<?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\Routing\Loader;

use Symfony\Component\Routing\RouteCollection;
use Symfony\Component\Config\Resource\FileResource;
use Symfony\Component\Config\Loader\FileLoader;
use Symfony\Component\Config\FileLocatorInterface;

/**
 * AnnotationFileLoader loads routing information from annotations set
 * on a PHP class and its methods.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class AnnotationFileLoader extends FileLoader
{
    protected $loader;

    /**
     * @throws \RuntimeException
     */
    public function __construct(FileLocatorInterface $locator, AnnotationClassLoader $loader)
    {
        if (!function_exists('token_get_all')) {
            throw new \RuntimeException('The Tokenizer extension is required for the routing annotation loaders.');
        }

        parent::__construct($locator);

        $this->loader = $loader;
    }

    /**
     * Loads from annotations from a file.
     *
     * @param string      $file A PHP file path
     * @param string|null $type The resource type
     *
     * @return RouteCollection A RouteCollection instance
     *
     * @throws \InvalidArgumentException When the file does not exist or its routes cannot be parsed
     */
    public function load($file, $type = null)
    {
        $path = $this->locator->locate($file);

        $collection = new RouteCollection();
        if ($class = $this->findClass($path)) {
            $collection->addResource(new FileResource($path));
            $collection->addCollection($this->loader->load($class, $type));
        }
        if (\PHP_VERSION_ID >= 70000) {
            // PHP 7 memory manager will not release after token_get_all(), see https://bugs.php.net/70098
            gc_mem_caches();
        }

        return $collection;
    }

    /**
     * {@inheritdoc}
     */
    public function supports($resource, $type = null)
    {
        return is_string($resource) && 'php' === pathinfo($resource, PATHINFO_EXTENSION) && (!$type || 'annotation' === $type);
    }

    /**
     * Returns the full class name for the first class in the file.
     *
     * @param string $file A PHP file path
     *
     * @return string|false Full class name if found, false otherwise
     */
    protected function findClass($file)
    {
        $class = false;
        $namespace = false;
        $tokens = token_get_all(file_get_contents($file));
        for ($i = 0; isset($tokens[$i]); ++$i) {
            $token = $tokens[$i];

            if (!isset($token[1])) {
                continue;
            }

            if (true === $class && T_STRING === $token[0]) {
                return $namespace.'\\'.$token[1];
            }

            if (true === $namespace && T_STRING === $token[0]) {
                $namespace = $token[1];
                while (isset($tokens[++$i][1]) && in_array($tokens[$i][0], array(T_NS_SEPARATOR, T_STRING))) {
                    $namespace .= $tokens[$i][1];
                }
                $token = $tokens[$i];
            }

            if (T_CLASS === $token[0]) {
                // Skip usage of ::class constant
                $isClassConstant = false;
                for ($j = $i - 1; $j > 0; --$j) {
                    if (!isset($tokens[$j][1])) {
                        break;
                    }

                    if (T_DOUBLE_COLON === $tokens[$j][0]) {
                        $isClassConstant = true;
                        break;
                    } elseif (!in_array($tokens[$j][0], array(T_WHITESPACE, T_DOC_COMMENT, T_COMMENT))) {
                        break;
                    }
                }

                if (!$isClassConstant) {
                    $class = true;
                }
            }

            if (T_NAMESPACE === $token[0]) {
                $namespace = true;
            }
        }

        return false;
    }
}
