<?php
  /**
   * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */

  namespace OC\Cache;

  class FileGlobal {

  	static protected function getCacheDir() {

  		$cache_dir = get_temp_dir().'/owncloud-' . \OC_Util::getInstanceId().'/';

  		if (!is_dir($cache_dir)) {
  			mkdir($cache_dir);
  		}
  		return $cache_dir;
  	}
  
  	protected function fixKey($key) {
  		return str_replace('/', '_', $key);
  	}
  
  	public function get($key) {
  		$key = $this->fixKey($key);
  		if ($this->hasKey($key)) {
  			$cache_dir = self::getCacheDir();
  			return file_get_contents($cache_dir.$key);
  		}
  		return null;
  	}
  
  	public function set($key, $value, $ttl=0) {
  		$key = $this->fixKey($key);
  		$cache_dir = self::getCacheDir();
  		if ($cache_dir and file_put_contents($cache_dir.$key, $value)) {
  			if ($ttl === 0) {
  				$ttl = 86400; // 60*60*24
  			}
  			return touch($cache_dir.$key, time() + $ttl);
  		}
  		return false;
  	}
  
  	public function hasKey($key) {
  		$key = $this->fixKey($key);
  		$cache_dir = self::getCacheDir();
  		if ($cache_dir && is_file($cache_dir.$key)) {
  			$mtime = filemtime($cache_dir.$key);
  			if ($mtime < time()) {
  				unlink($cache_dir.$key);
  				return false;
  			}
  			return true;
  		}
  		return false;
  	}
  
  	public function remove($key) {
  		$cache_dir = self::getCacheDir();
  		if(!$cache_dir) {
  			return false;
  		}
  		$key = $this->fixKey($key);
  		return unlink($cache_dir.$key);
  	}
  
  	public function clear($prefix='') {
  		$cache_dir = self::getCacheDir();
  		$prefix = $this->fixKey($prefix);
  		if($cache_dir and is_dir($cache_dir)) {
  			$dh=opendir($cache_dir);
  			if(is_resource($dh)) {
  				while (($file = readdir($dh)) !== false) {
  					if($file!='.' and $file!='..' and ($prefix==='' || strpos($file, $prefix) === 0)) {
  						unlink($cache_dir.$file);
  					}
  				}
  			}
  		}
  	}
  
  	static public function gc() {

  		$last_run = \OC_AppConfig::getValue('core', 'global_cache_gc_lastrun', 0);

  		$now = time();
  		if (($now - $last_run) < 300) {
  			// only do cleanup every 5 minutes
  			return;
  		}

  		\OC_AppConfig::setValue('core', 'global_cache_gc_lastrun', $now);

  		$cache_dir = self::getCacheDir();
  		if($cache_dir and is_dir($cache_dir)) {
  			$dh=opendir($cache_dir);
  			if(is_resource($dh)) {
  				while (($file = readdir($dh)) !== false) {
  					if($file!='.' and $file!='..') {
  						$mtime = filemtime($cache_dir.$file);
  						if ($mtime < $now) {
  							unlink($cache_dir.$file);
  						}
  					}
  				}
  			}
  		}
  	}
  }