<?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\Cache;
  
  /**
   * listen to filesystem hooks and change the cache accordingly
   */
  class Updater {
  
  	/**
  	 * resolve a path to a storage and internal path
  	 *
  	 * @param string $path
  	 * @return array consisting of the storage and the internal path
  	 */
  	static public function resolvePath($path) {
  		$view = \OC\Files\Filesystem::getView();
  		return $view->resolvePath($path);
  	}
  
  	static public function writeUpdate($path) {
  		/**
  		 * @var \OC\Files\Storage\Storage $storage
  		 * @var string $internalPath
  		 */
  		list($storage, $internalPath) = self::resolvePath($path);
  		if ($storage) {
  			$cache = $storage->getCache($internalPath);
  			$scanner = $storage->getScanner($internalPath);
  			$scanner->scan($internalPath, Scanner::SCAN_SHALLOW);
  			$cache->correctFolderSize($internalPath);
  			self::correctFolder($path, $storage->filemtime($internalPath));
  		}
  	}
  
  	static public function deleteUpdate($path) {
  		/**
  		 * @var \OC\Files\Storage\Storage $storage
  		 * @var string $internalPath
  		 */
  		list($storage, $internalPath) = self::resolvePath($path);
  		if ($storage) {
  			$cache = $storage->getCache($internalPath);
  			$cache->remove($internalPath);
  			$cache->correctFolderSize($internalPath);
  			self::correctFolder($path, time());
  		}
  	}
  
  	static public function renameUpdate($from, $to) {
  		/**
  		 * @var \OC\Files\Storage\Storage $storageFrom
  		 * @var \OC\Files\Storage\Storage $storageTo
  		 * @var string $internalFrom
  		 * @var string $internalTo
  		 */
  		list($storageFrom, $internalFrom) = self::resolvePath($from);
  		list($storageTo, $internalTo) = self::resolvePath($to);
  		if ($storageFrom && $storageTo) {
  			if ($storageFrom === $storageTo) {
  				$cache = $storageFrom->getCache($internalFrom);
  				$cache->move($internalFrom, $internalTo);
  				$cache->correctFolderSize($internalFrom);
  				$cache->correctFolderSize($internalTo);
  				self::correctFolder($from, time());
  				self::correctFolder($to, time());
  			} else {
  				self::deleteUpdate($from);
  				self::writeUpdate($to);
  			}
  		}
  	}
  
  	/**
  	 * @brief get file owner and path
  	 * @param string $filename
  	 * @return array with the oweners uid and the owners path
  	 */
  	private static function getUidAndFilename($filename) {
  		$uid = \OC\Files\Filesystem::getOwner($filename);
  		\OC\Files\Filesystem::initMountPoints($uid);
  		if ( $uid != \OCP\User::getUser() ) {
  			$info = \OC\Files\Filesystem::getFileInfo($filename);
  			$ownerView = new \OC\Files\View('/'.$uid.'/files');
  			$filename = $ownerView->getPath($info['fileid']);
  		}
  		return array($uid, '/files/'.$filename);
  	}
  
  	/**
  	 * Update the mtime and ETag of all parent folders
  	 *
  	 * @param string $path
  	 * @param string $time
  	 */
  	static public function correctFolder($path, $time) {
  
  		if ($path !== '' && $path !== '/') {
  
  			list($owner, $realPath) = self::getUidAndFilename(dirname($path));
  
  			/**
  			 * @var \OC\Files\Storage\Storage $storage
  			 * @var string $internalPath
  			 */
  
  			$view = new \OC\Files\View('/' . $owner);
  
  			list($storage, $internalPath) = $view->resolvePath($realPath);
  			$cache = $storage->getCache();
  			$id = $cache->getId($internalPath);
  
  			while ($id !== -1) {
  				$cache->update($id, array('mtime' => $time, 'etag' => $storage->getETag($internalPath)));
  				$realPath = dirname($realPath);
  				// check storage for parent in case we change the storage in this step
  				list($storage, $internalPath) = $view->resolvePath($realPath);
  				if ($internalPath) {
  					$cache = $storage->getCache();
  					$id = $cache->getId($internalPath);
  				} else {
  					$id = -1;
  				}
  
  			}
  
  		}
  	}
  
  	/**
  	 * @param array $params
  	 */
  	static public function writeHook($params) {
  		self::writeUpdate($params['path']);
  	}
  
  	/**
  	 * @param array $params
  	 */
  	static public function touchHook($params) {
  		$path = $params['path'];
  		list($storage, $internalPath) = self::resolvePath($path);
  		$cache = $storage->getCache();
  		$id = $cache->getId($internalPath);
  		if ($id !== -1) {
  			$cache->update($id, array('etag' => $storage->getETag($internalPath)));
  		}
  		self::writeUpdate($path);
  	}
  
  	/**
  	 * @param array $params
  	 */
  	static public function renameHook($params) {
  		self::renameUpdate($params['oldpath'], $params['newpath']);
  	}
  
  	/**
  	 * @param array $params
  	 */
  	static public function deleteHook($params) {
  		self::deleteUpdate($params['path']);
  	}
  }