<?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;
  
  class Mount {
  	/**
  	 * @var Mount[]
  	 */
  	static private $mounts = array();
  
  	/**
  	 * @var \OC\Files\Storage\Storage $storage
  	 */
  	private $storage = null;
  	private $class;
  	private $storageId;
  	private $arguments = array();
  	private $mountPoint;
  
  	/**
  	 * @param string|\OC\Files\Storage\Storage $storage
  	 * @param string $mountpoint
  	 * @param array $arguments (optional)
  	 */
  	public function __construct($storage, $mountpoint, $arguments = null) {
  		if (is_null($arguments)) {
  			$arguments = array();
  		}
  
  		$mountpoint = self::formatPath($mountpoint);
  		if ($storage instanceof \OC\Files\Storage\Storage) {
  			$this->class = get_class($storage);
  			$this->storage = $storage;
  		} else {
  			// Update old classes to new namespace
  			if (strpos($storage, 'OC_Filestorage_') !== false) {
  				$storage = '\OC\Files\Storage\\' . substr($storage, 15);
  			}
  			$this->class = $storage;
  			$this->arguments = $arguments;
  		}
  		$this->mountPoint = $mountpoint;
  
  		self::$mounts[$this->mountPoint] = $this;
  	}
  
  	/**
  	 * @return string
  	 */
  	public function getMountPoint() {
  		return $this->mountPoint;
  	}
  
  	/**
  	 * @return \OC\Files\Storage\Storage
  	 */
  	private function createStorage() {
  		if (class_exists($this->class)) {
  			try {
  				return new $this->class($this->arguments);
  			} catch (\Exception $exception) {
  				\OC_Log::write('core', $exception->getMessage(), \OC_Log::ERROR);
  				return null;
  			}
  		} else {
  			\OC_Log::write('core', 'storage backend ' . $this->class . ' not found', \OC_Log::ERROR);
  			return null;
  		}
  	}
  
  	/**
  	 * @return \OC\Files\Storage\Storage
  	 */
  	public function getStorage() {
  		if (is_null($this->storage)) {
  			$this->storage = $this->createStorage();
  		}
  		return $this->storage;
  	}
  
  	/**
  	 * @return string
  	 */
  	public function getStorageId() {
  		if (!$this->storageId) {
  			if (is_null($this->storage)) {
  				$storage = $this->createStorage(); //FIXME: start using exceptions
  				if (is_null($storage)) {
  					return null;
  				}
  				$this->storage = $storage;
  			}
  			$this->storageId = $this->storage->getId();
  			if (strlen($this->storageId) > 64) {
  				$this->storageId = md5($this->storageId);
  			}
  		}
  		return $this->storageId;
  	}
  
  	/**
  	 * @param string $path
  	 * @return string
  	 */
  	public function getInternalPath($path) {
  		if ($this->mountPoint === $path or $this->mountPoint . '/' === $path) {
  			$internalPath = '';
  		} else {
  			$internalPath = substr($path, strlen($this->mountPoint));
  		}
  		return $internalPath;
  	}
  
  	/**
  	 * @param string $path
  	 * @return string
  	 */
  	private static function formatPath($path) {
  		$path = Filesystem::normalizePath($path);
  		if (strlen($path) > 1) {
  			$path .= '/';
  		}
  		return $path;
  	}
  
  	/**
  	 * Find the mount for $path
  	 *
  	 * @param $path
  	 * @return Mount
  	 */
  	public static function find($path) {
  		$path = self::formatPath($path);
  		if (isset(self::$mounts[$path])) {
  			return self::$mounts[$path];
  		}
  
  		\OC_Hook::emit('OC_Filesystem', 'get_mountpoint', array('path' => $path));
  		$foundMountPoint = '';
  		$mountPoints = array_keys(self::$mounts);
  		foreach ($mountPoints as $mountpoint) {
  			if (strpos($path, $mountpoint) === 0 and strlen($mountpoint) > strlen($foundMountPoint)) {
  				$foundMountPoint = $mountpoint;
  			}
  		}
  		if (isset(self::$mounts[$foundMountPoint])) {
  			return self::$mounts[$foundMountPoint];
  		} else {
  			return null;
  		}
  	}
  
  	/**
  	 * Find all mounts in $path
  	 *
  	 * @param $path
  	 * @return Mount[]
  	 */
  	public static function findIn($path) {
  		$path = self::formatPath($path);
  		$result = array();
  		$pathLength = strlen($path);
  		$mountPoints = array_keys(self::$mounts);
  		foreach ($mountPoints as $mountPoint) {
  			if (substr($mountPoint, 0, $pathLength) === $path and strlen($mountPoint) > $pathLength) {
  				$result[] = self::$mounts[$mountPoint];
  			}
  		}
  		return $result;
  	}
  
  	public static function clear() {
  		self::$mounts = array();
  	}
  
  	/**
  	 * Find mounts by storage id
  	 *
  	 * @param string $id
  	 * @return Mount[]
  	 */
  	public static function findByStorageId($id) {
  		if (strlen($id) > 64) {
  			$id = md5($id);
  		}
  		$result = array();
  		foreach (self::$mounts as $mount) {
  			if ($mount->getStorageId() === $id) {
  				$result[] = $mount;
  			}
  		}
  		return $result;
  	}
  
  	/**
  	 * Find mounts by numeric storage id
  	 *
  	 * @param string $id
  	 * @return Mount
  	 */
  	public static function findByNumericId($id) {
  		$query = \OC_DB::prepare('SELECT `id` FROM `*PREFIX*storages` WHERE `numeric_id` = ?');
  		$result = $query->execute(array($id))->fetchOne();
  		if ($result) {
  			$id = $result;
  			foreach (self::$mounts as $mount) {
  				if ($mount->getStorageId() === $id) {
  					return $mount;
  				}
  			}
  		}
  		return false;
  	}
  }