Router.php

<?php

class Router
{
    private $routes;

    public function __construct()
    {
        $routesPath = 'config/routes.php';
        $this->routes = include($routesPath);
    }

    private function getURI()
    {
        $uri = $_SERVER['REQUEST_URI'];

        if (!empty($uri)) {
            return trim($uri, '/');
        }
    }

    public function run()
    {
        $uri = $this->getURI();

        foreach ($this->routes as $uriPattern => $path) {
            if (preg_match("~$uriPattern~", $uri)) {
                $internalRoute = preg_replace("~$uriPattern~", $path, $uri);

                $segments = explode('/', $internalRoute);

                $controllerName = ucfirst(array_shift($segments)) . 'Controller';
                $actionName = 'action' . ucfirst(array_shift($segments));
                $params = $segments;

                $controllerFile = 'controller/' . $controllerName . '.php';
                if (file_exists($controllerFile)) {
                    include_once($controllerFile);
                }

                $controller = new $controllerName;

                session_start();

                return call_user_func_array([$controller, $actionName], $params);
            }
        }
    }
}