gistfile1.php

<?php
namespace ynd\thsx\core;
class Router {
    protected $prefix;
    protected $routes;

    // Used in specificity calculations.
    const MAX_PATH_SEGMENTS = 10;

    public function __construct($routes, $prefix = NULL) {
        $this->prefix = $prefix;
        $this->routes = $routes;
    }

    private function routeToRegex($route) {
        $mappings =
            array(
                  ':(\w+)=(\w+)' => '(?<$1>$2)',
                  ':(\w+)'       => '(?<$1>[A-Za-z0-9\$\-_\.\+!\*\'\(\),]+)',
                  );

        $regex = $route;
        foreach ($mappings as $route_part => $regex_part) {
            $regex = preg_replace("/$route_part/", $regex_part, $regex);
        }

        $prefix_path = isset($this->prefix) ? '/' . $this->prefix : '' ;
        $regex = '@^' . $prefix_path . $regex . '/?$@i';
        return $regex;
    }

    private function routeSpecificity($route) {
        $segments = array_filter(explode('/', $route));

        $total      = count($segments);
        $variables  = count(preg_grep('/^:\w+$/', $segments));
        $invariants = $total - $variables;

        return (self::MAX_PATH_SEGMENTS * $invariants) + $variables;
    }

    public function route($path) {
        $routes = array_keys($this->routes);
        $route_assoc_array = array_combine($routes, $routes);
        $route_regexps = array_map(array($this, 'RouteToRegex'), $route_assoc_array);
        $matching_route_regexps = array_filter($route_regexps, function($regex) use ($path){return preg_match($regex, $path);});

        $number_of_matching_routes = count($matching_route_regexps);
        if ($number_of_matching_routes == 0) {
            throw new UnknownPathRouteException("Could not find a matching route for request path: $path");
        } else if ($number_of_matching_routes == 1) {
            $routes = array_keys($matching_route_regexps);
            $route = $routes[0];
        } else {
            $route_specificities = array();
            foreach ($matching_route_regexps as $route => $regexp) {
                $route_specificity = $this->routeSpecificity($route);
                if (isset($route_specificities[$route_specificity])) {
                    throw new AmbiguousRouteException("Ambiguous matching routes found! $route  and {$route_specificities[$route_specificity]} both have a route specificity of $route_specificity !");
                } else {
                    $route_specificities[$route_specificity] = $route;
                }
            }
            $specificities = array_keys($route_specificities);
            rsort($specificities);
            $route = $route_specificities[$specificities[0]];
        }

        $variables = array();
        preg_match($matching_route_regexps[$route], $path, $variables);
        unset($variables[0]);

        return array($this->routes[$route], $variables);
    }
}

class AmbiguousRouteException   extends \DomainException {}
class UnknownPathRouteException extends \UnexpectedValueException {}


?>