<?php

/*

  Belokan Micro Framework

  Licensed under GNU GPL

  http://gitorious.org/belokan

  ---

  Belokan/Cache.php:

  Cache system

*/

class Belokan_Cache {

  private

    $_file,

    $_updateType,

    $_updateValue,

    $_buffer;

  public function __construct ($key=null, $cond_type='time', $cond_value='3600')

  {

    $config = Belokan_Config::getInstance();

    if ($key == null) $key = md5($_SERVER['REQUEST_URI']);

    if ($config->exists('dir', 'cache'))

      $this->_file = $config->get('dir', 'cache').$key.'.cache';

    else if ($config->get('log', 'belokan')) {

      Belokan_Log::getInstance()->add('Belokan', 'ERROR: No cache directory specified in the configuration.');

      exit;

    }

    $this->_updateType = $cond_type;

    $this->_updateValue = $cond_value;

    $this->_buffer = null;

  }

  public function get ()

  {

    if (!file_exists($this->_file)) return false;

    if ($this->_updateType == 'forced') return false;

    if ($this->_updateType == 'time' && (time() - filemtime($this->_file)) > $this->_updateValue)

      return false;

    if ($this->_updateType == 'date' && date($this->_updateValue, filemtime($this->_file)) != date($this->_updateValue))

      return false;

    readfile($this->_file);

    return true;

  }

  public function start ()

  {

    ob_start();

  }

  public function end ()

  {

    $this->_buffer = ob_get_clean();

    $this->save();

    echo $this->_buffer;

  }

  private function save ()

  {

    if ($cacheFile = fopen($this->_file, 'w')) {

      fwrite($cacheFile, $this->_buffer);

      fclose($cacheFile);

    }

  }

}