<?php

/*
 * This file is part of Phraseanet
 *
 * (c) 2005-2012 Alchemy
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Alchemy\Phrasea\Loader;

require_once __DIR__ . '/Autoloader.php';

/**
 * Loop throught op cache code adapter to cache autoloading
 * OpCache code available are apc et xcache
 *
 * @license     http://opensource.org/licenses/gpl-3.0 GPLv3
 * @link        www.phraseanet.com
 */
class CacheAutoloader extends Autoloader
{
    /**
     * Array of all cache adapters
     * @var type
     */
    private $cacheAdapters = array(
        'Apc',
        'Xcache'
    );

    /**
     * The cache adapater
     * @var type
     */
    private $cacheAdapter;

    /**
     * The prefix used to store id's in cache
     * @var string
     */
    private $prefix;

    /**
     * Take a identifier cache key prefix
     * @param  string         $prefix
     * @throws \Exceptionwhen none of the op cache code are available
     */
    public function __construct($prefix, $namespace = null)
    {
        parent::__construct();

        $this->prefix = $prefix;

        foreach ($this->cacheAdapters as $className) {
            $file = sprintf("%s/%sAutoloader.php", __DIR__, $className);

            if ( ! file_exists($file)) {
                continue;
            }

            require_once $file;

            $className = sprintf("\Alchemy\Phrasea\Loader\%sAutoloader", $className);

            if ( ! class_exists($className)) {
                continue;
            }

            $method = new $className();

            if ($namespace) {
                $method->setNamespace($namespace);
            }

            if ($method instanceof LoaderStrategy && $method->isAvailable()) {
                $this->cacheAdapter = $method;
                break;
            }
        }

        if (null === $this->cacheAdapter) {
            throw new \Exception('No Cache available');
        }
    }

    /**
     * {@inheritdoc}
     */
    public function findFile($class)
    {
        $file = $this->cacheAdapter->fetch($this->prefix . $class);

        if (false === $file) {
            $this->cacheAdapter->save($this->prefix . $class, $file = parent::findFile($class));
        }

        return $file;
    }

    /**
     * {@inheritdoc}
     */
    public function register($prepend = false)
    {
        spl_autoload_register(array($this, 'loadClass'), true, $prepend);
    }

    /**
     * Get the current cache Adapter
     * @return LoaderStrategy
     */
    public function getAdapter()
    {
        return $this->cacheAdapter;
    }

    /**
     * Get the identifier cache key prefix
     * @return string
     */
    public function getPrefix()
    {
        return $this->prefix;
    }
}