<?php
  /**
   * Copyright (c) 2012 Robin Appelman <icewind@owncloud.com>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  /**
   * Class for abstraction of filesystem functions

   * This class won't call any filesystem functions for itself but will pass them to the correct OC_Filestorage object

   * this class should also handle all the file permission related stuff
   *
   * Hooks provided:
   *   read(path)
   *   write(path, &run)
   *   post_write(path)
   *   create(path, &run) (when a file is created, both create and write will be emitted in that order)
   *   post_create(path)
   *   delete(path, &run)
   *   post_delete(path)
   *   rename(oldpath,newpath, &run)
   *   post_rename(oldpath,newpath)
   *   copy(oldpath,newpath, &run) (if the newpath doesn't exists yes, copy, create and write will be emitted in that order)
   *   post_rename(oldpath,newpath)
   *   post_initMountPoints(user, user_dir)
   *
   *   the &run parameter can be set to false to prevent the operation from occurring
   */
  
  namespace OC\Files;

  use OC\Files\Storage\Loader;
  const SPACE_NOT_COMPUTED = -1;
  const SPACE_UNKNOWN = -2;
  const SPACE_UNLIMITED = -3;

  
  class Filesystem {

  	/**
  	 * @var Mount\Manager $mounts
  	 */
  	private static $mounts;

  	public static $loaded = false;
  	/**
  	 * @var \OC\Files\View $defaultInstance
  	 */
  	static private $defaultInstance;
  
  
  	/**
  	 * classname which used for hooks handling
  	 * used as signalclass in OC_Hooks::emit()
  	 */
  	const CLASSNAME = 'OC_Filesystem';
  
  	/**
  	 * signalname emitted before file renaming
  	 *
  	 * @param string $oldpath
  	 * @param string $newpath
  	 */
  	const signal_rename = 'rename';
  
  	/**
  	 * signal emitted after file renaming
  	 *
  	 * @param string $oldpath
  	 * @param string $newpath
  	 */
  	const signal_post_rename = 'post_rename';
  
  	/**
  	 * signal emitted before file/dir creation
  	 *
  	 * @param string $path
  	 * @param bool $run changing this flag to false in hook handler will cancel event
  	 */
  	const signal_create = 'create';
  
  	/**
  	 * signal emitted after file/dir creation
  	 *
  	 * @param string $path
  	 * @param bool $run changing this flag to false in hook handler will cancel event
  	 */
  	const signal_post_create = 'post_create';
  
  	/**
  	 * signal emits before file/dir copy
  	 *
  	 * @param string $oldpath
  	 * @param string $newpath
  	 * @param bool $run changing this flag to false in hook handler will cancel event
  	 */
  	const signal_copy = 'copy';
  
  	/**
  	 * signal emits after file/dir copy
  	 *
  	 * @param string $oldpath
  	 * @param string $newpath
  	 */
  	const signal_post_copy = 'post_copy';
  
  	/**
  	 * signal emits before file/dir save
  	 *
  	 * @param string $path
  	 * @param bool $run changing this flag to false in hook handler will cancel event
  	 */
  	const signal_write = 'write';
  
  	/**
  	 * signal emits after file/dir save
  	 *
  	 * @param string $path
  	 */
  	const signal_post_write = 'post_write';
  
  	/**

  	 * signal emitted before file/dir update
  	 *
  	 * @param string $path
  	 * @param bool $run changing this flag to false in hook handler will cancel event
  	 */
  	const signal_update = 'update';
  
  	/**
  	 * signal emitted after file/dir update
  	 *
  	 * @param string $path
  	 * @param bool $run changing this flag to false in hook handler will cancel event
  	 */
  	const signal_post_update = 'post_update';
  
  	/**

  	 * signal emits when reading file/dir
  	 *
  	 * @param string $path
  	 */
  	const signal_read = 'read';
  
  	/**
  	 * signal emits when removing file/dir
  	 *
  	 * @param string $path
  	 */
  	const signal_delete = 'delete';
  
  	/**
  	 * parameters definitions for signals
  	 */
  	const signal_param_path = 'path';
  	const signal_param_oldpath = 'oldpath';
  	const signal_param_newpath = 'newpath';
  
  	/**
  	 * run - changing this flag to false in hook handler will cancel event
  	 */
  	const signal_param_run = 'run';
  
  	/**

  	 * @var \OC\Files\Storage\Loader $loader
  	 */
  	private static $loader;
  
  	/**
  	 * @param callable $wrapper
  	 */

  	public static function addStorageWrapper($wrapperName, $wrapper) {
  		self::getLoader()->addStorageWrapper($wrapperName, $wrapper);

  
  		$mounts = self::getMountManager()->getAll();
  		foreach ($mounts as $mount) {
  			$mount->wrapStorage($wrapper);
  		}
  	}
  
  	public static function getLoader() {
  		if (!self::$loader) {
  			self::$loader = new Loader();
  		}
  		return self::$loader;
  	}
  
  	public static function getMountManager() {
  		if (!self::$mounts) {
  			\OC_Util::setupFS();
  		}
  		return self::$mounts;
  	}
  
  	/**

  	 * get the mountpoint of the storage object for a path
  	 * ( note: because a storage is not always mounted inside the fakeroot, the
  	 * returned mountpoint is relative to the absolute root of the filesystem
  	 * and doesn't take the chroot into account )
  	 *
  	 * @param string $path
  	 * @return string
  	 */
  	static public function getMountPoint($path) {

  		if (!self::$mounts) {
  			\OC_Util::setupFS();
  		}
  		$mount = self::$mounts->find($path);

  		if ($mount) {
  			return $mount->getMountPoint();
  		} else {
  			return '';
  		}
  	}
  
  	/**
  	 * get a list of all mount points in a directory
  	 *
  	 * @param string $path
  	 * @return string[]
  	 */
  	static public function getMountPoints($path) {

  		if (!self::$mounts) {
  			\OC_Util::setupFS();
  		}

  		$result = array();

  		$mounts = self::$mounts->findIn($path);

  		foreach ($mounts as $mount) {
  			$result[] = $mount->getMountPoint();
  		}
  		return $result;
  	}
  
  	/**
  	 * get the storage mounted at $mountPoint
  	 *
  	 * @param string $mountPoint
  	 * @return \OC\Files\Storage\Storage
  	 */
  	public static function getStorage($mountPoint) {

  		if (!self::$mounts) {
  			\OC_Util::setupFS();
  		}
  		$mount = self::$mounts->find($mountPoint);

  		return $mount->getStorage();
  	}
  
  	/**

  	 * @param string $id

  	 * @return Mount\Mount[]
  	 */
  	public static function getMountByStorageId($id) {
  		if (!self::$mounts) {
  			\OC_Util::setupFS();
  		}
  		return self::$mounts->findByStorageId($id);
  	}
  
  	/**

  	 * @param int $id

  	 * @return Mount\Mount[]
  	 */
  	public static function getMountByNumericId($id) {
  		if (!self::$mounts) {
  			\OC_Util::setupFS();
  		}
  		return self::$mounts->findByNumericId($id);
  	}
  
  	/**

  	 * resolve a path to a storage and internal path
  	 *
  	 * @param string $path

  	 * @return array an array consisting of the storage and the internal path

  	 */
  	static public function resolvePath($path) {

  		if (!self::$mounts) {
  			\OC_Util::setupFS();
  		}
  		$mount = self::$mounts->find($path);

  		if ($mount) {
  			return array($mount->getStorage(), $mount->getInternalPath($path));
  		} else {
  			return array(null, null);
  		}
  	}
  
  	static public function init($user, $root) {
  		if (self::$defaultInstance) {
  			return false;
  		}

  		self::getLoader();

  		self::$defaultInstance = new View($root);

  		if (!self::$mounts) {
  			self::$mounts = new Mount\Manager();
  		}

  		//load custom mount config
  		self::initMountPoints($user);
  
  		self::$loaded = true;
  
  		return true;
  	}

  	static public function initMounts() {
  		if (!self::$mounts) {
  			self::$mounts = new Mount\Manager();
  		}
  	}

  	/**
  	 * Initialize system and personal mount points for a user
  	 *
  	 * @param string $user
  	 */
  	public static function initMountPoints($user = '') {
  		if ($user == '') {
  			$user = \OC_User::getUser();
  		}
  		$parser = new \OC\ArrayParser();
  
  		$root = \OC_User::getHome($user);

  
  		$userObject = \OC_User::getManager()->get($user);
  
  		if (!is_null($userObject)) {

  			$homeStorage = \OC_Config::getValue( 'objectstore' );
  			if (!empty($homeStorage)) {
  				// sanity checks
  				if (empty($homeStorage['class'])) {
  					\OCP\Util::writeLog('files', 'No class given for objectstore', \OCP\Util::ERROR);
  				}
  				if (!isset($homeStorage['arguments'])) {
  					$homeStorage['arguments'] = array();
  				}
  				// instantiate object store implementation
  				$homeStorage['arguments']['objectstore'] = new $homeStorage['class']($homeStorage['arguments']);
  				// mount with home object store implementation
  				$homeStorage['class'] = '\OC\Files\ObjectStore\HomeObjectStoreStorage';
  			} else {
  				$homeStorage = array(
  					//default home storage configuration:
  					'class' => '\OC\Files\Storage\Home',
  					'arguments' => array()
  				);
  			}
  			$homeStorage['arguments']['user'] = $userObject;

  			// check for legacy home id (<= 5.0.12)
  			if (\OC\Files\Cache\Storage::exists('local::' . $root . '/')) {

  				$homeStorage['arguments']['legacy'] = true;

  			}

  
  			self::mount($homeStorage['class'], $homeStorage['arguments'], $user);
  
  			$home = \OC\Files\Filesystem::getStorage($user);

  		}
  		else {

  			self::mount('\OC\Files\Storage\Local', array('datadir' => $root), $user);

  		}

  		self::mountCacheDir($user);

  
  		// Chance to mount for other storages
  		\OC_Hook::emit('OC_Filesystem', 'post_initMountPoints', array('user' => $user, 'user_dir' => $root));
  	}
  
  	/**

  	 * Mounts the cache directory
  	 * @param string $user user name

  	 */

  	private static function mountCacheDir($user) {
  		$cacheBaseDir = \OC_Config::getValue('cache_path', '');
  		if ($cacheBaseDir === '') {
  			// use local cache dir relative to the user's home
  			$subdir = 'cache';
  			$view = new \OC\Files\View('/' . $user);
  			if(!$view->file_exists($subdir)) {
  				$view->mkdir($subdir);
  			}
  		} else {
  			$cacheDir = rtrim($cacheBaseDir, '/') . '/' . $user;
  			if (!file_exists($cacheDir)) {
  				mkdir($cacheDir, 0770, true);
  			}
  			// mount external cache dir to "/$user/cache" mount point
  			self::mount('\OC\Files\Storage\Local', array('datadir' => $cacheDir), '/' . $user . '/cache');
  		}

  	}
  
  	/**
  	 * get the default filesystem view
  	 *
  	 * @return View
  	 */
  	static public function getView() {
  		return self::$defaultInstance;
  	}
  
  	/**
  	 * tear down the filesystem, removing all storage providers
  	 */
  	static public function tearDown() {
  		self::clearMounts();
  		self::$defaultInstance = null;
  	}
  
  	/**

  	 * get the relative path of the root data directory for the current user

  	 * @return string
  	 *
  	 * Returns path like /admin/files
  	 */
  	static public function getRoot() {

  		if (!self::$defaultInstance) {
  			return null;
  		}

  		return self::$defaultInstance->getRoot();
  	}
  
  	/**
  	 * clear all mounts and storage backends
  	 */
  	public static function clearMounts() {

  		if (self::$mounts) {
  			self::$mounts->clear();
  		}

  	}
  
  	/**
  	 * mount an \OC\Files\Storage\Storage in our virtual filesystem
  	 *
  	 * @param \OC\Files\Storage\Storage|string $class
  	 * @param array $arguments
  	 * @param string $mountpoint
  	 */
  	static public function mount($class, $arguments, $mountpoint) {

  		if (!self::$mounts) {
  			\OC_Util::setupFS();
  		}
  		$mount = new Mount\Mount($class, $mountpoint, $arguments, self::getLoader());
  		self::$mounts->addMount($mount);

  	}
  
  	/**
  	 * return the path to a local version of the file
  	 * we need this because we can't know if a file is stored local or not from
  	 * outside the filestorage and for some purposes a local file is needed
  	 *
  	 * @param string $path
  	 * @return string
  	 */
  	static public function getLocalFile($path) {
  		return self::$defaultInstance->getLocalFile($path);
  	}
  
  	/**
  	 * @param string $path
  	 * @return string
  	 */
  	static public function getLocalFolder($path) {
  		return self::$defaultInstance->getLocalFolder($path);
  	}
  
  	/**
  	 * return path to file which reflects one visible in browser
  	 *
  	 * @param string $path
  	 * @return string
  	 */
  	static public function getLocalPath($path) {
  		$datadir = \OC_User::getHome(\OC_User::getUser()) . '/files';
  		$newpath = $path;
  		if (strncmp($newpath, $datadir, strlen($datadir)) == 0) {
  			$newpath = substr($path, strlen($datadir));
  		}
  		return $newpath;
  	}
  
  	/**
  	 * check if the requested path is valid
  	 *
  	 * @param string $path
  	 * @return bool
  	 */
  	static public function isValidPath($path) {
  		$path = self::normalizePath($path);
  		if (!$path || $path[0] !== '/') {
  			$path = '/' . $path;
  		}
  		if (strstr($path, '/../') || strrchr($path, '/') === '/..') {
  			return false;
  		}
  		return true;
  	}
  
  	/**
  	 * checks if a file is blacklisted for storage in the filesystem
  	 * Listens to write and rename hooks
  	 *
  	 * @param array $data from hook
  	 */
  	static public function isBlacklisted($data) {
  		if (isset($data['path'])) {
  			$path = $data['path'];
  		} else if (isset($data['newpath'])) {
  			$path = $data['newpath'];
  		}
  		if (isset($path)) {
  			if (self::isFileBlacklisted($path)) {
  				$data['run'] = false;
  			}
  		}
  	}
  
  	/**
  	 * @param string $filename
  	 * @return bool
  	 */
  	static public function isFileBlacklisted($filename) {
  		$blacklist = \OC_Config::getValue('blacklisted_files', array('.htaccess'));
  		$filename = strtolower(basename($filename));
  		return (in_array($filename, $blacklist));
  	}
  
  	/**

  	 * check if the directory should be ignored when scanning

  	 * NOTE: the special directories . and .. would cause never ending recursion
  	 * @param String $dir
  	 * @return boolean
  	 */
  	static public function isIgnoredDir($dir) {
  		if ($dir === '.' || $dir === '..') {
  			return true;
  		}
  		return false;
  	}
  
  	/**
  	 * following functions are equivalent to their php builtin equivalents for arguments/return values.
  	 */
  	static public function mkdir($path) {
  		return self::$defaultInstance->mkdir($path);
  	}
  
  	static public function rmdir($path) {
  		return self::$defaultInstance->rmdir($path);
  	}
  
  	static public function opendir($path) {
  		return self::$defaultInstance->opendir($path);
  	}
  
  	static public function readdir($path) {
  		return self::$defaultInstance->readdir($path);
  	}
  
  	static public function is_dir($path) {
  		return self::$defaultInstance->is_dir($path);
  	}
  
  	static public function is_file($path) {
  		return self::$defaultInstance->is_file($path);
  	}
  
  	static public function stat($path) {
  		return self::$defaultInstance->stat($path);
  	}
  
  	static public function filetype($path) {
  		return self::$defaultInstance->filetype($path);
  	}
  
  	static public function filesize($path) {
  		return self::$defaultInstance->filesize($path);
  	}
  
  	static public function readfile($path) {
  		return self::$defaultInstance->readfile($path);
  	}
  
  	static public function isCreatable($path) {
  		return self::$defaultInstance->isCreatable($path);
  	}
  
  	static public function isReadable($path) {
  		return self::$defaultInstance->isReadable($path);
  	}
  
  	static public function isUpdatable($path) {
  		return self::$defaultInstance->isUpdatable($path);
  	}
  
  	static public function isDeletable($path) {
  		return self::$defaultInstance->isDeletable($path);
  	}
  
  	static public function isSharable($path) {
  		return self::$defaultInstance->isSharable($path);
  	}
  
  	static public function file_exists($path) {
  		return self::$defaultInstance->file_exists($path);
  	}
  
  	static public function filemtime($path) {
  		return self::$defaultInstance->filemtime($path);
  	}
  
  	static public function touch($path, $mtime = null) {
  		return self::$defaultInstance->touch($path, $mtime);
  	}

  	/**
  	 * @return string
  	 */

  	static public function file_get_contents($path) {
  		return self::$defaultInstance->file_get_contents($path);
  	}
  
  	static public function file_put_contents($path, $data) {
  		return self::$defaultInstance->file_put_contents($path, $data);
  	}
  
  	static public function unlink($path) {
  		return self::$defaultInstance->unlink($path);
  	}
  
  	static public function rename($path1, $path2) {
  		return self::$defaultInstance->rename($path1, $path2);
  	}
  
  	static public function copy($path1, $path2) {
  		return self::$defaultInstance->copy($path1, $path2);
  	}
  
  	static public function fopen($path, $mode) {
  		return self::$defaultInstance->fopen($path, $mode);
  	}

  	/**
  	 * @return string
  	 */

  	static public function toTmpFile($path) {
  		return self::$defaultInstance->toTmpFile($path);
  	}
  
  	static public function fromTmpFile($tmpFile, $path) {
  		return self::$defaultInstance->fromTmpFile($tmpFile, $path);
  	}
  
  	static public function getMimeType($path) {
  		return self::$defaultInstance->getMimeType($path);
  	}
  
  	static public function hash($type, $path, $raw = false) {
  		return self::$defaultInstance->hash($type, $path, $raw);
  	}
  
  	static public function free_space($path = '/') {
  		return self::$defaultInstance->free_space($path);
  	}
  
  	static public function search($query) {
  		return self::$defaultInstance->search($query);
  	}

  	/**
  	 * @param string $query
  	 */

  	static public function searchByMime($query) {
  		return self::$defaultInstance->searchByMime($query);
  	}
  
  	/**
  	 * check if a file or folder has been updated since $time
  	 *
  	 * @param string $path
  	 * @param int $time
  	 * @return bool
  	 */
  	static public function hasUpdated($path, $time) {
  		return self::$defaultInstance->hasUpdated($path, $time);
  	}
  
  	/**

  	 * Fix common problems with a file path

  	 * @param string $path
  	 * @param bool $stripTrailingSlash
  	 * @return string
  	 */
  	public static function normalizePath($path, $stripTrailingSlash = true) {
  		if ($path == '') {
  			return '/';
  		}
  		//no windows style slashes
  		$path = str_replace('\\', '/', $path);

  		//add leading slash
  		if ($path[0] !== '/') {
  			$path = '/' . $path;
  		}

  
  		// remove '/./'
  		// ugly, but str_replace() can't replace them all in one go
  		// as the replacement itself is part of the search string
  		// which will only be found during the next iteration
  		while (strpos($path, '/./') !== false) {
  			$path = str_replace('/./', '/', $path);

  		}

  		// remove sequences of slashes
  		$path = preg_replace('#/{2,}#', '/', $path);

  		//remove trailing slash
  		if ($stripTrailingSlash and strlen($path) > 1 and substr($path, -1, 1) === '/') {
  			$path = substr($path, 0, -1);
  		}

  
  		// remove trailing '/.'
  		if (substr($path, -2) == '/.') {
  			$path = substr($path, 0, -2);
  		}

  		//normalize unicode if possible
  		$path = \OC_Util::normalizeUnicode($path);

  		return $path;
  	}
  
  	/**
  	 * get the filesystem info
  	 *
  	 * @param string $path

  	 * @param boolean $includeMountPoints whether to add mountpoint sizes,
  	 * defaults to true

  	 * @return \OC\Files\FileInfo

  	 */

  	public static function getFileInfo($path, $includeMountPoints = true) {
  		return self::$defaultInstance->getFileInfo($path, $includeMountPoints);

  	}
  
  	/**
  	 * change file metadata
  	 *
  	 * @param string $path
  	 * @param array $data
  	 * @return int
  	 *
  	 * returns the fileid of the updated file
  	 */
  	public static function putFileInfo($path, $data) {
  		return self::$defaultInstance->putFileInfo($path, $data);
  	}
  
  	/**
  	 * get the content of a directory
  	 *
  	 * @param string $directory path under datadirectory

  	 * @param string $mimetype_filter limit returned content to this mimetype or mimepart

  	 * @return \OC\Files\FileInfo[]

  	 */

  	public static function getDirectoryContent($directory, $mimetype_filter = '') {
  		return self::$defaultInstance->getDirectoryContent($directory, $mimetype_filter);

  	}
  
  	/**
  	 * Get the path of a file by id
  	 *

  	 * Note that the resulting path is not guaranteed to be unique for the id, multiple paths can point to the same file

  	 *
  	 * @param int $id
  	 * @return string
  	 */
  	public static function getPath($id) {
  		return self::$defaultInstance->getPath($id);
  	}
  
  	/**
  	 * Get the owner for a file or folder
  	 *
  	 * @param string $path
  	 * @return string
  	 */
  	public static function getOwner($path) {
  		return self::$defaultInstance->getOwner($path);
  	}
  
  	/**
  	 * get the ETag for a file or folder
  	 *
  	 * @param string $path
  	 * @return string
  	 */
  	static public function getETag($path) {
  		return self::$defaultInstance->getETag($path);
  	}
  }
  
  \OC_Util::setupFS();