<?php
/**
 * @author Björn Schießle <schiessle@owncloud.com>
 * @author Joas Schilling <nickvergessen@owncloud.com>
 * @author Michael Gapczynski <GapczynskiM@gmail.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Roeland Jago Douma <rullzer@owncloud.com>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @copyright Copyright (c) 2016, ownCloud, Inc.
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program 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, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC\Files\Cache;

class Shared_Updater {

	/**
	 * Walk up the users file tree and update the etags.
	 *
	 * @param string $user user id
	 * @param string $path share mount point path, relative to the user's "files" folder
	 */
	static private function correctUsersFolder($user, $path) {
		// $path points to the mount point which is a virtual folder, so we start with
		// the parent
		$path = '/' . ltrim($path, '/');
		$path = '/files' . dirname($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);
		}
	}

	/**
	 * @param array $params
	 */
	static public function renameHook($params) {
		self::renameChildren($params['oldpath'], $params['newpath']);
		self::moveShareToShare($params['newpath']);
	}

	/**
	 * Fix for https://github.com/owncloud/core/issues/20769
	 *
	 * The owner is allowed to move their files (if they are shared) into a receiving folder
	 * In this case we need to update the parent of the moved share. Since they are
	 * effectively handing over ownership of the file the rest of the code needs to know
	 * they need to build up the reshare tree.
	 *
	 * @param string $path
	 */
	static private function moveShareToShare($path) {
		$userFolder = \OC::$server->getUserFolder();

		// If the user folder can't be constructed (e.g. link share) just return.
		if ($userFolder === null) {
			return;
		}

		$src = $userFolder->get($path);

		$shareManager = \OC::$server->getShareManager();

		$shares = $shareManager->getSharesBy($userFolder->getOwner()->getUID(), \OCP\Share::SHARE_TYPE_USER, $src, false, -1);
		$shares = array_merge($shares, $shareManager->getSharesBy($userFolder->getOwner()->getUID(), \OCP\Share::SHARE_TYPE_GROUP, $src, false, -1));

		// If the path we move is not a share we don't care
		if (empty($shares)) {
			return;
		}

		// Check if the destination is inside a share
		$mountManager = \OC::$server->getMountManager();
		$dstMount = $mountManager->find($src->getPath());
		if (!($dstMount instanceof \OCA\Files_Sharing\SharedMount)) {
			return;
		}

		$newOwner = $dstMount->getShare()->getShareOwner();

		//Ownership is moved over
		foreach ($shares as $share) {
			/** @var \OCP\Share\IShare $share */
			$share->setShareOwner($newOwner);
			$shareManager->updateShare($share);
		}
	}

	/**
	 * @param array $params
	 */
	static public function deleteHook($params) {
		$path = $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, $params['fileTarget']);
			} elseif ($shareType === \OCP\Share::SHARE_TYPE_GROUP) {
				foreach (\OC_Group::usersInGroup($shareWith) as $user) {
					self::correctUsersFolder($user, $params['fileTarget']);
				}
			}
		}
	}

	/**
	 * update etags if a file was unshared
	 *
	 * @param array $params
	 */
	static public function postUnshareHook($params) {

		// only update etags for file/folders shared to local users/groups
		if (($params['itemType'] === 'file' || $params['itemType'] === 'folder') &&
				$params['shareType'] !== \OCP\Share::SHARE_TYPE_LINK &&
				$params['shareType'] !== \OCP\Share::SHARE_TYPE_REMOTE) {

			$deletedShares = isset($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, $share['fileTarget']);
					}
				} else {
					self::correctUsersFolder($share['shareWith'], $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, $item['fileTarget']);
					}
				} else {
					self::correctUsersFolder($item['shareWith'], $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 = \OCP\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);
			}
		}
	}

}