/**
  * add calendar owner as attendee if not already set
  * 
  * @param string $calendarId
  * @param Tinebase_DateTime $from
  * @param Tinebase_DateTime $until
  * @param boolean $dry run
  * 
  * @return number of updated events
  */
 public function repairAttendee($calendarId, $from, $until, $dry = false)
 {
     $container = Tinebase_Container::getInstance()->getContainerById($calendarId);
     if ($container->type !== Tinebase_Model_Container::TYPE_PERSONAL) {
         throw new Calendar_Exception('Only allowed for personal containers!');
     }
     if ($container->owner_id !== Tinebase_Core::getUser()->getId()) {
         throw new Calendar_Exception('Only allowed for own containers!');
     }
     $updateCount = 0;
     while ($from->isEarlier($until)) {
         $endWeek = $from->getClone()->addWeek(1);
         if (Tinebase_Core::isLogLevel(Zend_Log::INFO)) {
             Tinebase_Core::getLogger()->info(__METHOD__ . '::' . __LINE__ . ' Repairing period ' . $from . ' - ' . $endWeek);
         }
         // TODO we need to detect events with DECLINED/DELETED attendee
         $events = $this->_getEventsForPeriodAndCalendar($calendarId, $from, $endWeek);
         $from->addWeek(1);
         if (count($events) == 0) {
             if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
                 Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . ' No events found');
             }
             continue;
         }
         foreach ($events as $event) {
             // add attendee if not already set
             if ($event->isRecurInstance()) {
                 // TODO get base event
                 if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
                     Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . ' Skip recur instance ' . $event->toShortString());
                 }
                 continue;
             }
             $ownAttender = Calendar_Model_Attender::getOwnAttender($event->attendee);
             if (!$ownAttender) {
                 if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
                     Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . ' Add missing attender to event ' . $event->toShortString());
                 }
                 $attender = new Calendar_Model_Attender(array('user_type' => Calendar_Model_Attender::USERTYPE_USER, 'user_id' => Tinebase_Core::getUser()->contact_id, 'status' => Calendar_Model_Attender::STATUS_ACCEPTED));
                 $event->attendee->addRecord($attender);
                 if (!$dry) {
                     $this->update($event);
                 }
                 $updateCount++;
             }
         }
     }
     return $updateCount;
 }