<?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;
  
  /**
   * Provide read only support for the old filecache
   */
  class Legacy {
  	private $user;
  
  	private $cacheHasItems = null;
  
  	public function __construct($user) {
  		$this->user = $user;
  	}

  	/**
  	 * get the numbers of items in the legacy cache
  	 *
  	 * @return int
  	 */

  	function getCount() {

  		$sql = 'SELECT COUNT(`id`) AS `count` FROM `*PREFIX*fscache` WHERE `user` = ?';
  		$result = \OC_DB::executeAudited($sql, array($this->user));

  		if ($row = $result->fetchRow()) {
  			return $row['count'];
  		} else {
  			return 0;
  		}
  	}
  
  	/**
  	 * check if a legacy cache is present and holds items
  	 *
  	 * @return bool
  	 */
  	function hasItems() {
  		if (!is_null($this->cacheHasItems)) {
  			return $this->cacheHasItems;
  		}
  		try {
  			$query = \OC_DB::prepare('SELECT `id` FROM `*PREFIX*fscache` WHERE `user` = ?',1);
  		} catch (\Exception $e) {
  			$this->cacheHasItems = false;
  			return false;
  		}
  		try {
  			$result = $query->execute(array($this->user));
  		} catch (\Exception $e) {
  			$this->cacheHasItems = false;
  			return false;
  		}
  
  		if ($result === false || property_exists($result, 'error_message_prefix')) {
  			$this->cacheHasItems = false;
  			return false;
  		}
  
  		$this->cacheHasItems = (bool)$result->fetchRow();
  		return $this->cacheHasItems;
  	}
  
  	/**

  	 * get an item from the legacy cache
  	 *

  	 * @param string|int $path
  	 * @return array
  	 */
  	function get($path) {
  		if (is_numeric($path)) {

  			$sql = 'SELECT * FROM `*PREFIX*fscache` WHERE `id` = ?';

  		} else {

  			$sql = 'SELECT * FROM `*PREFIX*fscache` WHERE `path` = ?';

  		}

  		$result = \OC_DB::executeAudited($sql, array($path));

  		$data = $result->fetchRow();
  		$data['etag'] = $this->getEtag($data['path'], $data['user']);
  		return $data;
  	}
  
  	/**
  	 * Get the ETag for the given path
  	 *
  	 * @param type $path
  	 * @return string
  	 */
  	function getEtag($path, $user = null) {
  		static $query = null;
  
  		$pathDetails = explode('/', $path, 4);
  		if((!$user) && !isset($pathDetails[1])) {
  			//no user!? Too odd, return empty string.
  			return '';
  		} else if(!$user) {
  			//guess user from path, if no user passed.
  			$user = $pathDetails[1];
  		}
  
  		if(!isset($pathDetails[3]) || is_null($pathDetails[3])) {
  			$relativePath = '';
  		} else {
  			$relativePath = $pathDetails[3];
  		}
  
  		if(is_null($query)){
  			$query = \OC_DB::prepare('SELECT `propertyvalue` FROM `*PREFIX*properties` WHERE `userid` = ? AND `propertypath` = ? AND `propertyname` = \'{DAV:}getetag\'');
  		}

  		$result = \OC_DB::executeAudited($query,array($user, '/' . $relativePath));

  		if ($row = $result->fetchRow()) {
  			return trim($row['propertyvalue'], '"');
  		} else {
  			return '';
  		}
  	}
  
  	/**

  	 * get all child items of an item from the legacy cache
  	 *

  	 * @param int $id
  	 * @return array
  	 */
  	function getChildren($id) {

  		$result = \OC_DB::executeAudited('SELECT * FROM `*PREFIX*fscache` WHERE `parent` = ?', array($id));

  		$data = $result->fetchAll();
  		foreach ($data as $i => $item) {
  			$data[$i]['etag'] = $this->getEtag($item['path'], $item['user']);
  		}
  		return $data;
  	}
  }