Local routing for PHP debug built-in server

local_routing.php

<?php
// routing.php
if (preg_match('/\.(?:png|jpg|jpeg|gif|svg|html)$/', $_SERVER["REQUEST_URI"])) {

  $isNotInPublicFoler = preg_match('/^((?!app|css).)*$/s', $_SERVER["REQUEST_URI"]);

  if ($isNotInPublicFoler) {
    $file_requested = $_SERVER["DOCUMENT_ROOT"] . $_SERVER["REQUEST_URI"];
  } else {
    $file_requested = str_replace('/public', '', $_SERVER["DOCUMENT_ROOT"]) . $_SERVER["REQUEST_URI"];

  }

  $file_mime = mime_content_type($file_requested);

  header('Content-Type: ' . $file_mime . '; charset=utf-8');

  return readfile($file_requested);

} else if (preg_match('/\.(?:css)$/', $_SERVER["REQUEST_URI"])) {

  header('Content-Type: text/css; charset=utf-8');

  include __DIR__ . $_SERVER["REQUEST_URI"];

} else if (preg_match('/\.(?:js)$/', $_SERVER["REQUEST_URI"])) {

  header('Content-Type: application/x-javascript; charset=utf-8');

  include __DIR__ . $_SERVER["REQUEST_URI"];

} else if ($_SERVER["REQUEST_URI"] === '/') {

  include __DIR__ . '/public/index.php';

} else {

  if (file_exists(__DIR__ . '/public' . $_SERVER["REQUEST_URI"])) {
    include __DIR__ . '/public' . $_SERVER["REQUEST_URI"];
    exit;
  }

  include __DIR__ . '/public/index.php';
}