<?php
  /**
  * ownCloud
  *
  * @author Michael Gapczynski
  * @copyright 2012 Michael Gapczynski mtgap@owncloud.com
  * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
  * License as published by the Free Software Foundation; either
  * version 3 of the License, or any later version.
  *
  * This library 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 library.  If not, see <http://www.gnu.org/licenses/>.
  */
  
  class OC_Share_Backend_Calendar implements OCP\Share_Backend_Collection {
  	const FORMAT_CALENDAR = 1;
  
  	/**
  	* @brief Get the source of the item to be stored in the database
  	* @param string Item
  	* @param string Owner of the item
  	* @return mixed|array|false Source
  	*
  	* Return an array if the item is file dependent, the array needs two keys: 'item' and 'file'
  	* Return false if the item does not exist for the user
  	*
  	* The formatItems() function will translate the source returned back into the item
  	*/
  	public function isValidSource($itemSource, $uidOwner) {
  		$calendar = OC_Calendar_App::getCalendar( $itemSource );
  		if ($calendar === false || $calendar['userid'] != $uidOwner) {
  			return false;
  		}
  		return true;
  	}
  
  	/**
  	* @brief Get a unique name of the item for the specified user
  	* @param string Item
  	* @param string|false User the item is being shared with
  	* @param array|null List of similar item names already existing as shared items
  	* @return string Target name
  	*
  	* This function needs to verify that the user does not already have an item with this name.
  	* If it does generate a new name e.g. name_#
  	*/
  	public function generateTarget($itemSource, $shareWith, $exclude = null) {
  		$calendar = OC_Calendar_App::getCalendar( $itemSource );
  		$user_calendars = array();
  		foreach(OC_Calendar_Calendar::allCalendars($shareWith) as $user_calendar) {
  			$user_calendars[] = $user_calendar['displayname'];
  		}
  		$name = $calendar['userid']."'s ".$calendar['displayname'];
  		$suffix = '';
  		while (in_array($name.$suffix, $user_calendars)) {
  			$suffix++;
  		}
  
  		return $name.$suffix;
  	}
  
  	/**
  	* @brief Converts the shared item sources back into the item in the specified format
  	* @param array Shared items
  	* @param int Format
  	* @return ?
  	*
  	* The items array is a 3-dimensional array with the item_source as the first key and the share id as the second key to an array with the share info.
  	* The key/value pairs included in the share info depend on the function originally called:
  	* If called by getItem(s)Shared: id, item_type, item, item_source, share_type, share_with, permissions, stime, file_source
  	* If called by getItem(s)SharedWith: id, item_type, item, item_source, item_target, share_type, share_with, permissions, stime, file_source, file_target
  	* This function allows the backend to control the output of shared items with custom formats.
  	* It is only called through calls to the public getItem(s)Shared(With) functions.
  	*/
  	public function formatItems($items, $format, $parameters = null) {
  		$calendars = array();
  		if ($format == self::FORMAT_CALENDAR) {
  			foreach ($items as $item) {
  				$calendar = OC_Calendar_App::getCalendar($item['item_source'], false);
  				if(!$calendar) {
  					continue;
  				}
  				// TODO: really check $parameters['permissions'] == 'rw'/'r'
  				if ($parameters['permissions'] == 'rw') {
  					continue; // TODO
  				}
  				$calendar['displaynamename'] = $item['item_target'];
  				$calendar['permissions'] = $item['permissions'];
  				$calendar['calendarid'] = $calendar['id'];
  				$calendar['owner'] = $calendar['userid'];
  				$calendars[] = $calendar;
  			}
  		}
  		return $calendars;
  	}
  
  	public function getChildren($itemSource) {
  		$query = OCP\DB::prepare('SELECT `id`, `summary` FROM `*PREFIX*clndr_objects` WHERE `calendarid` = ?');
  		$result = $query->execute(array($itemSource));
  		$children = array();
  		while ($object = $result->fetchRow()) {
  			$children[] = array('source' => $object['id'], 'target' => $object['summary']);
  		}
  		return $children;
  	}
  
  }