<?php
/**
 * Translation table cache.
 * @author     Wei Zhuo <weizhuo[at]gmail[dot]com>
 * @version    $Id: sfMessageCache.class.php 4340 2007-06-23 06:47:05Z fabien $
 * @package    symfony
 * @subpackage i18n
 */

/**
 * Cache the translation table into the file system.
 * It can cache each cataloug+variant or just the whole section.
 *
 * @package System.I18N.core
 * @author $Author: weizhuo $
 * @version $Id: sfMessageCache.class.php 4340 2007-06-23 06:47:05Z fabien $
 */
class sfMessageCache
{
  /**
   * Cache Lite instance.
   */
  protected $cache;

  /**
   * Cache life time, default is 1 year.
   */
  protected $lifetime = 3153600;

  /**
   * Creates a new Translation cache.
   *
   * @param string $cacheDir Directory to store the cache files.
   */
  public function initialize($options = array())
  {
    $this->cache = new sfFileCache();
    $this->cache->initialize($options);
  }

  /**
   * Gets the cache life time.
   *
   * @return int Cache life time.
   */
  public function getLifeTime()
  {
    return $this->lifetime;
  }

  /**
   * Sets the cache life time.
   *
   * @param int $time Cache life time.
   */
  public function setLifeTime($time)
  {
    $this->lifetime = intval($time);
  }

  /**
   * Gets the cache file ID based section and locale.
   *
   * @param string $catalogue The translation section.
   * @param string $culture The translation locale, e.g. "en_AU".
   */
  protected function getID($catalogue, $culture)
  {
    return $culture;
  }

  /**
   * Gets the cache file GROUP based section and locale.
   *
   * @param string $catalogue The translation section.
   * @param string $culture The translation locale, e.g. "en_AU".
   */
  protected function getGroup($catalogue, $culture)
  {
    return $catalogue;
  }

  /**
   * Gets the data from the cache.
   *
   * @param string $catalogue The translation section.
   * @param string $culture The translation locale, e.g. "en_AU".
   * @param string $filename If the source is a file, this file's modified time is newer than the cache's modified time, no cache hit.
   * @return mixed Boolean FALSE if no cache hit. Otherwise, translation
   * table data for the specified section and locale.
   */
  public function get($catalogue, $culture, $lastmodified = 0)
  {
    $ID = $this->getID($catalogue, $culture);
    $group = $this->getGroup($catalogue, $culture);

    if ($lastmodified <= 0 || $lastmodified > $this->cache->lastModified($ID, $group))
    {
      return false;
    }

    return unserialize($this->cache->get($ID, $group));
  }

  /**
   * Saves the data to cache for the specified section and locale.
   *
   * @param array $data The data to save.
   * @param string $catalogue The translation section.
   * @param string $culture The translation locale, e.g. "en_AU".
   */
  public function save($data, $catalogue, $culture)
  {
    $ID = $this->getID($catalogue, $culture);
    $group = $this->getGroup($catalogue, $culture);

    return $this->cache->set($ID, $group, serialize($data));
  }

  /**
   * Cleans up the cache for the specified section and locale.
   *
   * @param string $catalogue The translation section.
   * @param string $culture The translation locale, e.g. "en_AU".
   */
  public function clean($catalogue, $culture)
  {
    $group = $this->getGroup($catalogue, $culture);
    $this->cache->clean($group);
  }

  /**
   * Flushes the cache. Deletes all the cache files.
   */
  public function clear()
  {
    $this->cache->clean();
  }
}