--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/calendar/drivers/kolab/kolab_calendar.php	Sat Jan 13 08:56:12 2018 -0500
@@ -0,0 +1,869 @@
+<?php
+
+/**
+ * Kolab calendar storage class
+ *
+ * @version @package_version@
+ * @author Thomas Bruederli <bruederli@kolabsys.com>
+ * @author Aleksander Machniak <machniak@kolabsys.com>
+ *
+ * Copyright (C) 2012-2015, 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 kolab_calendar extends kolab_storage_folder_api
+{
+  public $ready = false;
+  public $rights = 'lrs';
+  public $editable = false;
+  public $attachments = true;
+  public $alarms = false;
+  public $history = false;
+  public $subscriptions = true;
+  public $categories = array();
+  public $storage;
+
+  public $type = 'event';
+
+  protected $cal;
+  protected $events = array();
+  protected $search_fields = array('title', 'description', 'location', 'attendees');
+
+  /**
+   * Factory method to instantiate a kolab_calendar object
+   *
+   * @param string  Calendar ID (encoded IMAP folder name)
+   * @param object  calendar plugin object
+   * @return object kolab_calendar instance
+   */
+  public static function factory($id, $calendar)
+  {
+    $imap = $calendar->rc->get_storage();
+    $imap_folder = kolab_storage::id_decode($id);
+    $info = $imap->folder_info($imap_folder, true);
+    if (empty($info) || $info['noselect'] || strpos(kolab_storage::folder_type($imap_folder), 'event') !== 0) {
+      return new kolab_user_calendar($imap_folder, $calendar);
+    }
+    else {
+      return new kolab_calendar($imap_folder, $calendar);
+    }
+  }
+
+  /**
+   * Default constructor
+   */
+  public function __construct($imap_folder, $calendar)
+  {
+    $this->cal = $calendar;
+    $this->imap = $calendar->rc->get_storage();
+    $this->name = $imap_folder;
+
+    // ID is derrived from folder name
+    $this->id = kolab_storage::folder_id($this->name, true);
+    $old_id   = kolab_storage::folder_id($this->name, false);
+
+    // fetch objects from the given IMAP folder
+    $this->storage = kolab_storage::get_folder($this->name);
+    $this->ready = $this->storage && $this->storage->valid;
+
+    // Set writeable and alarms flags according to folder permissions
+    if ($this->ready) {
+      if ($this->storage->get_namespace() == 'personal') {
+        $this->editable = true;
+        $this->rights = 'lrswikxteav';
+        $this->alarms = true;
+      }
+      else {
+        $rights = $this->storage->get_myrights();
+        if ($rights && !PEAR::isError($rights)) {
+          $this->rights = $rights;
+          if (strpos($rights, 't') !== false || strpos($rights, 'd') !== false)
+            $this->editable = strpos($rights, 'i');;
+        }
+      }
+      
+      // user-specific alarms settings win
+      $prefs = $this->cal->rc->config->get('kolab_calendars', array());
+      if (isset($prefs[$this->id]['showalarms']))
+        $this->alarms = $prefs[$this->id]['showalarms'];
+      else if (isset($prefs[$old_id]['showalarms']))
+        $this->alarms = $prefs[$old_id]['showalarms'];
+    }
+
+    $this->default = $this->storage->default;
+    $this->subtype = $this->storage->subtype;
+  }
+
+
+  /**
+   * Getter for the IMAP folder name
+   *
+   * @return string Name of the IMAP folder
+   */
+  public function get_realname()
+  {
+    return $this->name;
+  }
+
+  /**
+   *
+   */
+  public function get_title()
+  {
+    return null;
+  }
+
+
+  /**
+   * Return color to display this calendar
+   */
+  public function get_color($default = null)
+  {
+    // color is defined in folder METADATA
+    if ($color = $this->storage->get_color()) {
+      return $color;
+    }
+
+    // calendar color is stored in user prefs (temporary solution)
+    $prefs = $this->cal->rc->config->get('kolab_calendars', array());
+
+    if (!empty($prefs[$this->id]) && !empty($prefs[$this->id]['color']))
+      return $prefs[$this->id]['color'];
+
+    return $default ?: 'cc0000';
+  }
+
+  /**
+   * Compose an URL for CalDAV access to this calendar (if configured)
+   */
+  public function get_caldav_url()
+  {
+    if ($template = $this->cal->rc->config->get('calendar_caldav_url', null)) {
+      return strtr($template, array(
+        '%h' => $_SERVER['HTTP_HOST'],
+        '%u' => urlencode($this->cal->rc->get_user_name()),
+        '%i' => urlencode($this->storage->get_uid()),
+        '%n' => urlencode($this->name),
+      ));
+    }
+
+    return false;
+  }
+
+
+  /**
+   * Update properties of this calendar folder
+   *
+   * @see calendar_driver::edit_calendar()
+   */
+  public function update(&$prop)
+  {
+    $prop['oldname'] = $this->get_realname();
+    $newfolder = kolab_storage::folder_update($prop);
+
+    if ($newfolder === false) {
+      $this->cal->last_error = $this->cal->gettext(kolab_storage::$last_error);
+      return false;
+    }
+
+    // create ID
+    return kolab_storage::folder_id($newfolder);
+  }
+
+  /**
+   * Getter for a single event object
+   */
+  public function get_event($id)
+  {
+    // remove our occurrence identifier if it's there
+    $master_id = preg_replace('/-\d{8}(T\d{6})?$/', '', $id);
+
+    // directly access storage object
+    if (!$this->events[$id] && $master_id == $id && ($record = $this->storage->get_object($id))) {
+      $this->events[$id] = $this->_to_driver_event($record, true);
+    }
+
+    // maybe a recurring instance is requested
+    if (!$this->events[$id] && $master_id != $id) {
+      $instance_id = substr($id, strlen($master_id) + 1);
+
+      if ($record = $this->storage->get_object($master_id)) {
+        $master = $this->_to_driver_event($record);
+      }
+
+      if ($master) {
+        // check for match in top-level exceptions (aka loose single occurrences)
+        if ($master['_formatobj'] && ($instance = $master['_formatobj']->get_instance($instance_id))) {
+          $this->events[$id] = $this->_to_driver_event($instance, false, true, $master);
+        }
+        // check for match on the first instance already
+        else if ($master['_instance'] && $master['_instance'] == $instance_id) {
+          $this->events[$id] = $master;
+        }
+        else if (is_array($master['recurrence'])) {
+          $this->get_recurring_events($record, $master['start'], null, $id);
+        }
+      }
+    }
+
+    return $this->events[$id];
+  }
+
+  /**
+   * Get attachment body
+   * @see calendar_driver::get_attachment_body()
+   */
+  public function get_attachment_body($id, $event)
+  {
+    if (!$this->ready)
+        return false;
+
+    $data = $this->storage->get_attachment($event['id'], $id);
+
+    if ($data == null) {
+        // try again with master UID
+        $uid = preg_replace('/-\d+(T\d{6})?$/', '', $event['id']);
+        if ($uid != $event['id']) {
+            $data = $this->storage->get_attachment($uid, $id);
+        }
+    }
+
+    return $data;
+  }
+
+  /**
+   * @param  integer Event's new start (unix timestamp)
+   * @param  integer Event's new end (unix timestamp)
+   * @param  string  Search query (optional)
+   * @param  boolean Include virtual events (optional)
+   * @param  array   Additional parameters to query storage
+   * @param  array   Additional query to filter events
+   * @return array A list of event records
+   */
+  public function list_events($start, $end, $search = null, $virtual = 1, $query = array(), $filter_query = null)
+  {
+    // convert to DateTime for comparisons
+    // #5190: make the range a little bit wider
+    // to workaround possible timezone differences
+    try {
+      $start = new DateTime('@' . ($start - 12 * 3600));
+    }
+    catch (Exception $e) {
+      $start = new DateTime('@0');
+    }
+    try {
+      $end = new DateTime('@' . ($end + 12 * 3600));
+    }
+    catch (Exception $e) {
+      $end = new DateTime('today +10 years');
+    }
+
+    // get email addresses of the current user
+    $user_emails = $this->cal->get_user_emails();
+
+    // query Kolab storage
+    $query[] = array('dtstart', '<=', $end);
+    $query[] = array('dtend',   '>=', $start);
+
+    if (is_array($filter_query)) {
+      $query = array_merge($query, $filter_query);
+    }
+
+    if (!empty($search)) {
+        $search = mb_strtolower($search);
+        $words = rcube_utils::tokenize_string($search, 1);
+        foreach (rcube_utils::normalize_string($search, true) as $word) {
+            $query[] = array('words', 'LIKE', $word);
+        }
+    }
+    else {
+      $words = array();
+    }
+
+    // set partstat filter to skip pending and declined invitations
+    if (empty($filter_query) && $this->cal->rc->config->get('kolab_invitation_calendars')
+      && $this->get_namespace() != 'other'
+    ) {
+      $partstat_exclude = array('NEEDS-ACTION','DECLINED');
+    }
+    else {
+      $partstat_exclude = array();
+    }
+
+    $events = array();
+    foreach ($this->storage->select($query) as $record) {
+      $event = $this->_to_driver_event($record, !$virtual, false);
+
+      // remember seen categories
+      if ($event['categories']) {
+        $cat = is_array($event['categories']) ? $event['categories'][0] : $event['categories'];
+        $this->categories[$cat]++;
+      }
+
+      // list events in requested time window
+      if ($event['start'] <= $end && $event['end'] >= $start) {
+        unset($event['_attendees']);
+        $add = true;
+
+        // skip the first instance of a recurring event if listed in exdate
+        if ($virtual && !empty($event['recurrence']['EXDATE'])) {
+          $event_date = $event['start']->format('Ymd');
+          $exdates = (array)$event['recurrence']['EXDATE'];
+
+          foreach ($exdates as $exdate) {
+            if ($exdate->format('Ymd') == $event_date) {
+              $add = false;
+              break;
+            }
+          }
+        }
+
+        // find and merge exception for the first instance
+        if ($virtual && !empty($event['recurrence']) && is_array($event['recurrence']['EXCEPTIONS'])) {
+          foreach ($event['recurrence']['EXCEPTIONS'] as $exception) {
+            if ($event['_instance'] == $exception['_instance']) {
+              // clone date objects from main event before adjusting them with exception data
+              if (is_object($event['start'])) $event['start'] = clone $record['start'];
+              if (is_object($event['end']))   $event['end']   = clone $record['end'];
+              kolab_driver::merge_exception_data($event, $exception);
+            }
+          }
+        }
+
+        if ($add)
+          $events[] = $event;
+      }
+
+      // resolve recurring events
+      if ($record['recurrence'] && $virtual == 1) {
+        $events = array_merge($events, $this->get_recurring_events($record, $start, $end));
+      }
+      // add top-level exceptions (aka loose single occurrences)
+      else if (is_array($record['exceptions'])) {
+        foreach ($record['exceptions'] as $ex) {
+          $component = $this->_to_driver_event($ex, false, false, $record);
+          if ($component['start'] <= $end && $component['end'] >= $start) {
+            $events[] = $component;
+          }
+        }
+      }
+    }
+
+    // post-filter all events by fulltext search and partstat values
+    $me = $this;
+    $events = array_filter($events, function($event) use ($words, $partstat_exclude, $user_emails, $me) {
+      // fulltext search
+      if (count($words)) {
+        $hits = 0;
+        foreach ($words as $word) {
+          $hits += $me->fulltext_match($event, $word, false);
+        }
+        if ($hits < count($words)) {
+          return false;
+        }
+      }
+
+      // partstat filter
+      if (count($partstat_exclude) && is_array($event['attendees'])) {
+        foreach ($event['attendees'] as $attendee) {
+          if (in_array($attendee['email'], $user_emails) && in_array($attendee['status'], $partstat_exclude)) {
+            return false;
+          }
+        }
+      }
+
+      return true;
+    });
+
+    // Apply event-to-mail relations
+    $config = kolab_storage_config::get_instance();
+    $config->apply_links($events);
+
+    // avoid session race conditions that will loose temporary subscriptions
+    $this->cal->rc->session->nowrite = true;
+
+    return $events;
+  }
+
+  /**
+   *
+   * @param  integer Date range start (unix timestamp)
+   * @param  integer Date range end (unix timestamp)
+   * @param  array   Additional query to filter events
+   * @return integer Count
+   */
+  public function count_events($start, $end = null, $filter_query = null)
+  {
+    // convert to DateTime for comparisons
+    try {
+      $start = new DateTime('@'.$start);
+    }
+    catch (Exception $e) {
+      $start = new DateTime('@0');
+    }
+    if ($end) {
+      try {
+        $end = new DateTime('@'.$end);
+      }
+      catch (Exception $e) {
+        $end = null;
+      }
+    }
+
+    // query Kolab storage
+    $query[] = array('dtend',   '>=', $start);
+    
+    if ($end)
+      $query[] = array('dtstart', '<=', $end);
+
+    // add query to exclude pending/declined invitations
+    if (empty($filter_query)) {
+      foreach ($this->cal->get_user_emails() as $email) {
+        $query[] = array('tags', '!=', 'x-partstat:' . $email . ':needs-action');
+        $query[] = array('tags', '!=', 'x-partstat:' . $email . ':declined');
+      }
+    }
+    else if (is_array($filter_query)) {
+      $query = array_merge($query, $filter_query);
+    }
+
+    // we rely the Kolab storage query (no post-filtering)
+    return $this->storage->count($query);
+  }
+
+  /**
+   * Create a new event record
+   *
+   * @see calendar_driver::new_event()
+   * 
+   * @return mixed The created record ID on success, False on error
+   */
+  public function insert_event($event)
+  {
+    if (!is_array($event))
+      return false;
+
+    // email links are stored separately
+    $links = $event['links'];
+    unset($event['links']);
+
+    //generate new event from RC input
+    $object = $this->_from_driver_event($event);
+    $saved  = $this->storage->save($object, 'event');
+
+    if (!$saved) {
+      rcube::raise_error(array(
+        'code' => 600, 'type' => 'php',
+        'file' => __FILE__, 'line' => __LINE__,
+        'message' => "Error saving event object to Kolab server"),
+        true, false);
+      $saved = false;
+    }
+    else {
+      // save links in configuration.relation object
+      if ($this->save_links($event['uid'], $links)) {
+        $object['links'] = $links;
+      }
+
+      $this->events = array($event['uid'] => $this->_to_driver_event($object, true));
+    }
+
+    return $saved;
+  }
+
+  /**
+   * Update a specific event record
+   *
+   * @see calendar_driver::new_event()
+   * @return boolean True on success, False on error
+   */
+
+  public function update_event($event, $exception_id = null)
+  {
+    $updated = false;
+    $old = $this->storage->get_object($event['uid'] ?: $event['id']);
+    if (!$old || PEAR::isError($old))
+      return false;
+
+    // email links are stored separately
+    $links = $event['links'];
+    unset($event['links']);
+
+    $object = $this->_from_driver_event($event, $old);
+    $saved  = $this->storage->save($object, 'event', $old['uid']);
+
+    if (!$saved) {
+      rcube::raise_error(array(
+        'code' => 600, 'type' => 'php',
+        'file' => __FILE__, 'line' => __LINE__,
+        'message' => "Error saving event object to Kolab server"),
+        true, false);
+    }
+    else {
+      // save links in configuration.relation object
+      if ($this->save_links($event['uid'], $links)) {
+        $object['links'] = $links;
+      }
+
+      $updated = true;
+      $this->events = array($event['uid'] => $this->_to_driver_event($object, true));
+
+      // refresh local cache with recurring instances
+      if ($exception_id) {
+        $this->get_recurring_events($object, $event['start'], $event['end'], $exception_id);
+      }
+    }
+
+    return $updated;
+  }
+
+  /**
+   * Delete an event record
+   *
+   * @see calendar_driver::remove_event()
+   * @return boolean True on success, False on error
+   */
+  public function delete_event($event, $force = true)
+  {
+    $deleted = $this->storage->delete($event['uid'] ?: $event['id'], $force);
+
+    if (!$deleted) {
+      rcube::raise_error(array(
+        'code' => 600, 'type' => 'php',
+        'file' => __FILE__, 'line' => __LINE__,
+        'message' => sprintf("Error deleting event object '%s' from Kolab server", $event['id'])),
+        true, false);
+    }
+
+    return $deleted;
+  }
+
+  /**
+   * Restore deleted event record
+   *
+   * @see calendar_driver::undelete_event()
+   * @return boolean True on success, False on error
+   */
+  public function restore_event($event)
+  {
+    if ($this->storage->undelete($event['id'])) {
+        return true;
+    }
+    else {
+        rcube::raise_error(array(
+          'code' => 600, 'type' => 'php',
+          'file' => __FILE__, 'line' => __LINE__,
+          'message' => "Error undeleting the event object $event[id] from the Kolab server"),
+        true, false);
+    }
+
+    return false;
+  }
+
+  /**
+   * Find messages linked with an event
+   */
+  protected function get_links($uid)
+  {
+    $storage = kolab_storage_config::get_instance();
+    return $storage->get_object_links($uid);
+  }
+
+  /**
+   *
+   */
+  protected function save_links($uid, $links)
+  {
+    $storage = kolab_storage_config::get_instance();
+    return $storage->save_object_links($uid, (array) $links);
+  }
+
+  /**
+   * Create instances of a recurring event
+   *
+   * @param array  Hash array with event properties
+   * @param object DateTime Start date of the recurrence window
+   * @param object DateTime End date of the recurrence window
+   * @param string ID of a specific recurring event instance
+   * @return array List of recurring event instances
+   */
+  public function get_recurring_events($event, $start, $end = null, $event_id = null)
+  {
+    $object = $event['_formatobj'];
+    if (!$object) {
+      $rec = $this->storage->get_object($event['id']);
+      $object = $rec['_formatobj'];
+    }
+    if (!is_object($object))
+      return array();
+
+    // determine a reasonable end date if none given
+    if (!$end) {
+      $end = clone $event['start'];
+      $end->add(new DateInterval('P100Y'));
+    }
+
+    // copy the recurrence rule from the master event (to be used in the UI)
+    $recurrence_rule = $event['recurrence'];
+    unset($recurrence_rule['EXCEPTIONS'], $recurrence_rule['EXDATE']);
+
+    // read recurrence exceptions first
+    $events = array();
+    $exdata = array();
+    $futuredata = array();
+    $recurrence_id_format = libcalendaring::recurrence_id_format($event);
+
+    if (is_array($event['recurrence']['EXCEPTIONS'])) {
+      foreach ($event['recurrence']['EXCEPTIONS'] as $exception) {
+        if (!$exception['_instance'])
+          $exception['_instance'] = libcalendaring::recurrence_instance_identifier($exception, $event['allday']);
+
+        $rec_event = $this->_to_driver_event($exception, false, false, $event);
+        $rec_event['id'] = $event['uid'] . '-' . $exception['_instance'];
+        $rec_event['isexception'] = 1;
+
+        // found the specifically requested instance: register exception (single occurrence wins)
+        if ($rec_event['id'] == $event_id && (!$this->events[$event_id] || $this->events[$event_id]['thisandfuture'])) {
+          $rec_event['recurrence'] = $recurrence_rule;
+          $rec_event['recurrence_id'] = $event['uid'];
+          $this->events[$rec_event['id']] = $rec_event;
+        }
+
+        // remember this exception's date
+        $exdate = substr($exception['_instance'], 0, 8);
+        if (!$exdata[$exdate] || $exdata[$exdate]['thisandfuture']) {
+          $exdata[$exdate] = $rec_event;
+        }
+        if ($rec_event['thisandfuture']) {
+          $futuredata[$exdate] = $rec_event;
+        }
+      }
+    }
+
+    // found the specifically requested instance, exiting...
+    if ($event_id && !empty($this->events[$event_id])) {
+      return array($this->events[$event_id]);
+    }
+
+    // use libkolab to compute recurring events
+    if (class_exists('kolabcalendaring')) {
+        $recurrence = new kolab_date_recurrence($object);
+    }
+    else {
+      // fallback to local recurrence implementation
+      require_once($this->cal->home . '/lib/calendar_recurrence.php');
+      $recurrence = new calendar_recurrence($this->cal, $event);
+    }
+
+    $i = 0;
+    while ($next_event = $recurrence->next_instance()) {
+      $datestr     = $next_event['start']->format('Ymd');
+      $instance_id = $next_event['start']->format($recurrence_id_format);
+
+      // use this event data for future recurring instances
+      if ($futuredata[$datestr])
+        $overlay_data = $futuredata[$datestr];
+
+      $rec_id      = $event['uid'] . '-' . $instance_id;
+      $exception   = $exdata[$datestr] ?: $overlay_data;
+      $event_start = $next_event['start'];
+      $event_end   = $next_event['end'];
+
+      // copy some event from exception to get proper start/end dates
+      if ($exception) {
+        $event_copy = $next_event;
+        kolab_driver::merge_exception_dates($event_copy, $exception);
+        $event_start = $event_copy['start'];
+        $event_end   = $event_copy['end'];
+      }
+
+      // add to output if in range
+      if (($event_start <= $end && $event_end >= $start) || ($event_id && $rec_id == $event_id)) {
+        $rec_event = $this->_to_driver_event($next_event, false, false, $event);
+        $rec_event['_instance'] = $instance_id;
+        $rec_event['_count'] = $i + 1;
+
+        if ($exception)  // copy data from exception
+          kolab_driver::merge_exception_data($rec_event, $exception);
+
+        $rec_event['id'] = $rec_id;
+        $rec_event['recurrence_id'] = $event['uid'];
+        $rec_event['recurrence'] = $recurrence_rule;
+        unset($rec_event['_attendees']);
+        $events[] = $rec_event;
+
+        if ($rec_id == $event_id) {
+          $this->events[$rec_id] = $rec_event;
+          break;
+        }
+      }
+      else if ($next_event['start'] > $end)  // stop loop if out of range
+        break;
+
+      // avoid endless recursion loops
+      if (++$i > 100000)
+          break;
+    }
+    
+    return $events;
+  }
+
+  /**
+   * Convert from Kolab_Format to internal representation
+   */
+  private function _to_driver_event($record, $noinst = false, $links = true, $master_event = null)
+  {
+    $record['calendar'] = $this->id;
+
+    if ($links && !array_key_exists('links', $record)) {
+      $record['links'] = $this->get_links($record['uid']);
+    }
+
+    if ($this->get_namespace() == 'other') {
+      $record['className'] = 'fc-event-ns-other';
+      $record = kolab_driver::add_partstat_class($record, array('NEEDS-ACTION','DECLINED'), $this->get_owner());
+    }
+
+    // add instance identifier to first occurrence (master event)
+    $recurrence_id_format = libcalendaring::recurrence_id_format($master_event ? $master_event : $record);
+    if (!$noinst && $record['recurrence'] && !$record['recurrence_id'] && !$record['_instance']) {
+      $record['_instance'] = $record['start']->format($recurrence_id_format);
+    }
+    else if (is_a($record['recurrence_date'], 'DateTime')) {
+      $record['_instance'] = $record['recurrence_date']->format($recurrence_id_format);
+    }
+
+    // clean up exception data
+    if ($record['recurrence'] && is_array($record['recurrence']['EXCEPTIONS'])) {
+      array_walk($record['recurrence']['EXCEPTIONS'], function(&$exception) {
+        unset($exception['_mailbox'], $exception['_msguid'], $exception['_formatobj'], $exception['_attachments']);
+      });
+    }
+
+    return $record;
+  }
+
+   /**
+   * Convert the given event record into a data structure that can be passed to Kolab_Storage backend for saving
+   * (opposite of self::_to_driver_event())
+   */
+  private function _from_driver_event($event, $old = array())
+  {
+    // set current user as ORGANIZER
+    if ($identity = $this->cal->rc->user->list_emails(true)) {
+      $event['attendees'] = (array) $event['attendees'];
+      $found = false;
+
+      // there can be only resources on attendees list (T1484)
+      // let's check the existence of an organizer
+      foreach ($event['attendees'] as $attendee) {
+        if ($attendee['role'] == 'ORGANIZER') {
+          $found = true;
+          break;
+        }
+      }
+
+      if (!$found) {
+        $event['attendees'][] = array('role' => 'ORGANIZER', 'name' => $identity['name'], 'email' => $identity['email']);
+      }
+
+      $event['_owner'] = $identity['email'];
+    }
+
+    // remove EXDATE values if RDATE is given
+    if (!empty($event['recurrence']['RDATE'])) {
+      $event['recurrence']['EXDATE'] = array();
+    }
+
+    // remove recurrence information (e.g. EXDATES and EXCEPTIONS) entirely
+    if ($event['recurrence'] && empty($event['recurrence']['FREQ']) && empty($event['recurrence']['RDATE'])) {
+      $event['recurrence'] = array();
+    }
+
+    // keep 'comment' from initial itip invitation
+    if (!empty($old['comment'])) {
+      $event['comment'] = $old['comment'];
+    }
+
+    // clean up exception data
+    if (is_array($event['exceptions'])) {
+      array_walk($event['exceptions'], function(&$exception) {
+        unset($exception['_mailbox'], $exception['_msguid'], $exception['_formatobj'], $exception['_attachments'],
+          $event['attachments'], $event['deleted_attachments'], $event['recurrence_id']);
+      });
+    }
+
+    // remove some internal properties which should not be saved
+    unset($event['_savemode'], $event['_fromcalendar'], $event['_identity'], $event['_folder_id'],
+      $event['recurrence_id'], $event['attachments'], $event['deleted_attachments'], $event['className']);
+
+    // copy meta data (starting with _) from old object
+    foreach ((array)$old as $key => $val) {
+      if (!isset($event[$key]) && $key[0] == '_')
+        $event[$key] = $val;
+    }
+
+    return $event;
+  }
+
+  /**
+   * Match the given word in the event contents
+   */
+  public function fulltext_match($event, $word, $recursive = true)
+  {
+    $hits = 0;
+    foreach ($this->search_fields as $col) {
+      $sval = is_array($event[$col]) ? self::_complex2string($event[$col]) : $event[$col];
+      if (empty($sval))
+        continue;
+
+      // do a simple substring matching (to be improved)
+      $val = mb_strtolower($sval);
+      if (strpos($val, $word) !== false) {
+        $hits++;
+        break;
+      }
+    }
+
+    return $hits;
+  }
+
+  /**
+   * Convert a complex event attribute to a string value
+   */
+  private static function _complex2string($prop)
+  {
+      static $ignorekeys = array('role','status','rsvp');
+
+      $out = '';
+      if (is_array($prop)) {
+          foreach ($prop as $key => $val) {
+              if (is_numeric($key)) {
+                  $out .= self::_complex2string($val);
+              }
+              else if (!in_array($key, $ignorekeys)) {
+                $out .= $val . ' ';
+            }
+          }
+      }
+      else if (is_string($prop) || is_numeric($prop)) {
+          $out .= $prop . ' ';
+      }
+
+      return rtrim($out);
+  }
+
+}