<?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;
  
  class Upgrade {
  	/**
  	 * @var Legacy $legacy
  	 */
  	private $legacy;
  
  	private $numericIds = array();
  
  	private $mimeTypeIds = array();
  
  	/**
  	 * @param Legacy $legacy
  	 */
  	public function __construct($legacy) {
  		$this->legacy = $legacy;
  	}
  
  	/**

  	 * Preform a upgrade a path and it's childs

  	 *
  	 * @param string $path

  	 * @param bool $mode

  	 */
  	function upgradePath($path, $mode = Scanner::SCAN_RECURSIVE) {
  		if (!$this->legacy->hasItems()) {
  			return;
  		}
  		\OC_Hook::emit('\OC\Files\Cache\Upgrade', 'migrate_path', $path);
  		if ($row = $this->legacy->get($path)) {
  			$data = $this->getNewData($row);
  			if ($data) {
  				$this->insert($data);
  				$this->upgradeChilds($data['id'], $mode);
  			}
  		}
  	}
  
  	/**

  	 * upgrade all child elements of an item
  	 *

  	 * @param int $id

  	 * @param bool $mode

  	 */
  	function upgradeChilds($id, $mode = Scanner::SCAN_RECURSIVE) {
  		$children = $this->legacy->getChildren($id);
  		foreach ($children as $child) {
  			$childData = $this->getNewData($child);
  			\OC_Hook::emit('\OC\Files\Cache\Upgrade', 'migrate_path', $child['path']);
  			if ($childData) {
  				$this->insert($childData);
  				if ($mode == Scanner::SCAN_RECURSIVE) {
  					$this->upgradeChilds($child['id']);
  				}
  			}
  		}
  	}
  
  	/**

  	 * insert data into the new cache
  	 *

  	 * @param array $data the data for the new cache
  	 */
  	function insert($data) {
  		static $insertQuery = null;
  		if(is_null($insertQuery)) {
  			$insertQuery = \OC_DB::prepare('INSERT INTO `*PREFIX*filecache`
  				( `fileid`, `storage`, `path`, `path_hash`, `parent`, `name`, `mimetype`, `mimepart`, `size`, `mtime`, `encrypted`, `etag` )
  				VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)');
  		}
  		if (!$this->inCache($data['storage'], $data['path_hash'], $data['id'])) {

  			\OC_DB::executeAudited($insertQuery, array($data['id'], $data['storage'],

  				$data['path'], $data['path_hash'], $data['parent'], $data['name'],
  				$data['mimetype'], $data['mimepart'], $data['size'], $data['mtime'], $data['encrypted'], $data['etag']));
  		}
  	}
  
  	/**

  	 * check if an item is already in the new cache
  	 *

  	 * @param string $storage
  	 * @param string $pathHash
  	 * @param string $id
  	 * @return bool
  	 */
  	function inCache($storage, $pathHash, $id) {
  		static $query = null;
  		if(is_null($query)) {
  			$query = \OC_DB::prepare('SELECT `fileid` FROM `*PREFIX*filecache` WHERE (`storage` = ? AND `path_hash` = ?) OR `fileid` = ?');
  		}

  		$result = \OC_DB::executeAudited($query, array($storage, $pathHash, $id));

  		return (bool)$result->fetchRow();
  	}
  
  	/**
  	 * get the new data array from the old one
  	 *
  	 * @param array $data the data from the old cache
  	 * Example data array
  	 * Array
  	 *	(
  	 *		[id] => 418
  	 *		[path] => /tina/files/picture.jpg		//relative to datadir
  	 *		[path_hash] => 66d4547e372888deed80b24fec9b192b
  	 *		[parent] => 234
  	 *		[name] => picture.jpg
  	 *		[user] => tina
  	 *		[size] => 1265283
  	 *		[ctime] => 1363909709
  	 *		[mtime] => 1363909709
  	 *		[mimetype] => image/jpeg
  	 *		[mimepart] => image
  	 *		[encrypted] => 0
  	 *		[versioned] => 0
  	 *		[writable] => 1
  	 *	)
  	 *
  	 * @return array
  	 */
  	function getNewData($data) {
  		//Make sure there is a path, otherwise we can do nothing.
  		if(!isset($data['path'])) {
  			return false;
  		}
  		$newData = $data;
  		/**
  		 * @var \OC\Files\Storage\Storage $storage
  		 * @var string $internalPath;
  		 */
  		list($storage, $internalPath) = \OC\Files\Filesystem::resolvePath($data['path']);
  		if ($storage) {
  			$newData['etag'] = $data['etag'];
  			$newData['path_hash'] = md5($internalPath);
  			$newData['path'] = $internalPath;
  			$newData['storage'] = $this->getNumericId($storage);
  			$newData['parent'] = ($internalPath === '') ? -1 : $data['parent'];
  			$newData['permissions'] = ($data['writable']) ? \OCP\PERMISSION_ALL : \OCP\PERMISSION_READ;
  			$newData['storage_object'] = $storage;
  			$newData['mimetype'] = $this->getMimetypeId($newData['mimetype'], $storage);
  			$newData['mimepart'] = $this->getMimetypeId($newData['mimepart'], $storage);
  			return $newData;
  		} else {
  			\OC_Log::write('core', 'Unable to migrate data from old cache for '.$data['path'].' because the storage was not found', \OC_Log::ERROR);
  			return false;
  		}
  	}
  
  	/**
  	 * get the numeric storage id
  	 *
  	 * @param \OC\Files\Storage\Storage $storage
  	 * @return int
  	 */
  	function getNumericId($storage) {
  		$storageId = $storage->getId();
  		if (!isset($this->numericIds[$storageId])) {
  			$cache = $storage->getCache();
  			$this->numericIds[$storageId] = $cache->getNumericStorageId();
  		}
  		return $this->numericIds[$storageId];
  	}
  
  	/**

  	 * get the numeric id for a mimetype
  	 *

  	 * @param string $mimetype
  	 * @param \OC\Files\Storage\Storage $storage
  	 * @return int
  	 */
  	function getMimetypeId($mimetype, $storage) {
  		if (!isset($this->mimeTypeIds[$mimetype])) {
  			$cache = new Cache($storage);
  			$this->mimeTypeIds[$mimetype] = $cache->getMimetypeId($mimetype);
  		}
  		return $this->mimeTypeIds[$mimetype];
  	}
  
  	/**
  	 * check if a cache upgrade is required for $user
  	 *
  	 * @param string $user
  	 * @return bool
  	 */
  	static function needUpgrade($user) {
  		$cacheVersion = (int)\OCP\Config::getUserValue($user, 'files', 'cache_version', 4);

  		if ($cacheVersion < 5) {
  			$legacy = new \OC\Files\Cache\Legacy($user);
  			if ($legacy->hasItems()) {
  				return true;
  			}
  			self::upgradeDone($user);
  		}
  
  		return false;

  	}
  
  	/**
  	 * mark the filecache as upgrade
  	 *
  	 * @param string $user
  	 */
  	static function upgradeDone($user) {
  		\OCP\Config::setUserValue($user, 'files', 'cache_version', 5);
  	}
  
  	/**
  	 * Does a "silent" upgrade, i.e. without an Event-Source as triggered
  	 * on User-Login via Ajax. This method is called within the regular
  	 * ownCloud upgrade.
  	 *
  	 * @param string $user a User ID
  	 */
  	public static function doSilentUpgrade($user) {
  		if(!self::needUpgrade($user)) {
  			return;
  		}
  		$legacy = new \OC\Files\Cache\Legacy($user);
  		if ($legacy->hasItems()) {
  			\OC_DB::beginTransaction();
  			$upgrade = new \OC\Files\Cache\Upgrade($legacy);
  			$upgrade->upgradePath('/' . $user . '/files');
  			\OC_DB::commit();
  		}
  		\OC\Files\Cache\Upgrade::upgradeDone($user);
  	}
  }