<?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\Storage;

/**
 * Storage backend class for providing common filesystem operation methods
 * which are not storage-backend specific.
 *
 * \OC\Files\Storage\Common is never used directly; it is extended by all other
 * storage backends, where its methods may be overridden, and additional
 * (backend-specific) methods are defined.
 *
 * Some \OC\Files\Storage\Common methods call functions which are first defined
 * in classes which extend it, e.g. $this->stat() .
 */

abstract class Common implements \OC\Files\Storage\Storage {

	public function __construct($parameters) {}
	public function is_dir($path) {
		return $this->filetype($path)=='dir';
	}
	public function is_file($path) {
		return $this->filetype($path)=='file';
	}
	public function filesize($path) {
		if($this->is_dir($path)) {
			return 0;//by definition
		}else{
			$stat = $this->stat($path);
			return $stat['size'];
		}
	}
	public function isCreatable($path) {
		if ($this->is_dir($path) && $this->isUpdatable($path)) {
			return true;
		}
		return false;
	}
	public function isDeletable($path) {
		return $this->isUpdatable($path);
	}
	public function isSharable($path) {
		return $this->isReadable($path);
	}
	public function getPermissions($path){
		$permissions = 0;
		if($this->isCreatable($path)) {
			$permissions |= \OCP\PERMISSION_CREATE;
		}
		if($this->isReadable($path)) {
			$permissions |= \OCP\PERMISSION_READ;
		}
		if($this->isUpdatable($path)) {
			$permissions |= \OCP\PERMISSION_UPDATE;
		}
		if($this->isDeletable($path)) {
			$permissions |= \OCP\PERMISSION_DELETE;
		}
		if($this->isSharable($path)) {
			$permissions |= \OCP\PERMISSION_SHARE;
		}
		return $permissions;
	}
	public function filemtime($path) {
		$stat = $this->stat($path);
		return $stat['mtime'];
	}
	public function file_get_contents($path) {
		$handle = $this->fopen($path, "r");
		if(!$handle) {
			return false;
		}
		$size=$this->filesize($path);
		if($size==0) {
			return '';
		}
		return fread($handle, $size);
	}
	public function file_put_contents($path, $data) {
		$handle = $this->fopen($path, "w");
		return fwrite($handle, $data);
	}
	public function rename($path1, $path2) {
		if($this->copy($path1, $path2)) {
			return $this->unlink($path1);
		}else{
			return false;
		}
	}
	public function copy($path1, $path2) {
		$source=$this->fopen($path1, 'r');
		$target=$this->fopen($path2, 'w');
		$count=\OC_Helper::streamCopy($source, $target);
		return $count>0;
	}

	/**
	 * @brief Deletes all files and folders recursively within a directory
	 * @param string $directory The directory whose contents will be deleted
	 * @param bool $empty Flag indicating whether directory will be emptied
	 * @returns bool
	 *
	 * @note By default the directory specified by $directory will be
	 * deleted together with its contents. To avoid this set $empty to true
	 */
	public function deleteAll( $directory, $empty = false ) {
		$directory = trim($directory, '/');

		if ( !$this->file_exists( \OCP\USER::getUser() . '/' . $directory )
			|| !$this->is_dir( \OCP\USER::getUser() . '/' . $directory ) ) {
			return false;
		} elseif( !$this->isReadable( \OCP\USER::getUser() . '/' . $directory ) ) {
			return false;
		} else {
			$directoryHandle = $this->opendir( \OCP\USER::getUser() . '/' . $directory );
			while ( $contents = readdir( $directoryHandle ) ) {
				if ( $contents != '.' && $contents != '..') {
					$path = $directory . "/" . $contents;
					if ( $this->is_dir( $path ) ) {
						$this->deleteAll( $path );
					} else {
						$this->unlink( \OCP\USER::getUser() .'/' . $path ); // TODO: make unlink use same system path as is_dir
					}
				}
			}
			//$this->closedir( $directoryHandle ); // TODO: implement closedir in OC_FSV
			if ( $empty == false ) {
				if ( !$this->rmdir( $directory ) ) {
					return false;
				}
			}
			return true;
		}

	}
	public function getMimeType($path) {
		if(!$this->file_exists($path)) {
			return false;
		}
		if($this->is_dir($path)) {
			return 'httpd/unix-directory';
		}
		$source=$this->fopen($path, 'r');
		if(!$source) {
			return false;
		}
		$head=fread($source, 8192);//8kb should suffice to determine a mimetype
		if($pos=strrpos($path, '.')) {
			$extension=substr($path, $pos);
		}else{
			$extension='';
		}
		$tmpFile=\OC_Helper::tmpFile($extension);
		file_put_contents($tmpFile, $head);
		$mime=\OC_Helper::getMimeType($tmpFile);
		unlink($tmpFile);
		return $mime;
	}
	public function hash($type, $path, $raw = false) {
		$tmpFile=$this->getLocalFile($path);
		$hash=hash($type, $tmpFile, $raw);
		unlink($tmpFile);
		return $hash;
	}
	public function search($query) {
		return $this->searchInDir($query);
	}
	public function getLocalFile($path) {
		return $this->toTmpFile($path);
	}
	private function toTmpFile($path) {//no longer in the storage api, still useful here
		$source=$this->fopen($path, 'r');
		if(!$source) {
			return false;
		}
		if($pos=strrpos($path, '.')) {
			$extension=substr($path, $pos);
		}else{
			$extension='';
		}
		$tmpFile=\OC_Helper::tmpFile($extension);
		$target=fopen($tmpFile, 'w');
		\OC_Helper::streamCopy($source, $target);
		return $tmpFile;
	}
	public function getLocalFolder($path) {
		$baseDir=\OC_Helper::tmpFolder();
		$this->addLocalFolder($path, $baseDir);
		return $baseDir;
	}
	private function addLocalFolder($path, $target) {
		if($dh=$this->opendir($path)) {
			while($file=readdir($dh)) {
				if($file!=='.' and $file!=='..') {
					if($this->is_dir($path.'/'.$file)) {
						mkdir($target.'/'.$file);
						$this->addLocalFolder($path.'/'.$file, $target.'/'.$file);
					}else{
						$tmp=$this->toTmpFile($path.'/'.$file);
						rename($tmp, $target.'/'.$file);
					}
				}
			}
		}
	}

	protected function searchInDir($query, $dir='') {
		$files=array();
		$dh=$this->opendir($dir);
		if($dh) {
			while($item=readdir($dh)) {
				if ($item == '.' || $item == '..') continue;
				if(strstr(strtolower($item), strtolower($query))!==false) {
					$files[]=$dir.'/'.$item;
				}
				if($this->is_dir($dir.'/'.$item)) {
					$files=array_merge($files, $this->searchInDir($query, $dir.'/'.$item));
				}
			}
		}
		return $files;
	}

	/**
	 * check if a file or folder has been updated since $time
	 * @param string $path
	 * @param int $time
	 * @return bool
	 */
	public function hasUpdated($path, $time) {
		return $this->filemtime($path)>$time;
	}

	public function getCache($path=''){
		return new \OC\Files\Cache\Cache($this);
	}

	public function getScanner($path=''){
		return new \OC\Files\Cache\Scanner($this);
	}

	public function getPermissionsCache($path=''){
		return new \OC\Files\Cache\Permissions($this);
	}

	public function getWatcher($path=''){
		return new \OC\Files\Cache\Watcher($this);
	}

	/**
	 * get the owner of a path
	 * @param string $path The path to get the owner
	 * @return string uid or false
	 */
	public function getOwner($path) {
		return \OC_User::getUser();
	}

	/**
	 * get the ETag for a file or folder
	 *
	 * @param string $path
	 * @return string
	 */
	public function getETag($path){
		$ETagFunction = \OC_Connector_Sabre_Node::$ETagFunction;
		if($ETagFunction) {
			$hash = call_user_func($ETagFunction, $path);
			return $hash;
		}else{
			return uniqid();
		}
	}
	
	/**
	 * clean a path, i.e. remove all redundant '.' and '..'
	 * making sure that it can't point to higher than '/'
	 * @param $path The path to clean
	 * @return string cleaned path
	 */
	public function cleanPath($path) {
		if (strlen($path) == 0 or $path[0] != '/') {
			$path = '/' . $path;
		}
		
		$output = array();
		foreach (explode('/', $path) as $chunk) {
			if ($chunk == '..') {
				array_pop($output);
			} else if ($chunk == '.') {
			} else {
				$output[] = $chunk;
			}
		}
		return implode('/', $output);
	}
}