<?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;

/**

 * RouteCompiler compiles Route instances to CompiledRoute instances.

 *

 * @author Fabien Potencier <fabien@symfony.com>

 */

class RouteCompiler implements RouteCompilerInterface

{

    /**

     * Compiles the current route instance.

     *

     * @param Route $route A Route instance

     *

     * @return CompiledRoute A CompiledRoute instance

     */

    public function compile(Route $route)

    {

        $pattern = $route->getPattern();

        $len = strlen($pattern);

        $tokens = array();

        $variables = array();

        $pos = 0;

        preg_match_all('#.\{([\w\d_]+)\}#', $pattern, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);

        foreach ($matches as $match) {

            if ($text = substr($pattern, $pos, $match[0][1] - $pos)) {

                $tokens[] = array('text', $text);

            }

            $seps = array($pattern[$pos]);

            $pos = $match[0][1] + strlen($match[0][0]);

            $var = $match[1][0];

            if ($req = $route->getRequirement($var)) {

                $regexp = $req;

            } else {

                if ($pos !== $len) {

                    $seps[] = $pattern[$pos];

                }

                $regexp = sprintf('[^%s]+?', preg_quote(implode('', array_unique($seps)), '#'));

            }

            $tokens[] = array('variable', $match[0][0][0], $regexp, $var);

            $variables[] = $var;

        }

        if ($pos < $len) {

            $tokens[] = array('text', substr($pattern, $pos));

        }

        // find the first optional token

        $firstOptional = INF;

        for ($i = count($tokens) - 1; $i >= 0; $i--) {

            if ('variable' === $tokens[$i][0] && $route->hasDefault($tokens[$i][3])) {

                $firstOptional = $i;

            } else {

                break;

            }

        }

        // compute the matching regexp

        $regex = '';

        $indent = 1;

        if (1 === count($tokens) && 0 === $firstOptional) {

            $token = $tokens[0];

            ++$indent;

            $regex .= str_repeat(' ', $indent * 4).sprintf("%s(?:\n", preg_quote($token[1], '#'));

            $regex .= str_repeat(' ', $indent * 4).sprintf("(?P<%s>%s)\n", $token[3], $token[2]);

        } else {

            foreach ($tokens as $i => $token) {

                if ('text' === $token[0]) {

                    $regex .= str_repeat(' ', $indent * 4).preg_quote($token[1], '#')."\n";

                } else {

                    if ($i >= $firstOptional) {

                        $regex .= str_repeat(' ', $indent * 4)."(?:\n";

                        ++$indent;

                    }

                    $regex .= str_repeat(' ', $indent * 4).sprintf("%s(?P<%s>%s)\n", preg_quote($token[1], '#'), $token[3], $token[2]);

                }

            }

        }

        while (--$indent) {

            $regex .= str_repeat(' ', $indent * 4).")?\n";

        }

        return new CompiledRoute(

            $route,

            'text' === $tokens[0][0] ? $tokens[0][1] : '',

            sprintf("#^\n%s$#x", $regex),

            array_reverse($tokens),

            $variables

        );

    }

}