<?php
/**
 * Updates the fiels of an aplication
 *
 * @name Application Update
 * @author Alexandru Savin hide@address.com
 * @version 1.00
 * @http://www.ozz.ro/appupdate
 */

class appupdate {
	var $server_address;
	var $current_version;
	var $server_version;
	var $updated_files_list;
	var $writable_files;
	var $charlen_file;

	/**
	 * The constructor for the class
	 *
	 * @param string $server_address
	 * @param integer $current_version
	 * @return update
	 */

	function appupdate($server_address, $current_version){
		$this->server_address=$server_address;
		$this->current_version=$current_version;
		$this->get_server_variables();
	}

	/**
	 * Checks whatever there are updates for the software
	 *
	 */

	function check_for_updates() {
		if($this->current_version < $this->server_version)
			return true;
		else
			return false;
	}

	/**
	 * Connects to the server and retrives the variables needed for the update.
	 *
	 */

	private function get_server_variables() {
		$variables_file_address=$this->server_address."/update_vars.php";
		$file=file($variables_file_address);
		foreach ($file as $line) {
			if(strstr($line,"[server_version]")!==false)
				$this->server_version=trim(substr($line,strpos($line,"=")+1));
			elseif(strstr($line,"[server_file_list]")!==false)
				$this->updated_files_list[]=trim(substr($line,strpos($line,"=")+1));
			elseif(strstr($line,"[charlen_file]")!==false)
				$this->charlen_file[]=trim(substr($line,strpos($line,"=")+1));
		}
	}

	/**
	 * Returns the files to be updated in a html format.
	 *
	 * @return string
	 */
	function print_updated_files_list() {
		$filelist="";
		foreach ($this->updated_files_list as $filename) {
			$filelist.=$filename."<br>";
		}
		return $filelist;
	}

	/**
	 * Single file writable atribute check.
	 * Thanks to legolas558.users.sf.net
	 *
	 * @param unknown_type $path
	 * @return true
	 */

	private function is__writable($path) {
	//will work in despite of Windows ACLs bug
	//NOTE: use a trailing slash for folders!!!
	//see http://bugs.php.net/bug.php?id=27609
	//see http://bugs.php.net/bug.php?id=30931

	    if ($path{strlen($path)-1}=='/') // recursively return a temporary file path
	        return is__writable($path.uniqid(mt_rand()).'.tmp');
	    else if (is_dir($path))
	        return is__writable($path.'/'.uniqid(mt_rand()).'.tmp');
	    // check tmp file for read/write capabilities
	    $rm = file_exists($path);
	    $f = @fopen($path, 'a');
	    if ($f===false)
	        return false;
	    fclose($f);
	    if (!$rm)
	        unlink($path);
	    return true;
	}

	/**
	 * Checks watever the files are writable or not. Return boolean and the list of filles in a string;
	 *
	 * @return true
	 */

	function check_if_are_writable() {
		$err="";
		foreach ($this->updated_files_list as $filename) {
			if($this->is__writable($filename)===true) {
				$this->writable_files[$filename]="yes";
			} else {
				$this->writable_files[$filename]="no";
				$err=1;
			}
		}
		return $err==1?false:true;
	}

	function get_total_charlen() {
		foreach($this->charlen_file as $len) {
			$total_len+=$len;
		}
		return $total_len;
	}


	/**
	 * Updates the files with the ones from the server
	 *
	 * @return error string for error or true
	 */

	function update_files() {
		$err="";
		if($this->check_if_are_writable()===true) {
			$i=0;
			foreach ($this->updated_files_list as $filename) {

				$updated_file_url=$this->server_address."/update_".$this->server_version."/".str_replace(".php",".upd",$filename);
				$updated_file_contents=file_get_contents($updated_file_url);

				if($updated_file_contents!="") {

					$file=fopen($filename,"w");
					fwrite($file,$updated_file_contents);
					fclose($file);
				}

				$len_till_now+=$this->charlen_file[$i];
				$perc=$len_till_now*100/$this->get_total_charlen();
				echo str_repeat(".",$perc);
				$i++;
			}
		} else {
			$err="Some file or all are not writable.";

			foreach ($this->writable_files as $id=>$value) {
				if($value == "no") {
					echo $id." file is not writable!<br>";
				}
			}

			$err.="No file was updated.<br>";
		}
		return $err==""?true:$err;
	}
}
?>