<?php
	class FileEventHandler extends kDBEventHandler {

		/**
		 * [HOOK] Allows to apply file functionality to specific config
		 * When main item is created, then #file config is cloned
		 *
		 * @param kEvent $event
		 */
		function OnDefineFiles(&$event)
		{
			$clones = $this->Application->getUnitOption('#file', 'Clones');
			$clones[$event->MasterEvent->Prefix.'-file'] = Array (
				'ParentPrefix' => $event->MasterEvent->Prefix,
			);
			$this->Application->setUnitOption('#file', 'Clones', $clones);
		}

		/**
		 * Remembers user, who is created file record. Makes file primary if no other files are uploaded.
		 *
		 * @param kEvent $event
		 */
		function OnBeforeItemCreate(&$event)
		{
			parent::OnBeforeItemCreate($event);

			$object =& $event->getObject();

			$this->resetPrimary($object);

			if (!$this->primaryFileFound($object)) {
				$object->SetDBField('IsPrimary', 1);
				$object->SetDBField('Status', STATUS_ACTIVE);
			}

			$object->SetDBField('CreatedById', $this->Application->RecallVar('user_id'));
		}

		/**
		 * Resets primary file mark when more then one file is marked as primary
		 *
		 * @param kEvent $event
		 */
		function OnBeforeItemUpdate(&$event)
		{
			$object =& $event->getObject();

			$this->resetPrimary($object);

			if (!$object->GetDBField('FileName')) {
				$object->SetDBField('FileName', basename($object->GetDBField('FilePath')));
			}
		}

		/**
		 * Checks for primary file along all files with same main item
		 *
		 * @param kDBItem $object
		 * @return int
		 */
		function primaryFileFound(&$object)
		{
			$sql = 'SELECT '.$object->IDField.'
					FROM '.$object->TableName.'
					WHERE (IsPrimary = 1) AND ('.$this->getParentClause($object).')';
			return $this->Conn->GetOne($sql);
		}

		/**
		 * Resets primary mark from all item files
		 *
		 * @param kDBItem $object
		 */
		function resetPrimary(&$object)
		{
			if (!$object->GetDBField('IsPrimary')) {
				return ;
			}

			$sql = 'UPDATE '.$object->TableName.'
					SET IsPrimary = 0
					WHERE '.$this->getParentClause($object);
			$this->Conn->Query($sql);

			$object->SetDBField('Status', STATUS_ACTIVE);
		}

		/**
		 * Makes selected file primary
		 *
		 * @param kEvent $event
		 */
		function OnSetPrimary(&$event)
		{
			$ids = $this->StoreSelectedIDs($event);
			if (!$ids) {
				return ;
			}

			$object =& $event->getObject( Array('skip_autoload' => true) );
			$object->Load( array_shift($ids) );

			$object->SetDBField('IsPrimary', 1);
			$object->Update();

			$this->clearSelectedIDs($event);
		}

		/**
		 * Don't allow to delete other user's messages
		 *
		 * @param kEvent $event
		 */
		function customProcessing(&$event, $type)
		{
			parent::customProcessing($event, $type);
			if ($event->Name == 'OnMassDelete' && $type == 'before') {
		        $ids = $event->getEventParam('ids');
		        if ($ids) {
		            $object =& $event->getObject();
		            /* @var $object kDBItem */

					$primary_file_id = $this->primaryFileFound($object);
					if ($primary_file_id && ($primary_index = array_search($primary_file_id, $ids))) {
						$sql = 'SELECT COUNT(*)
								FROM '.$object->TableName.'
								WHERE (IsPrimary = 0) AND ('.$this->getParentClause($object).')';
						$non_primary_found = $this->Conn->Query($sql);

						if ($non_primary_found) {
							// non-primary files found for same main item -> don't delete primary file until all non-primary files are deleted
							unset($ids[$primary_index]);
						}
					}

		            $event->setEventParam('ids', $ids);
		        }
		    }
		}

		function SetCustomQuery(&$event)
		{
			parent::SetCustomQuery($event);

			$object =& $event->getObject();

			if (!$this->Application->IsAdmin()) {
				$object->addFilter('active_filter', '%1$s.Status = '.STATUS_ACTIVE);
			}
		}

		/**
		 * Returns sql clause, that links file to it's parent item
		 *
		 * @param kDBItem $object
		 * @return string
		 */
		function getParentClause(&$object)
		{
			$parent_info = $object->getLinkedInfo($object->Special);
			return $parent_info['ForeignKey'].' = '.$parent_info['ParentId'];
		}
	}

?>