<?php
/**
 *  Zoocache - Intelligent, neatly integrating, easily extenable output caching tool
 *  Copyright (C) 2011  Marcel Klehr <hide@address.com>
 *
 *  This program is free software; you can redistribute it and/or modify it under the 
 *  terms of the GNU General Public License as published by the Free Software Foundation;
 *  either version 3 of the License, or (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with this program;
 *  if not, see <http://www.gnu.org/licenses/>.
 *
 * @package Zoocache
 * @author Marcel Klehr <hide@address.com>
 * @copyright (c) 2011, Marcel Klehr
 */
namespace Zoo\drivers;
use \Zoo;

class File implements Zoo\Driver
{
	function install()
	{
		if(!is_dir($dir = Zoo\Config::get('file.dir')))
			mkdir($dir);
		return;
	}
	
	function get($key)
	{		
		$file = Zoo\Config::get('file.dir') . '/zoo.'.$key;
		
		// Open file
		if (($fp = @fopen($file, 'rb')) === FALSE)
		{
			Zoo\Cache::log('Couldn\'t open cache file');
			return FALSE;
		}
		
		// Get a shared lock
		flock($fp, LOCK_SH);
		
		Zoo\Cache::log('Reading cache file');
		
		$data = file_get_contents($file);

		// Release lock
		flock($fp, LOCK_UN);
		fclose($fp);
		
		$cache = unserialize($data);
		
		Zoo\Cache::log('Parsing cache data');
		
		if(!is_array($cache))
			return FALSE;
		
		return $cache;
	}
	
	function store($key, $data, $timestamp, $size, $crc)
	{
		$cache = serialize(array('data'=>$data, 'timestamp'=>$timestamp, 'size'=>$size, 'crc'=>$crc));
		
		$file = Zoo\Config::get('file.dir') . '/zoo.'.$key;
		if(file_exists($file))
			unlink($file);
		
		$return = FALSE;
		// Lock file, ignore warnings as we might be creating this file
		$fpt = @fopen($file, 'rb');
		@flock($fpt, LOCK_EX);

		// php.net suggested I should use wb to make it work under Windows
		$fp=fopen($file, 'wb+');
		if(!$fp)
		{
			// Strange! We are not able to write the file!
			Zoo\Cache::log("Failed to open for write of $file");
		} else {
			fwrite($fp, $cache, strlen($cache));
			fclose($fp);
			$return = TRUE;
			
			Zoo\Cache::log("Wrote cache to file: $file");
		}

		// Release lock
		@flock($fpt, LOCK_UN);
		@fclose($fpt);
		
		// Return
		return $return;
	}
	
	function resetCache()
	{
		self::emptyDir( Zoo\Config::get('file.dir') );
	}
	
	static function emptyDir($directory)
	{
		if(substr($directory,-1) == "/") {
			$directory = substr($directory,0,-1);
		}

		if(!file_exists($directory) || !is_dir($directory)) {
			return false;
		} elseif(!is_readable($directory)) {
			return false;
		} else {
			$directoryHandle = opendir($directory);
		   
			while ($contents = readdir($directoryHandle)) {
				if($contents != '.' && $contents != '..') {
					$path = $directory . "/" . $contents;
				   
					if(is_dir($path)) {
						deleteAll($path);
					} else {
						unlink($path);
					}
				}
			}
		   
			closedir($directoryHandle);
		   
			return true;
		}
	}
}

/**
 * Register Driver
 */
Zoo\Cache::$driver = new File;
?>