<?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.
   */
  
  namespace OC\Files\Storage;

  use OC\Files\Filesystem;
  use OC\Files\Cache\Watcher;

  /**
   * Storage backend class for providing common filesystem operation methods
   * which are not storage-backend specific.
   *
   * \OC\Files\Storage\Common is never used directly; it is extended by all other
   * storage backends, where its methods may be overridden, and additional
   * (backend-specific) methods are defined.
   *
   * Some \OC\Files\Storage\Common methods call functions which are first defined
   * in classes which extend it, e.g. $this->stat() .
   */

  abstract class Common implements \OC\Files\Storage\Storage {

  	protected $cache;
  	protected $scanner;
  	protected $permissioncache;
  	protected $watcher;
  	protected $storageCache;

  	/**
  	 * @var string[]
  	 */
  	protected $cachedFiles = array();

  	public function __construct($parameters) {
  	}

  	/**
  	 * Remove a file of folder
  	 *
  	 * @param string $path
  	 * @return bool
  	 */
  	protected function remove($path) {
  		if ($this->is_dir($path)) {
  			return $this->rmdir($path);
  		} else if ($this->is_file($path)) {
  			return $this->unlink($path);
  		} else {
  			return false;
  		}
  	}

  	public function is_dir($path) {
  		return $this->filetype($path) == 'dir';
  	}
  
  	public function is_file($path) {
  		return $this->filetype($path) == 'file';
  	}
  
  	public function filesize($path) {
  		if ($this->is_dir($path)) {
  			return 0; //by definition
  		} else {
  			$stat = $this->stat($path);
  			if (isset($stat['size'])) {
  				return $stat['size'];
  			} else {
  				return 0;
  			}
  		}
  	}

  	public function isReadable($path) {
  		// at least check whether it exists
  		// subclasses might want to implement this more thoroughly
  		return $this->file_exists($path);
  	}
  
  	public function isUpdatable($path) {
  		// at least check whether it exists
  		// subclasses might want to implement this more thoroughly
  		// a non-existing file/folder isn't updatable
  		return $this->file_exists($path);
  	}

  	public function isCreatable($path) {
  		if ($this->is_dir($path) && $this->isUpdatable($path)) {
  			return true;
  		}
  		return false;
  	}
  
  	public function isDeletable($path) {
  		return $this->isUpdatable($path);
  	}
  
  	public function isSharable($path) {

  		if (\OC_Util::isSharingDisabledForUser()) {
  			return false;
  		}

  		return $this->isReadable($path);
  	}
  
  	public function getPermissions($path) {
  		$permissions = 0;
  		if ($this->isCreatable($path)) {
  			$permissions |= \OCP\PERMISSION_CREATE;
  		}
  		if ($this->isReadable($path)) {
  			$permissions |= \OCP\PERMISSION_READ;
  		}
  		if ($this->isUpdatable($path)) {
  			$permissions |= \OCP\PERMISSION_UPDATE;
  		}
  		if ($this->isDeletable($path)) {
  			$permissions |= \OCP\PERMISSION_DELETE;
  		}
  		if ($this->isSharable($path)) {
  			$permissions |= \OCP\PERMISSION_SHARE;
  		}
  		return $permissions;
  	}
  
  	public function filemtime($path) {
  		$stat = $this->stat($path);
  		if (isset($stat['mtime'])) {
  			return $stat['mtime'];
  		} else {
  			return 0;
  		}
  	}
  
  	public function file_get_contents($path) {
  		$handle = $this->fopen($path, "r");
  		if (!$handle) {
  			return false;
  		}

  		$data = stream_get_contents($handle);
  		fclose($handle);
  		return $data;

  	}
  
  	public function file_put_contents($path, $data) {
  		$handle = $this->fopen($path, "w");

  		$this->removeCachedFile($path);
  		$count = fwrite($handle, $data);
  		fclose($handle);
  		return $count;

  	}
  
  	public function rename($path1, $path2) {

  		$this->remove($path2);

  		$this->removeCachedFile($path1);
  		return $this->copy($path1, $path2) and $this->remove($path1);

  	}

  	public function copy($path1, $path2) {
  		if ($this->is_dir($path1)) {
  			$this->remove($path2);
  			$dir = $this->opendir($path1);
  			$this->mkdir($path2);
  			while ($file = readdir($dir)) {
  				if (!Filesystem::isIgnoredDir($file)) {
  					if (!$this->copy($path1 . '/' . $file, $path2 . '/' . $file)) {
  						return false;

  					}
  				}
  			}

  			closedir($dir);

  			return true;

  		} else {
  			$source = $this->fopen($path1, 'r');
  			$target = $this->fopen($path2, 'w');
  			list(, $result) = \OC_Helper::streamCopy($source, $target);
  			$this->removeCachedFile($path2);
  			return $result;

  		}

  	}
  
  	public function getMimeType($path) {

  		if ($this->is_dir($path)) {
  			return 'httpd/unix-directory';

  		} elseif ($this->file_exists($path)) {
  			return \OC_Helper::getFileNameMimeType($path);

  		} else {

  			return false;

  		}

  	}
  
  	public function hash($type, $path, $raw = false) {

  		$fh = $this->fopen($path, 'rb');
  		$ctx = hash_init($type);
  		hash_update_stream($ctx, $fh);
  		fclose($fh);
  		return hash_final($ctx, $raw);

  	}
  
  	public function search($query) {
  		return $this->searchInDir($query);
  	}
  
  	public function getLocalFile($path) {

  		return $this->getCachedFile($path);

  	}

  	/**
  	 * @param string $path
  	 * @return string
  	 */
  	protected function toTmpFile($path) { //no longer in the storage api, still useful here

  		$source = $this->fopen($path, 'r');
  		if (!$source) {
  			return false;
  		}
  		if ($pos = strrpos($path, '.')) {
  			$extension = substr($path, $pos);
  		} else {
  			$extension = '';
  		}
  		$tmpFile = \OC_Helper::tmpFile($extension);
  		$target = fopen($tmpFile, 'w');
  		\OC_Helper::streamCopy($source, $target);
  		return $tmpFile;
  	}
  
  	public function getLocalFolder($path) {
  		$baseDir = \OC_Helper::tmpFolder();
  		$this->addLocalFolder($path, $baseDir);
  		return $baseDir;
  	}

  	/**
  	 * @param string $path
  	 * @param string $target
  	 */

  	private function addLocalFolder($path, $target) {

  		$dh = $this->opendir($path);
  		if (is_resource($dh)) {

  			while (($file = readdir($dh)) !== false) {
  				if ($file !== '.' and $file !== '..') {
  					if ($this->is_dir($path . '/' . $file)) {
  						mkdir($target . '/' . $file);
  						$this->addLocalFolder($path . '/' . $file, $target . '/' . $file);
  					} else {
  						$tmp = $this->toTmpFile($path . '/' . $file);
  						rename($tmp, $target . '/' . $file);
  					}
  				}
  			}
  		}
  	}

  	/**
  	 * @param string $query
  	 */

  	protected function searchInDir($query, $dir = '') {
  		$files = array();
  		$dh = $this->opendir($dir);
  		if (is_resource($dh)) {
  			while (($item = readdir($dh)) !== false) {
  				if ($item == '.' || $item == '..') continue;
  				if (strstr(strtolower($item), strtolower($query)) !== false) {
  					$files[] = $dir . '/' . $item;
  				}
  				if ($this->is_dir($dir . '/' . $item)) {
  					$files = array_merge($files, $this->searchInDir($query, $dir . '/' . $item));
  				}
  			}
  		}
  		return $files;
  	}
  
  	/**
  	 * check if a file or folder has been updated since $time
  	 *

  	 * The method is only used to check if the cache needs to be updated. Storage backends that don't support checking
  	 * the mtime should always return false here. As a result storage implementations that always return false expect
  	 * exclusive access to the backend and will not pick up files that have been added in a way that circumvents
  	 * ownClouds filesystem.
  	 *

  	 * @param string $path
  	 * @param int $time
  	 * @return bool
  	 */
  	public function hasUpdated($path, $time) {
  		return $this->filemtime($path) > $time;
  	}

  	public function getCache($path = '', $storage = null) {
  		if (!$storage) {
  			$storage = $this;
  		}

  		if (!isset($this->cache)) {

  			$this->cache = new \OC\Files\Cache\Cache($storage);

  		}
  		return $this->cache;
  	}

  	public function getScanner($path = '', $storage = null) {
  		if (!$storage) {
  			$storage = $this;
  		}

  		if (!isset($this->scanner)) {

  			$this->scanner = new \OC\Files\Cache\Scanner($storage);

  		}
  		return $this->scanner;
  	}

  	public function getWatcher($path = '', $storage = null) {
  		if (!$storage) {
  			$storage = $this;

  		}

  		if (!isset($this->watcher)) {

  			$this->watcher = new \OC\Files\Cache\Watcher($storage);
  			$this->watcher->setPolicy(\OC::$server->getConfig()->getSystemValue('filesystem_check_changes', Watcher::CHECK_ONCE));

  		}
  		return $this->watcher;
  	}

  	public function getStorageCache($storage = null) {
  		if (!$storage) {
  			$storage = $this;
  		}

  		if (!isset($this->storageCache)) {

  			$this->storageCache = new \OC\Files\Cache\Storage($storage);

  		}
  		return $this->storageCache;
  	}

  	/**
  	 * get the owner of a path
  	 *
  	 * @param string $path The path to get the owner
  	 * @return string uid or false
  	 */
  	public function getOwner($path) {
  		return \OC_User::getUser();
  	}
  
  	/**
  	 * get the ETag for a file or folder
  	 *
  	 * @param string $path
  	 * @return string
  	 */
  	public function getETag($path) {
  		$ETagFunction = \OC_Connector_Sabre_Node::$ETagFunction;
  		if ($ETagFunction) {
  			$hash = call_user_func($ETagFunction, $path);
  			return $hash;
  		} else {
  			return uniqid();
  		}
  	}
  
  	/**
  	 * clean a path, i.e. remove all redundant '.' and '..'
  	 * making sure that it can't point to higher than '/'
  	 *

  	 * @param string $path The path to clean

  	 * @return string cleaned path
  	 */
  	public function cleanPath($path) {
  		if (strlen($path) == 0 or $path[0] != '/') {
  			$path = '/' . $path;
  		}
  
  		$output = array();
  		foreach (explode('/', $path) as $chunk) {
  			if ($chunk == '..') {
  				array_pop($output);
  			} else if ($chunk == '.') {
  			} else {
  				$output[] = $chunk;
  			}
  		}
  		return implode('/', $output);
  	}
  
  	public function test() {
  		if ($this->stat('')) {
  			return true;
  		}
  		return false;
  	}
  
  	/**
  	 * get the free space in the storage
  	 *

  	 * @param string $path

  	 * @return int

  	 */
  	public function free_space($path) {

  		return \OC\Files\SPACE_UNKNOWN;

  	}

  
  	/**
  	 * {@inheritdoc}
  	 */
  	public function isLocal() {
  		// the common implementation returns a temporary file by
  		// default, which is not local
  		return false;
  	}
  
  	/**
  	 * @param string $path
  	 */
  	protected function getCachedFile($path) {
  		if (!isset($this->cachedFiles[$path])) {
  			$this->cachedFiles[$path] = $this->toTmpFile($path);
  		}
  		return $this->cachedFiles[$path];
  	}
  
  	protected function removeCachedFile($path) {
  		unset($this->cachedFiles[$path]);
  	}
  
  	/**
  	 * Check if the storage is an instance of $class or is a wrapper for a storage that is an instance of $class
  	 *
  	 * @param string $class
  	 * @return bool
  	 */
  	public function instanceOfStorage($class) {
  		return is_a($this, $class);
  	}

  }