<?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\Generator;

use Symfony\Component\Routing\Route;
use Symfony\Component\Routing\RouteCollection;
use Symfony\Component\Routing\RequestContext;
use Symfony\Component\Routing\Exception\InvalidParameterException;
use Symfony\Component\Routing\Exception\RouteNotFoundException;
use Symfony\Component\Routing\Exception\MissingMandatoryParametersException;

/**
 * UrlGenerator generates URL based on a set of routes.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 *
 * @api
 */
class UrlGenerator implements UrlGeneratorInterface
{
    protected $context;

    private $routes;
    private $cache;

    /**
     * Constructor.
     *
     * @param RouteCollection $routes  A RouteCollection instance
     * @param RequestContext  $context The context
     *
     * @api
     */
    public function __construct(RouteCollection $routes, RequestContext $context)
    {
        $this->routes = $routes;
        $this->context = $context;
        $this->cache = array();
    }

    /**
     * Sets the request context.
     *
     * @param RequestContext $context The context
     *
     * @api
     */
    public function setContext(RequestContext $context)
    {
        $this->context = $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 $absolute   Whether to generate an absolute URL
     *
     * @return string The generated URL
     *
     * @throws Symfony\Component\Routing\Exception\RouteNotFoundException When route doesn't exist
     *
     * @api
     */
    public function generate($name, array $parameters = array(), $absolute = false)
    {
        if (null === $route = $this->routes->get($name)) {
            throw new RouteNotFoundException(sprintf('Route "%s" does not exist.', $name));
        }

        if (!isset($this->cache[$name])) {
            $this->cache[$name] = $route->compile();
        }

        return $this->doGenerate($this->cache[$name]->getVariables(), $route->getDefaults(), $route->getRequirements(), $this->cache[$name]->getTokens(), $parameters, $name, $absolute);
    }

    /**
     * @throws Symfony\Component\Routing\Exception\MissingMandatoryParametersException When route has some missing mandatory parameters
     * @throws Symfony\Component\Routing\Exception\InvalidParameterException When a parameter value is not correct
     */
    protected function doGenerate($variables, $defaults, $requirements, $tokens, $parameters, $name, $absolute)
    {
        $variables = array_flip($variables);

        $originParameters = $parameters;
        $parameters = array_replace($this->context->getParameters(), $parameters);
        $tparams = array_replace($defaults, $parameters);

        // all params must be given
        if ($diff = array_diff_key($variables, $tparams)) {
            throw new MissingMandatoryParametersException(sprintf('The "%s" route has some missing mandatory parameters ("%s").', $name, implode('", "', array_keys($diff))));
        }

        $url = '';
        $optional = true;
        foreach ($tokens as $token) {
            if ('variable' === $token[0]) {
                if (false === $optional || !array_key_exists($token[3], $defaults) || (isset($parameters[$token[3]]) && $parameters[$token[3]] != $defaults[$token[3]])) {
                    if (!$isEmpty = in_array($tparams[$token[3]], array(null, '', false), true)) {
                        // check requirement
                        if ($tparams[$token[3]] && !preg_match('#^'.$token[2].'$#', $tparams[$token[3]])) {
                            throw new InvalidParameterException(sprintf('Parameter "%s" for route "%s" must match "%s" ("%s" given).', $token[3], $name, $token[2], $tparams[$token[3]]));
                        }
                    }

                    if (!$isEmpty || !$optional) {
                        $url = $token[1].strtr($tparams[$token[3]], array('%'=>'%25', '+'=>'%2B')).$url;
                    }

                    $optional = false;
                }
            } elseif ('text' === $token[0]) {
                $url = $token[1].$url;
                $optional = false;
            }
        }

        if (!$url) {
            $url = '/';
        }

        // add a query string if needed
        if ($extra = array_diff_key($originParameters, $variables, $defaults)) {
            $url .= '?'.http_build_query($extra);
        }

        $url = $this->context->getBaseUrl().$url;

        if ($this->context->getHost()) {
            $scheme = $this->context->getScheme();
            if (isset($requirements['_scheme']) && ($req = strtolower($requirements['_scheme'])) && $scheme != $req) {
                $absolute = true;
                $scheme = $req;
            }

            if ($absolute) {
                $port = '';
                if ('http' === $scheme && 80 != $this->context->getHttpPort()) {
                    $port = ':'.$this->context->getHttpPort();
                } elseif ('https' === $scheme && 443 != $this->context->getHttpsPort()) {
                    $port = ':'.$this->context->getHttpsPort();
                }

                $url = $scheme.'://'.$this->context->getHost().$port.$url;
            }
        }

        return $url;
    }
}