<?php

/**
* ownCloud
*
* @author Frank Karlitschek 
* @copyright 2012 Frank Karlitschek frank@owncloud.org 
* 
* 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/>.
* 
*/


/**
 * Class for abstraction of filesystem functions
 * This class won't call any filesystem functions for itself but but will pass them to the correct OC_Filestorage object
 * this class should also handle all the file premission related stuff
 *
 * Hooks provided:
 *   read(path)
 *   write(path, &run)
 *   post_write(path)
 *   create(path, &run) (when a file is created, both create and write will be emited in that order)
 *   post_create(path)
 *   delete(path, &run)
 *   post_delete(path)
 *   rename(oldpath,newpath, &run)
 *   post_rename(oldpath,newpath)
 *   copy(oldpath,newpath, &run) (if the newpath doesn't exists yes, copy, create and write will be emited in that order)
 *   post_rename(oldpath,newpath)
 *
 *   the &run parameter can be set to false to prevent the operation from occuring
 */

class OC_Filesystem{
	static private $storages=array();
	static private $mounts=array();
	static private $storageTypes=array();
	public static $loaded=false;
	private $fakeRoot='';
	static private $defaultInstance;


  /**
   * classname which used for hooks handling
   * used as signalclass in OC_Hooks::emit()
   */
  const CLASSNAME = 'OC_Filesystem';

  /**
   * signalname emited before file renaming
   * @param oldpath
   * @param newpath
   */
  const signal_rename = 'rename';

  /**
   * signal emited after file renaming
   * @param oldpath
   * @param newpath
   */
  const signal_post_rename = 'post_rename';
	
  /**
   * signal emited before file/dir creation
   * @param path
   * @param run changing this flag to false in hook handler will cancel event
   */
  const signal_create = 'create';

  /**
   * signal emited after file/dir creation
   * @param path
   * @param run changing this flag to false in hook handler will cancel event
   */
  const signal_post_create = 'post_create';

  /**
   * signal emits before file/dir copy
   * @param oldpath
   * @param newpath
   * @param run changing this flag to false in hook handler will cancel event
   */
  const signal_copy = 'copy';

  /**
   * signal emits after file/dir copy
   * @param oldpath
   * @param newpath
   */
  const signal_post_copy = 'post_copy';

  /**
   * signal emits before file/dir save
   * @param path
   * @param run changing this flag to false in hook handler will cancel event
   */
  const signal_write = 'write';

  /**
   * signal emits after file/dir save
   * @param path
   */
  const signal_post_write = 'post_write';
	
  /**
   * signal emits when reading file/dir
   * @param path
   */
  const signal_read = 'read';

  /**
   * signal emits when removing file/dir
   * @param path
   */
  const signal_delete = 'delete';

  /**
   * parameters definitions for signals
   */
  const signal_param_path = 'path';
  const signal_param_oldpath = 'oldpath';
  const signal_param_newpath = 'newpath';

  /**
   * run - changing this flag to false in hook handler will cancel event
   */
  const signal_param_run = 'run';

  /**
	* get the mountpoint of the storage object for a path
	( note: because a storage is not always mounted inside the fakeroot, the returned mountpoint is relative to the absolute root of the filesystem and doesn't take the chroot into account
	*
	* @param string path
	* @return string
	*/
	static public function getMountPoint($path){
		OC_Hook::emit(self::CLASSNAME,'get_mountpoint',array('path'=>$path));
		if(!$path){
			$path='/';
		}
		if(substr($path,0,1)!=='/'){
			$path='/'.$path;
		}
		$foundMountPoint='';
		foreach(OC_Filesystem::$mounts as $mountpoint=>$storage){
			if($mountpoint==$path){
				return $mountpoint;
			}
			if(strpos($path,$mountpoint)===0 and strlen($mountpoint)>strlen($foundMountPoint)){
				$foundMountPoint=$mountpoint;
			}
		}
		return $foundMountPoint;
	}

	/**
	* get the part of the path relative to the mountpoint of the storage it's stored in
	* @param  string  path
	* @return bool
	*/
	static public function getInternalPath($path){
		$mountPoint=self::getMountPoint($path);
		$internalPath=substr($path,strlen($mountPoint));
		return $internalPath;
	}
	/**
	* get the storage object for a path
	* @param string path
	* @return OC_Filestorage
	*/
	static public function getStorage($path){
		$mountpoint=self::getMountPoint($path);
		if($mountpoint){
			if(!isset(OC_Filesystem::$storages[$mountpoint])){
				$mount=OC_Filesystem::$mounts[$mountpoint];
				OC_Filesystem::$storages[$mountpoint]=OC_Filesystem::createStorage($mount['class'],$mount['arguments']);
			}
			return OC_Filesystem::$storages[$mountpoint];
		}
	}
	
	static public function init($root){
		if(self::$defaultInstance){
			return false;
		}
		self::$defaultInstance=new OC_FilesystemView($root);

		//load custom mount config
		if(is_file(OC::$SERVERROOT.'/config/mount.php')){
			$mountConfig=include(OC::$SERVERROOT.'/config/mount.php');
			if(isset($mountConfig['global'])){
				foreach($mountConfig['global'] as $mountPoint=>$options){
					self::mount($options['class'],$options['options'],$mountPoint);
				}
			}

			if(isset($mountConfig['group'])){
				foreach($mountConfig['group'] as $group=>$mounts){
					if(OC_Group::inGroup(OC_User::getUser(),$group)){
						foreach($mounts as $mountPoint=>$options){
							$mountPoint=self::setUserVars($mountPoint);
							foreach($options as &$option){
								$option=self::setUserVars($option);
							}
							self::mount($options['class'],$options['options'],$mountPoint);
						}
					}
				}
			}

			if(isset($mountConfig['user'])){
				foreach($mountConfig['user'] as $user=>$mounts){
					if($user==='all' or strtolower($user)===strtolower(OC_User::getUser())){
						foreach($mounts as $mountPoint=>$options){
							$mountPoint=self::setUserVars($mountPoint);
							foreach($options as &$option){
								$option=self::setUserVars($option);
							}
							self::mount($options['class'],$options['options'],$mountPoint);
						}
					}
				}
			}
		}
		
		self::$loaded=true;
	}

	/**
	 * fill in the correct values for $user, and $password placeholders
	 * @param string intput
	 * @return string
	 */
	private static function setUserVars($input){
		return str_replace('$user',OC_User::getUser(),$input);
	}

	/**
	 * get the default filesystem view
	 * @return OC_FilesystemView
	 */
	static public function getView(){
		return self::$defaultInstance;
	}
	
	/**
	 * tear down the filesystem, removing all storage providers
	 */
	static public function tearDown(){
		foreach(self::$storages as $mountpoint=>$storage){
			unset(self::$storages[$mountpoint]);
		}
		$fakeRoot='';
	}
	
	/**
	* create a new storage of a specific type
	* @param  string  type
	* @param  array  arguments
	* @return OC_Filestorage
	*/
	static private function createStorage($class,$arguments){
		if(class_exists($class)){
			return new $class($arguments);
		}else{
			OC_Log::write('core','storage backend '.$class.' not found',OC_Log::ERROR);
			return false;
		}
	}
	
	/**
	* change the root to a fake root
	* @param  string  fakeRoot
	* @return bool
	*/
	static public function chroot($fakeRoot){
		return self::$defaultInstance->chroot($path);
	}

	/**
	 * @brief get the relative path of the root data directory for the current user
	 * @return string
	 *
	 * Returns path like /admin/files
	 */
	static public function getRoot(){
		return self::$defaultInstance->getRoot();
	}

	/**
	 * clear all mounts and storage backends
	 */
	public static function clearMounts(){
		self::$mounts=array();
		self::$storages=array();
	}

	/**
	* mount an OC_Filestorage in our virtual filesystem
	* @param OC_Filestorage storage
	* @param string mountpoint
	*/
	static public function mount($class,$arguments,$mountpoint){
		if(substr($mountpoint,-1)!=='/'){
			$mountpoint=$mountpoint.'/';
		}
		if(substr($mountpoint,0,1)!=='/'){
			$mountpoint='/'.$mountpoint;
		}
		self::$mounts[$mountpoint]=array('class'=>$class,'arguments'=>$arguments);
	}

	/**
	 * create all storage backends mounted in the filesystem
	 */
	static private function mountAll(){
		foreach(self::$mounts as $mountPoint=>$mount){
			if(!isset(self::$storages[$mountPoint])){
				self::$storages[$mountPoint]=self::createStorage($mount['type'],$mount['arguments']);
			}
		}
	}
	
	/**
	* return the path to a local version of the file
	* we need this because we can't know if a file is stored local or not from outside the filestorage and for some purposes a local file is needed
	* @param string path
	* @return string
	*/
	static public function getLocalFile($path){
		return self::$defaultInstance->getLocalFile($path);
	}
	
	/**
	 * check if the requested path is valid
	 * @param string path
	 * @return bool
	 */
	static public function isValidPath($path){
		if(substr($path,0,1)!=='/'){
			$path='/'.$path;
		}
		if(strstr($path,'/../') || strrchr($path, '/') === '/..' ){
			return false;
		}
		return true;
	}
	
	/**
	 * checks if a file is blacklsited for storage in the filesystem
	 * @param array $data from hook
	 */
	static public function isBlacklisted($data){
		$blacklist = array('.htaccess');
		$filename = strtolower(basename($data['path']));
		if(in_array($filename,$blacklist)){
			$data['run'] = false;	
		}
	}
	
	/**
	 * following functions are equivilent to their php buildin equivilents for arguments/return values.
	 */
	static public function mkdir($path){
		return self::$defaultInstance->mkdir($path);
	}
	static public function rmdir($path){
		return self::$defaultInstance->rmdir($path);
	}
	static public function opendir($path){
		return self::$defaultInstance->opendir($path);
	}
	static public function is_dir($path){
		return self::$defaultInstance->is_dir($path);
	}
	static public function is_file($path){
		return self::$defaultInstance->is_file($path);
	}
	static public function stat($path){
		return self::$defaultInstance->stat($path);
	}
	static public function filetype($path){
		return self::$defaultInstance->filetype($path);
	}
	static public function filesize($path){
		return self::$defaultInstance->filesize($path);
	}
	static public function readfile($path){
		return self::$defaultInstance->readfile($path);
	}
	static public function is_readable($path){
		return self::$defaultInstance->is_readable($path);
	}
	static public function is_writable($path){
		return self::$defaultInstance->is_writable($path);
	}
	static public function file_exists($path){
		return self::$defaultInstance->file_exists($path);
	}
	static public function filectime($path){
		return self::$defaultInstance->filectime($path);
	}
	static public function filemtime($path){
		return self::$defaultInstance->filemtime($path);
	}
	static public function touch($path, $mtime=null){
		return self::$defaultInstance->touch($path, $mtime);
	}
	static public function file_get_contents($path){
		return self::$defaultInstance->file_get_contents($path);
	}
	static public function file_put_contents($path,$data){
		return self::$defaultInstance->file_put_contents($path,$data);
	}
	static public function unlink($path){
		return self::$defaultInstance->unlink($path);
	}
	static public function rename($path1,$path2){
		return self::$defaultInstance->rename($path1,$path2);
	}
	static public function copy($path1,$path2){
		return self::$defaultInstance->copy($path1,$path2);
	}
	static public function fopen($path,$mode){
		return self::$defaultInstance->fopen($path,$mode);
	}
	static public function toTmpFile($path){
		return self::$defaultInstance->toTmpFile($path);
	}
	static public function fromTmpFile($tmpFile,$path){
		return self::$defaultInstance->fromTmpFile($tmpFile,$path);
	}

	static public function getMimeType($path){
		return self::$defaultInstance->getMimeType($path);
	}
	static public function hash($type,$path){
		return self::$defaultInstance->hash($type,$path);
	}
	
	static public function free_space($path='/'){
		return self::$defaultInstance->free_space($path);
	}
	
	static public function search($query){
		return OC_FileCache::search($query);
	}
}

require_once('filecache.php');