Příhlášení třída

<?php
require_once('connect.php');
class Prihlaseni{

 public username;
 public heslo;
 public pravo;
 public id_adresa;
 public id_uzivatele;


 public function __construct($username,$heslo){
   $this->username=$username;
   $this->heslo=$heslo;
 }

 public function existUser(){
   try {
  $select="SELECT count(*) as pocet FROM uzivatele WHERE username=:username";
  $select_user=DB::connect()->prepare($select);
  $select_user->bindParam(":username", $this->username);
  $select_user->execute();
  $vysledek=$select_user->fetch(PDO::FETCH_ASSOC);
  if(vysledek['pocet']>0){
    return true;
  }else{
    return false;
       }
  } catch (PDOException $e) {
    echo $e->getMessage();
    die();
   }

 }

 public function porovnaniHesla(){
  try {
    $select="SELECT heslo as hash FROM uzivatele WHERE username=:username";
    $select_hash=DB::connect()->prepare($select);
    $select_hash->bindParam(":username", $this->username);
    $select_hash->execute();
    $vysledek=$select_hash->fetch(PDO::FETCH_ASSOC);
    if(password_verify($this->heslo,$vysledek['hash'])){
      return true;
    }else{
      return false;
         }

  } catch (PDOException $e) {
    echo $e->getMessage();
    die();
  }



 }

 public function updateLogin(){
   try {
     $update="UPDATE uzivatele
          SET lastlogin=NOW()
          WHERE username=:username";
     $up=DB::connect()->prepare($update);
     $up->bindParam(':username', $this->username);
     $stav=$up->execute();
     if($stav){
       return true;
     }else{
       return false;
     }
   } catch (PDOException $e) {
     echo $e->getMessage();
     die();
   }

 }

 public getInformation(){
  try {
    $select="SELECT id_uzivatele,pravo,id_adresa FROM uzivatele WHERE username=:username";
    $select_info=DB::connect()->prepare($select);
    $select_info->bindParam(":username", $username);
    $select_info->execute();
    $info=$select_info->fetch(PDO::FETCH_ASSOC);
    $this->pravo=$info['pravo'];
    $this->id_adresa=$info['id_adresa'];
    $this->id_uzivatele=$info['id_uzivatele'];
  } catch (PDOException $e) {
    echo $e->getMessage();
    die();
  }

 }

}
?>

<?php
require_once('prihlaseni.class.php');
require_once('uzivatel.class.php');
$username=$_POST['username'];
$password=$_POST['password'];

$user=new Prihlaseni($username,$password);
if($user->existUser()){
  $errors_message='Daný uživatel nebyl nalezen, prosím zaregistrujte se';
  header("Location:prihlaseni.php?errors=$errors_message");
}else{
 if($user->porovnaniHesla()){
   if($user->updateLogin() && $user->porovnaniHesla()){
       session_start();
       $user->getInformation();
       $uzivatel = new Uzivatel($user->id_uzivatele, $user->username, $user->pravo, $user->id_adresa);
       $_SESSION['uzivatel']=$uzivatel;
       header("Location:my_profile.php");
   }
 }else{
   $errors_message='Heslo není správné';
   header("Location:prihlaseni.php?errors=$errors_message&username=$user->username");

 }

}

?>