<?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;

use Symfony\Component\Config\Loader\LoaderInterface;
use Symfony\Component\Config\ConfigCache;

/**
 * The Router class is an example of the integration of all pieces of the
 * routing system for easier use.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class Router implements RouterInterface
{
    private $matcher;
    private $generator;
    private $options;
    private $defaults;
    private $context;
    private $loader;
    private $collection;
    private $resource;

    /**
     * Constructor.
     *
     * Available options:
     *
     *   * cache_dir:     The cache directory (or null to disable caching)
     *   * debug:         Whether to enable debugging or not (false by default)
     *   * resource_type: Type hint for the main resource (optional)
     *
     * @param LoaderInterface $loader   A LoaderInterface instance
     * @param mixed           $resource The main resource to load
     * @param array           $options  An array of options
     * @param RequestContext  $context  The context
     * @param array           $defaults The default values
     *
     * @throws \InvalidArgumentException When unsupported option is provided
     */
    public function __construct(LoaderInterface $loader, $resource, array $options = array(), RequestContext $context = null, array $defaults = array())
    {
        $this->loader = $loader;
        $this->resource = $resource;
        $this->context = null === $context ? new RequestContext() : $context;
        $this->defaults = $defaults;
        $this->options = array(
            'cache_dir'              => null,
            'debug'                  => false,
            'generator_class'        => 'Symfony\\Component\\Routing\\Generator\\UrlGenerator',
            'generator_base_class'   => 'Symfony\\Component\\Routing\\Generator\\UrlGenerator',
            'generator_dumper_class' => 'Symfony\\Component\\Routing\\Generator\\Dumper\\PhpGeneratorDumper',
            'generator_cache_class'  => 'ProjectUrlGenerator',
            'matcher_class'          => 'Symfony\\Component\\Routing\\Matcher\\UrlMatcher',
            'matcher_base_class'     => 'Symfony\\Component\\Routing\\Matcher\\UrlMatcher',
            'matcher_dumper_class'   => 'Symfony\\Component\\Routing\\Matcher\\Dumper\\PhpMatcherDumper',
            'matcher_cache_class'    => 'ProjectUrlMatcher',
            'resource_type'          => null,
        );

        // check option names and live merge, if errors are encountered Exception will be thrown
        $invalid = array();
        $isInvalid = false;
        foreach ($options as $key => $value) {
            if (array_key_exists($key, $this->options)) {
                $this->options[$key] = $value;
            } else {
                $isInvalid = true;
                $invalid[] = $key;
            }
        }

        if ($isInvalid) {
            throw new \InvalidArgumentException(sprintf('The Router does not support the following options: \'%s\'.', implode('\', \'', $invalid)));
        }
    }

    /**
     * Gets the RouteCollection instance associated with this Router.
     *
     * @return RouteCollection A RouteCollection instance
     */
    public function getRouteCollection()
    {
        if (null === $this->collection) {
            $this->collection = $this->loader->load($this->resource, $this->options['resource_type']);
        }

        return $this->collection;
    }

    /**
     * Sets the request context.
     *
     * @param RequestContext $context The context
     */
    public function setContext(RequestContext $context)
    {
        $this->context = $context;

        $this->getMatcher()->setContext($context);
        $this->getGenerator()->setContext($context);
    }

    /**
     * Gets the request context.
     *
     * @return RequestContext The context
     */
    public function getContext()
    {
        return $this->context;
    }

    /**
     * Generates a URL from the given parameters.
     *
     * @param  string  $name       The name of the route
     * @param  array   $parameters An array of parameters
     * @param  Boolean $absolute   Whether to generate an absolute URL
     *
     * @return string The generated URL
     */
    public function generate($name, array $parameters = array(), $absolute = false)
    {
        return $this->getGenerator()->generate($name, $parameters, $absolute);
    }

    /**
     * Tries to match a URL with a set of routes.
     *
     * Returns false if no route matches the URL.
     *
     * @param  string $url URL to be parsed
     *
     * @return array|false An array of parameters or false if no route matches
     */
    public function match($url)
    {
        return $this->getMatcher()->match($url);
    }

    /**
     * Gets the UrlMatcher instance associated with this Router.
     *
     * @return UrlMatcherInterface A UrlMatcherInterface instance
     */
    public function getMatcher()
    {
        if (null !== $this->matcher) {
            return $this->matcher;
        }

        if (null === $this->options['cache_dir'] || null === $this->options['matcher_cache_class']) {
            return $this->matcher = new $this->options['matcher_class']($this->getRouteCollection(), $this->context, $this->defaults);
        }

        $class = $this->options['matcher_cache_class'];
        $cache = new ConfigCache($this->options['cache_dir'].'/'.$class.'.php', $this->options['debug']);
        if (!$cache->isFresh($class)) {
            $dumper = new $this->options['matcher_dumper_class']($this->getRouteCollection());

            $options = array(
                'class'      => $class,
                'base_class' => $this->options['matcher_base_class'],
            );

            $cache->write($dumper->dump($options), $this->getRouteCollection()->getResources());
        }

        require_once $cache;

        return $this->matcher = new $class($this->context, $this->defaults);
    }

    /**
     * Gets the UrlGenerator instance associated with this Router.
     *
     * @return UrlGeneratorInterface A UrlGeneratorInterface instance
     */
    public function getGenerator()
    {
        if (null !== $this->generator) {
            return $this->generator;
        }

        if (null === $this->options['cache_dir'] || null === $this->options['generator_cache_class']) {
            return $this->generator = new $this->options['generator_class']($this->getRouteCollection(), $this->context, $this->defaults);
        }

        $class = $this->options['generator_cache_class'];
        $cache = new ConfigCache($this->options['cache_dir'].'/'.$class.'.php', $this->options['debug']);
        if (!$cache->isFresh($class)) {
            $dumper = new $this->options['generator_dumper_class']($this->getRouteCollection());

            $options = array(
                'class'      => $class,
                'base_class' => $this->options['generator_base_class'],
            );

            $cache->write($dumper->dump($options), $this->getRouteCollection()->getResources());
        }

        require_once $cache;

        return $this->generator = new $class($this->context, $this->defaults);
    }
}