<?php
  /**
   * ownCloud
   *
   * @author Michael Gapczynski
   * @copyright 2012 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;
  use OCP\Share_Backend_Collection;
  
  /**
   * Metadata cache for shared files
   *
   * don't use this class directly if you need to get metadata, use \OC\Files\Filesystem::getFileInfo instead
   */
  class Shared_Cache extends Cache {
  
  	private $storage;
  	private $files = array();
  
  	public function __construct($storage) {
  		$this->storage = $storage;
  	}
  
  	/**
  	 * @brief Get the source cache of a shared file or folder
  	 * @param string $target Shared target file path
  	 * @return \OC\Files\Cache\Cache
  	 */
  	private function getSourceCache($target) {
  		$source = \OC_Share_Backend_File::getSource($target);
  		if (isset($source['path']) && isset($source['fileOwner'])) {
  			\OC\Files\Filesystem::initMountPoints($source['fileOwner']);

  			$mount = \OC\Files\Filesystem::getMountByNumericId($source['storage']);
  			if (is_array($mount)) {
  				$fullPath = $mount[key($mount)]->getMountPoint().$source['path'];

  				list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($fullPath);
  				if ($storage) {
  					$this->files[$target] = $internalPath;
  					$cache = $storage->getCache();
  					$this->storageId = $storage->getId();
  					$this->numericId = $cache->getNumericStorageId();
  					return $cache;
  				}
  			}
  		}
  		return false;
  	}

  	public function getNumericStorageId() {
  		if (isset($this->numericId)) {
  			return $this->numericId;
  		} else {
  			return false;
  		}
  	}

  	/**
  	 * get the stored metadata of a file or folder
  	 *
  	 * @param string/int $file
  	 * @return array
  	 */
  	public function get($file) {
  		if ($file == '') {
  			$data = \OCP\Share::getItemsSharedWith('file', \OC_Share_Backend_File::FORMAT_FILE_APP_ROOT);
  			$etag = \OCP\Config::getUserValue(\OCP\User::getUser(), 'files_sharing', 'etag');
  			if (!isset($etag)) {
  				$etag = $this->storage->getETag('');
  				\OCP\Config::setUserValue(\OCP\User::getUser(), 'files_sharing', 'etag', $etag);
  			}
  			$data['etag'] = $etag;
  			return $data;
  		} else if (is_string($file)) {
  			if ($cache = $this->getSourceCache($file)) {
  				return $cache->get($this->files[$file]);
  			}
  		} else {
  			$query = \OC_DB::prepare(
  				'SELECT `fileid`, `storage`, `path`, `parent`, `name`, `mimetype`, `mimepart`,'

  				.' `size`, `mtime`, `encrypted`, `unencrypted_size`'

  				.' FROM `*PREFIX*filecache` WHERE `fileid` = ?');
  			$result = $query->execute(array($file));
  			$data = $result->fetchRow();
  			$data['fileid'] = (int)$data['fileid'];

  			$data['mtime'] = (int)$data['mtime'];

  			$data['storage_mtime'] = (int)$data['storage_mtime'];

  			$data['encrypted'] = (bool)$data['encrypted'];
  			$data['mimetype'] = $this->getMimetype($data['mimetype']);
  			$data['mimepart'] = $this->getMimetype($data['mimepart']);

  			if ($data['storage_mtime'] === 0) {
  				$data['storage_mtime'] = $data['mtime'];
  			}

  			if ($data['encrypted'] or ($data['unencrypted_size'] > 0 and $data['mimetype'] === 'httpd/unix-directory')) {
  				$data['encrypted_size'] = (int)$data['size'];
  				$data['size'] = (int)$data['unencrypted_size'];
  			} else {
  				$data['size'] = (int)$data['size'];
  			}

  			return $data;
  		}
  		return false;
  	}
  
  	/**
  	 * get the metadata of all files stored in $folder
  	 *
  	 * @param string $folder
  	 * @return array
  	 */
  	public function getFolderContents($folder) {
  		if ($folder == '') {
  			$files = \OCP\Share::getItemsSharedWith('file', \OC_Share_Backend_File::FORMAT_GET_FOLDER_CONTENTS);
  			foreach ($files as &$file) {
  				$file['mimetype'] = $this->getMimetype($file['mimetype']);
  				$file['mimepart'] = $this->getMimetype($file['mimepart']);

  				$file['usersPath'] = 'files/Shared/' . ltrim($file['path'], '/');

  			}
  			return $files;
  		} else {

  			$cache = $this->getSourceCache($folder);
  			if ($cache) {
  				$sourceFolderContent = $cache->getFolderContents($this->files[$folder]);
  				foreach ($sourceFolderContent as $key => $c) {
  					$sourceFolderContent[$key]['usersPath'] = 'files/Shared/' . $folder . '/' . $c['name'];
  				}
  
  				return $sourceFolderContent;

  			}
  		}
  		return false;
  	}
  
  	/**
  	 * store meta data for a file or folder
  	 *
  	 * @param string $file
  	 * @param array $data
  	 *
  	 * @return int file id
  	 */
  	public function put($file, array $data) {
  		if ($file === '' && isset($data['etag'])) {
  			return \OCP\Config::setUserValue(\OCP\User::getUser(), 'files_sharing', 'etag', $data['etag']);
  		} else if ($cache = $this->getSourceCache($file)) {
  			return $cache->put($this->files[$file], $data);
  		}
  		return false;
  	}
  
  	/**
  	 * get the file id for a file
  	 *
  	 * @param string $file
  	 * @return int
  	 */
  	public function getId($file) {
  		if ($cache = $this->getSourceCache($file)) {
  			return $cache->getId($this->files[$file]);
  		}
  		return -1;
  	}
  
  	/**
  	 * check if a file is available in the cache
  	 *
  	 * @param string $file
  	 * @return bool
  	 */
  	public function inCache($file) {
  		if ($file == '') {
  			return true;
  		}
  		return parent::inCache($file);
  	}
  
  	/**
  	 * remove a file or folder from the cache
  	 *
  	 * @param string $file
  	 */
  	public function remove($file) {
  		if ($cache = $this->getSourceCache($file)) {
  			$cache->remove($this->files[$file]);
  		}
  	}
  
  	/**
  	 * Move a file or folder in the cache
  	 *
  	 * @param string $source
  	 * @param string $target
  	 */
  	public function move($source, $target) {
  		if ($cache = $this->getSourceCache($source)) {
  			$file = \OC_Share_Backend_File::getSource($target);
  			if ($file && isset($file['path'])) {
  				$cache->move($this->files[$source], $file['path']);
  			}
  		}
  	}
  
  	/**
  	 * remove all entries for files that are stored on the storage from the cache
  	 */
  	public function clear() {
  		// Not a valid action for Shared Cache
  	}
  
  	/**
  	 * @param string $file
  	 *
  	 * @return int, Cache::NOT_FOUND, Cache::PARTIAL, Cache::SHALLOW or Cache::COMPLETE
  	 */
  	public function getStatus($file) {
  		if ($file == '') {
  			return self::COMPLETE;
  		}
  		if ($cache = $this->getSourceCache($file)) {
  			return $cache->getStatus($this->files[$file]);
  		}
  		return self::NOT_FOUND;
  	}
  
  	/**
  	 * search for files matching $pattern
  	 *
  	 * @param string $pattern
  	 * @return array of file data
  	 */
  	public function search($pattern) {
  
  		$where = '`name` LIKE ? AND ';
  
  		// normalize pattern
  		$value = $this->normalize($pattern);

  		return $this->searchWithWhere($where, $value);

  
  	}
  
  	/**
  	 * search for files by mimetype
  	 *
  	 * @param string $mimetype
  	 * @return array
  	 */
  	public function searchByMime($mimetype) {

  		$mimepart = null;
  		if (strpos($mimetype, '/') === false) {
  			$mimepart = $mimetype;
  			$mimetype = null;

  		}

  		// note: searchWithWhere is currently broken as it doesn't
  		// recurse into subdirs nor returns the correct
  		// file paths, so using getFolderContents() for now

  		$result = array();
  		$exploreDirs = array('');
  		while (count($exploreDirs) > 0) {
  			$dir = array_pop($exploreDirs);
  			$files = $this->getFolderContents($dir);
  			// no results?
  			if (!$files) {
  				continue;
  			}
  			foreach ($files as $file) {
  				if ($file['mimetype'] === 'httpd/unix-directory') {
  					$exploreDirs[] = ltrim($dir . '/' . $file['name'], '/');
  				}
  				else if (($mimepart && $file['mimepart'] === $mimepart) || ($mimetype && $file['mimetype'] === $mimetype)) {
  					// usersPath not reliable
  					//$file['path'] = $file['usersPath'];
  					$file['path'] = ltrim($dir . '/' . $file['name'], '/');
  					$result[] = $file;
  				}
  			}
  		}
  		return $result;

  	}

  	/**
  	 * The maximum number of placeholders that can be used in an SQL query.

  	 * Value MUST be <= 1000 for oracle:
  	 * see ORA-01795 maximum number of expressions in a list is 1000
  	 * FIXME we should get this from doctrine as other DBs allow a lot more placeholders

  	 */

  	const MAX_SQL_CHUNK_SIZE = 1000;

  	/**
  	 * search for files with a custom where clause and value
  	 * the $wherevalue will be array_merge()d with the file id chunks
  	 *
  	 * @param string $sqlwhere
  	 * @param string $wherevalue
  	 * @return array
  	 */
  	private function searchWithWhere($sqlwhere, $wherevalue, $chunksize = self::MAX_SQL_CHUNK_SIZE) {
  
  		$ids = $this->getAll();
  
  		$files = array();

  		// divide into chunks

  		$chunks = array_chunk($ids, $chunksize);

  		foreach ($chunks as $chunk) {
  			$placeholders = join(',', array_fill(0, count($chunk), '?'));
  			$sql = 'SELECT `fileid`, `storage`, `path`, `parent`, `name`, `mimetype`, `mimepart`, `size`, `mtime`,
  					`encrypted`, `unencrypted_size`, `etag`
  					FROM `*PREFIX*filecache` WHERE ' . $sqlwhere . ' `fileid` IN (' . $placeholders . ')';

  			$stmt = \OC_DB::prepare($sql);

  			$result = $stmt->execute(array_merge(array($wherevalue), $chunk));
  
  			while ($row = $result->fetchRow()) {
  				if (substr($row['path'], 0, 6) === 'files/') {
  					$row['path'] = substr($row['path'], 6); // remove 'files/' from path as it's relative to '/Shared'
  				}
  				$row['mimetype'] = $this->getMimetype($row['mimetype']);
  				$row['mimepart'] = $this->getMimetype($row['mimepart']);

  				if ($row['encrypted'] or ($row['unencrypted_size'] > 0 and $row['mimetype'] === 'httpd/unix-directory')) {
  					$row['encrypted_size'] = $row['size'];
  					$row['size'] = $row['unencrypted_size'];
  				} else {
  					$row['size'] = $row['size'];
  				}

  				$files[] = $row;
  			}
  		}
  		return $files;
  	}
  
  	/**
  	 * get the size of a folder and set it in the cache
  	 *
  	 * @param string $path
  	 * @return int
  	 */
  	public function calculateFolderSize($path) {
  		if ($cache = $this->getSourceCache($path)) {
  			return $cache->calculateFolderSize($this->files[$path]);
  		}
  		return 0;
  	}
  
  	/**
  	 * get all file ids on the files on the storage
  	 *
  	 * @return int[]
  	 */
  	public function getAll() {
  		$ids = \OCP\Share::getItemsSharedWith('file', \OC_Share_Backend_File::FORMAT_GET_ALL);
  		$folderBackend = \OCP\Share::getBackend('folder');
  		if ($folderBackend instanceof Share_Backend_Collection) {
  			foreach ($ids as $file) {
  				/** @var $folderBackend Share_Backend_Collection */
  				$children = $folderBackend->getChildren($file);
  				foreach ($children as $child) {
  					$ids[] = (int)$child['source'];
  				}
  
  			}
  		}
  
  		return $ids;
  	}

  	/**
  	 * find a folder in the cache which has not been fully scanned
  	 *
  	 * If multiply incomplete folders are in the cache, the one with the highest id will be returned,
  	 * use the one with the highest id gives the best result with the background scanner, since that is most
  	 * likely the folder where we stopped scanning previously
  	 *
  	 * @return string|bool the path of the folder or false when no folder matched
  	 */
  	public function getIncomplete() {
  		return false;
  	}

  }