<?php
include_once 'config.php';
include_once 'router.php';
session_start();
function loader( $class ) {
  $directories = [
    'model/',
    'controller/'
    ];
    
    foreach( $directories as $directory ) {
        if( file_exists( $directory.$class.'.php') ) {
          include_once $directory.$class.'.php';
        }
    }
}
spl_autoload_register('loader');

if( !isset($_GET['action']) )
{
  $action = $_GET['action'];
}
else
{
  $action = 'default';
}
$db = new DB($config);
router($action,$db);


^
INDEX
===
<?php

function router($action)
{
  switch($action) {
    case 'default':
      $controller = new DefaultController($db);
      $controller->index();
      break;
      
    case 'show':
      $controller = new DefaultController($db);
      $controller->show();
      break;
    
    case 'indexlist':
      $controller = new DefaultController($db);
      $controller->indexlist();
      break;
      
    default:
      $controller = new DefaultController($db);
      $controller->index();
      
  }
}
========
<?php

class DefaultController
{
    public function index() 
    {
      $content = 'domyslna akcja';
      include 'view/main.html.php';
    }
    public function show()
    {
      $content = 'inna akcja';
      include 'view/main.html.php';
    }
 public function indexlist()
    {
      $content = 'akcja indexlist';
      include 'view/main.html.php';
    }
  
}
=====
<?php

class DB
{
  protected $connection;
  
  public function __construct($config)
  {
    try {
      $dsn ='mysql:host='.$config['host'].';dbname='.$config['dbname'];
      $this->connection = new PDO ($dsn, $config['user'],$config['password']);
    } 
    catch (PDOException $e){
      echo $e->getMessage();
    }
   }
   public function getConnection()
   {
     return $this->connection;
   }
 }
==========
<?php
$config = [
    'host' => 'localhost',
    'dbname' => 'database',
    'login' => 'root',
    'password' => 'uczen4',
];

?>
=========