<?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.
 */

require_once 'Archive/Tar.php';

class OC_Archive_TAR extends OC_Archive{
	const PLAIN=0;
	const GZIP=1;
	const BZIP=2;

	private $fileList;
	private $cachedHeaders;

	/**
	 * @var Archive_Tar tar
	 */
	private $tar=null;
	private $path;

	function __construct($source) {
		$types=array(null,'gz','bz');
		$this->path=$source;
		$this->tar=new Archive_Tar($source, $types[self::getTarType($source)]);
	}

	/**
	 * try to detect the type of tar compression
	 * @param string file
	 * @return str
	 */
	static public function getTarType($file) {
		if(strpos($file, '.')) {
			$extension=substr($file, strrpos($file, '.'));
			switch($extension) {
				case 'gz':
				case 'tgz':
					return self::GZIP;
				case 'bz':
				case 'bz2':
					return self::BZIP;
				default:
					return self::PLAIN;
			}
		}else{
			return self::PLAIN;
		}
	}

	/**
	 * add an empty folder to the archive
	 * @param string path
	 * @return bool
	 */
	function addFolder($path) {
		$tmpBase=OC_Helper::tmpFolder();
		if(substr($path, -1, 1)!='/') {
			$path.='/';
		}
		if($this->fileExists($path)) {
			return false;
		}
		$parts=explode('/', $path);
		$folder=$tmpBase;
		foreach($parts as $part) {
			$folder.='/'.$part;
			if(!is_dir($folder)) {
				mkdir($folder);
			}
		}
		$result=$this->tar->addModify(array($tmpBase.$path), '', $tmpBase);
		rmdir($tmpBase.$path);
		$this->fileList=false;
		$this->cachedHeaders=false;
		return $result;
	}
	/**
	 * add a file to the archive
	 * @param string path
	 * @param string source either a local file or string data
	 * @return bool
	 */
	function addFile($path, $source='') {
		if($this->fileExists($path)) {
			$this->remove($path);
		}
		if($source and $source[0]=='/' and file_exists($source)) {
			$header=array();
			$dummy='';
			$this->tar->_openAppend();
			$result=$this->tar->_addfile($source, $header, $dummy, $dummy, $path);
		}else{
			$result=$this->tar->addString($path, $source);
		}
		$this->fileList=false;
		$this->cachedHeaders=false;
		return $result;
	}

	/**
	 * rename a file or folder in the archive
	 * @param string source
	 * @param string dest
	 * @return bool
	 */
	function rename($source, $dest) {
		//no proper way to delete, rename entire archive, rename file and remake archive
		$tmp=OCP\Files::tmpFolder();
		$this->tar->extract($tmp);
		rename($tmp.$source, $tmp.$dest);
		$this->tar=null;
		unlink($this->path);
		$types=array(null, 'gz', 'bz');
		$this->tar=new Archive_Tar($this->path, $types[self::getTarType($this->path)]);
		$this->tar->createModify(array($tmp), '', $tmp.'/');
		$this->fileList=false;
		$this->cachedHeaders=false;
		return true;
	}

	private function getHeader($file) {
		if ( ! $this->cachedHeaders ) {
			$this->cachedHeaders = $this->tar->listContent();
		}
		foreach($this->cachedHeaders as $header) {
			if(        $file     == $header['filename']
				or     $file.'/' == $header['filename']
				or '/'.$file.'/' == $header['filename']
				or '/'.$file     == $header['filename'])
			{
				return $header;
			}
		}
		return null;
	}

	/**
	 * get the uncompressed size of a file in the archive
	 * @param string path
	 * @return int
	 */
	function filesize($path) {
		$stat=$this->getHeader($path);
		return $stat['size'];
	}
	/**
	 * get the last modified time of a file in the archive
	 * @param string path
	 * @return int
	 */
	function mtime($path) {
		$stat=$this->getHeader($path);
		return $stat['mtime'];
	}

	/**
	 * get the files in a folder
	 * @param path
	 * @return array
	 */
	function getFolder($path) {
		$files=$this->getFiles();
		$folderContent=array();
		$pathLength=strlen($path);
		foreach($files as $file) {
			if($file[0]=='/') {
				$file=substr($file, 1);
			}
			if(substr($file, 0, $pathLength)==$path and $file!=$path) {
				$result=substr($file, $pathLength);
				if($pos=strpos($result, '/')) {
					$result=substr($result, 0, $pos+1);
				}
				if(array_search($result, $folderContent)===false) {
					$folderContent[]=$result;
				}
			}
		}
		return $folderContent;
	}
	/**
	 *get all files in the archive
	 * @return array
	 */
	function getFiles() {
		if($this->fileList) {
			return $this->fileList;
		}
		if ( ! $this->cachedHeaders ) {
			$this->cachedHeaders = $this->tar->listContent();
		}
		$files=array();
		foreach($this->cachedHeaders as $header) {
			$files[]=$header['filename'];
		}
		$this->fileList=$files;
		return $files;
	}
	/**
	 * get the content of a file
	 * @param string path
	 * @return string
	 */
	function getFile($path) {
		return $this->tar->extractInString($path);
	}
	/**
	 * extract a single file from the archive
	 * @param string path
	 * @param string dest
	 * @return bool
	 */
	function extractFile($path, $dest) {
		$tmp=OCP\Files::tmpFolder();
		if(!$this->fileExists($path)) {
			return false;
		}
		if($this->fileExists('/'.$path)) {
			$success=$this->tar->extractList(array('/'.$path), $tmp);
		}else{
			$success=$this->tar->extractList(array($path), $tmp);
		}
		if($success) {
			rename($tmp.$path, $dest);
		}
		OCP\Files::rmdirr($tmp);
		return $success;
	}
	/**
	 * extract the archive
	 * @param string path
	 * @param string dest
	 * @return bool
	 */
	function extract($dest) {
		return $this->tar->extract($dest);
	}
	/**
	 * check if a file or folder exists in the archive
	 * @param string path
	 * @return bool
	 */
	function fileExists($path) {
		$files=$this->getFiles();
		if((array_search($path, $files)!==false) or (array_search($path.'/', $files)!==false)) {
			return true;
		}else{
			$folderPath=$path;
			if(substr($folderPath, -1, 1)!='/') {
				$folderPath.='/';
			}
			$pathLength=strlen($folderPath);
			foreach($files as $file) {
				if(strlen($file)>$pathLength and substr($file, 0, $pathLength)==$folderPath) {
					return true;
				}
			}
		}
		if($path[0]!='/') {//not all programs agree on the use of a leading /
			return $this->fileExists('/'.$path);
		}else{
			return false;
		}
	}

	/**
	 * remove a file or folder from the archive
	 * @param string path
	 * @return bool
	 */
	function remove($path) {
		if(!$this->fileExists($path)) {
			return false;
		}
		$this->fileList=false;
		$this->cachedHeaders=false;
		//no proper way to delete, extract entire archive, delete file and remake archive
		$tmp=OCP\Files::tmpFolder();
		$this->tar->extract($tmp);
		OCP\Files::rmdirr($tmp.$path);
		$this->tar=null;
		unlink($this->path);
		$this->reopen();
		$this->tar->createModify(array($tmp), '', $tmp);
		return true;
	}
	/**
	 * get a file handler
	 * @param string path
	 * @param string mode
	 * @return resource
	 */
	function getStream($path, $mode) {
		if(strrpos($path, '.')!==false) {
			$ext=substr($path, strrpos($path, '.'));
		}else{
			$ext='';
		}
		$tmpFile=OCP\Files::tmpFile($ext);
		if($this->fileExists($path)) {
			$this->extractFile($path, $tmpFile);
		}elseif($mode=='r' or $mode=='rb') {
			return false;
		}
		if($mode=='r' or $mode=='rb') {
			return fopen($tmpFile, $mode);
		}else{
			OC_CloseStreamWrapper::$callBacks[$tmpFile]=array($this,'writeBack');
			self::$tempFiles[$tmpFile]=$path;
			return fopen('close://'.$tmpFile, $mode);
		}
	}

	private static $tempFiles=array();
	/**
	 * write back temporary files
	 */
	function writeBack($tmpFile) {
		if(isset(self::$tempFiles[$tmpFile])) {
			$this->addFile(self::$tempFiles[$tmpFile], $tmpFile);
			unlink($tmpFile);
		}
	}

	/**
	 * reopen the archive to ensure everything is written
	 */
	private function reopen() {
		if($this->tar) {
			$this->tar->_close();
			$this->tar=null;
		}
		$types=array(null,'gz','bz');
		$this->tar=new Archive_Tar($this->path, $types[self::getTarType($this->path)]);
	}
}