.htaccess like router file for php dev web server

router.php

<?php
// php -S localhost:3000 router.php

$root = $_SERVER['DOCUMENT_ROOT'];
chdir($root);
$path = '/'.ltrim(parse_url($_SERVER['REQUEST_URI'])['path'],'/');
set_include_path(get_include_path().':'.__DIR__);
if(file_exists($root.$path))
{
	if(is_dir($root.$path) && substr($path,strlen($path) - 1, 1) !== '/')
		$path = rtrim($path,'/').'/index.php';
	if(strpos($path,'.php') === false) return false;
	else {
		chdir(dirname($root.$path));
		require_once $root.$path;
	}
}
elseif (file_exists($root.'/public'.$path)) {
	$array = explode('.', $path);
	$extension = end($array);

	if ($extension == 'css') header('Content-Type: text/css');
	require_once $root.'/public'.$path;
}
else include_once 'index.php';
?>