<?php
  /**
   * ownCloud
   *
   * @author Michael Gapczynski
   * @copyright 2013 Michael Gapczynski mtgap@owncloud.com
   *
   * 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/>.
   */
  
  namespace OC\Files\Cache;
  
  class Shared_Updater {

  	// shares which can be removed from oc_share after the delete operation was successful
  	static private $toRemove = array();

  	/**
  	* Correct the parent folders' ETags for all users shared the file at $target
  	*
  	* @param string $target
  	*/
  	static public function correctFolders($target) {
  		$uid = \OCP\User::getUser();
  		$uidOwner = \OC\Files\Filesystem::getOwner($target);
  		$info = \OC\Files\Filesystem::getFileInfo($target);
  		$checkedUser = array($uidOwner);
  		// Correct Shared folders of other users shared with
  		$users = \OCP\Share::getUsersItemShared('file', $info['fileid'], $uidOwner, true);
  		if (!empty($users)) {
  			while (!empty($users)) {
  				$reshareUsers = array();
  				foreach ($users as $user) {
  					if ( !in_array($user, $checkedUser) ) {
  						$etag = \OC\Files\Filesystem::getETag('');
  						\OCP\Config::setUserValue($user, 'files_sharing', 'etag', $etag);
  						// Look for reshares
  						$reshareUsers = array_merge($reshareUsers, \OCP\Share::getUsersItemShared('file', $info['fileid'], $user, true));
  						$checkedUser[] = $user;
  					}
  				}
  				$users = $reshareUsers;
  			}
  		}
  	}
  
  	/**
  	 * @brief remove all shares for a given file if the file was deleted
  	 *
  	 * @param string $path
  	 */
  	private static function removeShare($path) {

  		$fileSource = self::$toRemove[$path];

  		if (!\OC\Files\Filesystem::file_exists($path)) {
  			$query = \OC_DB::prepare('DELETE FROM `*PREFIX*share` WHERE `file_source`=?');
  			try	{
  				\OC_DB::executeAudited($query, array($fileSource));
  			} catch (\Exception $e) {
  				\OCP\Util::writeLog('files_sharing', "can't remove share: " . $e->getMessage(), \OCP\Util::WARN);
  			}

  		}

  		unset(self::$toRemove[$path]);

  	}
  
  	/**
  	 * @param array $params
  	 */
  	static public function writeHook($params) {
  		self::correctFolders($params['path']);
  	}
  
  	/**
  	 * @param array $params
  	 */
  	static public function renameHook($params) {
  		self::correctFolders($params['newpath']);
  		self::correctFolders(pathinfo($params['oldpath'], PATHINFO_DIRNAME));
  	}
  
  	/**
  	 * @param array $params
  	 */
  	static public function deleteHook($params) {
  		self::correctFolders($params['path']);

  		$fileInfo = \OC\Files\Filesystem::getFileInfo($params['path']);
  		// mark file as deleted so that we can clean up the share table if
  		// the file was deleted successfully
  		self::$toRemove[$params['path']] =  $fileInfo['fileid'];

  	}

  	/**
  	 * @param array $params
  	 */
  	static public function postDeleteHook($params) {
  		self::removeShare($params['path']);
  	}

  
  	/**
  	 * @param array $params
  	 */
  	static public function shareHook($params) {
  		if ($params['itemType'] === 'file' || $params['itemType'] === 'folder') {

  			if (isset($params['uidOwner'])) {
  				$uidOwner = $params['uidOwner'];
  			} else {
  				$uidOwner = \OCP\User::getUser();
  			}
  			$users = \OCP\Share::getUsersItemShared($params['itemType'], $params['fileSource'], $uidOwner, true, false);

  			if (!empty($users)) {
  				while (!empty($users)) {
  					$reshareUsers = array();
  					foreach ($users as $user) {
  						if ($user !== $uidOwner) {
  							$etag = \OC\Files\Filesystem::getETag('');
  							\OCP\Config::setUserValue($user, 'files_sharing', 'etag', $etag);
  							// Look for reshares
  							$reshareUsers = array_merge($reshareUsers, \OCP\Share::getUsersItemShared('file', $params['fileSource'], $user, true));
  						}
  					}
  					$users = $reshareUsers;
  				}
  			}
  		}
  	}
  
  }