<?php
/**
 * ownCloud
 *
 * @author Frank Karlitschek
 * @author Jakob Sack
 * @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/>.
 *
 */

/**
 * Collection of useful functions
 */
class OC_Helper {
	private static $mimetypes=array();
	private static $tmpFiles=array();

	/**
	 * @brief Creates an url
	 * @param $app app
	 * @param $file file
	 * @returns the url
	 *
	 * Returns a url to the given app and file.
	 */
	public static function linkTo( $app, $file ){
		if( $app != '' ){
			$app_path = OC_App::getAppPath($app);
			// Check if the app is in the app folder
			if( $app_path && file_exists( $app_path.'/'.$file )){
				if(substr($file, -3) == 'php' || substr($file, -3) == 'css'){
					$urlLinkTo =  OC::$WEBROOT . '/?app=' . $app;
					$urlLinkTo .= ($file!='index.php')?'&getfile=' . urlencode($file):'';
				}else{
					$urlLinkTo =  OC_App::getAppWebPath($app) . '/' . $file;
				}
			}
			else{
				$urlLinkTo =  OC::$WEBROOT . '/' . $app . '/' . $file;
			}
		}
		else{
			if( file_exists( OC::$SERVERROOT . '/core/'. $file )){
				$urlLinkTo =  OC::$WEBROOT . '/core/'.$file;
			}
			else{
				$urlLinkTo =  OC::$WEBROOT . '/'.$file;
			}
		}

		return $urlLinkTo;
	}

	/**
	 * @brief Returns the server host
	 * @returns the server host
	 *
	 * Returns the server host, even if the website uses one or more
	 * reverse proxies
	 */
	public static function serverHost() {
		if(OC::$CLI){
			return 'localhost';
		}
		if (isset($_SERVER['HTTP_X_FORWARDED_HOST'])) {
			if (strpos($_SERVER['HTTP_X_FORWARDED_HOST'], ",") !== false) {
				$host = trim(array_pop(explode(",", $_SERVER['HTTP_X_FORWARDED_HOST'])));
			}
			else{
				$host=$_SERVER['HTTP_X_FORWARDED_HOST'];
			}
		}
		else{
			$host = $_SERVER['HTTP_HOST'];
		}
		return $host;
	}


	/**
	* @brief Returns the server protocol
	* @returns the server protocol
	*
	* Returns the server protocol. It respects reverse proxy servers and load balancers
	*/
	public static function serverProtocol() {
		if (isset($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
			$proto = strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']);
		}else{
			if(isset($_SERVER['HTTPS']) and !empty($_SERVER['HTTPS']) and ($_SERVER['HTTPS']!='off')) {
				$proto = 'https';
			}else{
				$proto = 'http';
			}
		}
		return($proto);
	}


	/**
	 * @brief Creates an absolute url
	 * @param $app app
	 * @param $file file
	 * @returns the url
	 *
	 * Returns a absolute url to the given app and file.
	 */
	public static function linkToAbsolute( $app, $file ) {
		$urlLinkTo = self::linkTo( $app, $file );
		$urlLinkTo = self::serverProtocol(). '://'  . self::serverHost() . $urlLinkTo;
		return $urlLinkTo;
	}

	/**
	 * @brief Creates an absolute url for remote use
	 * @param $service id
	 * @returns the url
	 *
	 * Returns a absolute url to the given service.
	 */
	public static function linkToRemote( $service, $add_slash = true ) {
		return self::linkToAbsolute( '', 'remote.php') . '/' . $service . (($add_slash && $service[strlen($service)-1]!='/')?'/':'');
	}

	/**
	 * @brief Creates path to an image
	 * @param $app app
	 * @param $image image name
	 * @returns the url
	 *
	 * Returns the path to the image.
	 */
	public static function imagePath( $app, $image ){
		// Read the selected theme from the config file
		$theme=OC_Config::getValue( "theme" );

		// Check if the app is in the app folder
		if( file_exists( OC::$SERVERROOT."/themes/$theme/apps/$app/img/$image" )){
			return OC::$WEBROOT."/themes/$theme/apps/$app/img/$image";
		}elseif( file_exists(OC_App::getAppPath($app)."/img/$image" )){
			return OC_App::getAppWebPath($app)."/img/$image";
		}elseif( !empty( $app ) and file_exists( OC::$SERVERROOT."/themes/$theme/$app/img/$image" )){
			return OC::$WEBROOT."/themes/$theme/$app/img/$image";
		}elseif( !empty( $app ) and file_exists( OC::$SERVERROOT."/$app/img/$image" )){
			return OC::$WEBROOT."/$app/img/$image";
		}elseif( file_exists( OC::$SERVERROOT."/themes/$theme/core/img/$image" )){
			return OC::$WEBROOT."/themes/$theme/core/img/$image";
		}elseif( file_exists( OC::$SERVERROOT."/core/img/$image" )){
			return OC::$WEBROOT."/core/img/$image";
		}else{
			echo('image not found: image:'.$image.' webroot:'.OC::$WEBROOT.' serverroot:'.OC::$SERVERROOT);
			die();
		}
	}

	/**
	 * @brief get path to icon of file type
	 * @param $mimetype mimetype
	 * @returns the url
	 *
	 * Returns the path to the image of this file type.
	 */
	public static function mimetypeIcon( $mimetype ){
		$alias=array('application/xml'=>'code/xml');
		if(isset($alias[$mimetype])){
			$mimetype=$alias[$mimetype];
		}
		// Replace slash with a minus
		$mimetype = str_replace( "/", "-", $mimetype );

		// Is it a dir?
		if( $mimetype == "dir" ){
			return OC::$WEBROOT."/core/img/filetypes/folder.png";
		}

		// Icon exists?
		if( file_exists( OC::$SERVERROOT."/core/img/filetypes/$mimetype.png" )){
			return OC::$WEBROOT."/core/img/filetypes/$mimetype.png";
		}
		//try only the first part of the filetype
		$mimetype=substr($mimetype,0,strpos($mimetype,'-'));
		if( file_exists( OC::$SERVERROOT."/core/img/filetypes/$mimetype.png" )){
			return OC::$WEBROOT."/core/img/filetypes/$mimetype.png";
		}
		else{
			return OC::$WEBROOT."/core/img/filetypes/file.png";
		}
	}

	/**
	 * @brief Make a human file size
	 * @param $bytes file size in bytes
	 * @returns a human readable file size
	 *
	 * Makes 2048 to 2 kB.
	 */
	public static function humanFileSize( $bytes ){
		if( $bytes < 1024 ){
			return "$bytes B";
		}
		$bytes = round( $bytes / 1024, 1 );
		if( $bytes < 1024 ){
			return "$bytes kB";
		}
		$bytes = round( $bytes / 1024, 1 );
		if( $bytes < 1024 ){
			return "$bytes MB";
		}

		// Wow, heavy duty for owncloud
		$bytes = round( $bytes / 1024, 1 );
		return "$bytes GB";
	}

	/**
	 * @brief Make a computer file size
	 * @param $str file size in a fancy format
	 * @returns a file size in bytes
	 *
	 * Makes 2kB to 2048.
	 *
	 * Inspired by: http://www.php.net/manual/en/function.filesize.php#92418
	 */
	public static function computerFileSize( $str ){
		$bytes = 0;
		$str=strtolower($str);

		$bytes_array = array(
			'b' => 1,
			'k' => 1024,
			'kb' => 1024,
			'mb' => 1024 * 1024,
			'm'  => 1024 * 1024,
			'gb' => 1024 * 1024 * 1024,
			'g'  => 1024 * 1024 * 1024,
			'tb' => 1024 * 1024 * 1024 * 1024,
			't'  => 1024 * 1024 * 1024 * 1024,
			'pb' => 1024 * 1024 * 1024 * 1024 * 1024,
			'p'  => 1024 * 1024 * 1024 * 1024 * 1024,
		);

		$bytes = floatval($str);

		if (preg_match('#([kmgtp]?b?)$#si', $str, $matches) && !empty($bytes_array[$matches[1]])) {
			$bytes *= $bytes_array[$matches[1]];
		}

		$bytes = round($bytes, 2);

		return $bytes;
	}

	/**
	 * @brief Recusive editing of file permissions
	 * @param $path path to file or folder
	 * @param $filemode unix style file permissions as integer
	 *
	 */
	static function chmodr($path, $filemode) {
		if (!is_dir($path))
			return chmod($path, $filemode);
		$dh = opendir($path);
		while (($file = readdir($dh)) !== false) {
			if($file != '.' && $file != '..') {
				$fullpath = $path.'/'.$file;
				if(is_link($fullpath))
					return FALSE;
				elseif(!is_dir($fullpath) && !@chmod($fullpath, $filemode))
						return FALSE;
				elseif(!self::chmodr($fullpath, $filemode))
					return FALSE;
			}
		}
		closedir($dh);
		if(@chmod($path, $filemode))
			return TRUE;
		else
			return FALSE;
	}

	/**
	 * @brief Recusive copying of folders
	 * @param string $src source folder
	 * @param string $dest target folder
	 *
	 */
	static function copyr($src, $dest) {
		if(is_dir($src)){
			if(!is_dir($dest)){
				mkdir($dest);
			}
			$files = scandir($src);
			foreach ($files as $file){
				if ($file != "." && $file != ".."){
					self::copyr("$src/$file", "$dest/$file");
				}
			}
		}elseif(file_exists($src)){
			copy($src, $dest);
		}
	}

	/**
	 * @brief Recusive deletion of folders
	 * @param string $dir path to the folder
	 *
	 */
	static function rmdirr($dir) {
		if(is_dir($dir)) {
			$files=scandir($dir);
			foreach($files as $file){
				if ($file != "." && $file != ".."){
					self::rmdirr("$dir/$file");
				}
			}
			rmdir($dir);
		}elseif(file_exists($dir)){
			unlink($dir);
		}
		if(file_exists($dir)) {
			return false;
		}
	}

	/**
	 * get the mimetype form a local file
	 * @param string path
	 * @return string
	 * does NOT work for ownClouds filesystem, use OC_FileSystem::getMimeType instead
	 */
	static function getMimeType($path){
		$isWrapped=(strpos($path,'://')!==false) and (substr($path,0,7)=='file://');

		if (@is_dir($path)) {
			// directories are easy
			return "httpd/unix-directory";
		}

		if(strpos($path,'.')){
			//try to guess the type by the file extension
			if(!self::$mimetypes || self::$mimetypes != include('mimetypes.list.php')){
				self::$mimetypes=include('mimetypes.list.php');
			}
			$extension=strtolower(strrchr(basename($path), "."));
			$extension=substr($extension,1);//remove leading .
			$mimeType=(isset(self::$mimetypes[$extension]))?self::$mimetypes[$extension]:'application/octet-stream';
		}else{
			$mimeType='application/octet-stream';
		}
		
		if($mimeType=='application/octet-stream' and function_exists('finfo_open') and function_exists('finfo_file') and $finfo=finfo_open(FILEINFO_MIME)){
			$info = @strtolower(finfo_file($finfo,$path));
			if($info){
				$mimeType=substr($info,0,strpos($info,';'));
			}
			finfo_close($finfo);
		}
		if (!$isWrapped and $mimeType=='application/octet-stream' && function_exists("mime_content_type")) {
			// use mime magic extension if available
			$mimeType = mime_content_type($path);
		}
		if (!$isWrapped and $mimeType=='application/octet-stream' && OC_Helper::canExecute("file")) {
			// it looks like we have a 'file' command,
			// lets see it it does have mime support
			$path=escapeshellarg($path);
			$fp = popen("file -i -b $path 2>/dev/null", "r");
			$reply = fgets($fp);
			pclose($fp);

			//trim the character set from the end of the response
			$mimeType=substr($reply,0,strrpos($reply,' '));

			//trim ;
			if (strpos($mimeType, ';') !== false) {
				$mimeType = strstr($mimeType, ';', true);
			}

		}
		return $mimeType;
	}

	/**
	 * get the mimetype form a data string
	 * @param string data
	 * @return string
	 */
	static function getStringMimeType($data){
		if(function_exists('finfo_open') and function_exists('finfo_file')){
			$finfo=finfo_open(FILEINFO_MIME);
			return finfo_buffer($finfo, $data);
		}else{
			$tmpFile=OC_Helper::tmpFile();
			$fh=fopen($tmpFile,'wb');
			fwrite($fh,$data,8024);
			fclose($fh);
			$mime=self::getMimeType($tmpFile);
			unset($tmpFile);
			return $mime;
		}
	}

	/**
	 * @brief Checks $_REQUEST contains a var for the $s key. If so, returns the html-escaped value of this var; otherwise returns the default value provided by $d.
	 * @param $s name of the var to escape, if set.
	 * @param $d default value.
	 * @returns the print-safe value.
	 *
	 */

	//FIXME: should also check for value validation (i.e. the email is an email).
	public static function init_var($s, $d="") {
		$r = $d;
		if(isset($_REQUEST[$s]) && !empty($_REQUEST[$s]))
			$r = stripslashes(htmlspecialchars($_REQUEST[$s]));

		return $r;
	}

	/**
	 * returns "checked"-attribut if request contains selected radio element OR if radio element is the default one -- maybe?
	 * @param string $s Name of radio-button element name
	 * @param string $v Value of current radio-button element
	 * @param string $d Value of default radio-button element
	 */
	public static function init_radio($s, $v, $d) {
		if((isset($_REQUEST[$s]) && $_REQUEST[$s]==$v) || (!isset($_REQUEST[$s]) && $v == $d))
			print "checked=\"checked\" ";
	}

	/**
	* detect if a given program is found in the search PATH
	*
	* @param  string  program name
	* @param  string  optional search path, defaults to $PATH
	* @return bool    true if executable program found in path
	*/
	public static function canExecute($name, $path = false){
		// path defaults to PATH from environment if not set
		if ($path === false) {
			$path = getenv("PATH");
		}
		// check method depends on operating system
		if (!strncmp(PHP_OS, "WIN", 3)) {
			// on Windows an appropriate COM or EXE file needs to exist
			$exts = array(".exe", ".com");
			$check_fn = "file_exists";
		} else {
			// anywhere else we look for an executable file of that name
			$exts = array("");
			$check_fn = "is_executable";
		}
		// Default check will be done with $path directories :
		$dirs = explode(PATH_SEPARATOR, $path);
		// WARNING : We have to check if open_basedir is enabled :
		$obd = ini_get('open_basedir');
		if($obd != "none")
			$obd_values = explode(PATH_SEPARATOR, $obd);
		if(count($obd_values) > 0 and $obd_values[0])
		{
			// open_basedir is in effect !
			// We need to check if the program is in one of these dirs :
			$dirs = $obd_values;
		}
		foreach($dirs as $dir)
		{
			foreach($exts as $ext)
			{
				if($check_fn("$dir/$name".$ext))
					return true;
			}
		}
		return false;
	}

	/**
	 * copy the contents of one stream to another
	 * @param resource source
	 * @param resource target
	 * @return int the number of bytes copied
	 */
	public static function streamCopy($source,$target){
		if(!$source or !$target){
			return false;
		}
		$count=0;
		while(!feof($source)){
			$count+=fwrite($target,fread($source,8192));
		}
		return $count;
	}

	/**
	 * create a temporary file with an unique filename
	 * @param string postfix
	 * @return string
	 *
	 * temporary files are automatically cleaned up after the script is finished
	 */
	public static function tmpFile($postfix=''){
		$file=get_temp_dir().'/'.md5(time().rand()).$postfix;
		$fh=fopen($file,'w');
		fclose($fh);
		self::$tmpFiles[]=$file;
		return $file;
	}

	/**
	 * create a temporary folder with an unique filename
	 * @return string
	 *
	 * temporary files are automatically cleaned up after the script is finished
	 */
	public static function tmpFolder(){
		$path=get_temp_dir().'/'.md5(time().rand());
		mkdir($path);
		self::$tmpFiles[]=$path;
		return $path.'/';
	}

	/**
	 * remove all files created by self::tmpFile
	 */
	public static function cleanTmp(){
		$leftoversFile=get_temp_dir().'/oc-not-deleted';
		if(file_exists($leftoversFile)){
			$leftovers=file($leftoversFile);
			foreach($leftovers as $file) {
				self::rmdirr($file);
			}
			unlink($leftoversFile);
		}

		foreach(self::$tmpFiles as $file){
			if(file_exists($file)){
				if(!self::rmdirr($file)) {
					file_put_contents($leftoversFile, $file."\n", FILE_APPEND);
				}
			}
		}
	}

	/**
	* Adds a suffix to the name in case the file exists
	*
	* @param $path
	* @param $filename
	* @return string
	*/
	public static function buildNotExistingFileName($path, $filename){
		if($path==='/'){
			$path='';
		}
		if ($pos = strrpos($filename, '.')) {
			$name = substr($filename, 0, $pos);
			$ext = substr($filename, $pos);
		} else {
			$name = $filename;
		}

		$newpath = $path . '/' . $filename;
		$newname = $filename;
		$counter = 2;
		while (OC_Filesystem::file_exists($newpath)) {
			$newname = $name . ' (' . $counter . ')' . $ext;
			$newpath = $path . '/' . $newname;
			$counter++;
		}

		return $newpath;
	}

	/*
	 * checks if $sub is a subdirectory of $parent
	 *
	 * @param $sub
	 * @param $parent
	 * @return bool
	 */
	public static function issubdirectory($sub, $parent){
		if($sub == null || $sub == '' || $parent == null || $parent == ''){
			return false;
		}
		$realpath_sub = realpath($sub);
		$realpath_parent = realpath($parent);
		if(($realpath_sub == false && substr_count($realpath_sub, './') != 0) || ($realpath_parent == false && substr_count($realpath_parent, './') != 0)){ //it checks for  both ./ and ../
			return false;
		}
		if($realpath_sub && $realpath_sub != '' && $realpath_parent && $realpath_parent != ''){
			if(substr($realpath_sub, 0, strlen($realpath_parent)) == $realpath_parent){
				return true;
			}
		}else{
			if(substr($sub, 0, strlen($parent)) == $parent){
				return true;
			}
		}
		/*echo 'SUB: ' . $sub . "\n";
		echo 'PAR: ' . $parent . "\n";
		echo 'REALSUB: ' . $realpath_sub . "\n";
		echo 'REALPAR: ' . $realpath_parent . "\n";
		echo substr($realpath_sub, 0, strlen($realpath_parent));
		exit;*/
		return false;
	}

	/**
	* @brief Returns an array with all keys from input lowercased or uppercased. Numbered indices are left as is.
	*
	* @param $input The array to work on
	* @param $case Either MB_CASE_UPPER or MB_CASE_LOWER (default)
	* @param $encoding The encoding parameter is the character encoding. Defaults to UTF-8
	* @return array
	*
	* Returns an array with all keys from input lowercased or uppercased. Numbered indices are left as is.
	* based on http://www.php.net/manual/en/function.array-change-key-case.php#107715
	*
	*/
	public static function mb_array_change_key_case($input, $case = MB_CASE_LOWER, $encoding = 'UTF-8'){
		$case = ($case != MB_CASE_UPPER) ? MB_CASE_LOWER : MB_CASE_UPPER;
		$ret = array();
		foreach ($input as $k => $v) {
			$ret[mb_convert_case($k, $case, $encoding)] = $v;
		}
		return $ret;
	}

	/**
	* @brief replaces a copy of string delimited by the start and (optionally) length parameters with the string given in replacement.
	*
	* @param $input The input string. .Opposite to the PHP build-in function does not accept an array.
	* @param $replacement The replacement string.
	* @param $start If start is positive, the replacing will begin at the start'th offset into string. If start is negative, the replacing will begin at the start'th character from the end of string.
	* @param $length Length of the part to be replaced
	* @param $encoding The encoding parameter is the character encoding. Defaults to UTF-8
	* @return string
	*
	*/
	public static function mb_substr_replace($string, $replacement, $start, $length = null, $encoding = 'UTF-8') {
		$start = intval($start);
		$length = intval($length);
		$string = mb_substr($string, 0, $start, $encoding) .
		          $replacement .
		          mb_substr($string, $start+$length, mb_strlen($string, 'UTF-8')-$start, $encoding);

		return $string;
	}

	/**
	* @brief Replace all occurrences of the search string with the replacement string
	*
	* @param $search The value being searched for, otherwise known as the needle. String.
	* @param $replace The replacement string.
	* @param $subject The string or array being searched and replaced on, otherwise known as the haystack.
	* @param $encoding The encoding parameter is the character encoding. Defaults to UTF-8
	* @param $count If passed, this will be set to the number of replacements performed.
	* @return string
	*
	*/
	public static function mb_str_replace($search, $replace, $subject, $encoding = 'UTF-8', &$count = null) {
		$offset = -1;
		$length = mb_strlen($search, $encoding);
		while(($i = mb_strrpos($subject, $search, $offset, $encoding))) {
			$subject = OC_Helper::mb_substr_replace($subject, $replace, $i, $length);
			$offset = $i - mb_strlen($subject, $encoding) - 1;
			$count++;
		}
		return $subject;
	}
}