<?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();

  	/**

  	 * walk up the users file tree and update the etags
  	 * @param string $user
  	 * @param string $path
  	 */
  	static private function correctUsersFolder($user, $path) {
  		// $path points to the mount point which is a virtual folder, so we start with
  		// the parent
  		$path = '/files' . dirname($path);
  		\OC\Files\Filesystem::initMountPoints($user);
  		$view = new \OC\Files\View('/' . $user);
  		if ($view->file_exists($path)) {
  			while ($path !== dirname($path)) {
  				$etag = $view->getETag($path);
  				$view->putFileInfo($path, array('etag' => $etag));
  				$path = dirname($path);
  			}
  		} else {
  			\OCP\Util::writeLog('files_sharing', 'can not update etags on ' . $path . ' for user ' . $user . '. Path does not exists', \OCP\Util::DEBUG);
  		}
  	}
  
  	/**

  	* Correct the parent folders' ETags for all users shared the file at $target
  	*
  	* @param string $target
  	*/
  	static public function correctFolders($target) {

  
  		// ignore part files
  		if (pathinfo($target, PATHINFO_EXTENSION) === 'part') {
  			return false;
  		}

  		// Correct Shared folders of other users shared with

  		$shares = \OCA\Files_Sharing\Helper::getSharesFromItem($target);
  
  		foreach ($shares as $share) {
  			if ((int)$share['share_type'] === \OCP\Share::SHARE_TYPE_USER) {
  				self::correctUsersFolder($share['share_with'], $share['file_target']);
  			} elseif ((int)$share['share_type'] === \OCP\Share::SHARE_TYPE_GROUP) {
  				$users = \OC_Group::usersInGroup($share['share_with']);

  				foreach ($users as $user) {

  					self::correctUsersFolder($user, $share['file_target']);

  				}

  			} else { //unique name for group share
  				self::correctUsersFolder($share['share_with'], $share['file_target']);

  			}
  		}
  	}
  
  	/**

  	 * 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));

  		self::renameChildren($params['oldpath'], $params['newpath']);

  	}
  
  	/**
  	 * @param array $params
  	 */
  	static public function deleteHook($params) {

  		$path = $params['path'];
  		self::correctFolders($path);
  
  		$fileInfo = \OC\Files\Filesystem::getFileInfo($path);

  		// mark file as deleted so that we can clean up the share table if
  		// the file was deleted successfully

  		self::$toRemove[$path] =  $fileInfo['fileid'];

  	}

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

  
  	/**

  	 * update etags if a file was shared
  	 * @param array $params
  	 */
  	static public function postShareHook($params) {
  
  		if ($params['itemType'] === 'folder' || $params['itemType'] === 'file') {
  
  			$shareWith = $params['shareWith'];
  			$shareType = $params['shareType'];
  
  			if ($shareType === \OCP\Share::SHARE_TYPE_USER) {
  				self::correctUsersFolder($shareWith, '/');
  			} elseif ($shareType === \OCP\Share::SHARE_TYPE_GROUP) {
  				foreach (\OC_Group::usersInGroup($shareWith) as $user) {
  					self::correctUsersFolder($user, '/');
  				}
  			}
  		}
  	}
  
  	/**
  	 * update etags if a file was unshared
  	 *

  	 * @param array $params
  	 */

  	static public function postUnshareHook($params) {

  		if ($params['itemType'] === 'file' || $params['itemType'] === 'folder') {

  
  			$deletedShares = isset($params['deletedShares']) ? $params['deletedShares'] : array();
  
  			foreach ($deletedShares as $share) {
  				if ($share['shareType'] === \OCP\Share::SHARE_TYPE_GROUP) {
  					foreach (\OC_Group::usersInGroup($share['shareWith']) as $user) {
  						self::correctUsersFolder($user, dirname($share['fileTarget']));
  					}
  				} else {
  					self::correctUsersFolder($share['shareWith'], dirname($share['fileTarget']));
  				}

  			}

  		}
  	}
  
  	/**
  	 * update etags if file was unshared from self
  	 * @param array $params
  	 */
  	static public function postUnshareFromSelfHook($params) {
  		if ($params['itemType'] === 'file' || $params['itemType'] === 'folder') {
  			foreach ($params['unsharedItems'] as $item) {
  				if ($item['shareType'] === \OCP\Share::SHARE_TYPE_GROUP) {
  					foreach (\OC_Group::usersInGroup($item['shareWith']) as $user) {
  						self::correctUsersFolder($user, dirname($item['fileTarget']));

  					}

  				} else {
  					self::correctUsersFolder($item['shareWith'], dirname($item['fileTarget']));

  				}
  			}
  		}
  	}

  	/**
  	 * clean up oc_share table from files which are no longer exists
  	 *
  	 * This fixes issues from updates from files_sharing < 0.3.5.6 (ownCloud 4.5)
  	 * It will just be called during the update of the app
  	 */
  	static public function fixBrokenSharesOnAppUpdate() {
  		// delete all shares where the original file no longer exists
  		$findAndRemoveShares = \OC_DB::prepare('DELETE FROM `*PREFIX*share` ' .
  			'WHERE `item_type` IN (\'file\', \'folder\') ' .
  			'AND `file_source` NOT IN (SELECT `fileid` FROM `*PREFIX*filecache`)'
  		);
  		$findAndRemoveShares->execute(array());
  	}
  
  	/**
  	 * rename mount point from the children if the parent was renamed
  	 * 
  	 * @param string $oldPath old path relative to data/user/files
  	 * @param string $newPath new path relative to data/user/files
  	 */
  	static private function renameChildren($oldPath, $newPath) {
  
  		$absNewPath =  \OC\Files\Filesystem::normalizePath('/' . \OCP\User::getUser() . '/files/' . $newPath);
  		$absOldPath =  \OC\Files\Filesystem::normalizePath('/' . \OCP\User::getUser() . '/files/' . $oldPath);
  
  		$mountManager = \OC\Files\Filesystem::getMountManager();
  		$mountedShares = $mountManager->findIn('/' . \OCP\User::getUser() . '/files/' . $oldPath);
  		foreach ($mountedShares as $mount) {
  			if ($mount->getStorage()->instanceOfStorage('OCA\Files_Sharing\ISharedStorage')) {
  				$mountPoint = $mount->getMountPoint();
  				$target = str_replace($absOldPath, $absNewPath, $mountPoint);
  				$mount->moveMount($target);
  			}
  		}
  	}

  }