ui.start.setTime(freebusy_ui.start.getTime() + DAY_MS * delta);
         fix_date(freebusy_ui.start);
         
         // skip weekends if in workinhoursonly-mode
         if (Math.abs(delta) == 1 && freebusy_ui.workinhoursonly) {
           while (is_weekend(freebusy_ui.start))
             freebusy_ui.start.setTime(freebusy_ui.start.getTime() + DAY_MS * delta);
           fix_date(freebusy_ui.start);
         }
         
         freebusy_ui.end = new Date(freebusy_ui.start.getTime() + DAY_MS * freebusy_ui.numdays);
       }
       
       var dayslots = Math.floor(1440 / freebusy_ui.interval);
       var date_format = 'ddd '+ (dayslots <= 2 ? settings.date_short : settings.date_format);
       var lastdate, datestr, css,
         curdate = new Date(),
         allday = (freebusy_ui.interval == 1440),
         interval = allday ? 1440 : (freebusy_ui.interval * (settings.timeslots || 1));
         times_css = (allday ? 'allday ' : ''),
         dates_row = '<tr class="dates">',
         times_row = '<tr class="times">',
         slots_row = '';
 
       for (var s = 0, t = freebusy_ui.start.getTime(); t < freebusy_ui.end.getTime(); s++) {
         curdate.setTime(t);
         datestr = format_date(curdate, date_format);
         if (datestr != lastdate) {
           if (lastdate && !allday) break;
           dates_row += '<th colspan="' + dayslots + '" class="boxtitle date' + format_date(curdate, 'DDMMYYYY') + '">' + Q(datestr) + '</th>';
           lastdate = datestr;
         }
         
         // set css class according to working hours
         css = is_weekend(curdate) || (freebusy_ui.interval <= 60 && !is_workinghour(curdate)) ? 'offhours' : 'workinghours';
         times_row += '<td class="' + times_css + css + '" id="t-' + Math.floor(t/1000) + '">' + Q(allday ? rcmail.gettext('all-day','calendar') : format_date(curdate, settings.time_format)) + '</td>';
         slots_row += '<td class="' + css + '">&nbsp;</td>';
         
         t += interval * 60000;
       }
       dates_row += '</tr>';
       times_row += '</tr>';
       
       // render list of attendees
       var domid, data, list_html = '', times_html = '';
       for (var i=0; i < event_attendees.length; i++) {
         data = event_attendees[i];
         domid = String(data.email).replace(rcmail.identifier_expr, '');
         times_html += '<tr id="fbrow' + domid + '" class="fbcontent">' + slots_row + '</tr>';
       }
       
       // add line for all/required attendees
       times_html += '<tr class="spacer"><td colspan="' + (dayslots * freebusy_ui.numdays) + '"></td>';
       times_html += '<tr id="fbrowall" class="fbcontent">' + slots_row + '</tr>';
       
       var table = $('#schedule-freebusy-times');
       table.children('thead').html(dates_row + times_row);
       table.children('tbody').html(times_html);
       
       // initialize event handlers on grid
       if (!freebusy_ui.grid_events) {
         freebusy_ui.grid_events = true;
         table.children('thead').click(function(e){
           // move event to the clicked date/time
           if (e.target.id && e.target.id.match(/t-(\d+)/)) {
             var newstart = new Date(RegExp.$1 * 1000);
             // set time to 00:00
             if (me.selected_event.allDay) {
               newstart.setMinutes(0);
               newstart.setHours(0);
             }
             update_freebusy_dates(newstart, new Date(newstart.getTime() + freebusy_ui.startdate.data('duration') * 1000));
             render_freebusy_overlay();
           }
         });
       }
       
       // if we have loaded free-busy data, show it
       if (!freebusy_ui.loading) {
         if (freebusy_ui.start < freebusy_data.start || freebusy_ui.end > freebusy_data.end || freebusy_ui.interval != freebusy_data.interval) {
           load_freebusy_data(freebusy_ui.start, freebusy_ui.interval);
         }
         else {
           for (var email, i=0; i < event_attendees.length; i++) {
             if ((email = event_attendees[i].email))
               update_freebusy_display(email);
           }
         }
       }
       
       // render current event date/time selection over grid table
       // use timeout to let the dom attributes (width/height/offset) be set first
       window.setTimeout(function(){ render_freebusy_overlay(); }, 10);
     };
     
     // render overlay element over the grid to visiualize the current event date/time
     var render_freebusy_overlay = function()
     {
       var overlay = $('#schedule-event-time'),
         event_start = 'toDate' in me.selected_event.start ? me.selected_event.start.toDate() : me.selected_event.start;
         event_end = 'toDate' in me.selected_event.end ? me.selected_event.end.toDate() : me.selected_event.end;
 
       if (event_end.getTime() <= freebusy_ui.start.getTime() || event_start.getTime() >= freebusy_ui.end.getTime()) {
         overlay.hide();
         if (overlay.data('isdraggable'))
           overlay.draggable('disable');
       }
       else {
         var i, n, table = $('#schedule-freebusy-times'),
           width = 0,
           pos = { top:table.children('thead').height(), left:0 },
           eventstart = date2unixtime(clone_date(me.selected_event.start, me.selected_event.allDay?1:0)),
           eventend = date2unixtime(clone_date(me.selected_event.end, me.selected_event.allDay?2:0)) - 60,
           slotstart = date2unixtime(freebusy_ui.start),
           slotsize = freebusy_ui.interval * 60,
           slotnum = freebusy_ui.interval > 60 ? 1 : (60 / freebusy_ui.interval),
           cells = table.children('thead').find('td'),
           cell_width = cells.first().get(0).offsetWidth,
           h_margin = table.parents('table').data('h-margin'),
           v_margin = table.parents('table').data('v-margin'),
           slotend;
 
         if (h_margin === undefined)
           h_margin = 4;
         if (v_margin === undefined)
           v_margin = 4;
 
         // iterate through slots to determine position and size of the overlay
         for (i=0; i < cells.length; i++) {
           for (n=0; n < slotnum; n++) {
             slotend = slotstart + slotsize - 1;
             // event starts in this slot: compute left
             if (eventstart >= slotstart && eventstart <= slotend) {
               pos.left = Math.round(i * cell_width + (cell_width / slotnum) * n);
             }
             // event ends in this slot: compute width
             if (eventend >= slotstart && eventend <= slotend) {
               width = Math.round(i * cell_width + (cell_width / slotnum) * (n + 1)) - pos.left;
             }
             slotstart += slotsize;
           }
         }
 
         if (!width)
           width = table.width() - pos.left;
 
         // overlay is visible
         if (width > 0) {
           overlay.css({
             width: (width - h_margin) + 'px',
             height: (table.children('tbody').height() - v_margin) + 'px',
             left: pos.left + 'px',
             top: pos.top + 'px'
           }).show();
 
           // configure draggable
           if (!overlay.data('isdraggable')) {
             overlay.draggable({
               axis: 'x',
               scroll: true,
               stop: function(e, ui){
                 // convert pixels to time
                 var px = ui.position.left;
                 var range_p = $('#schedule-freebusy-times').width();
                 var range_t = freebusy_ui.end.getTime() - freebusy_ui.start.getTime();
                 var newstart = new Date(freebusy_ui.start.getTime() + px * (range_t / range_p));
                 newstart.setSeconds(0); newstart.setMilliseconds(0);
                 // snap to day boundaries
                 if (me.selected_event.allDay) {
                   if (newstart.getHours() >= 12)  // snap to next day
                     newstart.setTime(newstart.getTime() + DAY_MS);
                   newstart.setMinutes(0);
                   newstart.setHours(0);
                 }
                 else {
                   // round to 5 minutes
                   // @TODO: round to timeslots?
                   var round = newstart.getMinutes() % 5;
                   if (round > 2.5) newstart.setTime(newstart.getTime() + (5 - round) * 60000);
                   else if (round > 0) newstart.setTime(newstart.getTime() - round * 60000);
                 }
                 // update event times and display
                 update_freebusy_dates(newstart, new Date(newstart.getTime() + freebusy_ui.startdate.data('duration') * 1000));
                 if (me.selected_event.allDay)
                   render_freebusy_overlay();
               }
             }).data('isdraggable', true);
           }
           else
             overlay.draggable('enable');
         }
         else
           overlay.draggable('disable').hide();
       }
     };
 
     // fetch free-busy information for each attendee from server
     var load_freebusy_data = function(from, interval)
     {
       var start = new Date(from.getTime() - DAY_MS * 2);  // start 2 days before event
       fix_date(start);
       var end = new Date(start.getTime() + DAY_MS * Math.max(14, freebusy_ui.numdays + 7));   // load min. 14 days
       freebusy_ui.numrequired = 0;
       freebusy_data.all = [];
       freebusy_data.required = [];
 
       // load free-busy information for every attendee
       var domid, email;
       for (var i=0; i < event_attendees.length; i++) {
         if ((email = event_attendees[i].email)) {
           domid = String(email).replace(rcmail.identifier_expr, '');
           $('#rcmli' + domid).addClass('loading');
           freebusy_ui.loading++;
           
           $.ajax({
             type: 'GET',
             dataType: 'json',
             url: rcmail.url('freebusy-times'),
             data: { email:email, start:date2servertime(clone_date(start, 1)), end:date2servertime(clone_date(end, 2)), interval:interval, _remote:1 },
             success: function(data) {
               freebusy_ui.loading--;
               
               // find attendee
               var i, attendee = null;
               for (i=0; i < event_attendees.length; i++) {
                 if (freebusy_ui.attendees[i].email == data.email) {
                   attendee = freebusy_ui.attendees[i];
                   break;
                 }
               }
               
               // copy data to member var
               var ts, status,
                 req = attendee.role != 'OPT-PARTICIPANT',
                 start = parseISO8601(data.start);
 
               freebusy_data.start = new Date(start);
               freebusy_data.end = parseISO8601(data.end);
               freebusy_data.interval = data.interval;
               freebusy_data[data.email] = {};
 
               for (i=0; i < data.slots.length; i++) {
                 ts = date2timestring(start, data.interval > 60);
                 status = data.slots.charAt(i);
                 freebusy_data[data.email][ts] = status
                 start = new Date(start.getTime() + data.interval * 60000);
                 
                 // set totals
                 if (!freebusy_data.required[ts])
                   freebusy_data.required[ts] = [0,0,0,0];
                 if (req)
                   freebusy_data.required[ts][status]++;
                 
                 if (!freebusy_data.all[ts])
                   freebusy_data.all[ts] = [0,0,0,0];
                 freebusy_data.all[ts][status]++;
               }
 
               // hide loading indicator
               var domid = String(data.email).replace(rcmail.identifier_expr, '');
               $('#rcmli' + domid).removeClass('loading');
               
               // update display
               update_freebusy_display(data.email);
             }
           });
           
           // count required attendees
           if (freebusy_ui.attendees[i].role != 'OPT-PARTICIPANT')
             freebusy_ui.numrequired++;
         }
       }
     };
     
     // re-calculate total status after role change
     var compute_freebusy_totals = function()
     {
       freebusy_ui.numrequired = 0;
       freebusy_data.all = [];
       freebusy_data.required = [];
       
       var email, req, status;
       for (var i=0; i < event_attendees.length; i++) {
         if (!(email = event_attendees[i].email))
           continue;
         
         req = freebusy_ui.attendees[i].role != 'OPT-PARTICIPANT';
         if (req)
           freebusy_ui.numrequired++;
         
         for (var ts in freebusy_data[email]) {
           if (!freebusy_data.required[ts])
             freebusy_data.required[ts] = [0,0,0,0];
           if (!freebusy_data.all[ts])
             freebusy_data.all[ts] = [0,0,0,0];
           
           status = freebusy_data[email][ts];
           freebusy_data.all[ts][status]++;
           
           if (req)
             freebusy_data.required[ts][status]++;
         }
       }
     };
 
     // update free-busy grid with status loaded from server
     var update_freebusy_display = function(email)
     {
       var status_classes = ['unknown','free','busy','tentative','out-of-office'];
       var domid = String(email).replace(rcmail.identifier_expr, '');
       var row = $('#fbrow' + domid);
       var rowall = $('#fbrowall').children();
       var dateonly = freebusy_ui.interval > 60,
         t, ts = date2timestring(freebusy_ui.start, dateonly),
         curdate = new Date(),
         fbdata = freebusy_data[email];
 
       if (fbdata && fbdata[ts] !== undefined && row.length) {
         t = freebusy_ui.start.getTime();
         row.children().each(function(i, cell) {
           var j, n, attr, last, all_slots = [], slots = [],
             all_cell = rowall.get(i),
             cnt = dateonly ? 1 : (60 / freebusy_ui.interval),
             percent = (100 / cnt);
 
           for (n=0; n < cnt; n++) {
             curdate.setTime(t);
             ts = date2timestring(curdate, dateonly);
             attr = {
               'style': 'float:left; width:' + percent.toFixed(2) + '%',
               'class': fbdata[ts] ? status_classes[fbdata[ts]] : 'unknown'
             };
 
             slots.push($('<div>').attr(attr));
 
             // also update total row if all data was loaded
             if (!freebusy_ui.loading && freebusy_data.all[ts] && all_cell) {
               var w, all_status = freebusy_data.all[ts][2] ? 'busy' : 'unknown',
                 req_status = freebusy_data.required[ts][2] ? 'busy' : 'free';
 
               for (j=1; j < status_classes.length; j++) {
                 if (freebusy_ui.numrequired && freebusy_data.required[ts][j] >= freebusy_ui.numrequired)
                   req_status = status_classes[j];
                 if (freebusy_data.all[ts][j] == event_attendees.length)
                   all_status = status_classes[j];
               }
 
               attr['class'] = req_status + ' all-' + all_status;
 
               // these elements use some specific styling, so we want to minimize their number
               if (last && last.attr('class').startsWith(attr['class'])) {
                 w = percent + parseFloat(last.css('width').replace('%', ''));
                 last.css('width', w.toFixed(2) + '%').attr('class', attr['class'] + ' w' + w.toFixed(0));
               }
               else {
                 last = $('<div>').attr(attr).addClass('w' + percent.toFixed(0)).append('<span>');
                 all_slots.push(last);
               }
             }
 
             t += freebusy_ui.interval * 60000;
           }
 
           $(cell).html('').append(slots);
           if (all_slots.length)
             $(all_cell).html('').append(all_slots);
         });
       }
     };
 
     // write changed event date/times back to form fields
     var update_freebusy_dates = function(start, end)
     {
       // fix all-day evebt times
       if (me.selected_event.allDay) {
         var numdays = Math.floor((me.selected_event.end.getTime() - me.selected_event.start.getTime()) / DAY_MS);
         start.setHours(12);
         start.setMinutes(0);
         end.setTime(start.getTime() + numdays * DAY_MS);
         end.setHours(13);
         end.setMinutes(0);
       }
       me.selected_event.start = start;
       me.selected_event.end = end;
       freebusy_ui.startdate.val(format_date(start, settings.date_format));
       freebusy_ui.starttime.val(format_date(start, settings.time_format));
       freebusy_ui.enddate.val(format_date(end, settings.date_format));
       freebusy_ui.endtime.val(format_date(end, settings.time_format));
       freebusy_ui.needsupdate = true;
     };
 
     // attempt to find a time slot where all attemdees are available
     var freebusy_find_slot = function(dir)
     {
       // exit if free-busy data isn't available yet
       if (!freebusy_data || !freebusy_data.start)
         return false;
 
       var event = me.selected_event,
         eventstart = clone_date(event.start, event.allDay ? 1 : 0).getTime(),  // calculate with integers
         eventend = clone_date(event.end, event.allDay ? 2 : 0).getTime(),
         duration = eventend - eventstart - (event.allDay ? HOUR_MS : 0),  /* make sure we don't cross day borders on DST change */
         sinterval = freebusy_data.interval * 60000,
         intvlslots = 1,
         numslots = Math.ceil(duration / sinterval),
         fb_start = freebusy_data.start.getTime(),
         fb_end = freebusy_data.end.getTime(),
         checkdate, slotend, email, ts, slot, slotdate = new Date(),
         candidatecount = 0, candidatestart = false, success = false;
 
       // shift event times to next possible slot
       eventstart += sinterval * intvlslots * dir;
       eventend += sinterval * intvlslots * dir;
 
       // iterate through free-busy slots and find candidates
       for (slot = dir > 0 ? fb_start : fb_end - sinterval;
             (dir > 0 && slot < fb_end) || (dir < 0 && slot >= fb_start);
             slot += sinterval * dir
       ) {
         slotdate.setTime(slot);
         // fix slot if just crossed a DST change
         if (event.allDay) {
           fix_date(slotdate);
           slot = slotdate.getTime();
         }
         slotend = slot + sinterval;
 
         if ((dir > 0 && slotend <= eventstart) || (dir < 0 && slot >= eventend))  // skip
           continue;
 
         // respect workinghours setting
         if (freebusy_ui.workinhoursonly) {
           if (is_weekend(slotdate) || (freebusy_data.interval <= 60 && !is_workinghour(slotdate))) {  // skip off-hours
             candidatestart = false;
             candidatecount = 0;
             continue;
           }
         }
 
         if (!candidatestart)
           candidatestart = slot;
 
         ts = date2timestring(slotdate, freebusy_data.interval > 60);
 
         // check freebusy data for all attendees
         for (var i=0; i < event_attendees.length; i++) {
           if (freebusy_ui.attendees[i].role != 'OPT-PARTICIPANT' && (email = freebusy_ui.attendees[i].email) && freebusy_data[email] && freebusy_data[email][ts] > 1) {
             candidatestart = false;
             break;
           }
         }
         
         // occupied slot
         if (!candidatestart) {
           slot += Math.max(0, intvlslots - candidatecount - 1) * sinterval * dir;
           candidatecount = 0;
           continue;
         }
         else if (dir < 0)
           candidatestart = slot;
         
         candidatecount++;
         
         // if candidate is big enough, this is it!
         if (candidatecount == numslots) {
           'toDate' in event.start ? (event.start = new Date(candidatestart)) : event.start.setTime(candidatestart);
           'toDate' in event.end ? (event.end = new Date(candidatestart + duration)) : event.end.setTime(candidatestart + duration);
           success = true;
           break;
         }
       }
 
       // update event date/time display
       if (success) {
         update_freebusy_dates(event.start, event.end);
 
         // move freebusy grid if necessary
         var event_start = 'toDate' in event.start ? event.start.toDate() : event.start,
           event_end = 'toDate' in event.end ? event.end.toDate() : event.end,
           offset = Math.ceil((event_start.getTime() - freebusy_ui.end.getTime()) / DAY_MS),
           now = new Date();
 
         if (event_start.getTime() >= freebusy_ui.end.getTime())
           render_freebusy_grid(Math.max(1, offset));
         else if (event_end.getTime() <= freebusy_ui.start.getTime())
           render_freebusy_grid(Math.min(-1, offset));
         else
           render_freebusy_overlay();
 
         $('#schedule-find-prev').prop('disabled', event_start.getTime() < now.getTime());
 
         // speak new selection
         rcmail.display_message(rcmail.gettext('suggestedslot', 'calendar') + ': ' + me.event_date_text(event, true), 'voice');
       }
       else {
         rcmail.alert_dialog(rcmail.gettext('noslotfound','calendar'));
       }
     };
 
     // update event properties and attendees availability if event times have changed
     var event_times_changed = function()
     {
       if (me.selected_event) {
         var allday = $('#edit-allday').get(0);
         me.selected_event.allDay = allday.checked;
         me.selected_event.start = me.parse_datetime(allday.checked ? '12:00' : $('#edit-starttime').val(), $('#edit-startdate').val());
         me.selected_event.end   = me.parse_datetime(allday.checked ? '13:00' : $('#edit-endtime').val(), $('#edit-enddate').val());
         if (event_attendees)
           freebusy_ui.needsupdate = true;
         $('#edit-startdate').data('duration', Math.round((me.selected_event.end.getTime() - me.selected_event.start.getTime()) / 1000));
       }
     };
 
     // add the given list of participants
     var add_attendees = function(names, params)
     {
       names = explode_quoted_string(names.replace(/,\s*$/, ''), ',');
 
       // parse name/email pairs
       var item, email, name, success = false;
       for (var i=0; i < names.length; i++) {
         email = name = '';
         item = $.trim(names[i]);
         
         if (!item.length) {
           continue;
         } // address in brackets without name (do nothing)
         else if (item.match(/^<[^@]+@[^>]+>$/)) {
           email = item.replace(/[<>]/g, '');
         } // address without brackets and without name (add brackets)
         else if (rcube_check_email(item)) {
           email = item;
         } // address with name
         else if (item.match(/([^\s<@]+@[^>]+)>*$/)) {
           email = RegExp.$1;
           name = item.replace(email, '').replace(/^["\s<>]+/, '').replace(/["\s<>]+$/, '');
         }
         if (email) {
           add_attendee($.extend({ email:email, name:name }, params));
           success = true;
         }
         else {
           rcmail.alert_dialog(rcmail.gettext('noemailwarning'));
         }
       }
       
       return success;
     };
 
     // add the given attendee to the list
     var add_attendee = function(data, readonly, before)
     {
       if (!me.selected_event)
         return false;
 
       // check for dupes...
       var exists = false;
       $.each(event_attendees, function(i, v){ exists |= (v.email == data.email); });
       if (exists)
         return false;
 
       var calendar = me.selected_event && me.calendars[me.selected_event.calendar] ? me.calendars[me.selected_event.calendar] : me.calendars[me.selected_calendar];
 
       var dispname = Q(data.name || data.email);
       dispname = '<span' + ((data.email && data.email != dispname) ? ' title="' + Q(data.email) + '"' : '') + '>' + dispname + '</span>';
 
       // role selection
       var organizer = data.role == 'ORGANIZER';
       var opts = {};
       if (organizer)
         opts.ORGANIZER = rcmail.gettext('calendar.roleorganizer');
       opts['REQ-PARTICIPANT'] = rcmail.gettext('calendar.rolerequired');
       opts['OPT-PARTICIPANT'] = rcmail.gettext('calendar.roleoptional');
       opts['NON-PARTICIPANT'] = rcmail.gettext('calendar.rolenonparticipant');
 
       if (data.cutype != 'RESOURCE')
         opts['CHAIR'] =  rcmail.gettext('calendar.rolechair');
 
       if (organizer && !readonly)
         dispname = rcmail.env['identities-selector'];
 
       var select = '<select class="edit-attendee-role form-control custom-select"'
         + (organizer || readonly ? ' disabled="true"' : '')
         + ' aria-label="' + rcmail.gettext('role','calendar') + '">';
       for (var r in opts)
         select += '<option value="'+ r +'" class="' + r.toLowerCase() + '"' + (data.role == r ? ' selected="selected"' : '') +'>' + Q(opts[r]) + '</option>';
       select += '</select>';
 
       // delete icon
       var icon = rcmail.env.deleteicon ? '<img src="' + rcmail.env.deleteicon + '" alt="" />' : '<span class="inner">' + Q(rcmail.gettext('delete')) + '</span>';
       var dellink = '<a href="#delete" class="iconlink icon button delete deletelink" title="' + Q(rcmail.gettext('delete')) + '">' + icon + '</a>';
       var tooltip = '', status = (data.status || '').toLowerCase(),
         status_label = rcmail.gettext('status' + status, 'libcalendaring');
 
       // send invitation checkbox
       var invbox = '<input type="checkbox" class="edit-attendee-reply" value="' + Q(data.email) +'" title="' + Q(rcmail.gettext('calendar.sendinvitations')) + '" '
         + (!data.noreply && settings.itip_notify & 1 ? 'checked="checked" ' : '') + '/>';
 
       if (data['delegated-to'])
         tooltip = rcmail.gettext('libcalendaring.delegatedto') + ' ' + data['delegated-to'];
       else if (data['delegated-from'])
         tooltip = rcmail.gettext('libcalendaring.delegatedfrom') + ' ' + data['delegated-from'];
       else if (!status && organizer)
         tooltip = rcmail.gettext('statusorganizer', 'libcalendaring');
       else if (status)
         tooltip = status_label;
 
       // add expand button for groups
       if (data.cutype == 'GROUP') {
         dispname += ' <a href="#expand" data-email="' + Q(data.email) + '" class="iconbutton add expandlink" title="' + rcmail.gettext('expandattendeegroup','libcalendaring') + '">' +
           rcmail.gettext('expandattendeegroup','libcalendaring') + '</a>';
       }
 
       var avail = data.email ? 'loading' : 'unknown';
       var table = rcmail.env.calendar_resources && data.cutype == 'RESOURCE' ? resources_list : attendees_list;
       var img_src = rcmail.assets_path('program/resources/blank.gif');
       var elastic = $(table).parents('.no-img').length > 0;
       var avail_tag = elastic ? ('<span class="' + avail + '"') : ('<img alt="" src="' + img_src + '" class="availabilityicon '  + avail + '"');
       var html = '<td class="role">' + select + '</td>' +
         '<td class="name"><span class="attendee-name">' + dispname + '</span></td>' +
         '<td class="availability">' + avail_tag + ' data-email="' + data.email + '" /></td>' +
         '<td class="confirmstate"><span class="attendee ' + (status || 'organizer') + '" title="' + Q(tooltip) + '">' + Q(status && !elastic ? status_label : '') + '</span></td>' +
         (data.cutype != 'RESOURCE' ? '<td class="invite">' + (organizer || readonly || !invbox ? '' : invbox) + '</td>' : '') +
         '<td class="options">' + (organizer || readonly ? '' : dellink) + '</td>';
 
       var tr = $('<tr>')
         .addClass(String(data.role).toLowerCase())
         .html(html);
 
       if (before)
         tr.insertBefore(before)
       else
         tr.appendTo(table);
 
       tr.find('a.deletelink').click({ id:(data.email || data.name) }, function(e) { remove_attendee(this, e.data.id); return false; });
       tr.find('a.expandlink').click(data, function(e) { me.expand_attendee_group(e, add_attendee, remove_attendee); return false; });
       tr.find('input.edit-attendee-reply').click(function() {
         var enabled = $('#edit-attendees-invite:checked').length || $('input.edit-attendee-reply:checked').length;
         $('#eventedit .attendees-commentbox')[enabled ? 'show' : 'hide']();
       });
 
       // select organizer identity
       if (data.identity_id)
         $('#edit-identities-list').val(data.identity_id);
 
       // check free-busy status
       if (avail == 'loading') {
         check_freebusy_status(tr.find('.availability > *:first'), data.email, me.selected_event);
       }
 
       // Make Elastic checkboxes pretty
       if (window.UI && UI.pretty_checkbox) {
         $(tr).find('input[type=checkbox]').each(function() { UI.pretty_checkbox(this); });
         $(tr).find('select').each(function() { UI.pretty_select(this); });
       }
 
       event_attendees.push(data);
       return true;
     };
 
     // iterate over all attendees and update their free-busy status display
     var update_freebusy_status = function(event)
     {
       attendees_list.find('.availability > *').each(function(i,v) {
         var email, icon = $(this);
         if (email = icon.attr('data-email'))
           check_freebusy_status(icon, email, event);
       });
       
       freebusy_ui.needsupdate = false;
     };
     
     // load free-busy status from server and update icon accordingly
     var check_freebusy_status = function(icon, email, event)
     {
       var calendar = event.calendar && me.calendars[event.calendar] ? me.calendars[event.calendar] : { freebusy:false };
       if (!calendar.freebusy) {
         $(icon).attr('class', 'availabilityicon unknown');
         return;
       }
       
       icon = $(icon).attr('class', 'availabilityicon loading');
       
       $.ajax({
         type: 'GET',
         dataType: 'html',
         url: rcmail.url('freebusy-status'),
         data: { email:email, start:date2servertime(clone_date(event.start, event.allDay?1:0)), end:date2servertime(clone_date(event.end, event.allDay?2:0)), _remote: 1 },
         success: function(status){
           var avail = String(status).toLowerCase();
           icon.removeClass('loading').addClass(avail).attr('title', rcmail.gettext('avail' + avail, 'calendar'));
         },
         error: function(){
           icon.removeClass('loading').addClass('unknown').attr('title', rcmail.gettext('availunknown', 'calendar'));
         }
       });
     };
     
     // remove an attendee from the list
     var remove_attendee = function(elem, id)
     {
       $(elem).closest('tr').remove();
       event_attendees = $.grep(event_attendees, function(data){ return (data.name != id && data.email != id) });
     };
 
     // open a dialog to display detailed free-busy information and to find free slots
     var event_resources_dialog = function(search)
     {
       var $dialog = $('#eventresourcesdialog');
 
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
 
       // dialog buttons
       var buttons = [
         {
           text: rcmail.gettext('addresource', 'calendar'),
           'class': 'mainaction save',
           click: function() { rcmail.command('add-resource'); $dialog.dialog("close"); }
         },
         {
           text: rcmail.gettext('close'),
           'class': 'cancel',
           click: function() { $dialog.dialog("close"); }
         }
       ];
 
       var resize = function() {
         var container = $(rcmail.gui_objects.resourceinfocalendar);
         container.fullCalendar('option', 'height', container.height() + 1);
       };
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: false, // prevents from Availability tab reflow bugs on resize
         closeOnEscape: true,
         title: rcmail.gettext('findresources', 'calendar'),
         classes: {'ui-dialog': 'selection-dialog resources-dialog'},
         open: function() {
           rcmail.ksearch_blur();
           $dialog.attr('aria-hidden', 'false');
 
           // for Elastic
           if ($('html.layout-small,html.layout-phone').length) {
             $('#eventresourcesdialog .resource-selection').css('display', 'flex');
             $('#eventresourcesdialog .resource-content').css('display', 'none');
           }
           setTimeout(resize, 50);
         },
         close: function() {
           $dialog.dialog('destroy').attr('aria-hidden', 'true').hide();
         },
         resize: resize,
         buttons: buttons,
         width: 900,
         height: 500
       }).show();
 
       $('.ui-dialog-buttonset button', $dialog.parent()).first().attr('id', 'rcmbtncalresadd');
 
       me.dialog_resize($dialog.get(0), 540, Math.min(1000, $(window).width() - 50));
 
       // set search query
       $('#resourcesearchbox').val(search || '');
 
       // initialize the treelist widget
       if (!resources_treelist) {
         resources_treelist = new rcube_treelist_widget(rcmail.gui_objects.resourceslist, {
           id_prefix: 'rcres',
           id_encode: rcmail.html_identifier_encode,
           id_decode: rcmail.html_identifier_decode,
           selectable: true,
           save_state: true
         });
         resources_treelist.addEventListener('select', function(node) {
           if (resources_data[node.id]) {
             resource_showinfo(resources_data[node.id]);
             rcmail.enable_command('add-resource', me.selected_event && $("#eventedit").is(':visible'));
 
             // on elastic mobile display resource info box
             if ($('html.layout-small,html.layout-phone').length) {
               $('#eventresourcesdialog .resource-selection').css('display', 'none');
               $('#eventresourcesdialog .resource-content').css('display', 'flex');
               $(window).resize();
               resize();
             }
           }
           else {
             rcmail.enable_command('add-resource', false);
             $(rcmail.gui_objects.resourceinfo).hide();
             $(rcmail.gui_objects.resourceownerinfo).hide();
             $(rcmail.gui_objects.resourceinfocalendar).fullCalendar('removeEventSources');
           }
         });
 
         // fetch (all) resource data from server
         me.loading_lock = rcmail.set_busy(true, 'loading', me.loading_lock);
         rcmail.http_request('resources-list', {}, me.loading_lock);
 
         // register button
         rcmail.register_button('add-resource', 'rcmbtncalresadd', 'button');
 
         // initialize resource calendar display
         var resource_cal = $(rcmail.gui_objects.resourceinfocalendar);
         resource_cal.fullCalendar($.extend({}, fullcalendar_defaults, {
           header: { left: '', center: '', right: '' },
           height: resource_cal.height() + 4,
           defaultView: 'agendaWeek',
           eventSources: [],
           slotMinutes: 60,
           allDaySlot: false,
           eventRender: function(event, element, view) {
             var title = rcmail.get_label(event.status, 'calendar');
             element.addClass('status-' + event.status);
             element.find('.fc-title').text(title);
             element.attr('aria-label', me.event_date_text(event, true) + ': ' + title);
           }
         }));
 
         $('#resource-calendar-prev').click(function(){
           resource_cal.fullCalendar('prev');
           return false;
         });
         $('#resource-calendar-next').click(function(){
           resource_cal.fullCalendar('next');
           return false;
         });
       }
       else if (search) {
         resource_search();
       }
       else {
         resource_render_list(resources_index);
       }
 
       if (me.selected_event && me.selected_event.start) {
         $(rcmail.gui_objects.resourceinfocalendar).fullCalendar('gotoDate', me.selected_event.start);
       }
     };
 
     // render the resource details UI box
     var resource_showinfo = function(resource)
     {
       // inline function to render a resource attribute
       function render_attrib(value) {
         if (typeof value == 'boolean') {
           return value ? rcmail.get_label('yes') : rcmail.get_label('no');
         }
 
         return value;
       }
 
       if (rcmail.gui_objects.resourceinfo) {
         var tr, table = $(rcmail.gui_objects.resourceinfo).show().find('tbody').html(''),
           attribs = $.extend({ name:resource.name }, resource.attributes||{})
           attribs.description = resource.description;
 
         for (var k in attribs) {
           if (typeof attribs[k] == 'undefined')
             continue;
           table.append($('<tr>').addClass(k + ' form-group row')
             .append('<td class="title col-sm-4"><label class="col-form-label">' + Q(ucfirst(rcmail.get_label(k, 'calendar'))) + '</label></td>')
             .append('<td class="value col-sm-8 form-control-plaintext">' + text2html(render_attrib(attribs[k])) + '</td>')
           );
         }
 
         $(rcmail.gui_objects.resourceownerinfo).hide();
         $(rcmail.gui_objects.resourceinfocalendar).fullCalendar('removeEventSources');
 
         if (resource.owner) {
           // display cached data
           if (resource_owners[resource.owner]) {
             resource_owner_load(resource_owners[resource.owner]);
           }
           else {
             // fetch owner data from server
             me.loading_lock = rcmail.set_busy(true, 'loading', me.loading_lock);
             rcmail.http_request('resources-owner', { _id: resource.owner }, me.loading_lock);
           }
         }
 
         // load resource calendar
         resources_events_source.url = "./?_task=calendar&_action=resources-calendar&_id="+urlencode(resource.ID);
         $(rcmail.gui_objects.resourceinfocalendar).fullCalendar('addEventSource', resources_events_source);
       }
     };
 
     // callback from server for resource listing
     var resource_data_load = function(data)
     {
       var resources_tree = {};
 
       // store data by ID
       $.each(data, function(i, rec) {
         resources_data[rec.ID] = rec;
 
         // assign parent-relations
         if (rec.members) {
           $.each(rec.members, function(j, m){
             resources_tree[m] = rec.ID;
           });
         }
       });
 
       // walk the parent-child tree to determine the depth of each node
       $.each(data, function(i, rec) {
         rec._depth = 0;
         if (resources_tree[rec.ID])
           rec.parent_id = resources_tree[rec.ID];
 
         var parent_id = resources_tree[rec.ID];
         while (parent_id) {
           rec._depth++;
           parent_id = resources_tree[parent_id];
         }
       });
 
       // sort by depth, collection and name
       data.sort(function(a,b) {
         var j = a._type == 'collection' ? 1 : 0,
             k = b._type == 'collection' ? 1 : 0,
             d = a._depth - b._depth;
         if (!d) d = (k - j);
         if (!d) d = b.name < a.name ? 1 : -1;
         return d;
       });
 
       $.each(data, function(i, rec) {
         resources_index.push(rec.ID);
       });
 
       // apply search filter...
       if ($('#resourcesearchbox').val() != '')
         resource_search();
       else  // ...or render full list
         resource_render_list(resources_index);
 
       rcmail.set_busy(false, null, me.loading_lock);
     };
 
     // renders the given list of resource records into the treelist
     var resource_render_list = function(index) {
       var rec, link;
 
       resources_treelist.reset();
 
       $.each(index, function(i, dn) {
         if (rec = resources_data[dn]) {
           link = $('<a>').attr('href', '#')
             .attr('rel', rec.ID)
             .html(Q(rec.name));
 
           resources_treelist.insert({ id:rec.ID, html:link, classes:[rec._type], collapsed:true }, rec.parent_id, false);
         }
       });
     };
 
     // callback from server for owner information display
     var resource_owner_load = function(data)
     {
       if (data) {
         // cache this!
         resource_owners[data.ID] = data;
 
         var table = $(rcmail.gui_objects.resourceownerinfo).find('tbody').html('');
 
         for (var k in data) {
           if (k == 'event' || k == 'ID')
             continue;
 
           table.append($('<tr>').addClass(k)
             .append('<td class="title">' + Q(ucfirst(rcmail.get_label(k, 'calendar'))) + '</td>')
             .append('<td class="value">' + text2html(data[k]) + '</td>')
           );
         }
 
         table.parent().show();
       }
     }
 
     // quick-filter the loaded resource data
     var resource_search = function()
     {
       var dn, rec, dataset = [],
         q = $('#resourcesearchbox').val().toLowerCase();
 
       if (q.length && resources_data) {
         // search by iterating over all resource records
         for (dn in resources_data) {
           rec = resources_data[dn];
           if ((rec.name && String(rec.name).toLowerCase().indexOf(q) >= 0)
             || (rec.email && String(rec.email).toLowerCase().indexOf(q) >= 0)
             || (rec.description && String(rec.description).toLowerCase().indexOf(q) >= 0)
           ) {
             dataset.push(rec.ID);
           }
         }
 
         resource_render_list(dataset);
 
         // select single match
         if (dataset.length == 1) {
           resources_treelist.select(dataset[0]);
         }
       }
       else {
         $('#resourcesearchbox').val('');
       }
     };
 
     // 
     var reset_resource_search = function()
     {
       $('#resourcesearchbox').val('').focus();
       resource_render_list(resources_index);
     };
 
     // 
     var add_resource2event = function()
     {
       var resource = resources_data[resources_treelist.get_selection()];
       if (resource)
         add_attendee($.extend({ role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:'RESOURCE' }, resource));
     }
 
+    var is_this_me = function(email)
+    {
+      if (settings.identity.emails.indexOf(';'+email) >= 0 || settings.identity.ownedResources.indexOf(';'+email) >= 0) {
+        return true;
+      }
+      return false;
+    };
+
     // when the user accepts or declines an event invitation
     var event_rsvp = function(response, delegate, replymode, event)
     {
       var btn;
       if (typeof response == 'object') {
         btn = $(response);
         response = btn.attr('rel')
       }
       else {
         btn = $('#event-rsvp input.button[rel='+response+']');
       }
 
       // show menu to select rsvp reply mode (current or all)
       if (me.selected_event && me.selected_event.recurrence && !replymode) {
         rcube_libcalendaring.itip_rsvp_recurring(btn, function(resp, mode) {
           event_rsvp(resp, null, mode, event);
         }, event);
         return;
       }
 
       if (me.selected_event && me.selected_event.attendees && response) {
         // bring up delegation dialog
         if (response == 'delegated' && !delegate) {
           rcube_libcalendaring.itip_delegate_dialog(function(data) {
             data.rsvp = data.rsvp ? 1 : '';
             event_rsvp('delegated', data, replymode, event);
           });
           return;
         }
 
         // update attendee status
         attendees = [];
         for (var data, i=0; i < me.selected_event.attendees.length; i++) {
           data = me.selected_event.attendees[i];
-          if (settings.identity.emails.indexOf(';'+String(data.email).toLowerCase()) >= 0) {
+          //FIXME this can only work if there is a single resource per invitation
+          if (is_this_me(String(data.email).toLowerCase())) {
             data.status = response.toUpperCase();
             data.rsvp = 0;  // unset RSVP flag
 
             if (data.status == 'DELEGATED') {
               data['delegated-to'] = delegate.to;
               data.rsvp = delegate.rsvp
             }
             else {
               if (data['delegated-to']) {
                 delete data['delegated-to'];
                 if (data.role == 'NON-PARTICIPANT' && data.status != 'DECLINED')
                   data.role = 'REQ-PARTICIPANT';
               }
             }
 
             attendees.push(i)
           }
           else if (response != 'DELEGATED' && data['delegated-from'] &&
               settings.identity.emails.indexOf(';'+String(data['delegated-from']).toLowerCase()) >= 0) {
             delete data['delegated-from'];
           }
 
           // set free_busy status to transparent if declined (#4425)
           if (data.status == 'DECLINED' || data.role == 'NON-PARTICIPANT') {
             me.selected_event.free_busy = 'free';
           }
           else {
             me.selected_event.free_busy = 'busy';
           }
         }
 
         // submit status change to server
         var submit_data = $.extend({}, { source:null, comment:$('#reply-comment-event-rsvp').val(), _savemode: replymode || 'all' }, (delegate || {})),
           submit_items = 'id,uid,_instance,calendar,_mbox,_uid,_part,attendees,free_busy,allDay',
           noreply = $('#noreply-event-rsvp:checked').length ? 1 : 0;
 
         // Submit only that data we really need
         $.each(submit_items.split(','), function() {
           if (this in me.selected_event)
             submit_data[this] = me.selected_event[this];
         });
 
         // import event from mail (temporary iTip event)
         if (submit_data._mbox && submit_data._uid) {
           me.saving_lock = rcmail.set_busy(true, 'calendar.savingdata');
           rcmail.http_post('mailimportitip', {
             _mbox: submit_data._mbox,
             _uid:  submit_data._uid,
             _part: submit_data._part,
             _status:  response,
             _to: (delegate ? delegate.to : null),
             _rsvp: (delegate && delegate.rsvp) ? 1 : 0,
             _noreply: noreply,
             _comment: submit_data.comment,
             _instance: submit_data._instance,
             _savemode: submit_data._savemode
           });
         }
         else if (settings.invitation_calendars) {
           update_event('rsvp', submit_data, { status:response, noreply:noreply, attendees:attendees });
         }
         else {
           me.saving_lock = rcmail.set_busy(true, 'calendar.savingdata');
           rcmail.http_post('calendar/event', { action:'rsvp', e:submit_data, status:response, attendees:attendees, noreply:noreply });
         }
 
         event_show_dialog(me.selected_event);
       }
     };
 
     // add the given date to the RDATE list
     var add_rdate = function(date)
     {
       var li = $('<li>')
         .attr('data-value', date2servertime(date))
         .append($('<span>').text(format_date(date, settings.date_format)))
         .appendTo('#edit-recurrence-rdates');
 
       $('<a>').attr('href', '#del')
         .addClass('iconbutton delete')
         .html(rcmail.get_label('delete', 'calendar'))
         .attr('title', rcmail.get_label('delete', 'calendar'))
         .appendTo(li);
     };
 
     // re-sort the list items by their 'data-value' attribute
     var sort_rdates = function()
     {
       var mylist = $('#edit-recurrence-rdates'),
         listitems = mylist.children('li').get();
       listitems.sort(function(a, b) {
          var compA = $(a).attr('data-value');
          var compB = $(b).attr('data-value');
          return (compA < compB) ? -1 : (compA > compB) ? 1 : 0;
       })
       $.each(listitems, function(idx, item) { mylist.append(item); });
     }
 
     // remove the link reference matching the given uri
     function remove_link(elem)
     {
       var $elem = $(elem), uri = $elem.attr('data-uri');
 
       me.selected_event.links = $.grep(me.selected_event.links, function(link) { return link.uri != uri; });
 
       // remove UI list item
       $elem.hide().closest('li').addClass('deleted');
     }
 
     // post the given event data to server
     var update_event = function(action, data, add)
     {
       me.saving_lock = rcmail.set_busy(true, 'calendar.savingdata');
       rcmail.http_post('calendar/event', $.extend({ action:action, e:data }, (add || {})));
 
       // render event temporarily into the calendar
       if ((data.start && data.end) || data.id) {
         var tmp, event = data.id ? $.extend(fc.fullCalendar('clientEvents', data.id)[0], data) : data;
 
         if (data.start)
           event.start = data.start;
         if (data.end)
           event.end = data.end;
         if (data.allDay !== undefined)
           event.allDay = !!data.allDay; // must be boolean for fullcalendar
 
         // For fullCalendar all-day event's end date must be exclusive
         if (event.allDay && data.end && (tmp = moment(data.end)) && tmp.format('Hms') !== '000') {
           event.end = moment().year(tmp.year()).month(tmp.month()).date(tmp.date()).hour(0).minute(0).second(0).add(1, 'days');
         }
 
         event.editable = false;
         event.temp = true;
         event.className = ['fc-event-temp'];
 
         fc.fullCalendar(data.id ? 'updateEvent' : 'renderEvent', event);
 
         // mark all recurring instances as temp
         if (event.recurrence || event.recurrence_id) {
           var base_id = event.recurrence_id ? event.recurrence_id : String(event.id).replace(/-\d+(T\d{6})?$/, '');
           $.each(fc.fullCalendar('clientEvents', function(e){ return e.id == base_id || e.recurrence_id == base_id; }), function(i,ev) {
             ev.temp = true;
             ev.editable = false;
             event.className.push('fc-event-temp');
             fc.fullCalendar('updateEvent', ev);
           });
         }
       }
     };
 
     // mouse-click handler to check if the show dialog is still open and prevent default action
     var dialog_check = function(e)
     {
       var showd = $("#eventshow");
       if (showd.is(':visible') && !$(e.target).closest('.ui-dialog').length && !$(e.target).closest('.popupmenu').length) {
         showd.dialog('close');
         e.stopImmediatePropagation();
         ignore_click = true;
         return false;
       }
       else if (ignore_click) {
         window.setTimeout(function(){ ignore_click = false; }, 20);
         return false;
       }
       return true;
     };
 
     // display confirm dialog when modifying/deleting an event
     var update_event_confirm = function(action, event, data)
     {
       // Allow other plugins to do actions here
       // E.g. when you move/resize the event init wasn't called
       // but we need it as some plugins may modify user identities
       // we depend on here (kolab_delegation)
       rcmail.triggerEvent('calendar-event-init', {o: event});
 
       if (!data) data = event;
       var decline = false, notify = false, html = '', cal = me.calendars[event.calendar],
         _is_invitation = String(event.calendar).match(/^--invitation--(declined|pending)/) && RegExp.$1,
         _has_attendees = me.has_attendees(event),
         _is_attendee = _has_attendees && me.is_attendee(event),
         _is_organizer = me.is_organizer(event);
 
       // event has attendees, ask whether to notify them
       if (_has_attendees) {
         var checked = (settings.itip_notify & 1 ? ' checked="checked"' : '');
 
         if (action == 'remove' && cal.group != 'shared' && !_is_organizer && _is_attendee && _is_invitation != 'declined') {
           decline = true;
           checked = event.status != 'CANCELLED' ? checked : '';
           html += '<div class="message dialog-message ui alert boxwarning">' +
             '<label><input class="confirm-attendees-decline pretty-checkbox" type="checkbox"' + checked + ' value="1" name="decline" />&nbsp;' +
             rcmail.gettext('itipdeclineevent', 'calendar') +
             '</label></div>';
         }
         else if (_is_organizer) {
           notify = true;
           if (settings.itip_notify & 2) {
             html += '<div class="message dialog-message ui alert boxwarning">' +
               '<label><input class="confirm-attendees-donotify pretty-checkbox" type="checkbox"' + checked + ' value="1" name="notify" />&nbsp;' +
                 rcmail.gettext((action == 'remove' ? 'sendcancellation' : 'sendnotifications'), 'calendar') +
               '</label></div>';
           }
           else {
             data._notify = settings.itip_notify;
           }
         }
         else if (cal.group != 'shared' && !_is_invitation) {
           html += '<div class="message dialog-message ui alert boxwarning">' + $('#edit-localchanges-warning').html() + '</div>';
           data._notify = 0;
         }
       }
 
       // recurring event: user needs to select the savemode
       if (event.recurrence) {
         var future_disabled = '', message_label = (action == 'remove' ? 'removerecurringeventwarning' : 'changerecurringeventwarning');
 
         // disable the 'future' savemode if I'm an attendee
         // reason: no calendaring system supports the thisandfuture range parameter in iTip REPLY
         if (action == 'remove' && !_is_organizer && _is_attendee) {
           future_disabled = ' disabled';
         }
 
         html += '<div class="message dialog-message ui alert boxwarning">' + rcmail.gettext(message_label, 'calendar') + '</div>' +
           '<div class="savemode">' +
             '<a href="#current" class="button btn btn-secondary">' + rcmail.gettext('currentevent', 'calendar') + '</a>' +
             '<a href="#future" class="button btn btn-secondary' + future_disabled + '">' + rcmail.gettext('futurevents', 'calendar') + '</a>' +
             '<a href="#all" class="button btn btn-secondary">' + rcmail.gettext('allevents', 'calendar') + '</a>' +
             (action != 'remove' ? '<a href="#new" class="button btn btn-secondary">' + rcmail.gettext('saveasnew', 'calendar') + '</a>' : '') +
           '</div>';
       }
 
       // show dialog
       if (html) {
         var $dialog = $('<div>').html(html);
 
         $dialog.find('a.button').filter(':not(.disabled)').click(function(e) {
           data._savemode = String(this.href).replace(/.+#/, '');
 
           // open event edit dialog when saving as new
           if (data._savemode == 'new') {
             event._savemode = 'new';
             event_edit_dialog('edit', event);
             fc.fullCalendar('refetchEvents');
           }
           else {
             if ($dialog.find('input.confirm-attendees-donotify').length)
               data._notify = $dialog.find('input.confirm-attendees-donotify').get(0).checked ? 1 : 0;
             if (decline) {
               data._decline = $dialog.find('input.confirm-attendees-decline:checked').length;
               data._notify = 0;
             }
             update_event(action, data);
           }
 
           $dialog.dialog("close");
           return false;
         });
 
         var buttons = [];
 
         if (!event.recurrence) {
           buttons.push({
             text: rcmail.gettext((action == 'remove' ? 'delete' : 'save'), 'calendar'),
             'class': action == 'remove' ? 'delete mainaction' : 'save mainaction',
             click: function() {
               data._notify = notify && $dialog.find('input.confirm-attendees-donotify:checked').length ? 1 : 0;
               data._decline = decline && $dialog.find('input.confirm-attendees-decline:checked').length ? 1 : 0;
               update_event(action, data);
               $(this).dialog("close");
             }
           });
         }
 
         buttons.push({
           text: rcmail.gettext('cancel', 'calendar'),
           'class': 'cancel',
           click: function() {
             $(this).dialog("close");
           }
         });
 
         $dialog.dialog({
           modal: true,
           width: 460,
           dialogClass: 'warning',
           title: rcmail.gettext((action == 'remove' ? 'removeeventconfirm' : 'changeeventconfirm'), 'calendar'),
           buttons: buttons,
           open: function() {
             setTimeout(function(){
               $dialog.parent().find('button:not(.ui-dialog-titlebar-close)').first().focus();
             }, 5);
           },
           close: function(){
             $dialog.dialog("destroy").remove();
             if (!rcmail.busy)
               fc.fullCalendar('refetchEvents');
           }
         }).addClass('event-update-confirm').show();
 
         return false;
       }
       // show regular confirm box when deleting
       else if (action == 'remove' && !cal.undelete) {
         if (!confirm(rcmail.gettext('deleteventconfirm', 'calendar')))
           return false;
       }
 
       // do update
       update_event(action, data);
 
       return true;
     };
 
 
     /*** public methods ***/
 
     /**
      * Remove saving lock and free the UI for new input
      */
     this.unlock_saving = function()
     {
         if (me.saving_lock)
             rcmail.set_busy(false, null, me.saving_lock);
     };
 
     // opens the given calendar in a popup dialog
     this.quickview = function(id, shift)
     {
       var src, in_quickview = false;
       $.each(this.quickview_sources, function(i,cal) {
         if (cal.id == id) {
           in_quickview = true;
           src = cal;
         }
       });
 
       // remove source from quickview
       if (in_quickview && shift) {
         this.quickview_sources = $.grep(this.quickview_sources, function(src) { return src.id != id; });
       }
       else {
         if (!shift) {
           // remove all current quickview event sources
           if (this.quickview_active) {
             fc.fullCalendar('removeEventSources');
           }
 
           this.quickview_sources = [];
 
           // uncheck all active quickview icons
           calendars_list.container.find('div.focusview')
             .add('#calendars .searchresults div.focusview')
             .removeClass('focusview')
               .find('a.quickview').attr('aria-checked', 'false');
         }
 
         if (!in_quickview) {
           // clone and modify calendar properties
           src = $.extend({}, this.calendars[id]);
           src.url += '&_quickview=1';
           this.quickview_sources.push(src);
         }
       }
 
       // disable quickview
       if (this.quickview_active && !this.quickview_sources.length) {
         // register regular calendar event sources
         $.each(this.calendars, function(k, cal) {
           if (cal.active)
             fc.fullCalendar('addEventSource', cal);
         });
 
         this.quickview_active = false;
         $('body').removeClass('quickview-active');
 
         // uncheck all active quickview icons
         calendars_list.container.find('div.focusview')
           .add('#calendars .searchresults div.focusview')
           .removeClass('focusview')
             .find('a.quickview').attr('aria-checked', 'false');
       }
       // activate quickview
       else if (!this.quickview_active) {
         // remove regular calendar event sources
         fc.fullCalendar('removeEventSources');
 
         // register quickview event sources
         $.each(this.quickview_sources, function(i, src) {
           fc.fullCalendar('addEventSource', src);
         });
 
         this.quickview_active = true;
         $('body').addClass('quickview-active');
       }
       // update quickview sources
       else if (in_quickview) {
         fc.fullCalendar('removeEventSource', src);
       }
       else if (src) {
         fc.fullCalendar('addEventSource', src);
       }
 
       // activate quickview icon
       if (this.quickview_active) {
         $(calendars_list.get_item(id)).find('.calendar').first()
           .add('#calendars .searchresults .cal-' + id)
           [in_quickview ? 'removeClass' : 'addClass']('focusview')
             .find('a.quickview').attr('aria-checked', in_quickview ? 'false' : 'true');
       }
     };
 
     // disable quickview mode
     function reset_quickview()
     {
       // remove all current quickview event sources
       if (me.quickview_active) {
         fc.fullCalendar('removeEventSources');
         me.quickview_sources = [];
       }
 
       // register regular calendar event sources
       $.each(me.calendars, function(k, cal) {
         if (cal.active)
           fc.fullCalendar('addEventSource', cal);
       });
 
       // uncheck all active quickview icons
       calendars_list.container.find('div.focusview')
         .add('#calendars .searchresults div.focusview')
         .removeClass('focusview')
           .find('a.quickview').attr('aria-checked', 'false');
 
       me.quickview_active = false;
       $('body').removeClass('quickview-active');
     };
 
     //public method to show the print dialog.
     this.print_calendars = function(view)
     {
       if (!view) view = fc.fullCalendar('getView').name;
       var date = fc.fullCalendar('getDate').toDate();
 
       rcmail.open_window(rcmail.url('print', {
           view: view,
           date: date2unixtime(date),
           range: settings.agenda_range,
           search: this.search_query
         }), true, true);
     };
 
     // public method to bring up the new event dialog
     this.add_event = function(templ) {
       if (this.selected_calendar) {
         var now = new Date();
         var date = fc.fullCalendar('getDate').toDate();
         date.setHours(now.getHours()+1);
         date.setMinutes(0);
         var end = new Date(date.getTime());
         end.setHours(date.getHours()+1);
         event_edit_dialog('new', $.extend({ start:date, end:end, allDay:false, calendar:this.selected_calendar }, templ || {}));
       }
     };
 
     // delete the given event after showing a confirmation dialog
     this.delete_event = function(event) {
       // show confirm dialog for recurring events, use jquery UI dialog
       return update_event_confirm('remove', event, { id:event.id, calendar:event.calendar, attendees:event.attendees });
     };
 
     // opens a jquery UI dialog with event properties (or empty for creating a new calendar)
     this.calendar_edit_dialog = function(calendar)
     {
       if (!calendar)
         calendar = { name:'', color:'cc0000', editable:true, showalarms:true };
 
       var title = rcmail.gettext((calendar.id ? 'editcalendar' : 'createcalendar'), 'calendar'),
         params = {action: calendar.id ? 'form-edit' : 'form-new', c: {id: calendar.id}, _framed: 1},
         $dialog = $('<iframe>').attr('src', rcmail.url('calendar', params)).on('load', function() {
           var contents = $(this).contents();
           contents.find('#calendar-name')
             .prop('disabled', !calendar.editable)
             .val(calendar.editname || calendar.name)
             .select();
           contents.find('#calendar-color')
             .val(calendar.color);
           contents.find('#calendar-showalarms')
             .prop('checked', calendar.showalarms);
         }),
         save_func = function() {
           var data,
             form = $dialog.contents().find('#calendarpropform'),
             name = form.find('#calendar-name');
 
           // form is not loaded
           if (!form || !form.length)
             return false;
 
           // do some input validation
           if (!name.val() || name.val().length < 2) {
             rcmail.alert_dialog(rcmail.gettext('invalidcalendarproperties', 'calendar'), function() {
               name.select();
             });
 
             return false;
           }
 
           // post data to server
           data = form.serializeJSON();
           if (data.color)
             data.color = data.color.replace(/^#/, '');
           if (calendar.id)
             data.id = calendar.id;
 
           me.saving_lock = rcmail.set_busy(true, 'calendar.savingdata');
           rcmail.http_post('calendar', { action:(calendar.id ? 'edit' : 'new'), c:data });
           $dialog.dialog("close");
         };
 
       rcmail.simple_dialog($dialog, title, save_func, {
         width: 600,
         height: 400
       });
     };
 
     this.calendar_remove = function(calendar)
     {
       this.calendar_destroy_source(calendar.id);
       rcmail.http_post('calendar', { action:'subscribe', c:{ id:calendar.id, active:0, permanent:0, recursive:1 } });
       return true;
     };
 
     this.calendar_delete = function(calendar)
     {
       var label = calendar.children ? 'deletecalendarconfirmrecursive' : 'deletecalendarconfirm';
       rcmail.confirm_dialog(rcmail.gettext(label, 'calendar'), 'delete', function() {
         rcmail.http_post('calendar', { action:'delete', c:{ id:calendar.id } });
         return true;
       });
 
       return false;
     };
 
     this.calendar_refresh_source = function(id)
     {
       // got race-conditions fc.currentFetchID when using refetchEventSources,
       // so we remove and add the source instead
       // fc.fullCalendar('refetchEventSources', me.calendars[id]);
       // TODO: Check it again with fullcalendar >= 3.9
       fc.fullCalendar('removeEventSource', me.calendars[id]);
       fc.fullCalendar('addEventSource', me.calendars[id]);
     };
 
     this.calendar_destroy_source = function(id)
     {
       var delete_ids = [];
 
       if (this.calendars[id]) {
         // find sub-calendars
         if (this.calendars[id].children) {
           for (var child_id in this.calendars) {
             if (String(child_id).indexOf(id) == 0)
               delete_ids.push(child_id);
           }
         }
         else {
           delete_ids.push(id);
         }
       }
 
       // delete all calendars in the list
       for (var i=0; i < delete_ids.length; i++) {
         id = delete_ids[i];
         calendars_list.remove(id);
         fc.fullCalendar('removeEventSource', this.calendars[id]);
         $('#edit-calendar option[value="'+id+'"]').remove();
         delete this.calendars[id];
       }
 
       if (this.selected_calendar == id) {
         this.init_calendars(true);
       }
     };
 
     // open a dialog to upload an .ics file with events to be imported
     this.import_events = function(calendar)
     {
       // close show dialog first
       var $dialog = $("#eventsimport"),
         form = rcmail.gui_objects.importform;
 
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
 
       if (calendar)
         $('#event-import-calendar').val(calendar.id);
 
       var buttons = [
         {
           text: rcmail.gettext('import', 'calendar'),
           'class' : 'mainaction import',
           click: function() {
             if (form && form.elements._data.value) {
               rcmail.async_upload_form(form, 'import_events', function(e) {
                 rcmail.set_busy(false, null, me.saving_lock);
                 $('.ui-dialog-buttonpane button', $dialog.parent()).prop('disabled', false);
 
                 // display error message if no sophisticated response from server arrived (e.g. iframe load error)
                 if (me.import_succeeded === null)
                   rcmail.display_message(rcmail.get_label('importerror', 'calendar'), 'error');
               });
 
               // display upload indicator (with extended timeout)
               var timeout = rcmail.env.request_timeout;
               rcmail.env.request_timeout = 600;
               me.import_succeeded = null;
               me.saving_lock = rcmail.set_busy(true, 'uploading');
               $('.ui-dialog-buttonpane button', $dialog.parent()).prop('disabled', true);
 
               // restore settings
               rcmail.env.request_timeout = timeout;
             }
           }
         },
         {
           text: rcmail.gettext('cancel', 'calendar'),
           'class': 'cancel',
           click: function() { $dialog.dialog("close"); }
         }
       ];
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: false,
         closeOnEscape: false,
         title: rcmail.gettext('importevents', 'calendar'),
         close: function() {
           $('.ui-dialog-buttonpane button', $dialog.parent()).prop('disabled', false);
           $dialog.dialog("destroy").hide();
         },
         buttons: buttons,
         width: 520
       }).show();
     };
 
     // callback from server if import succeeded
     this.import_success = function(p)
     {
       this.import_succeeded = true;
       $("#eventsimport:ui-dialog").dialog('close');
       rcmail.set_busy(false, null, me.saving_lock);
       rcmail.gui_objects.importform.reset();
 
       if (p.refetch)
         this.refresh(p);
     };
 
     // callback from server to report errors on import
     this.import_error = function(p)
     {
       this.import_succeeded = false;
       rcmail.set_busy(false, null, me.saving_lock);
       rcmail.display_message(p.message || rcmail.get_label('importerror', 'calendar'), 'error');
     }
 
     // open a dialog to select calendars for export
     this.export_events = function(calendar)
     {
       // close show dialog first
       var $dialog = $("#eventsexport"),
         form = rcmail.gui_objects.exportform;
 
       if ($dialog.is(':ui-dialog'))
         $dialog.dialog('close');
 
       if (calendar)
         $('#event-export-calendar').val(calendar.id);
 
       $('#event-export-range').change(function(e){
         var custom = $(this).val() == 'custom', input = $('#event-export-startdate');
 
         $(this)[custom ? 'removeClass' : 'addClass']('rounded-right'); // Elastic/Bootstrap
         input[custom ? 'show' : 'hide']();
         if (custom)
           input.select();
       })
 
       var buttons = [
         {
           text: rcmail.gettext('export', 'calendar'),
           'class': 'mainaction export',
           click: function() {
             if (form) {
               var start = 0, range = $('#event-export-range', this).val(),
                 source = $('#event-export-calendar').val(),
                 attachmt = $('#event-export-attachments').get(0).checked;
 
               if (range == 'custom')
                 start = date2unixtime(me.parse_datetime('00:00', $('#event-export-startdate').val()));
               else if (range > 0)
                 start = 'today -' + range + ' months';
 
               rcmail.goto_url('export_events', { source:source, start:start, attachments:attachmt?1:0 }, false);
             }
             $dialog.dialog("close");
           }
         },
         {
           text: rcmail.gettext('cancel', 'calendar'),
           'class': 'cancel',
           click: function() { $dialog.dialog("close"); }
         }
       ];
 
       // open jquery UI dialog
       $dialog.dialog({
         modal: true,
         resizable: false,
         closeOnEscape: false,
         title: rcmail.gettext('exporttitle', 'calendar'),
         close: function() {
           $('.ui-dialog-buttonpane button', $dialog.parent()).prop('disabled', false);
           $dialog.dialog("destroy").hide();
         },
         buttons: buttons,
         width: 520
       }).show();
     };
 
     // download the selected event as iCal
     this.event_download = function(event)
     {
       if (event && event.id) {
         rcmail.goto_url('export_events', { source:event.calendar, id:event.id, attachments:1 }, false);
       }
     };
 
     // open the message compose step with a calendar_event parameter referencing the selected event.
     // the server-side plugin hook will pick that up and attach the event to the message.
     this.event_sendbymail = function(event, e)
     {
       if (event && event.id) {
         rcmail.command('compose', { _calendar_event:event._id }, e ? e.target : null, e);
       }
     };
 
     // display the edit dialog, request 'new' action and pass the selected event
     this.event_copy = function(event) {
       if (event && event.id) {
         var copy = $.extend(true, {}, event);
 
         delete copy.id;
         delete copy._id;
         delete copy.created;
         delete copy.changed;
         delete copy.recurrence_id;
         delete copy.attachments; // @TODO
 
         $.each(copy.attendees, function (k, v) {
           if (v.role != 'ORGANIZER') {
             v.status = 'NEEDS-ACTION';
           }
         });
 
         setTimeout(function() { event_edit_dialog('new', copy); }, 50);
       }
     };
 
     // show URL of the given calendar in a dialog box
     this.showurl = function(calendar)
     {
       if (calendar.feedurl) {
         var dialog = $('#calendarurlbox').clone(true).removeClass('uidialog');
 
         if (calendar.caldavurl) {
           $('#caldavurl', dialog).val(calendar.caldavurl);
           $('#calendarcaldavurl', dialog).show();
         }
         else {
           $('#calendarcaldavurl', dialog).hide();
         }
 
         rcmail.simple_dialog(dialog, rcmail.gettext('showurl', 'calendar'), null, {
           open: function() { $('#calfeedurl', dialog).val(calendar.feedurl).select(); },
           cancel_button: 'close'
         });
       }
     };
 
     // show free-busy URL in a dialog box
     this.showfburl = function()
     {
       var dialog = $('#fburlbox').clone(true);
 
       rcmail.simple_dialog(dialog, rcmail.gettext('showfburl', 'calendar'), null, {
         open: function() { $('#fburl', dialog).val(settings.freebusy_url).select(); },
         cancel_button: 'close'
       });
     };
 
     // refresh the calendar view after saving event data
     this.refresh = function(p)
     {
       var source = me.calendars[p.source];
 
       // helper function to update the given fullcalendar view
       function update_view(view, event, source) {
         var existing = view.fullCalendar('clientEvents', event._id);
         if (existing.length) {
           delete existing[0].temp;
           delete existing[0].editable;
           $.extend(existing[0], event);
 
           view.fullCalendar('updateEvent', existing[0]);
           // remove old recurrence instances
           if (event.recurrence && !event.recurrence_id)
             view.fullCalendar('removeEvents', function(e){ return e._id.indexOf(event._id+'-') == 0; });
         }
         else {
           event.source = view.fullCalendar('getEventSourceById', source.id);  // link with source
           view.fullCalendar('renderEvent', event);
         }
       }
 
       // remove temp events
       fc.fullCalendar('removeEvents', function(e){ return e.temp; });
 
       if (source && (p.refetch || (p.update && !source.active))) {
         // activate event source if new event was added to an invisible calendar
         if (this.quickview_active) {
           // map source to the quickview_sources equivalent
           $.each(this.quickview_sources, function(src) {
             if (src.id == source.id) {
               source = src;
               return false;
             }
           });
         }
         else if (!source.active) {
           source.active = true;
           $('#rcmlical' + source.id + ' input').prop('checked', true);
         }
 
         fc.fullCalendar('refetchEventSources', source.id);
         fetch_counts();
       }
       // add/update single event object
       else if (source && p.update) {
         var event = p.update;
 
         // update main view
         update_view(fc, event, source);
 
         // update the currently displayed event dialog
         if ($('#eventshow').is(':visible') && me.selected_event && me.selected_event.id == event.id)
           event_show_dialog(event);
       }
       // refetch all calendars
       else if (p.refetch) {
         fc.fullCalendar('refetchEvents');
         fetch_counts();
       }
     };
 
     // modify query parameters for refresh requests
     this.before_refresh = function(query)
     {
       var view = fc.fullCalendar('getView');
 
       query.start = date2unixtime(view.start.toDate());
       query.end = date2unixtime(view.end.toDate());
 
       if (this.search_query)
         query.q = this.search_query;
 
       return query;
     };
 
     // callback from server providing event counts
     this.update_counts = function(p)
     {
       $.each(p.counts, function(cal, count) {
         var li = calendars_list.get_item(cal),
           bubble = $(li).children('.calendar').find('span.count');
 
         if (!bubble.length && count > 0) {
           bubble = $('<span>')
             .addClass('count')
             .appendTo($(li).children('.calendar').first())
         }
 
         if (count > 0) {
           bubble.text(count).show();
         }
         else {
           bubble.text('').hide();
         }
       });
     };
 
     // callback after an iTip message event was imported
     this.itip_message_processed = function(data)
     {
       // remove temporary iTip source
       fc.fullCalendar('removeEventSource', this.calendars['--invitation--itip']);
 
       $('#eventshow:ui-dialog').dialog('close');
       this.selected_event = null;
 
       // refresh destination calendar source
       this.refresh({ source:data.calendar, refetch:true });
 
       this.unlock_saving();
 
       // process 'after_action' in mail task
       if (window.opener && window.opener.rcube_libcalendaring)
         window.opener.rcube_libcalendaring.itip_message_processed(data);
     };
 
     // reload the calendar view by keeping the current date/view selection
     this.reload_view = function()
     {
       var query = { view: fc.fullCalendar('getView').name },
         date = fc.fullCalendar('getDate');
       if (date)
         query.date = date2unixtime(date.toDate());
       rcmail.redirect(rcmail.url('', query));
     }
 
     // update browser location to remember current view
     this.update_state = function()
     {
       var query = { view: current_view },
         date = fc.fullCalendar('getDate');
       if (date)
         query.date = date2unixtime(date.toDate());
 
       if (window.history.replaceState)
         window.history.replaceState({}, document.title, rcmail.url('', query).replace('&_action=', ''));
     };
 
     this.resource_search = resource_search;
     this.reset_resource_search = reset_resource_search;
     this.add_resource2event = add_resource2event;
     this.resource_data_load = resource_data_load;
     this.resource_owner_load = resource_owner_load;
 
 
     /***  event searching  ***/
 
     // execute search
     this.quicksearch = function()
     {
       if (rcmail.gui_objects.qsearchbox) {
         var q = rcmail.gui_objects.qsearchbox.value;
         if (q != '') {
           var id = 'search-'+q;
           var sources = [];
           
           if (me.quickview_active)
             reset_quickview();
           
           if (this._search_message)
             rcmail.hide_message(this._search_message);
           
           $.each(fc.fullCalendar('getEventSources'), function() {
             this.url = this.url.replace(/&q=.+/, '') + '&q=' + urlencode(q);
             me.calendars[this.id].url = this.url;
             sources.push(this.id);
           });
           id += '@'+sources.join(',');
           
           // ignore if query didn't change
           if (this.search_request == id) {
             return;
           }
           // remember current view
           else if (!this.search_request) {
             this.default_view = fc.fullCalendar('getView').name;
           }
           
           this.search_request = id;
           this.search_query = q;
           
           // change to list view
           fc.fullCalendar('changeView', 'list');
 
           // refetch events with new url (if not already triggered by changeView)
           if (!this.is_loading)
             fc.fullCalendar('refetchEvents');
         }
         else  // empty search input equals reset
           this.reset_quicksearch();
       }
     };
 
     // reset search and get back to normal event listing
     this.reset_quicksearch = function()
     {
       $(rcmail.gui_objects.qsearchbox).val('');
 
       if (this._search_message)
         rcmail.hide_message(this._search_message);
 
       if (this.search_request) {
         $.each(fc.fullCalendar('getEventSources'), function() {
           this.url = this.url.replace(/&q=.+/, '');
           me.calendars[this.id].url = this.url;
         });
 
         this.search_request = this.search_query = null;
 
         fc.fullCalendar('refetchEvents');
       }
     };
 
     // callback if all sources have been fetched from server
     this.events_loaded = function()
     {
       if (this.search_request && !fc.fullCalendar('clientEvents').length) {
         this._search_message = rcmail.display_message(rcmail.gettext('searchnoresults', 'calendar'), 'notice');
       }
     };
 
     // adjust calendar view size
     this.view_resize = function()
     {
       var footer = fc.fullCalendar('getView').name == 'list' ? $('#agendaoptions').outerHeight() : 0;
       fc.fullCalendar('option', 'height', $('#calendar').height() - footer);
     };
 
     // mark the given calendar folder as selected
     this.select_calendar = function(id, nolistupdate)
     {
       if (!nolistupdate)
         calendars_list.select(id);
 
       // trigger event hook
       rcmail.triggerEvent('selectfolder', { folder:id, prefix:'rcmlical' });
 
       this.selected_calendar = id;
 
       rcmail.update_state({source: id});
       rcmail.enable_command('addevent', this.calendars[id] && this.calendars[id].editable);
     };
 
     // register the given calendar to the current view
     var add_calendar_source = function(cal)
     {
       var brightness, select, id = cal.id;
 
       me.calendars[id] = $.extend({
         url: rcmail.url('calendar/load_events', { source: id }),
         id: id
       }, cal);
 
       if (fc && (cal.active || cal.subscribed)) {
         if (cal.active)
           fc.fullCalendar('addEventSource', me.calendars[id]);
 
         var submit = { id: id, active: cal.active ? 1 : 0 };
         if (cal.subscribed !== undefined)
             submit.permanent = cal.subscribed ? 1 : 0;
         rcmail.http_post('calendar', { action:'subscribe', c:submit });
       }
 
       // insert to #calendar-select options if writeable
       select = $('#edit-calendar');
       if (fc && me.has_permission(cal, 'i') && select.length && !select.find('option[value="'+id+'"]').length) {
         $('<option>').attr('value', id).html(cal.name).appendTo(select);
       }
     }
 
     // fetch counts for some calendars from the server
     var fetch_counts = function()
     {
       if (count_sources.length) {
         setTimeout(function() {
           rcmail.http_request('calendar/count', { source:count_sources });
         }, 500);
       }
     };
 
     this.init_calendars = function(refresh)
     {
       var id, cal, active;
 
       for (id in rcmail.env.calendars) {
         cal = rcmail.env.calendars[id];
         active = cal.active || false;
 
         if (!refresh) {
           add_calendar_source(cal);
 
           // check active calendars
           $('#rcmlical'+id+' > .calendar input').prop('checked', active);
 
           if (active) {
             event_sources.push(this.calendars[id]);
           }
           if (cal.counts) {
             count_sources.push(id);
           }
         }
 
         if (cal.editable && (!this.selected_calendar || refresh)) {
           this.selected_calendar = id;
           if (refresh) {
             this.select_calendar(id);
             refresh = false;
           }
         }
       }
     };
 
 
     /***  startup code  ***/
 
     // initialize treelist widget that controls the calendars list
     var widget_class = window.kolab_folderlist || rcube_treelist_widget;
     calendars_list = new widget_class(rcmail.gui_objects.calendarslist, {
       id_prefix: 'rcmlical',
       selectable: true,
       save_state: true,
       keyboard: false,
       searchbox: '#calendarlistsearch',
       search_action: 'calendar/calendar',
       search_sources: [ 'folders', 'users' ],
       search_title: rcmail.gettext('calsearchresults','calendar')
     });
     calendars_list.addEventListener('select', function(node) {
       if (node && node.id && me.calendars[node.id]) {
         me.select_calendar(node.id, true);
         rcmail.enable_command('calendar-edit', 'calendar-showurl', 'calendar-showfburl', true);
         rcmail.enable_command('calendar-delete', me.calendars[node.id].editable);
         rcmail.enable_command('calendar-remove', me.calendars[node.id] && me.calendars[node.id].removable);
       }
     });
     calendars_list.addEventListener('insert-item', function(p) {
       var cal = p.data;
       if (cal && cal.id) {
         add_calendar_source(cal);
 
         // add css classes related to this calendar to document
         if (cal.css) {
           $('<style type="text/css"></style>')
             .html(cal.css)
             .appendTo('head');
         }
       }
     });
     calendars_list.addEventListener('subscribe', function(p) {
       var cal;
       if ((cal = me.calendars[p.id])) {
         cal.subscribed = p.subscribed || false;
         rcmail.http_post('calendar', { action:'subscribe', c:{ id:p.id, active:cal.active?1:0, permanent:cal.subscribed?1:0 } });
       }
     });
     calendars_list.addEventListener('remove', function(p) {
       if (me.calendars[p.id] && me.calendars[p.id].removable) {
         me.calendar_remove(me.calendars[p.id]);
       }
     });
     calendars_list.addEventListener('search-complete', function(data) {
       if (data.length)
         rcmail.display_message(rcmail.gettext('nrcalendarsfound','calendar').replace('$nr', data.length), 'voice');
       else
         rcmail.display_message(rcmail.gettext('nocalendarsfound','calendar'), 'notice');
     });
     calendars_list.addEventListener('click-item', function(event) {
       // handle clicks on quickview icon: temprarily add this source and open in quickview
       if ($(event.target).hasClass('quickview') && event.data) {
         if (!me.calendars[event.data.id]) {
           event.data.readonly = true;
           event.data.active = false;
           event.data.subscribed = false;
           add_calendar_source(event.data);
         }
         me.quickview(event.data.id, event.shiftKey || event.metaKey || event.ctrlKey);
         return false;
       }
     });
 
     // init (delegate) event handler on calendar list checkboxes
     $(rcmail.gui_objects.calendarslist).on('click', 'input[type=checkbox]', function(e) {
       e.stopPropagation();
 
       if (me.quickview_active) {
         this.checked = !this.checked;
         return false;
       }
 
       var id = this.value;
 
       // add or remove event source on click
       if (me.calendars[id]) {
         // adjust checked state of original list item
         if (calendars_list.is_search()) {
           calendars_list.container.find('input[value="'+id+'"]').prop('checked', this.checked);
         }
 
         me.calendars[id].active = this.checked;
 
         // add/remove event source
         fc.fullCalendar(this.checked ? 'addEventSource' : 'removeEventSource', me.calendars[id]);
         rcmail.http_post('calendar', {action: 'subscribe', c: {id: id, active: this.checked ? 1 : 0}});
       }
     })
     .on('keypress', 'input[type=checkbox]', function(e) {
         // select calendar on <Enter>
         if (e.keyCode == 13) {
             calendars_list.select(this.value);
             return rcube_event.cancel(e);
         }
     })
     // init (delegate) event handler on quickview links
     .on('click', 'a.quickview', function(e) {
       var id = $(this).closest('li').attr('id').replace(/^rcmlical/, '');
 
       if (calendars_list.is_search())
         id = id.replace(/--xsR$/, '');
 
       if (me.calendars[id])
         me.quickview(id, e.shiftKey || e.metaKey || e.ctrlKey);
 
       if (!rcube_event.is_keyboard(e) && this.blur)
         this.blur();
 
       e.stopPropagation();
       return false;
     });
 
     // register dbl-click handler to open calendar edit dialog
     $(rcmail.gui_objects.calendarslist).on('dblclick', ':not(.virtual) > .calname', function(e){
       var id = $(this).closest('li').attr('id').replace(/^rcmlical/, '');
       me.calendar_edit_dialog(me.calendars[id]);
     });
 
     // Make Elastic checkboxes pretty
     if (window.UI && UI.pretty_checkbox) {
       $(rcmail.gui_objects.calendarslist).find('input[type=checkbox]').each(function() {
         UI.pretty_checkbox(this);
       });
       calendars_list.addEventListener('add-item', function(prop) {
         UI.pretty_checkbox($(prop.li).find('input'));
       });
     }
 
     // create list of event sources AKA calendars
     this.init_calendars();
 
     // select default calendar
     if (rcmail.env.source && this.calendars[rcmail.env.source])
       this.selected_calendar = rcmail.env.source;
     else if (settings.default_calendar && this.calendars[settings.default_calendar] && this.calendars[settings.default_calendar].editable)
       this.selected_calendar = settings.default_calendar;
 
     if (this.selected_calendar)
       this.select_calendar(this.selected_calendar);
 
     var viewdate = new Date();
     if (rcmail.env.date)
       viewdate.setTime(fromunixtime(rcmail.env.date));
 
     // add source with iTip event data for rendering
     if (rcmail.env.itip_events && rcmail.env.itip_events.length) {
       me.calendars['--invitation--itip'] = {
         events: rcmail.env.itip_events,
         color: 'ffffff',
         editable: false,
         rights: 'lrs',
         attendees: true
       };
       event_sources.push(me.calendars['--invitation--itip']);
     }
 
     // initalize the fullCalendar plugin
     var fc = $('#calendar').fullCalendar($.extend({}, fullcalendar_defaults, {
       header: {
         right: 'prev,next today',
         center: 'title',
         left: 'agendaDay,agendaWeek,month,list'
       },
       defaultDate: viewdate,
       height: $('#calendar').height(),
       eventSources: event_sources,
       selectable: true,
       selectHelper: false,
       loading: function(isLoading) {
         me.is_loading = isLoading;
         this._rc_loading = rcmail.set_busy(isLoading, me.search_request ? 'searching' : 'loading', this._rc_loading);
         // trigger callback (using timeout, otherwise clientEvents is always empty)
         if (!isLoading)
           setTimeout(function() { me.events_loaded(); }, 20);
       },
       // callback for date range selection
       select: function(start, end, e, view) {
         var range_select = (start.hasTime() || start != end)
         if (dialog_check(e) && range_select)
           event_edit_dialog('new', { start:start, end:end, allDay:!start.hasTime(), calendar:me.selected_calendar });
         if (range_select || ignore_click)
           view.calendar.unselect();
       },
       // callback for clicks in all-day box
       dayClick: function(date, e, view) {
         var now = new Date().getTime();
         if (now - day_clicked_ts < 400 && day_clicked == date.toDate().getTime()) {  // emulate double-click on day
           var enddate = new Date();
           if (date.hasTime())
             enddate.setTime(date.toDate().getTime() + DAY_MS - 60000);
           return event_edit_dialog('new', { start:date, end:enddate, allDay:!date.hasTime(), calendar:me.selected_calendar });
         }
 
         if (!ignore_click) {
           view.calendar.gotoDate(date);
           if (day_clicked && new Date(day_clicked).getMonth() != date.toDate().getMonth())
             view.calendar.select(date, date);
         }
         day_clicked = date.toDate().getTime();
         day_clicked_ts = now;
       },
       // callback when an event was dragged and finally dropped
       eventDrop: function(event, delta, revertFunc) {
         if (!event.end || event.end.diff(event.start) < 0) {
           if (event.allDay)
             event.end = moment(event.start).hour(13).minute(0).second(0);
           else
             event.end = moment(event.start).add(2, 'hours');
         }
         else if (event.allDay) {
           event.end.subtract(1, 'days').hour(13);
         }
 
         if (event.allDay)
           event.start.hour(12);
 
         // send move request to server
         var data = {
           id: event.id,
           calendar: event.calendar,
           start: date2servertime(event.start),
           end: date2servertime(event.end),
           allDay: event.allDay?1:0
         };
 
         update_event_confirm('move', event, data);
       },
       // callback for event resizing
       eventResize: function(event, delta) {
         // sanitize event dates
         if (event.allDay) {
           event.start.hours(12);
           event.end.hour(13).subtract(1, 'days');
         }
 
         // send resize request to server
         var data = {
           id: event.id,
           calendar: event.calendar,
           start: date2servertime(event.start),
           end: date2servertime(event.end),
           allDay: event.allDay?1:0
         };
 
         update_event_confirm('resize', event, data);
       },
       viewRender: function(view, element) {
         $('#agendaoptions')[view.name == 'list' ? 'show' : 'hide']();
 
         if (minical) {
           window.setTimeout(function(){ minical.datepicker('setDate', fc.fullCalendar('getDate').toDate()); }, exec_deferred);
           if (view.name != current_view)
             me.view_resize();
           current_view = view.name;
           me.update_state();
         }
 
         var viewStart = moment(view.start);
 
         $('#calendar .fc-prev-button').off('click').on('click', function() {
           if (view.name == 'list')
             fc.fullCalendar('gotoDate', viewStart.subtract(settings.agenda_range, 'days'));
           else
             fc.fullCalendar('prev');
         });
         $('#calendar .fc-next-button').off('click').on('click', function() {
           if (view.name == 'list')
             fc.fullCalendar('gotoDate', viewStart.add(settings.agenda_range, 'days'));
           else
             fc.fullCalendar('next');
         });
       },
       eventAfterAllRender: function(view) {
         if (view.name == 'list') {
           // Fix colspan of headers after we added Location column
           fc.find('tr.fc-list-heading > td').attr('colspan', 4);
         }
       }
     }));
 
     // if start date is changed, shift end date according to initial duration
     var shift_enddate = function(dateText) {
       var newstart = me.parse_datetime('0', dateText);
       var newend = new Date(newstart.getTime() + $('#edit-startdate').data('duration') * 1000);
       $('#edit-enddate').val(format_date(newend, me.settings.date_format));
       event_times_changed();
     };
 
     // Set as calculateWeek to determine the week of the year based on the ISO 8601 definition.
     // Uses the default $.datepicker.iso8601Week() function but takes firstDay setting into account.
     // This is a temporary fix until http://bugs.jqueryui.com/ticket/8420 is resolved.
     var iso8601Week = me.datepicker_settings.calculateWeek = function(date) {
       var mondayOffset = Math.abs(1 - me.datepicker_settings.firstDay);
       return $.datepicker.iso8601Week(new Date(date.getTime() + mondayOffset * 86400000));
     };
 
     var minical;
     var init_calendar_ui = function()
     {
       var pretty_select = function(elem) {
         // for Elastic
         if (window.UI && UI.pretty_select) {
           $(elem).addClass('form-control custom-select').each(function() { UI.pretty_select(this); });
         }
       };
 
       // initialize small calendar widget using jQuery UI datepicker
       minical = $('#datepicker').datepicker($.extend(me.datepicker_settings, {
         inline: true,
         changeMonth: true,
         changeYear: true,
         onSelect: function(dateText, inst) {
           ignore_click = true;
           var d = minical.datepicker('getDate');
           fc.fullCalendar('gotoDate', d)
           fc.fullCalendar('select', d, d);
           setTimeout(function() { pretty_select($('select', minical)); }, 25);
         },
         onChangeMonthYear: function(year, month, inst) {
           minical.data('year', year).data('month', month);
           setTimeout(function() { pretty_select($('select', minical)); }, 25);
         },
         beforeShowDay: function(date) {
           // TODO: this pretty_select() calls should be implemented in a different way
           setTimeout(function() { pretty_select($('select', minical)); }, 25);
 
           var view = fc.fullCalendar('getView'),
             dt = moment(date).format('YYYYMMDD'),
             active = view.start && view.start.format('YYYYMMDD') <= dt && view.end.format('YYYYMMDD') > dt;
 
           return [ true, (active ? 'ui-datepicker-activerange ui-datepicker-active-' + view.name : ''), ''];
         }
       })) // set event handler for clicks on calendar week cell of the datepicker widget
         .on('click', 'td.ui-datepicker-week-col', function(e) {
           var cell = $(e.target);
           if (e.target.tagName == 'TD') {
             var base_date = minical.datepicker('getDate');
             if (minical.data('month'))
               base_date.setMonth(minical.data('month')-1);
             if (minical.data('year'))
               base_date.setYear(minical.data('year'));
             base_date.setHours(12);
             base_date.setDate(base_date.getDate() - ((base_date.getDay() + 6) % 7) + me.datepicker_settings.firstDay);
             var base_kw = iso8601Week(base_date),
               target_kw = parseInt(cell.html()),
               wdiff = target_kw - base_kw;
             if (wdiff > 10)  // year jump
               base_date.setYear(base_date.getFullYear() - 1);
             else if (wdiff < -10)
               base_date.setYear(base_date.getFullYear() + 1);
             // select monday of the chosen calendar week
             var day_off = base_date.getDay() - me.datepicker_settings.firstDay,
               date = new Date(base_date.getTime() - day_off * DAY_MS + wdiff * 7 * DAY_MS);
 
             fc.fullCalendar('changeView', 'agendaWeek', date);
             minical.datepicker('setDate', date);
             setTimeout(function() { pretty_select($('select', minical)); }, 25);
           }
         });
 
       minical.find('.ui-datepicker-inline').attr('aria-labelledby', 'aria-label-minical');
 
       if (rcmail.env.date) {
         var viewdate = new Date();
         viewdate.setTime(fromunixtime(rcmail.env.date));
         minical.datepicker('setDate', viewdate);
       }
 
       // init event dialog
       var tab_change = function(event, ui) {
           // newPanel.selector for jQuery-UI 1.10, newPanel.attr('id') for jQuery-UI 1.12, href for Bootstrap tabs
           var tab = (ui ? String(ui.newPanel.selector || ui.newPanel.attr('id')) : $(event.target).attr('href'))
             .replace(/^#?event-panel-/, '').replace(/s$/, '');
           var has_real_attendee = function(attendees) {
               for (var i=0; i < (attendees ? attendees.length : 0); i++) {
                 if (attendees[i].cutype != 'RESOURCE')
                   return true;
               }
             };
 
           if (tab == 'attendee' || tab == 'resource') {
             if (!rcube_event.is_keyboard(event))
               $('#edit-'+tab+'-name').select();
             // update free-busy status if needed
             if (freebusy_ui.needsupdate && me.selected_event)
               update_freebusy_status(me.selected_event);
             // add current user as organizer if non added yet
             if (tab == 'attendee' && !has_real_attendee(event_attendees)) {
               add_attendee($.extend({ role:'ORGANIZER' }, settings.identity));
               $('#edit-attendees-form .attendees-invitebox').show();
             }
           }
 
           // reset autocompletion on tab change (#3389)
           rcmail.ksearch_blur();
 
           // display recurrence warning in recurrence tab only
           if (tab == 'recurrence')
             $('#edit-recurrence-frequency').change();
           else
             $('#edit-recurrence-syncstart').hide();
       };
 
       $('#eventedit:not([data-notabs])').tabs({activate: tab_change});  // Larry
       $('#eventedit a.nav-link').on('show.bs.tab', tab_change);         // Elastic
 
       $('#edit-enddate').datepicker(me.datepicker_settings);
       $('#edit-startdate').datepicker(me.datepicker_settings).datepicker('option', 'onSelect', shift_enddate).change(function(){ shift_enddate(this.value); });
       $('#edit-enddate').datepicker('option', 'onSelect', event_times_changed).change(event_times_changed);
       $('#edit-allday').click(function(){ $('#edit-starttime, #edit-endtime')[(this.checked?'hide':'show')](); event_times_changed(); });
 
       // configure drop-down menu on time input fields based on jquery UI autocomplete
       $('#edit-starttime, #edit-endtime').each(function() {
         me.init_time_autocomplete(this, {
           container: '#eventedit',
           change: event_times_changed
         });
       });
 
       // adjust end time when changing start
       $('#edit-starttime').change(function(e) {
         var dstart = $('#edit-startdate'),
           newstart = me.parse_datetime(this.value, dstart.val()),
           newend = new Date(newstart.getTime() + dstart.data('duration') * 1000);
         $('#edit-endtime').val(format_date(newend, me.settings.time_format));
         $('#edit-enddate').val(format_date(newend, me.settings.date_format));
         event_times_changed();
       });
 
       // register events on alarms and recurrence fields
       me.init_alarms_edit('#edit-alarms');
       me.init_recurrence_edit('#eventedit');
 
       // reload free-busy status when changing the organizer identity
       $('#eventedit').on('change', '#edit-identities-list', function(e) {
         var email = settings.identities[$(this).val()],
           icon = $(this).closest('tr').find('.availability > *');
 
         if (email && icon.length) {
           icon.attr('data-email', email);
           check_freebusy_status(icon, email, me.selected_event);
         }
       });
 
       $('#event-export-startdate').datepicker(me.datepicker_settings);
 
       // init attendees autocompletion
       var ac_props;
       // parallel autocompletion
       if (rcmail.env.autocomplete_threads > 0) {
         ac_props = {
           threads: rcmail.env.autocomplete_threads,
           sources: rcmail.env.autocomplete_sources
         };
       }
       rcmail.init_address_input_events($('#edit-attendee-name'), ac_props);
       rcmail.addEventListener('autocomplete_insert', function(e) {
         var cutype, success = false;
         if (e.field.name == 'participant') {
           cutype = e.data && e.data.type == 'group' && e.result_type == 'person' ? 'GROUP' : 'INDIVIDUAL';
           success = add_attendees(e.insert, { role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:cutype });
         }
         else if (e.field.name == 'resource' && e.data && e.data.email) {
           success = add_attendee($.extend(e.data, { role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:'RESOURCE' }));
         }
         if (e.field && success) {
           e.field.value = '';
         }
       });
 
       $('#edit-attendee-add').click(function(){
         var input = $('#edit-attendee-name');
         rcmail.ksearch_blur();
         if (add_attendees(input.val(), { role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:'INDIVIDUAL' })) {
           input.val('');
         }
       });
 
       rcmail.init_address_input_events($('#edit-resource-name'), { action:'calendar/resources-autocomplete' });
 
       $('#edit-resource-add').click(function(){
         var input = $('#edit-resource-name');
         rcmail.ksearch_blur();
         if (add_attendees(input.val(), { role:'REQ-PARTICIPANT', status:'NEEDS-ACTION', cutype:'RESOURCE' })) {
           input.val('');
         }
       });
 
       $('#edit-resource-find').click(function(){
         event_resources_dialog();
         return false;
       });
 
       $('#resource-content a.nav-link').on('click', function() {
         e.preventDefault();
         $(this).tab('show');
       });
 
       // handle change of "send invitations" checkbox
       $('#edit-attendees-invite').change(function() {
         $('#edit-attendees-donotify,input.edit-attendee-reply').prop('checked', this.checked);
         // hide/show comment field
         $('#eventedit .attendees-commentbox')[this.checked ? 'show' : 'hide']();
       });
 
       // delegate change event to "send invitations" checkbox
       $('#edit-attendees-donotify').change(function() {
         $('#edit-attendees-invite').click();
         return false;
       });
 
       $('#edit-attendee-schedule').click(function(){
         event_freebusy_dialog();
       });
 
       $('#schedule-freebusy-prev').html('&#9668;').click(function() { render_freebusy_grid(-1); });
       $('#schedule-freebusy-next').html('&#9658;').click(function() { render_freebusy_grid(1); });
 
       $('#schedule-find-prev').click(function() { freebusy_find_slot(-1); });
       $('#schedule-find-next').click(function() { freebusy_find_slot(1); });
 
       $('#schedule-freebusy-workinghours').click(function(){
         freebusy_ui.workinhoursonly = this.checked;
         $('#workinghourscss').remove();
         if (this.checked)
           $('<style type="text/css" id="workinghourscss"> td.offhours { opacity:0.3; filter:alpha(opacity=30) } </style>').appendTo('head');
       });
 
       $('#event-rsvp input.button').click(function(e) {
         event_rsvp(this, null, null, e.originalEvent);
       });
 
       $('#eventedit input.edit-recurring-savemode').change(function(e) {
         var sel = $('input.edit-recurring-savemode:checked').val(),
           disabled = sel == 'current' || sel == 'future';
         $('#event-panel-recurrence input, #event-panel-recurrence select, #event-panel-attachments input').prop('disabled', disabled);
         $('#event-panel-recurrence, #event-panel-attachments')[(disabled?'addClass':'removeClass')]('disabled');
       })
 
       $('#eventshow .changersvp').click(function(e) {
         var d = $('#eventshow'),
           record = $(this).closest('.event-line,.form-group'),
           h = d.height() - record.height();
 
         record.toggle();
         $('#event-rsvp').slideDown(300, function() {
           me.dialog_resize(d.get(0), h + $(this).outerHeight());
           if (this.scrollIntoView)
             this.scrollIntoView(false);
         });
         return false;
       })
 
       // register click handler for message links
       $('#edit-event-links, #event-links').on('click', 'li a.messagelink', function(e) {
         rcmail.open_window(this.href);
         if (!rcube_event.is_keyboard(e) && this.blur)
           this.blur();
         return false;
       });
 
       // register click handler for message delete buttons
       $('#edit-event-links').on('click', 'li a.delete', function(e) {
           remove_link(e.target);
           return false;
       });
 
       $('#agenda-listrange').change(function(e){
         settings.agenda_range = parseInt($(this).val());
         fc.fullCalendar('changeView', 'list');
         // TODO: save new settings in prefs
       }).val(settings.agenda_range);
 
       // hide event dialog when clicking somewhere into document
       $(document).bind('mousedown', dialog_check);
 
       rcmail.set_busy(false, 'loading', ui_loading);
     }
 
     // initialize more UI elements (deferred)
     window.setTimeout(init_calendar_ui, exec_deferred);
 
     // fetch counts for some calendars
     fetch_counts();
 
     // Save-as-event dialog content
     if (rcmail.env.action == 'dialog-ui') {
       var date = new Date(), event = {allDay: false, calendar: me.selected_calendar};
 
       date.setHours(date.getHours()+1);
       date.setMinutes(0);
 
       var end = new Date(date.getTime());
       end.setHours(date.getHours()+1);
 
       event.start = date;
       event.end = end;
 
       // exec deferred because it must be after init_calendar_ui
       window.setTimeout(function() {
         event_edit_dialog('new', $.extend(event, rcmail.env.event_prop));
       }, exec_deferred);
 
       rcmail.register_command('event-save', function() { rcmail.env.event_save_func(); }, true);
       rcmail.addEventListener('plugin.unlock_saving', function(status) {
         me.unlock_saving();
         if (status)
           window.parent.kolab_event_dialog_element.dialog('destroy');
       });
     }
 } // end rcube_calendar class
 
 
 // Update layout after initialization
 // In devel mode we have to wait until all styles are applied by less
 if (rcmail.env.devel_mode && window.less) {
   less.pageLoadFinished.then(function() { $(window).resize(); });
 }
 
 /* calendar plugin initialization */
 window.rcmail && rcmail.addEventListener('init', function(evt) {
   // let's go
   var cal = new rcube_calendar_ui($.extend(rcmail.env.calendar_settings, rcmail.env.libcal_settings));
 
   if (rcmail.env.action == 'dialog-ui') {
     return;
   }
 
   // configure toolbar buttons
   rcmail.register_command('addevent', function(){ cal.add_event(); });
   rcmail.register_command('print', function(){ cal.print_calendars(); }, true);
 
   // configure list operations
   rcmail.register_command('calendar-create', function(){ cal.calendar_edit_dialog(null); }, true);
   rcmail.register_command('calendar-edit', function(){ cal.calendar_edit_dialog(cal.calendars[cal.selected_calendar]); }, false);
   rcmail.register_command('calendar-remove', function(){ cal.calendar_remove(cal.calendars[cal.selected_calendar]); }, false);
   rcmail.register_command('calendar-delete', function(){ cal.calendar_delete(cal.calendars[cal.selected_calendar]); }, false);
   rcmail.register_command('events-import', function(){ cal.import_events(cal.calendars[cal.selected_calendar]); }, true);
   rcmail.register_command('calendar-showurl', function(){ cal.showurl(cal.calendars[cal.selected_calendar]); }, false);
   rcmail.register_command('calendar-showfburl', function(){ cal.showfburl(); }, false);
   rcmail.register_command('event-download', function(){ cal.event_download(cal.selected_event); }, true);
   rcmail.register_command('event-sendbymail', function(p, obj, e){ cal.event_sendbymail(cal.selected_event, e); }, true);
   rcmail.register_command('event-copy', function(){ cal.event_copy(cal.selected_event); }, true);
   rcmail.register_command('event-history', function(p, obj, e){ cal.event_history_dialog(cal.selected_event); }, false);
 
   // search and export events
   rcmail.register_command('export', function(){ cal.export_events(cal.calendars[cal.selected_calendar]); }, true);
   rcmail.register_command('search', function(){ cal.quicksearch(); }, true);
   rcmail.register_command('reset-search', function(){ cal.reset_quicksearch(); }, true);
 
   // resource invitation dialog
   rcmail.register_command('search-resource', function(){ cal.resource_search(); }, true);
   rcmail.register_command('reset-resource-search', function(){ cal.reset_resource_search(); }, true);
   rcmail.register_command('add-resource', function(){ cal.add_resource2event(); }, false);
 
   // register callback commands
   rcmail.addEventListener('plugin.refresh_source', function(data) { cal.calendar_refresh_source(data); });
   rcmail.addEventListener('plugin.destroy_source', function(p){ cal.calendar_destroy_source(p.id); });
   rcmail.addEventListener('plugin.unlock_saving', function(p){ cal.unlock_saving(); });
   rcmail.addEventListener('plugin.refresh_calendar', function(p){ cal.refresh(p); });
   rcmail.addEventListener('plugin.import_success', function(p){ cal.import_success(p); });
   rcmail.addEventListener('plugin.import_error', function(p){ cal.import_error(p); });
   rcmail.addEventListener('plugin.update_counts', function(p){ cal.update_counts(p); });
   rcmail.addEventListener('plugin.reload_view', function(p){ cal.reload_view(p); });
   rcmail.addEventListener('plugin.resource_data', function(p){ cal.resource_data_load(p); });
   rcmail.addEventListener('plugin.resource_owner', function(p){ cal.resource_owner_load(p); });
   rcmail.addEventListener('plugin.render_event_changelog', function(data){ cal.render_event_changelog(data); });
   rcmail.addEventListener('plugin.event_show_diff', function(data){ cal.event_show_diff(data); });
   rcmail.addEventListener('plugin.close_history_dialog', function(data){ cal.close_history_dialog(); });
   rcmail.addEventListener('plugin.event_show_revision', function(data){ cal.event_show_dialog(data, null, true); });
   rcmail.addEventListener('plugin.itip_message_processed', function(data){ cal.itip_message_processed(data); });
   rcmail.addEventListener('requestrefresh', function(q){ return cal.before_refresh(q); });
 
   $(window).resize(function(e) {
     // check target due to bugs in jquery
     // http://bugs.jqueryui.com/ticket/7514
     // http://bugs.jquery.com/ticket/9841
     if (e.target == window) {
       cal.view_resize();
 
       // In Elastic append the datepicker back to sidebar/dialog when resizing
       // the window from tablet/phone to desktop and vice-versa
       var dp = $('#datepicker'), in_dialog = dp.is('.ui-dialog-content'), width = $(window).width();
       if (in_dialog && width > 768) {
         if (dp.is(':visible')) {
           dp.dialog('close');
         }
         dp.height('auto').removeClass('ui-dialog-content ui-widget-content')
           .data('dialog-parent', dp.closest('.ui-dialog'))
           .appendTo('#layout-sidebar');
       }
       else if (!in_dialog && dp.length && width <= 768 && dp.data('dialog-parent')) {
         dp.addClass('ui-dialog-content ui-widget-content')
           .insertAfter(dp.data('dialog-parent').find('.ui-dialog-titlebar'));
       }
     }
   }).resize();
 
   // show calendars list when ready
   $('#calendars').css('visibility', 'inherit');
 
   // show toolbar
   $('#toolbar').show();
 
   // Elastic mods
   if ($('#calendar').data('elastic-mode')) {
     var selector = $('<div class="btn-group btn-group-toggle" role="group">').appendTo('.fc-header-toolbar > .fc-left'),
         nav = $('<div class="btn-group btn-group-toggle" role="group">').appendTo('.fc-header-toolbar > .fc-right');
 
     $('.fc-header-toolbar > .fc-left button').each(function() {
       var new_btn, cl = 'btn btn-secondary', btn = $(this),
         activate = function(button) {
           selector.children('.active').removeClass('active');
           $(button).addClass('active');
         };
 
       if (btn.is('.fc-state-active')) {
         cl += ' active';
       }
 
       new_btn = $('<button>').attr({'class': cl, type: 'button'}).text(btn.text())
         .appendTo(selector)
         .on('click', function() {
           activate(this);
           btn.click();
         });
 
       if (window.MutationObserver) {
         // handle button active state changes
         new MutationObserver(function() { if (btn.is('.fc-state-active')) activate(new_btn); }).observe(this, {attributes: true});
       }
     });
 
     $.each(['prev', 'today', 'next'], function() {
       var btn = $('.fc-header-toolbar > .fc-right').find('.fc-' + this + '-button');
       $('<button>').attr({'class': 'btn btn-secondary ' + this, type: 'button'})
         .text(btn.text()).appendTo(nav).on('click', function() { btn.click(); });
     });
 
     $('#timezone-display').appendTo($('.fc-header-toolbar > .fc-center')).removeClass('hidden');
     $('#agendaoptions').detach().insertAfter('.fc-header-toolbar');
 
     $('.content-frame-navigation a.button.date').appendTo('#layout-content > .searchbar');
 
     // Mobile header title
     if (window.MutationObserver) {
       var title = $('.fc-header-toolbar > .fc-center h2'),
         mobile_header = $('#layout-content > .header > .header-title'),
         callback = function() {
           var text = title.text();
           mobile_header.html('').append([
             $('<span class="title">').text(text),
             $('<span class="tz">').text($('#timezone-display').text())
           ]);
         };
 
       // update the header when something changes on the calendar title
       new MutationObserver(callback).observe(title[0], {childList: true, subtree: true});
       // initialize the header
       callback();
     }
 
     window.calendar_datepicker = function() {
       $('#datepicker').dialog({
         modal: true,
         title: rcmail.gettext('calendar.selectdate'),
         buttons: [{
           text: rcmail.gettext('close', 'calendar'),
           'class': 'cancel',
           click: function() { $(this).dialog('close'); }
         }],
         width: 400,
         height: 520
       });
     }
   }
 });
diff --git a/plugins/calendar/drivers/ldap/resources_driver_ldap.php b/plugins/calendar/drivers/ldap/resources_driver_ldap.php
index 0be41261..6852b59c 100644
--- a/plugins/calendar/drivers/ldap/resources_driver_ldap.php
+++ b/plugins/calendar/drivers/ldap/resources_driver_ldap.php
@@ -1,157 +1,192 @@
 <?php
 
 /**
  * LDAP-based resource directory class using rcube_ldap functionality
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2014, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 /**
  * LDAP-based resource directory implementation
  */
 class resources_driver_ldap extends resources_driver
 {
     private $rc;
     private $ldap;
 
     /**
      * Default constructor
      */
     function __construct($cal)
     {
         $this->cal = $cal;
         $this->rc = $cal->rc;
     }
 
     /**
      * Fetch resource objects to be displayed for booking
      *
      * @param string $query Search query (optional)
      * @param int    $num   Max size of the result
      *
      * @return array List of resource records available for booking
      */
     public function load_resources($query = null, $num = 5000)
     {
         if (!($ldap = $this->connect())) {
             return [];
         }
 
         // TODO: apply paging
         $ldap->set_pagesize($num);
 
         if (isset($query)) {
             $results = $ldap->search('*', $query, 0, true, true);
         }
         else {
             $results = $ldap->list_records();
         }
 
         if ($results instanceof ArrayAccess) {
             foreach ($results as $i => $rec) {
                 $results[$i] = $this->decode_resource($rec);
             }
         }
 
         return $results;
     }
 
+    /**
+     * Fetch resource objects filtered by owner email addresses
+     *
+     * @param array $emails List of email addresses of the owner
+     * @param int   $num    Max size of the result
+     *
+     * @return array List of resource records
+     */
+    public function load_owned_resources($emails, $num = 5000)
+    {
+        if (!($ldap = $this->connect())) {
+            return [];
+        }
+
+        $ldap->set_pagesize($num);
+
+        $ownerDns = [];
+        $results = $ldap->search('email', $emails, 0, true, true);
+        if ($results instanceof ArrayAccess) {
+            foreach ($results as $i => $rec) {
+                $ownerDns[] = $rec['dn'];
+            }
+        }
+
+        $results = $ldap->search('owner', $ownerDns, 0, true, true);
+
+        if ($results instanceof ArrayAccess) {
+            foreach ($results as $i => $rec) {
+                $results[$i] = $this->decode_resource($rec);
+            }
+        }
+
+        return $results;
+    }
+
     /**
      * Return properties of a single resource
      *
      * @param string $id Unique resource identifier
      *
      * @return array Resource object as hash array
      */
     public function get_resource($dn)
     {
         $rec = null;
 
         if ($ldap = $this->connect()) {
             $rec = $ldap->get_record(rcube_ldap::dn_encode($dn), true);
 
             if (!empty($rec)) {
                 $rec = $this->decode_resource($rec);
             }
         }
 
         return $rec;
     }
 
     /**
      * Return properties of a resource owner
      *
      * @param string $dn Owner identifier
      *
      * @return array Resource object as hash array
      */
     public function get_resource_owner($dn)
     {
         $owner = null;
 
         if ($ldap = $this->connect()) {
             $owner = $ldap->get_record(rcube_ldap::dn_encode($dn), true);
             $owner['ID'] = rcube_ldap::dn_decode($owner['ID']);
             unset($owner['_raw_attrib'], $owner['_type']);
         }
 
         return $owner;
     }
 
     /**
      * Extract JSON-serialized attributes
      */
     private function decode_resource($rec)
     {
         $rec['ID'] = rcube_ldap::dn_decode($rec['ID']);
 
         $attributes = [];
 
         foreach ((array) $rec['attributes'] as $sattr) {
             $sattr = trim($sattr);
             if (!empty($sattr) && $sattr[0] === '{') {
                 $attr = @json_decode($sattr, true);
                 $attributes += $attr;
             }
             else if (!empty($sattr) && empty($rec['description'])) {
                 $rec['description'] = $sattr;
             }
         }
 
         $rec['attributes'] = $attributes;
 
         // force $rec['members'] to be an array
         if (!empty($rec['members']) && !is_array($rec['members'])) {
             $rec['members'] = [$rec['members']];
         }
 
         // remove unused cruft
         unset($rec['_raw_attrib']);
 
         return $rec;
     }
 
     private function connect()
     {
         if (!isset($this->ldap)) {
             $this->ldap = new rcube_ldap($this->rc->config->get('calendar_resources_directory'), true);
         }
 
         return $this->ldap->ready ? $this->ldap : null;
     }
 }
diff --git a/plugins/calendar/drivers/resources_driver.php b/plugins/calendar/drivers/resources_driver.php
index a81a0fff..1e70ffb3 100644
--- a/plugins/calendar/drivers/resources_driver.php
+++ b/plugins/calendar/drivers/resources_driver.php
@@ -1,118 +1,131 @@
 <?php
 
 /**
  * Resources directory interface definition
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2014, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 /**
  * Interface definition for a resources directory driver classe
  */
 abstract class resources_driver
 {
     protected $cal;
 
     /**
      * Default constructor
      */
     function __construct($cal)
     {
         $this->cal = $cal;
     }
 
     /**
      * Fetch resource objects to be displayed for booking
      *
      * @param string $query Search query (optional)
      *
      * @return array List of resource records available for booking
      */
     abstract public function load_resources($query = null);
 
+    /**
+     * Fetch resource objects filtered by owner email addresses
+     *
+     * @param array $emails List of email addresses of the owner
+     * @param int   $num    Max size of the result
+     *
+     * @return array List of resource records
+     */
+    public function load_owned_resources($emails, $num = 5000)
+    {
+        return [];
+    }
+
     /**
      * Return properties of a single resource
      *
      * @param string $id Unique resource identifier
      *
      * @return array Resource object as hash array
      */
     abstract public function get_resource($id);
 
     /**
      * Return properties of a resource owner
      *
      * @param string $id Owner identifier
      *
      * @return array Resource object as hash array
      */
     public function get_resource_owner($id)
     {
         return null;
     }
 
     /**
      * Get event data to display a resource's calendar
      *
      * The default implementation extracts the resource's email address
      * and fetches free-busy data using the calendar backend driver.
      *
      * @param string $id    Calendar identifier
      * @param int    $start Event's new start (unix timestamp)
      * @param int    $end   Event's new end (unix timestamp)
      *
      * @return array A list of event objects (see calendar_driver specification)
      */
     public function get_resource_calendar($id, $start, $end)
     {
         $events = [];
         $rec    = $this->get_resource($id);
 
         if ($rec && !empty($rec['email']) && !empty($this->cal->driver)) {
             $fbtypemap = [
                 calendar::FREEBUSY_BUSY      => 'busy',
                 calendar::FREEBUSY_TENTATIVE => 'tentative',
                 calendar::FREEBUSY_OOF       => 'outofoffice',
             ];
 
             // if the backend has free-busy information
             $fblist = $this->cal->driver->get_freebusy_list($rec['email'], $start, $end);
             if (is_array($fblist)) {
                 foreach ($fblist as $slot) {
                     list($from, $to, $type) = $slot;
                     if ($type == calendar::FREEBUSY_FREE || $type == calendar::FREEBUSY_UNKNOWN) {
                         continue;
                     }
 
                     if ($from < $end && $to > $start) {
                         $events[] = [
                             'id'     => sha1($id . $from . $to),
                             'title'  => $rec['name'],
                             'start'  => new DateTime('@' . $from),
                             'end'    => new DateTime('@' . $to),
                             'status' => $fbtypemap[$type],
                             'calendar' => '_resource',
                         ];
                     }
                 }
             }
         }
 
         return $events;
     }
 }
diff --git a/plugins/calendar/localization/en_US.inc b/plugins/calendar/localization/en_US.inc
index 0f97d566..5705f269 100644
--- a/plugins/calendar/localization/en_US.inc
+++ b/plugins/calendar/localization/en_US.inc
@@ -1,320 +1,324 @@
 <?php
 
 /**
  * Localizations for Kolab Calendar plugin
  *
  * Copyright (C) 2014, Kolab Systems AG
  *
  * For translation see https://www.transifex.com/projects/p/kolab/resource/calendar/
  */
 
 $labels = array();
 
 // preferences
 $labels['default_view'] = 'Default view';
 $labels['time_format'] = 'Time format';
 $labels['timeslots'] = 'Time slots per hour';
 $labels['first_day'] = 'First weekday';
 $labels['first_hour'] = 'First hour to show';
 $labels['workinghours'] = 'Working hours';
 $labels['add_category'] = 'Add category';
 $labels['remove_category'] = 'Remove category';
 $labels['defaultcalendar'] = 'Create new events in';
 $labels['eventcoloring'] = 'Event coloring';
 $labels['coloringmode0'] = 'According to calendar';
 $labels['coloringmode1'] = 'According to category';
 $labels['coloringmode2'] = 'Calendar for outline, category for content';
 $labels['coloringmode3'] = 'Category for outline, calendar for content';
 $labels['afternothing'] = 'Do nothing';
 $labels['aftertrash'] = 'Move to Trash';
 $labels['afterdelete'] = 'Delete the message';
 $labels['afterflagdeleted'] = 'Flag as deleted';
 $labels['aftermoveto'] = 'Move to...';
 $labels['itipoptions'] = 'Event Invitations';
 $labels['afteraction'] = 'After an invitation or update message is processed';
 $labels['showweekno'] = 'Display week numbers';
 $labels['weeknonone'] = 'never';
 $labels['weeknodatepicker'] = 'in datepicker only';
 $labels['weeknoall'] = 'in datepicker and calendar view';
 
 // calendar
 $labels['calendar'] = 'Calendar';
 $labels['calendars'] = 'Calendars';
 $labels['category'] = 'Category';
 $labels['categories'] = 'Categories';
 $labels['addcalendar'] = 'Add calendar';
 $labels['createcalendar'] = 'Create new calendar';
 $labels['editcalendar'] = 'Edit/Share calendar';
 $labels['deletecalendar'] = 'Delete calendar';
 $labels['name'] = 'Name';
 $labels['color'] = 'Color';
 $labels['day'] = 'Day';
 $labels['week'] = 'Week';
 $labels['month'] = 'Month';
 $labels['agenda'] = 'Agenda';
 $labels['new'] = 'New';
 $labels['new_event'] = 'New event';
 $labels['edit_event'] = 'Edit event';
 $labels['edit'] = 'Edit';
 $labels['save'] = 'Save';
 $labels['removelist'] = 'Remove from list';
 $labels['cancel'] = 'Cancel';
 $labels['select'] = 'Select';
 $labels['print'] = 'Print';
 $labels['printtitle'] = 'Print calendars';
 $labels['title'] = 'Summary';
 $labels['description'] = 'Description';
 $labels['all-day'] = 'all-day';
 $labels['export'] = 'Export';
 $labels['exporttitle'] = 'Export to iCalendar';
 $labels['exportrange'] = 'Events from';
 $labels['exportattachments'] = 'With attachments';
 $labels['customdate'] = 'Custom date';
 $labels['location'] = 'Location';
 $labels['url'] = 'URL';
 $labels['date'] = 'Date';
 $labels['start'] = 'Start';
 $labels['starttime'] = 'Start time';
 $labels['end'] = 'End';
 $labels['endtime'] = 'End time';
 $labels['repeat'] = 'Repeat';
 $labels['selectdate'] = 'Choose date';
 $labels['freebusy'] = 'Show me as';
 $labels['free'] = 'Free';
 $labels['busy'] = 'Busy';
 $labels['outofoffice'] = 'Out of Office';
 $labels['tentative'] = 'Tentative';
 $labels['mystatus'] = 'My status';
 $labels['status'] = 'Status';
 $labels['status-confirmed'] = 'Confirmed';
 $labels['status-cancelled'] = 'Cancelled';
 $labels['status-tentative'] = 'Tentative';
 $labels['priority'] = 'Priority';
 $labels['sensitivity'] = 'Privacy';
 $labels['public'] = 'public';
 $labels['private'] = 'private';
 $labels['confidential'] = 'confidential';
 $labels['links'] = 'Reference';
 $labels['alarms'] = 'Reminder';
 $labels['comment'] = 'Comment';
 $labels['created'] = 'Created';
 $labels['changed'] = 'Last Modified';
 $labels['unknown'] = 'Unknown';
 $labels['eventoptions'] = 'Options';
 $labels['generated'] = 'generated at';
 $labels['eventhistory'] = 'History';
 $labels['removelink'] = 'Remove email reference';
 $labels['printdescriptions'] = 'Print descriptions';
 $labels['parentcalendar'] = 'Insert inside';
 $labels['searchearlierdates'] = '« Search for earlier events';
 $labels['searchlaterdates'] = 'Search for later events »';
 $labels['earlierevents'] = 'Earlier';
 $labels['laterevents'] = 'Later';
 $labels['andnmore'] = '$nr more...';
 $labels['togglerole'] = 'Click to toggle role';
 $labels['createfrommail'] = 'Save as event';
 $labels['importevents'] = 'Import events';
 $labels['importrange'] = 'Events from';
 $labels['onemonthback'] = '1 month back';
 $labels['nmonthsback'] = '$nr months back';
 $labels['showurl'] = 'Show calendar URL';
 $labels['showurldescription'] = 'Use the following address to access (read only) your calendar from other applications. You can copy and paste this into any calendar software that supports the iCal format.';
 $labels['caldavurldescription'] = 'Copy this address to a <a href="http://en.wikipedia.org/wiki/CalDAV" target="_blank">CalDAV</a> client application (e.g. Evolution or Mozilla Thunderbird) to fully synchronize this specific calendar with your computer or mobile device.';
 $labels['showfburl'] = 'Show free-busy URL';
 $labels['fburldescription'] = 'Use the following address to access Free-Busy information from other applications. You can copy and paste this into any calendar software that supports free-busy information in iCal format. No authentication is required for this URL.';
 $labels['findcalendars'] = 'Find calendars...';
 $labels['searchterms'] = 'Search terms';
 $labels['findevents'] = 'Find events';
 $labels['calsearchresults'] = 'Available Calendars';
 $labels['calendarsubscribe'] = 'List permanently';
 $labels['nocalendarsfound'] = 'No calendars found';
 $labels['nrcalendarsfound'] = '$nr calendars found';
 $labels['quickview'] = 'View only this calendar';
 $labels['invitationspending'] = 'Pending invitations';
 $labels['invitationsdeclined'] = 'Declined invitations';
 $labels['changepartstat'] = 'Change participant status';
 $labels['rsvpcomment'] = 'Invitation text';
 $labels['eventstartsync'] = 'Move the event start date to the first occurrence';
 $labels['weekshort'] = 'Wk';
 
 // agenda view
 $labels['listrange'] = 'Range to display:';
 $labels['listsections'] = 'Divide into:';
 $labels['smartsections'] = 'Smart sections';
 $labels['until'] = 'until';
 $labels['today'] = 'Today';
 $labels['tomorrow'] = 'Tomorrow';
 $labels['thisweek'] = 'This week';
 $labels['nextweek'] = 'Next week';
 $labels['prevweek'] = 'Previous week';
 $labels['thismonth'] = 'This month';
 $labels['nextmonth'] = 'Next month';
 $labels['weekofyear'] = 'Week';
 $labels['pastevents'] = 'Past';
 $labels['futureevents'] = 'Future';
 
 // alarm/reminder settings
 $labels['showalarms'] = 'Show reminders';
 $labels['defaultalarmtype'] = 'Default reminder setting';
 $labels['defaultalarmoffset'] = 'Default reminder time';
 
 // attendees
 $labels['attendee'] = 'Participant';
 $labels['role'] = 'Role';
 $labels['availability'] = 'Avail.';
 $labels['confirmstate'] = 'Status';
 $labels['addattendee'] = 'Add participant';
 $labels['roleorganizer'] = 'Organizer';
 $labels['rolerequired'] = 'Required';
 $labels['roleoptional'] = 'Optional';
 $labels['rolechair'] = 'Chair';
 $labels['rolenonparticipant'] = 'Absent';
 $labels['cutypeindividual'] = 'Individual';
 $labels['cutypegroup'] = 'Group';
 $labels['cutyperesource'] = 'Resource';
 $labels['cutyperoom'] = 'Room';
 $labels['availfree'] = 'Free';
 $labels['availbusy'] = 'Busy';
 $labels['availunknown'] = 'Unknown';
 $labels['availtentative'] = 'Tentative';
 $labels['availoutofoffice'] = 'Out of Office';
 $labels['scheduletime'] = 'Find availability';
 $labels['sendinvitations'] = 'Send invitations';
 $labels['sendnotifications'] = 'Notify participants about modifications';
 $labels['sendcancellation'] = 'Notify participants about event cancellation';
 $labels['onlyworkinghours'] = 'Find availability within my working hours';
 $labels['reqallattendees'] = 'Required/all participants';
 $labels['prevslot'] = 'Previous Slot';
 $labels['nextslot'] = 'Next Slot';
 $labels['suggestedslot'] = 'Suggested Slot';
 $labels['noslotfound'] = 'Unable to find a free time slot';
 $labels['invitationsubject'] = 'You\'ve been invited to "$title"';
 $labels['invitationmailbody'] = "*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees\n\n\$description\n\nPlease find attached an iCalendar file with all the event details which you can import to your calendar application.";
 $labels['invitationattendlinks'] = "In case your email client doesn't support iTip requests you can use the following link to either accept or decline this invitation:\n\$url";
 $labels['eventupdatesubject'] = '"$title" has been updated';
 $labels['eventupdatesubjectempty'] = 'An event that concerns you has been updated';
 $labels['eventupdatemailbody'] = "*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees\n\nPlease find attached an iCalendar file with the updated event details which you can import to your calendar application.";
 $labels['eventcancelsubject'] = '"$title" has been cancelled';
 $labels['eventcancelmailbody'] = "*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees\n\nThe event has been cancelled by \$organizer.\n\nPlease find attached an iCalendar file with the updated event details.";
 
 // invitation handling (overrides labels from libcalendaring)
 $labels['itipobjectnotfound'] = 'The event referred by this message was not found in your calendar.';
 
 $labels['itipmailbodyaccepted'] = "\$sender has accepted the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
 $labels['itipmailbodytentative'] = "\$sender has tentatively accepted the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
 $labels['itipmailbodydeclined'] = "\$sender has declined the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
 $labels['itipmailbodycancel'] = "\$sender has rejected your participation in the following event:\n\n*\$title*\n\nWhen: \$date";
 $labels['itipmailbodydelegated'] = "\$sender has delegated the participation in the following event:\n\n*\$title*\n\nWhen: \$date";
 $labels['itipmailbodydelegatedto'] = "\$sender has delegated the participation in the following event to you:\n\n*\$title*\n\nWhen: \$date";
 
+$labels['itipmailbodyresourceaccepted'] = "\$sender has accepted the following resource booking:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
+$labels['itipmailbodyresourcetentative'] = "\$sender has tentatively accepted the following resource booking:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
+$labels['itipmailbodyresourcedeclined'] = "\$sender has declined the the following resource booking:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
+
 $labels['itipdeclineevent'] = 'Do you want to decline your invitation to this event?';
 $labels['declinedeleteconfirm'] = 'Do you also want to delete this declined event from your calendar?';
 $labels['itipcomment'] = 'Invitation/notification comment';
 $labels['itipcommenttitle'] = 'This comment will be attached to the invitation/notification message sent to participants';
 
 $labels['notanattendee'] = 'You\'re not listed as an attendee of this event';
 $labels['eventcancelled'] = 'The event has been cancelled';
 $labels['saveincalendar'] = 'save in';
 $labels['updatemycopy'] = 'Update in my calendar';
 $labels['savetocalendar'] = 'Save to calendar';
 $labels['openpreview'] = 'Check Calendar';
 $labels['noearlierevents'] = 'No earlier events';
 $labels['nolaterevents'] = 'No later events';
 $labels['legend'] = 'Legend';
 
 // resources
 $labels['resource'] = 'Resource';
 $labels['addresource'] = 'Book resource';
 $labels['findresources'] = 'Find resources';
 $labels['resourcedetails'] = 'Details';
 $labels['resourceavailability'] = 'Availability';
 $labels['resourceprops'] = 'Resource properties';
 $labels['resourceowner'] = 'Owner';
 $labels['resourceadded'] = 'The resource was added to your event';
 
 // event dialog tabs
 $labels['tabsummary'] = 'Summary';
 $labels['tabrecurrence'] = 'Recurrence';
 $labels['tabattendees'] = 'Participants';
 $labels['tabresources'] = 'Resources';
 $labels['tabattachments'] = 'Attachments';
 $labels['tabsharing'] = 'Sharing';
 
 // messages
 $labels['deleteobjectconfirm'] = 'Do you really want to delete this event?';
 $labels['deleteventconfirm'] = 'Do you really want to delete this event?';
 $labels['deletecalendarconfirm'] = 'Do you really want to delete this calendar with all its events?';
 $labels['deletecalendarconfirmrecursive'] = 'Do you really want to delete this calendar with all its events and sub-calendars?';
 $labels['savingdata'] = 'Saving data...';
 $labels['errorsaving'] = 'Failed to save changes.';
 $labels['operationfailed'] = 'The requested operation failed.';
 $labels['invalideventdates'] = 'Invalid dates entered! Please check your input.';
 $labels['emptyeventtitle'] = 'Event summary cannot be empty.';
 $labels['invalidcalendarproperties'] = 'Invalid calendar properties! Please set a valid name.';
 $labels['searchnoresults'] = 'No events found in the selected calendars.';
 $labels['successremoval'] = 'The event has been deleted successfully.';
 $labels['successrestore'] = 'The event has been restored successfully.';
 $labels['errornotifying'] = 'Failed to send notifications to event participants';
 $labels['errorimportingevent'] = 'Failed to import the event';
 $labels['importwarningexists'] = 'A copy of this event already exists in your calendar.';
 $labels['newerversionexists'] = 'A newer version of this event already exists! Aborted.';
 $labels['nowritecalendarfound'] = 'No calendar found to save the event';
 $labels['importedsuccessfully'] = 'The event was successfully added to \'$calendar\'';
 $labels['updatedsuccessfully'] = 'The event was successfully updated in \'$calendar\'';
 $labels['attendeupdateesuccess'] = 'Successfully updated the participant\'s status';
 $labels['errorunknownattendee'] = 'Failed to find the participant information.';
 $labels['itipsendsuccess'] = 'Invitation sent to participants.';
 $labels['itipresponseerror'] = 'Failed to send the response to this event invitation';
 $labels['itipinvalidrequest'] = 'This invitation is no longer valid';
 $labels['sentresponseto'] = 'Successfully sent invitation response to $mailto';
 $labels['localchangeswarning'] = 'You are about to make changes that will only be reflected on your calendar and not be sent to the organizer of the event.';
 $labels['importsuccess'] = 'Successfully imported $nr events';
 $labels['importnone'] = 'No events found to be imported';
 $labels['importerror'] = 'An error occured while importing';
 $labels['aclnorights'] = 'You do not have administrator rights on this calendar.';
 $labels['importtext'] = 'You can upload events in <a href="https://wikipedia.org/wiki/ICalendar">iCalendar</a> format (.ics).';
 
 $labels['changeeventconfirm'] = 'Change event';
 $labels['removeeventconfirm'] = 'Delete event';
 $labels['changerecurringeventwarning'] = 'This is a recurring event. Would you like to edit the current event only, this and all future occurences, all occurences or save it as a new event?';
 $labels['removerecurringeventwarning'] = 'This is a recurring event. Would you like to delete the current event only, this and all future occurences or all occurences of this event?';
 $labels['removerecurringallonly'] = 'This is a recurring event. As a participant, you can only delete the entire event with all occurences.';
 $labels['currentevent'] = 'Current';
 $labels['futurevents'] = 'Future';
 $labels['allevents'] = 'All';
 $labels['saveasnew'] = 'Save as new';
 $labels['recurrenceerror'] = 'Unable to resolve recurrence rule for specified start date.';
 
 // birthdays calendar
 $labels['birthdays'] = 'Birthdays';
 $labels['birthdayscalendar'] = 'Birthdays Calendar';
 $labels['displaybirthdayscalendar'] = 'Display birthdays calendar';
 $labels['birthdayscalendarsources'] = 'From these address books';
 $labels['birthdayeventtitle'] = '$name\'s Birthday';
 $labels['birthdayage'] = 'Age $age';
 
 // history dialog
 $labels['objectchangelog'] = 'Change History';
 $labels['objectdiff'] = 'Changes from $rev1 to $rev2';
 $labels['objectnotfound'] = 'Failed to load event data';
 $labels['objectchangelognotavailable'] = 'Change history is not available for this event';
 $labels['objectdiffnotavailable'] = 'No comparison possible for the selected revisions';
 $labels['revisionrestoreconfirm'] = 'Do you really want to restore revision $rev of this event? This will replace the current event with the old version.';
 $labels['objectrestoresuccess'] = 'Revision $rev successfully restored';
 $labels['objectrestoreerror'] = 'Failed to restore the old revision';
 
 // (hidden) titles and labels for accessibility annotations
 $labels['arialabelminical'] = 'Calendar date selection';
 $labels['arialabelcalendarview'] = 'Calendar view';
 $labels['arialabelsearchform'] = 'Event search form';
 $labels['arialabelquicksearchbox'] = 'Event search input';
 $labels['arialabelcalsearchform'] = 'Calendars search form';
 $labels['calendaractions'] = 'Calendar actions';
 $labels['calendarprops'] = 'Calendar properties';
 $labels['arialabeleventattendees'] = 'Event participants list';
 $labels['arialabeleventresources'] = 'Event resources list';
 $labels['arialabelresourcesearchform'] = 'Resources search form';
 $labels['arialabelresourceselection'] = 'Available resources';
 $labels['arialabeleventform'] = 'Event editing form';
 
 ?>
diff --git a/plugins/libcalendaring/lib/libcalendaring_itip.php b/plugins/libcalendaring/lib/libcalendaring_itip.php
index 93e0a26e..28866739 100644
--- a/plugins/libcalendaring/lib/libcalendaring_itip.php
+++ b/plugins/libcalendaring/lib/libcalendaring_itip.php
@@ -1,1011 +1,1016 @@
 <?php
 
 /**
  * iTIP functions for the calendar-based Roudncube plugins
  *
  * Class providing functionality to manage iTIP invitations
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2011-2014, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 class libcalendaring_itip
 {
     protected $rc;
     protected $lib;
     protected $plugin;
     protected $sender;
     protected $domain;
     protected $itip_send = false;
     protected $rsvp_actions = array('accepted','tentative','declined','delegated');
     protected $rsvp_status  = array('accepted','tentative','declined','delegated');
 
     function __construct($plugin, $domain = 'libcalendaring')
     {
         $this->plugin = $plugin;
         $this->rc = rcube::get_instance();
         $this->lib = libcalendaring::get_instance();
         $this->domain = $domain;
 
         $hook = $this->rc->plugins->exec_hook('calendar_load_itip',
             array('identity' => $this->rc->user->list_emails(true)));
         $this->sender = $hook['identity'];
 
         $this->plugin->add_hook('smtp_connect', array($this, 'smtp_connect_hook'));
     }
 
     public function set_sender_email($email)
     {
         if (!empty($email))
             $this->sender['email'] = $email;
     }
 
     public function set_rsvp_actions($actions)
     {
         $this->rsvp_actions = (array)$actions;
         $this->rsvp_status = array_merge($this->rsvp_actions, array('delegated'));
     }
 
     public function set_rsvp_status($status)
     {
         $this->rsvp_status = $status;
     }
 
     /**
      * Wrapper for rcube_plugin::gettext()
      * Checking for a label in different domains
      *
      * @see rcube::gettext()
      */
     public function gettext($p)
     {
         $label = is_array($p) ? $p['name'] : $p;
         $domain = $this->domain;
         if (!$this->rc->text_exists($label, $domain)) {
             $domain = 'libcalendaring';
         }
         return $this->rc->gettext($p, $domain);
     }
 
     /**
      * Send an iTip mail message
      *
      * @param array   Event object to send
      * @param string  iTip method (REQUEST|REPLY|CANCEL)
      * @param array   Hash array with recipient data (name, email)
      * @param string  Mail subject
      * @param string  Mail body text label
      * @param object  Mail_mime object with message data
      * @param boolean Request RSVP
      * @return boolean True on success, false on failure
      */
     public function send_itip_message($event, $method, $recipient, $subject, $bodytext, $message = null, $rsvp = true)
     {
         if (!$this->sender['name']) {
             $this->sender['name'] = $this->sender['email'];
         }
 
         if (!$message) {
             libcalendaring::identify_recurrence_instance($event);
             $message = $this->compose_itip_message($event, $method, $rsvp);
         }
 
         $mailto = rcube_utils::idn_to_ascii($recipient['email']);
 
         $headers = $message->headers();
         $headers['To'] = format_email_recipient($mailto, $recipient['name']);
         $headers['Subject'] = $this->gettext(array(
             'name' => $subject,
             'vars' => array(
                 'title' => $event['title'],
                 'name' => $this->sender['name'],
             )
         ));
 
         // compose a list of all event attendees
         $attendees_list = array();
         foreach ((array)$event['attendees'] as $attendee) {
             $attendees_list[] = (!empty($attendee['name']) && !empty($attendee['email'])) ?
                 $attendee['name'] . ' <' . $attendee['email'] . '>' :
                 (!empty($attendee['name']) ? $attendee['name'] : $attendee['email']);
         }
 
         $recurrence_info = '';
         if (!empty($event['recurrence_id'])) {
             $msg = $this->gettext(!empty($event['thisandfuture']) ? 'itipmessagefutureoccurrence' : 'itipmessagesingleoccurrence');
             $recurrence_info = "\n\n** $msg **";
         }
         else if (!empty($event['recurrence'])) {
             $recurrence_info = sprintf("\n%s: %s", $this->gettext('recurring'), $this->lib->recurrence_text($event['recurrence']));
         }
 
         $mailbody = $this->gettext(array(
             'name' => $bodytext,
             'vars' => array(
                 'title'       => $event['title'],
                 'date'        => $this->lib->event_date_text($event, true) . $recurrence_info,
                 'attendees'   => join(",\n ", $attendees_list),
                 'sender'      => $this->sender['name'],
                 'organizer'   => $this->sender['name'],
                 'description' => isset($event['description']) ? $event['description'] : '',
             )
         ));
 
         // remove redundant empty lines (e.g. when an event description is empty)
         $mailbody = preg_replace('/\n{3,}/', "\n\n", $mailbody);
 
         // if (!empty($event['comment'])) {
         //     $mailbody .= "\n\n" . $this->gettext('itipsendercomment') . $event['comment'];
         // }
 
         // append links for direct invitation replies
         if ($method == 'REQUEST' && $rsvp
             && $this->rc->config->get('calendar_itip_smtp_server')
             && ($token = $this->store_invitation($event, $recipient['email']))
         ) {
             $mailbody .= "\n\n" . $this->gettext(array(
                 'name' => 'invitationattendlinks',
                 'vars' => array('url' => $this->plugin->get_url(array('action' => 'attend', 't' => $token))),
             ));
         }
         else if ($method == 'CANCEL' && $event['cancelled']) {
             $this->cancel_itip_invitation($event);
         }
 
         $message->headers($headers, true);
         $message->setTXTBody(rcube_mime::format_flowed($mailbody, 79));
 
         if ($this->rc->config->get('libcalendaring_itip_debug', false)) {
             rcube::console('iTip ' . $method, $message->txtHeaders() . "\r\n" . $message->get());
         }
 
         // finally send the message
         $this->itip_send = true;
         $sent = $this->rc->deliver_message($message, $headers['X-Sender'], $mailto, $smtp_error);
         $this->itip_send = false;
 
         return $sent;
     }
 
     /**
      * Plugin hook to alter SMTP authentication.
      * This is used if iTip messages are to be sent from an unauthenticated session
      */
     public function smtp_connect_hook($p)
     {
         // replace smtp auth settings if we're not in an authenticated session
         if ($this->itip_send && !$this->rc->user->ID) {
             foreach (array('smtp_server', 'smtp_user', 'smtp_pass') as $prop) {
                 $p[$prop] = $this->rc->config->get("calendar_itip_$prop", $p[$prop]);
             }
         }
 
         return $p;
     }
 
     /**
      * Helper function to build a Mail_mime object to send an iTip message
      *
      * @param array   Event object to send
      * @param string  iTip method (REQUEST|REPLY|CANCEL)
      * @param boolean Request RSVP
      * @return object Mail_mime object with message data
      */
     public function compose_itip_message($event, $method, $rsvp = true)
     {
         $from     = rcube_utils::idn_to_ascii($this->sender['email']);
         $from_utf = rcube_utils::idn_to_utf8($from);
         $sender   = format_email_recipient($from, $this->sender['name']);
 
         // truncate list attendees down to the recipient of the iTip Reply.
         // constraints for a METHOD:REPLY according to RFC 5546
         if ($method == 'REPLY') {
             $replying_attendee = null;
             $reply_attendees = array();
             foreach ($event['attendees'] as $attendee) {
                 if ($attendee['role'] == 'ORGANIZER') {
                     $reply_attendees[] = $attendee;
                 }
+                // we accept on behalf of a resource
+                else if (strcasecmp($attendee['email'], $event['_resource']) == 0) {
+                    $replying_attendee = $attendee;
+                    $replying_attendee['sent-by'] = 'mailto:' . $from_utf;
+                }
                 else if (strcasecmp($attendee['email'], $from) == 0 || strcasecmp($attendee['email'], $from_utf) == 0) {
                     $replying_attendee = $attendee;
                     if ($attendee['status'] != 'DELEGATED') {
                         unset($replying_attendee['rsvp']);  // unset the RSVP attribute
                     }
                 }
                 // include attendees relevant for delegation (RFC 5546, Section 4.2.5)
                 else if ((!empty($attendee['delegated-to']) &&
                             (strcasecmp($attendee['delegated-to'], $from) == 0 || strcasecmp($attendee['delegated-to'], $from_utf) == 0)) ||
                          (!empty($attendee['delegated-from']) &&
                             (strcasecmp($attendee['delegated-from'], $from) == 0 || strcasecmp($attendee['delegated-from'], $from_utf) == 0))) {
                     $reply_attendees[] = $attendee;
                 }
             }
             if ($replying_attendee) {
                 array_unshift($reply_attendees, $replying_attendee);
                 $event['attendees'] = $reply_attendees;
             }
             if ($event['recurrence']) {
                 unset($event['recurrence']['EXCEPTIONS']);
             }
         }
         // set RSVP for every attendee
         else if ($method == 'REQUEST') {
             foreach ($event['attendees'] as $i => $attendee) {
                 if (
                     ($rsvp || !isset($attendee['rsvp']))
                     && (
                         (empty($attendee['status']) || $attendee['status'] != 'DELEGATED')
                         && $attendee['role'] != 'NON-PARTICIPANT'
                     )
                 ) {
                     $event['attendees'][$i]['rsvp']= (bool) $rsvp;
                 }
             }
         }
         else if ($method == 'CANCEL') {
             if ($event['recurrence']) {
                 unset($event['recurrence']['EXCEPTIONS']);
             }
         }
 
         // Set SENT-BY property if the sender is not the organizer
         if ($method == 'CANCEL' || $method == 'REQUEST') {
             foreach ((array)$event['attendees'] as $idx => $attendee) {
                 if ($attendee['role'] == 'ORGANIZER'
                     && $attendee['email']
                     && strcasecmp($attendee['email'], $from) != 0
                     && strcasecmp($attendee['email'], $from_utf) != 0
                 ) {
                     $attendee['sent-by'] = 'mailto:' . $from_utf;
                     $event['organizer'] = $event['attendees'][$idx] = $attendee;
                     break;
                 }
             }
         }
 
         // compose multipart message using PEAR:Mail_Mime
         $message = new Mail_mime("\r\n");
         $message->setParam('text_encoding', 'quoted-printable');
         $message->setParam('head_encoding', 'quoted-printable');
         $message->setParam('head_charset', RCUBE_CHARSET);
         $message->setParam('text_charset', RCUBE_CHARSET . ";\r\n format=flowed");
         $message->setContentType('multipart/alternative');
 
         // compose common headers array
         $headers = array(
             'From' => $sender,
             'Date' => $this->rc->user_date(),
             'Message-ID' => $this->rc->gen_message_id(),
             'X-Sender' => $from,
         );
         if ($agent = $this->rc->config->get('useragent')) {
             $headers['User-Agent'] = $agent;
         }
 
         $message->headers($headers);
 
         // attach ics file for this event
         $ical = libcalendaring::get_ical();
         $ics = $ical->export(array($event), $method, false, $method == 'REQUEST' && $this->plugin->driver ? array($this->plugin->driver, 'get_attachment_body') : false);
         $filename = !empty($event['_type']) && $event['_type'] == 'task' ? 'todo.ics' : 'event.ics';
         $message->addAttachment($ics, 'text/calendar', $filename, false, '8bit', '', RCUBE_CHARSET . "; method=" . $method);
 
         return $message;
     }
 
     /**
      * Forward the given iTip event as delegation to another person
      *
      * @param array Event object to delegate
      * @param mixed Delegatee as string or hash array with keys 'name' and 'mailto'
      * @param boolean The delegator's RSVP flag
      * @param array List with indexes of new/updated attendees
      * @return boolean True on success, False on failure
      */
     public function delegate_to(&$event, $delegate, $rsvp = false, &$attendees = array())
     {
         if (is_string($delegate)) {
             $delegates = rcube_mime::decode_address_list($delegate, 1, false);
             if (count($delegates) > 0) {
                 $delegate = reset($delegates);
             }
         }
 
         $emails = $this->lib->get_user_emails();
         $me     = $this->rc->user->list_emails(true);
 
         // find/create the delegate attendee
         $delegate_attendee = array(
             'email' => $delegate['mailto'],
             'name'  => $delegate['name'],
             'role'  => 'REQ-PARTICIPANT',
         );
         $delegate_index = count($event['attendees']);
 
         foreach ($event['attendees'] as $i => $attendee) {
           // set myself the DELEGATED-TO parameter
           if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
               $event['attendees'][$i]['delegated-to'] = $delegate['mailto'];
               $event['attendees'][$i]['status'] = 'DELEGATED';
               $event['attendees'][$i]['role'] = 'NON-PARTICIPANT';
               $event['attendees'][$i]['rsvp'] = $rsvp;
 
               $me['email'] = $attendee['email'];
               $delegate_attendee['role'] = $attendee['role'];
           }
           // the disired delegatee is already listed as an attendee
           else if (stripos($delegate['mailto'], $attendee['email']) !== false && $attendee['role'] != 'ORGANIZER') {
               $delegate_attendee = $attendee;
               $delegate_index = $i;
               break;
           }
           // TODO: remove previous delegatee (i.e. attendee that has DELEGATED-FROM == $me)
         }
 
         // set/add delegate attendee with RSVP=TRUE and DELEGATED-FROM parameter
         $delegate_attendee['rsvp'] = true;
         $delegate_attendee['status'] = 'NEEDS-ACTION';
         $delegate_attendee['delegated-from'] = $me['email'];
         $event['attendees'][$delegate_index] = $delegate_attendee;
 
         $attendees[] = $delegate_index;
 
         $this->set_sender_email($me['email']);
         return $this->send_itip_message($event, 'REQUEST', $delegate_attendee, 'itipsubjectdelegatedto', 'itipmailbodydelegatedto');
     }
 
     /**
      * Handler for calendar/itip-status requests
      */
     public function get_itip_status($event, $existing = null)
     {
         $action = $event['rsvp'] ? 'rsvp' : '';
         $status = $event['fallback'];
         $latest = $rescheduled = false;
         $html   = '';
 
         if (is_numeric($event['changed'])) {
             $event['changed'] = new DateTime('@'.$event['changed']);
         }
 
         // check if the given itip object matches the last state
         if ($existing) {
             $latest = (isset($event['sequence']) && intval($existing['sequence']) == intval($event['sequence'])) ||
                   (!isset($event['sequence']) && $existing['changed'] && $existing['changed'] >= $event['changed']);
         }
 
         // determine action for REQUEST
         if ($event['method'] == 'REQUEST') {
             $html = html::div('rsvp-status', $this->gettext('acceptinvitation'));
 
             if ($existing) {
                 $rsvp   = $event['rsvp'];
                 $emails = $this->lib->get_user_emails();
 
                 foreach ($existing['attendees'] as $attendee) {
                     if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
                         $status = strtoupper($attendee['status']);
                         break;
                     }
                 }
             }
             else {
                 $rsvp = $event['rsvp'] && $this->rc->config->get('calendar_allow_itip_uninvited', true);
             }
 
             $status_lc = strtolower($status);
 
             if ($status_lc == 'unknown' && !$this->rc->config->get('calendar_allow_itip_uninvited', true)) {
                 $html = html::div('rsvp-status', $this->gettext('notanattendee'));
                 $action = 'import';
             }
             else if (in_array($status_lc, $this->rsvp_status)) {
                 $status_text = $this->gettext(($latest ? 'youhave' : 'youhavepreviously') . $status_lc);
 
                 if ($existing && ($existing['sequence'] > $event['sequence']
                     || (!isset($event['sequence']) && $existing['changed'] && $existing['changed'] > $event['changed']))
                 ) {
                     $action = '';  // nothing to do here, outdated invitation
                     if ($status_lc == 'needs-action') {
                         $status_text = $this->gettext('outdatedinvitation');
                     }
                 }
                 else if (!$existing && !$rsvp) {
                     $action = 'import';
                 }
                 else {
                     if ($latest) {
                         $diff = $this->get_itip_diff($event, $existing);
 
                         // Detect re-scheduling
                         // FIXME: This is probably to simplistic, or maybe we should just check
                         //        attendee's RSVP flag in the new event?
                         $rescheduled = !empty($diff['start']) || !empty($diff['end']);
                         unset($diff['start'], $diff['end']);
                     }
 
                     if ($rescheduled) {
                         $action = 'rsvp';
                         $latest = false;
                     }
                     else if ($status_lc != 'needs-action') {
                         // check if there are any changes
                         if ($latest) {
                             $latest = empty($diff);
                         }
 
                         $action = !$latest ? 'update' : '';
                     }
                 }
 
                 $html = html::div('rsvp-status ' . $status_lc, $status_text);
             }
         }
         // determine action for REPLY
         else if ($event['method'] == 'REPLY') {
             // check whether the sender already is an attendee
             if ($existing) {
                 // Relax checking if that is a reply to the latest version of the event
                 // We accept versions with older SEQUENCE but no significant changes (Bifrost#T78144)
                 if (!$latest) {
                     $num = $got = 0;
                     foreach (array('start', 'end', 'due', 'allday', 'recurrence', 'location') as $key) {
                         if (isset($existing[$key])) {
                             if ($key == 'allday') {
                                 $event[$key] = $event[$key] == 'true';
                             }
                             $value = $existing[$key] instanceof DateTime ? $existing[$key]->format('c') : $existing[$key];
                             $num++;
                             $got += intval($value == $event[$key]);
                         }
                     }
 
                     $latest = $num === $got;
                 }
 
                 $action = $this->rc->config->get('calendar_allow_itip_uninvited', true) ? 'accept' : '';
                 $listed = false;
 
                 foreach ($existing['attendees'] as $attendee) {
                     if ($attendee['role'] != 'ORGANIZER' && strcasecmp($attendee['email'], $event['attendee']) == 0) {
                         $status_lc = strtolower($status);
                         if (in_array($status_lc, $this->rsvp_status)) {
                             $html = html::div('rsvp-status ' . $status_lc, $this->gettext(array(
                                 'name' => 'attendee' . $status_lc,
                                 'vars' => array(
                                     'delegatedto' => rcube::Q($event['delegated-to'] ?: ($attendee['delegated-to'] ?: '?')),
                                 )
                             )));
                         }
 
                         $action = $attendee['status'] == $status || !$latest ? '' : 'update';
                         $listed = true;
                         break;
                     }
                 }
 
                 if (!$listed) {
                     $html = html::div('rsvp-status', $this->gettext('itipnewattendee'));
                 }
             }
             else {
                 $html   = html::div('rsvp-status hint', $this->gettext('itipobjectnotfound'));
                 $action = '';
             }
         }
         else if ($event['method'] == 'CANCEL') {
             if (!$existing) {
                 $html   = html::div('rsvp-status hint', $this->gettext('itipobjectnotfound'));
                 $action = '';
             }
         }
 
         return array(
             'uid'        => $event['uid'],
             'id'         => asciiwords($event['uid'], true),
             'existing'   => $existing ? true : false,
             'saved'      => $existing ? true : false,
             'latest'     => $latest,
             'status'     => $status,
             'action'     => $action,
             'rescheduled' => $rescheduled,
             'html'       => $html,
         );
     }
 
     protected function get_itip_diff($event, $existing)
     {
         if (empty($event) || empty($existing) || empty($event['message_uid']) || empty($event['mime_id'])) {
             return;
         }
 
         $itip = $this->lib->mail_get_itip_object($event['mbox'], $event['message_uid'], $event['mime_id'],
             $event['task'] == 'calendar' ? 'event' : 'task');
 
         if ($itip) {
             // List of properties that could change without SEQUENCE bump
             $attrs = array('description', 'title', 'location', 'url');
             $diff  = array();
 
             foreach ($attrs as $attr) {
                 if (isset($itip[$attr]) && $itip[$attr] != $existing[$attr]) {
                     $diff[$attr] = array(
                         'new' => $itip[$attr],
                         'old' => $existing[$attr]
                     );
                 }
             }
 
             $status             = array();
             $itip_attendees     = array();
             $existing_attendees = array();
             $emails             = $this->lib->get_user_emails();
 
             // Compare list of attendees (ignoring current user status)
             foreach ((array) $existing['attendees'] as $idx => $attendee) {
                 if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
                     $status[strtolower($attendee['email'])] = $attendee['status'];
                 }
                 if ($attendee['role'] == 'ORGANIZER') {
                     $attendee['status'] = 'ACCEPTED'; // sometimes is not set for exceptions
                     $existing['attendees'][$idx] = $attendee;
                 }
                 $existing_attendees[] = $attendee['email'] . (isset($attendee['name']) ? $attendee['name'] : '');
             }
             foreach ((array) $itip['attendees'] as $idx => $attendee) {
                 if (!empty($attendee['email']) && !empty($status[strtolower($attendee['email'])])) {
                     $attendee['status'] = $status[strtolower($attendee['email'])];
                     $itip['attendees'][$idx] = $attendee;
                 }
                 $itip_attendees[] = $attendee['email'] . (isset($attendee['name']) ? $attendee['name'] : '');
             }
 
             if ($itip_attendees != $existing_attendees) {
                 $diff['attendees'] = array(
                     'new' => $itip['attendees'],
                     'old' => $existing['attendees']
                 );
             }
 
             if ($existing['start'] != $itip['start']) {
                 $diff['start'] = array(
                     'new' => $itip['start'],
                     'old' => $existing['start'],
                 );
             }
 
             if ($existing['end'] != $itip['end']) {
                 $diff['end'] = array(
                     'new' => $itip['end'],
                     'old' => $existing['end'],
                 );
             }
 
             return $diff;
         }
     }
 
     /**
      * Build inline UI elements for iTip messages
      */
     public function mail_itip_inline_ui($event, $method, $mime_id, $task, $message_date = null, $preview_url = null)
     {
         $buttons = array();
         $dom_id  = asciiwords($event['uid'], true);
 
         $rsvp_status  = 'unknown';
         $rsvp_buttons = '';
 
         // pass some metadata about the event and trigger the asynchronous status check
         $changed = is_object($event['changed']) ? $event['changed'] : $message_date;
         $metadata = array(
             'uid'      => $event['uid'],
             '_instance' => isset($event['_instance']) ? $event['_instance'] : null,
             'changed'  => $changed ? $changed->format('U') : 0,
             'sequence' => intval($event['sequence']),
             'method'   => $method,
             'task'     => $task,
             'mime_id'  => $mime_id,
         );
 
         // create buttons to be activated from async request checking existence of this event in local calendars
         $buttons[] = html::div(array('id' => 'loading-'.$dom_id, 'class' => 'rsvp-status loading'), $this->gettext('loading'));
 
         // on iTip REPLY we have two options:
         if ($method == 'REPLY') {
             $title = $this->gettext('itipreply');
 
             foreach ($event['attendees'] as $attendee) {
                 if (!empty($attendee['email']) && $attendee['role'] != 'ORGANIZER') {
                     if (empty($event['_sender']) || self::compare_email($attendee['email'], $event['_sender'], $event['_sender_utf'])) {
                         $metadata['attendee'] = $attendee['email'];
                         $rsvp_status = strtoupper($attendee['status']);
                         if ($attendee['delegated-to']) {
                             $metadata['delegated-to'] = $attendee['delegated-to'];
                         }
                         break;
                     }
                 }
             }
 
             // It may happen that sender's address is different in From: and the attached iTip
             // In such case use the ATTENDEE entry with the address from From: header
             if (empty($metadata['attendee']) && !empty($event['_sender'])) {
                 // remove the organizer
                 $itip_attendees = array_filter($event['attendees'], function($item) { return $item['role'] != 'ORGANIZER'; });
 
                 // there must be only one attendee
                 if (is_array($itip_attendees) && count($itip_attendees) == 1) {
                     $event_attendee       = $itip_attendees[key($itip_attendees)];
                     $metadata['attendee'] = $event['_sender'];
                     $rsvp_status          = strtoupper($event_attendee['status']);
                 }
             }
 
             // 1. update the attendee status on our copy
             $update_button = html::tag('input', array(
                 'type'    => 'button',
                 'class'   => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value'   => $this->gettext('updateattendeestatus'),
             ));
 
             // 2. accept or decline a new or delegate attendee
             $accept_buttons = html::tag('input', array(
                 'type'    => 'button',
                 'class'   => "button accept",
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value'   => $this->gettext('acceptattendee'),
             ));
             $accept_buttons .= html::tag('input', array(
                 'type'    => 'button',
                 'class'   => "button decline",
                 'onclick' => "rcube_libcalendaring.decline_attendee_reply('" . rcube::JQ($mime_id) . "', '$task')",
                 'value'   => $this->gettext('declineattendee'),
             ));
 
             $buttons[] = html::div(array('id' => 'update-'.$dom_id, 'style' => 'display:none'), $update_button);
             $buttons[] = html::div(array('id' => 'accept-'.$dom_id, 'style' => 'display:none'), $accept_buttons);
 
             // For replies we need more metadata
             foreach (array('start', 'end', 'due', 'allday', 'recurrence', 'location') as $key) {
                 if (isset($event[$key])) {
                     $metadata[$key] = $event[$key] instanceof DateTime ? $event[$key]->format('c') : $event[$key];
                 }
             }
         }
         // when receiving iTip REQUEST messages:
         else if ($method == 'REQUEST') {
             $emails = $this->lib->get_user_emails();
             $title = $event['sequence'] > 0 ? $this->gettext('itipupdate') : $this->gettext('itipinvitation');
             $metadata['rsvp'] = true;
             $metadata['sensitivity'] = $event['sensitivity'];
 
             if (is_object($event['start'])) {
                 $metadata['date'] = $event['start']->format('U');
             }
 
             // check for X-KOLAB-INVITATIONTYPE property and only show accept/decline buttons
             if (self::get_custom_property($event, 'X-KOLAB-INVITATIONTYPE') == 'CONFIRMATION') {
                 $this->rsvp_actions = array('accepted','declined');
                 $metadata['nosave'] = true;
             }
 
             // 1. display RSVP buttons (if the user was invited)
             foreach ($this->rsvp_actions as $method) {
                 $rsvp_buttons .= html::tag('input', array(
                     'type'    => 'button',
                     'class'   => "button $method",
                     'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task', '$method', '$dom_id')",
                     'value'   => $this->gettext('itip' . $method),
                 ));
             }
 
             // add button to open calendar/preview
             if (!empty($preview_url)) {
                 $msgref = $this->lib->ical_message->folder . '/' . $this->lib->ical_message->uid . '#' . $mime_id;
                 $rsvp_buttons .= html::tag('input', array(
                     'type'    => 'button',
                     // TODO: Temp. disable this button on small screen in Elastic (Bifrost#T105747)
                     'class'   => "button preview hidden-phone hidden-small",
                     'onclick' => "rcube_libcalendaring.open_itip_preview('" . rcube::JQ($preview_url) . "', '" . rcube::JQ($msgref) . "')",
                     'value'   => $this->gettext('openpreview'),
                 ));
             }
 
             // 2. update the local copy with minor changes
             $update_button = html::tag('input', array(
                 'type'    => 'button',
                 'class'   => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value'   => $this->gettext('updatemycopy'),
             ));
 
             // 3. Simply import the event without replying
             $import_button = html::tag('input', array(
                 'type'    => 'button',
                 'class'   => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value'   => $this->gettext('importtocalendar'),
             ));
 
             // check my status as an attendee
             foreach ($event['attendees'] as $attendee) {
                 if ($attendee['email'] && $attendee['role'] != 'ORGANIZER' && in_array(strtolower($attendee['email']), $emails)) {
                     $metadata['attendee'] = $attendee['email'];
                     $metadata['rsvp']     = $attendee['rsvp'] || $attendee['role'] != 'NON-PARTICIPANT';
                     $rsvp_status = !empty($attendee['status']) ? strtoupper($attendee['status']) : 'NEEDS-ACTION';
                     break;
                 }
             }
 
             // add itip reply message controls
             $rsvp_buttons .= html::div('itip-reply-controls', $this->itip_rsvp_options_ui($dom_id, !empty($metadata['nosave'])));
 
             $buttons[] = html::div(array('id' => 'rsvp-'.$dom_id, 'class' => 'rsvp-buttons', 'style' => 'display:none'), $rsvp_buttons);
             $buttons[] = html::div(array('id' => 'update-'.$dom_id, 'style' => 'display:none'), $update_button);
 
             // prepare autocompletion for delegation dialog
             if (in_array('delegated', $this->rsvp_actions)) {
                 $this->rc->autocomplete_init();
             }
         }
         // for CANCEL messages, we can:
         else if ($method == 'CANCEL') {
             $title = $this->gettext('itipcancellation');
             $event_prop = array_filter(array(
                 'uid'       => $event['uid'],
                 '_instance' => isset($event['_instance']) ? $event['_instance'] : null,
                 '_savemode' => isset($event['_savemode']) ? $event['_savemode'] : null,
             ));
 
             // 1. remove the event from our calendar
             $button_remove = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.remove_from_itip(" . rcube_output::json_serialize($event_prop) . ", '$task', '" . rcube::JQ($event['title']) . "')",
                 'value' => $this->gettext('removefromcalendar'),
             ));
 
             // 2. update our copy with status=cancelled
             $button_update = html::tag('input', array(
                 'type'    => 'button',
                 'class'   => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value'   => $this->gettext('updatemycopy'),
             ));
 
             $buttons[] = html::div(array('id' => 'rsvp-'.$dom_id, 'style' => 'display:none'), $button_remove . $button_update);
 
             $rsvp_status = 'CANCELLED';
             $metadata['rsvp'] = true;
         }
 
         // append generic import button
         if (!empty($import_button)) {
             $buttons[] = html::div(array('id' => 'import-'.$dom_id, 'style' => 'display:none'), $import_button);
         }
 
         // pass some metadata about the event and trigger the asynchronous status check
         $metadata['fallback'] = $rsvp_status;
         $metadata['rsvp'] = intval($metadata['rsvp']);
 
         $this->rc->output->add_script("rcube_libcalendaring.fetch_itip_object_status(" . rcube_output::json_serialize($metadata) . ")", 'docready');
 
         // get localized texts from the right domain
         foreach (array('savingdata','deleteobjectconfirm','declinedeleteconfirm','declineattendee',
             'cancel','itipdelegated','declineattendeeconfirm','itipcomment','delegateinvitation',
             'delegateto','delegatersvpme','delegateinvalidaddress') as $label) {
             $this->rc->output->command('add_label', "itip.$label", $this->gettext($label));
         }
 
         // show event details with buttons
         return $this->itip_object_details_table($event, $title) .
             html::div(array('class' => 'itip-buttons', 'id' => 'itip-buttons-' . asciiwords($metadata['uid'], true)), join('', $buttons));
     }
 
     /**
      * Render an RSVP UI widget with buttons to respond on iTip invitations
      */
     function itip_rsvp_buttons($attrib = array(), $actions = null)
     {
         $attrib += array('type' => 'button');
 
         if (!$actions) {
             $actions = $this->rsvp_actions;
         }
 
         $buttons = '';
 
         foreach ($actions as $method) {
             $buttons .= html::tag('input', array(
                 'type'  => $attrib['type'],
                 'name'  => !empty($attrib['iname']) ? $attrib['iname'] : null,
                 'class' => 'button',
                 'rel'   => $method,
                 'value' => $this->gettext('itip' . $method),
             ));
         }
 
         // add localized texts for the delegation dialog
         if (in_array('delegated', $actions)) {
             foreach (array('itipdelegated','itipcomment','delegateinvitation',
                   'delegateto','delegatersvpme','delegateinvalidaddress','cancel') as $label) {
                 $this->rc->output->command('add_label', "itip.$label", $this->gettext($label));
             }
         }
 
         foreach (array('all','current','future') as $mode) {
             $this->rc->output->command('add_label', "rsvpmode$mode", $this->gettext("rsvpmode$mode"));
         }
 
         $savemode_radio = new html_radiobutton(array('name' => '_rsvpmode', 'class' => 'rsvp-replymode'));
 
         return html::div($attrib,
             html::div('label', $this->gettext('acceptinvitation')) .
             html::div('rsvp-buttons itip-buttons',
                 $buttons .
                 html::div('itip-reply-controls', $this->itip_rsvp_options_ui($attrib['id']))
             )
         );
     }
 
     /**
      * Render UI elements to control iTip reply message sending
      */
     public function itip_rsvp_options_ui($dom_id, $disable = false)
     {
         $itip_sending = $this->rc->config->get('calendar_itip_send_option', 3);
 
         // itip sending is entirely disabled
         if ($itip_sending === 0) {
             return '';
         }
         // add checkbox to suppress itip reply message
         else if ($itip_sending >= 2) {
             $toggle_attrib = array(
                 'type'     => 'checkbox',
                 'id'       => 'noreply-'.$dom_id,
                 'value'    => 1,
                 'disabled' => $disable,
                 'checked'  => ($itip_sending & 1) == 0,
                 'class'    => 'pretty-checkbox',
             );
             $rsvp_additions = html::label(array('class' => 'noreply-toggle'),
                 html::tag('input', $toggle_attrib) . ' ' . $this->gettext('itipsuppressreply')
             );
         }
 
         // add input field for reply comment
         $toggle_attrib = array(
             'href'    => '#toggle',
             'class'   => 'reply-comment-toggle',
             'onclick' => '$(this).hide().parent().find(\'textarea\').show().focus()'
         );
         $textarea_attrib = array(
             'id'    => 'reply-comment-' . $dom_id,
             'name'  => '_comment',
             'cols'  => 40,
             'rows'  => 4,
             'class' => 'form-control',
             'style' => 'display:none',
             'placeholder' => $this->gettext('itipcomment')
         );
 
         $rsvp_additions .= html::a($toggle_attrib, $this->gettext('itipeditresponse'))
             . html::div('itip-reply-comment', html::tag('textarea', $textarea_attrib, ''));
 
         return $rsvp_additions;
     }
 
     /**
      * Render event/task details in a table
      */
     function itip_object_details_table($event, $title)
     {
         $table = new html_table(array('cols' => 2, 'border' => 0, 'class' => 'calendar-eventdetails'));
         $table->add('ititle', $title);
         $table->add('title', rcube::Q(trim($event['title'])));
         if ($event['start'] && $event['end']) {
             $table->add('label', $this->gettext('date'));
             $table->add('date', rcube::Q($this->lib->event_date_text($event)));
         }
         else if ($event['due'] && $event['_type'] == 'task') {
             $table->add('label', $this->gettext('date'));
             $table->add('date', rcube::Q($this->lib->event_date_text($event)));
         }
         if (!empty($event['recurrence_date'])) {
             $table->add('label', '');
             $table->add('recurrence-id', $this->gettext($event['thisandfuture'] ? 'itipfutureoccurrence' : 'itipsingleoccurrence'));
         }
         else if (!empty($event['recurrence'])) {
             $table->add('label', $this->gettext('recurring'));
             $table->add('recurrence', $this->lib->recurrence_text($event['recurrence']));
         }
         if (isset($event['location']) && ($location = trim($event['location']))) {
             $table->add('label', $this->gettext('location'));
             $table->add('location', rcube::Q($location));
         }
         if (($sensitivity = trim($event['sensitivity'])) && !preg_match('/^(x-|public$)/i', $sensitivity)) {
             $table->add('label', $this->gettext('sensitivity'));
             $table->add('sensitivity', ucfirst($this->gettext($sensitivity)) . '!');
         }
         if (!empty($event['status']) && ($event['status'] == 'COMPLETED' || $event['status'] == 'CANCELLED')) {
             $table->add('label', $this->gettext('status'));
             $table->add('status', $this->gettext('status-' . strtolower($event['status'])));
         }
         if (isset($event['comment']) && ($comment = trim($event['comment']))) {
             $table->add('label', $this->gettext('comment'));
             $table->add('location', rcube::Q($comment));
         }
 
         return $table->show();
     }
 
 
     /**
      * Create iTIP invitation token for later replies via URL
      *
      * @param array Hash array with event properties
      * @param string Attendee email address
      * @return string Invitation token
      */
     public function store_invitation($event, $attendee)
     {
         // empty stub
         return false;
     }
 
     /**
      * Mark invitations for the given event as cancelled
      *
      * @param array Hash array with event properties
      */
     public function cancel_itip_invitation($event)
     {
         // empty stub
         return false;
     }
 
     /**
      * Utility function to get the value of a custom property
      */
     public static function get_custom_property($event, $name)
     {
       $ret = false;
 
       if (is_array($event['x-custom'])) {
           array_walk($event['x-custom'], function($prop, $i) use ($name, &$ret) {
               if (strcasecmp($prop[0], $name) === 0) {
                   $ret = $prop[1];
               }
           });
       }
 
       return $ret;
     }
 
     /**
      * Compare email address
      */
     public static function compare_email($value, $email, $email_utf = null)
     {
         $v1 = !empty($email) && strcasecmp($value, $email) === 0;
         $v2 = !empty($email_utf) && strcasecmp($value, $email_utf) === 0;
 
         return $v1 || $v2;
     }
 }