<?php

/*

 * This file is part of the Symfony package.

 *

 * (c) Fabien Potencier <fabien@symfony.com>

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

namespace Symfony\Component\Templating\Loader;

use Symfony\Component\Templating\Storage\Storage;

use Symfony\Component\Templating\Storage\FileStorage;

use Symfony\Component\Templating\TemplateReferenceInterface;

/**

 * CacheLoader is a loader that caches other loaders responses

 * on the filesystem.

 *

 * This cache only caches on disk to allow PHP accelerators to cache the opcodes.

 * All other mechanism would imply the use of `eval()`.

 *

 * @author Fabien Potencier <fabien@symfony.com>

 */

class CacheLoader extends Loader

{

    protected $loader;

    protected $dir;

    /**

     * Constructor.

     *

     * @param LoaderInterface $loader A Loader instance

     * @param string          $dir    The directory where to store the cache files

     */

    public function __construct(LoaderInterface $loader, $dir)

    {

        $this->loader = $loader;

        $this->dir = $dir;

    }

    /**

     * Loads a template.

     *

     * @param TemplateReferenceInterface $template A template

     *

     * @return Storage|Boolean false if the template cannot be loaded, a Storage instance otherwise

     */

    public function load(TemplateReferenceInterface $template)

    {

        $key = md5($template->getLogicalName());

        $dir = $this->dir.DIRECTORY_SEPARATOR.substr($key, 0, 2);

        $file = substr($key, 2).'.tpl';

        $path = $dir.DIRECTORY_SEPARATOR.$file;

        if (file_exists($path)) {

            if (null !== $this->debugger) {

                $this->debugger->log(sprintf('Fetching template "%s" from cache', $template->get('name')));

            }

            return new FileStorage($path);

        }

        if (false === $storage = $this->loader->load($template)) {

            return false;

        }

        $content = $storage->getContent();

        if (!file_exists($dir)) {

            mkdir($dir, 0777, true);

        }

        file_put_contents($path, $content);

        if (null !== $this->debugger) {

            $this->debugger->log(sprintf('Storing template "%s" in cache', $template->get('name')));

        }

        return new FileStorage($path);

    }

    /**

     * Returns true if the template is still fresh.

     *

     * @param TemplateReferenceInterface $template A template

     * @param integer                    $time     The last modification time of the cached template (timestamp)

     */

    public function isFresh(TemplateReferenceInterface $template, $time)

    {

        return $this->loader->isFresh($template, $time);

    }

}