<?php

namespace Symfony\Components\Routing\Loader;

use Symfony\Components\Routing\RouteCollection;
use Symfony\Components\Routing\Route;
use Symfony\Components\Routing\FileResource;
use Symfony\Components\Yaml\Yaml;

/*
 * This file is part of the symfony framework.
 *
 * (c) Fabien Potencier <fabien.potencier@symfony-project.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

/**
 * YamlFileLoader loads Yaml routing files.
 *
 * @package    symfony
 * @subpackage routing
 * @author     Fabien Potencier <fabien.potencier@symfony-project.com>
 */
class YamlFileLoader extends FileLoader
{
  /**
   * Loads a Yaml file.
   *
   * @param  string $file A Yaml file path
   *
   * @return RouteCollection A RouteCollection instance
   *
   * @throws \InvalidArgumentException When route can't be parsed
   */
  public function load($file)
  {
    $path = $this->findFile($file);

    $config = $this->loadFile($path);

    $collection = new RouteCollection();
    $collection->addResource(new FileResource($path));

    foreach ($config as $name => $config)
    {
      if (isset($config['resource']))
      {
        $this->parseImport($collection, $name, $config, $path);
      }
      elseif (isset($config['pattern']))
      {
        $this->parseRoute($collection, $name, $config, $path);
      }
      else
      {
        throw new \InvalidArgumentException(sprintf('Unable to parse the "%s" route.', $name));
      }
    }

    return $collection;
  }

  /**
   * @throws \InvalidArgumentException When config pattern is not defined for the given route
   */
  protected function parseRoute(RouteCollection $collection, $name, $config, $file)
  {
    $defaults = isset($config['defaults']) ? $config['defaults'] : array();
    $requirements = isset($config['requirements']) ? $config['requirements'] : array();
    $options = isset($config['options']) ? $config['options'] : array();

    if (!isset($config['pattern']))
    {
      throw new \InvalidArgumentException(sprintf('You must define a "pattern" for the "%s" route.', $name));
    }

    $route = new Route($config['pattern'], $defaults, $requirements, $options);

    $collection->addRoute($name, $route);
  }

  /**
   * @throws \InvalidArgumentException When import resource is not defined
   */
  protected function parseImport(RouteCollection $collection, $name, $import, $file)
  {
    if (!isset($import['resource']))
    {
      throw new \InvalidArgumentException(sprintf('You must define a "resource" when importing (%s).', $name));
    }

    $class = null;
    if (isset($import['class']) && $import['class'] !== get_class($this))
    {
      $class = $import['class'];
    }
    else
    {
      // try to detect loader with the extension
      switch (pathinfo($import['resource'], PATHINFO_EXTENSION))
      {
        case 'xml':
          $class = 'Symfony\\Components\\Routing\\Loader\\XmlFileLoader';
          break;
      }
    }

    $loader = null === $class ? $this : new $class($this->paths);

    $importedFile = $this->getAbsolutePath($import['resource'], dirname($file));

    $collection->addCollection($loader->load($importedFile), isset($import['prefix']) ? $import['prefix'] : null);
  }

  protected function loadFile($file)
  {
    return Yaml::load($file);
  }
}