<?php
  /**
   * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  use Symfony\Component\Routing\Matcher\UrlMatcher;
  use Symfony\Component\Routing\Generator\UrlGenerator;
  use Symfony\Component\Routing\RequestContext;
  use Symfony\Component\Routing\RouteCollection;
  //use Symfony\Component\Routing\Route;
  
  class OC_Router {
  	protected $collections = array();
  	protected $collection = null;
  	protected $root = null;
  
  	protected $generator = null;
  	protected $routing_files;
  	protected $cache_key;
  
  	public function __construct() {
  		$baseUrl = OC_Helper::linkTo('', 'index.php');
  		if ( !OC::$CLI) {
  			$method = $_SERVER['REQUEST_METHOD'];
  		}else{
  			$method = 'GET';
  		}
  		$host = OC_Request::serverHost();
  		$schema = OC_Request::serverProtocol();
  		$this->context = new RequestContext($baseUrl, $method, $host, $schema);
  		// TODO cache
  		$this->root = $this->getCollection('root');
  	}
  
  	public function getRoutingFiles() {
  		if (!isset($this->routing_files)) {
  			$this->routing_files = array();
  			foreach(OC_APP::getEnabledApps() as $app) {
  				$file = OC_App::getAppPath($app).'/appinfo/routes.php';
  				if(file_exists($file)) {
  					$this->routing_files[$app] = $file;
  				}
  			}
  		}
  		return $this->routing_files;
  	}
  
  	public function getCacheKey() {
  		if (!isset($this->cache_key)) {
  			$files = $this->getRoutingFiles();
  			$files[] = 'settings/routes.php';
  			$files[] = 'core/routes.php';
  			$files[] = 'ocs/routes.php';
  			$this->cache_key = OC_Cache::generateCacheKeyFromFiles($files);
  		}
  		return $this->cache_key;
  	}
  
  	/**
  	 * loads the api routes
  	 */
  	public function loadRoutes() {
  		foreach($this->getRoutingFiles() as $app => $file) {
  			$this->useCollection($app);

  			$this->requireRouteFile($file);

  			$collection = $this->getCollection($app);
  			$this->root->addCollection($collection, '/apps/'.$app);
  		}
  		$this->useCollection('root');
  		require_once 'settings/routes.php';
  		require_once 'core/routes.php';
  
  		// include ocs routes
  		require_once 'ocs/routes.php';
  		$collection = $this->getCollection('ocs');
  		$this->root->addCollection($collection, '/ocs');
  	}
  
  	protected function getCollection($name) {
  		if (!isset($this->collections[$name])) {
  			$this->collections[$name] = new RouteCollection();
  		}
  		return $this->collections[$name];
  	}
  
  	/**
  	 * Sets the collection to use for adding routes
  	 *
  	 * @param string $name Name of the colletion to use.
  	 */
  	public function useCollection($name) {
  		$this->collection = $this->getCollection($name);
  	}
  
  	/**
  	 * Create a OC_Route.
  	 *
  	 * @param string $name Name of the route to create.
  	 * @param string $pattern The pattern to match
  	 * @param array  $defaults     An array of default parameter values
  	 * @param array  $requirements An array of requirements for parameters (regexes)
  	 */
  	public function create($name, $pattern, array $defaults = array(), array $requirements = array()) {
  		$route = new OC_Route($pattern, $defaults, $requirements);
  		$this->collection->add($name, $route);
  		return $route;
  	}
  
  	/**
  	 * Find the route matching $url.
  	 *
  	 * @param string $url The url to find
  	 */
  	public function match($url) {
  		$matcher = new UrlMatcher($this->root, $this->context);
  		$parameters = $matcher->match($url);
  		if (isset($parameters['action'])) {
  			$action = $parameters['action'];
  			if (!is_callable($action)) {
  				var_dump($action);
  				throw new Exception('not a callable action');
  			}
  			unset($parameters['action']);
  			call_user_func($action, $parameters);
  		} elseif (isset($parameters['file'])) {
  			include $parameters['file'];
  		} else {
  			throw new Exception('no action available');
  		}
  	}
  
  	/**
  	 * Get the url generator
  	 *
  	 */
  	public function getGenerator()
  	{
  		if (null !== $this->generator) {
  			return $this->generator;
  		}
  
  		return $this->generator = new UrlGenerator($this->root, $this->context);
  	}
  
  	/**
  	 * Generate url based on $name and $parameters
  	 *
  	 * @param string $name Name of the route to use.
  	 * @param array $parameters Parameters for the route
  	 */
  	public function generate($name, $parameters = array(), $absolute = false)
  	{
  		return $this->getGenerator()->generate($name, $parameters, $absolute);
  	}
  
  	/**
  	 * Generate JSON response for routing in javascript
  	 */
  	public static function JSRoutes()
  	{
  		$router = OC::getRouter();
  
  		$etag = $router->getCacheKey();
  		OC_Response::enableCaching();
  		OC_Response::setETagHeader($etag);
  
  		$root = $router->getCollection('root');
  		$routes = array();
  		foreach($root->all() as $name => $route) {
  			$compiled_route = $route->compile();
  			$defaults = $route->getDefaults();
  			unset($defaults['action']);
  			$routes[$name] = array(
  				'tokens' => $compiled_route->getTokens(),
  				'defaults' => $defaults,
  			);
  		}
  		OCP\JSON::success ( array( 'data' => $routes ) );
  	}

  
  	/**
  	 * To isolate the variable scope used inside the $file it is required in it's own method
  	 * @param $file
  	 */
  	private function requireRouteFile($file) {
  		require_once $file;
  	}

  }