public function addtocart()
 {
     if (isset($_SESSION['account'])) {
         $account = $_SESSION['account'];
         $productId = $_POST['productid'];
         $quantity = $_POST['quantity'];
         /* Checking availability */
         $database = new Database('localhost', 'pdo_ret', 'root', '');
         $sql = "select product_name, quantity_left, price from product where product_id='{$productId}';";
         $result = $database->query($sql);
         $result = $result[0];
         $product_name = $result[0];
         $quantity_left = $result[1];
         $price = $result[2];
         if ($quantity <= $quantity_left) {
             /* Adding to cart */
             $product = new Product($productId, $product_name, $price);
             $product->setQuantity($quantity);
             $bool = $account->getCart()->addToCart($product, (double) $quantity);
             if ($bool == TRUE) {
                 echo '<script>window.location.href=\'?controller=pages&action=shop\';</script>';
             } else {
                 echo '<script>alert(\'Unknown error occurred\');</script>';
                 echo '<script>window.location.href=\'?controller=pages&action=shop\';</script>';
             }
         } else {
             echo '<script>alert(\'Quantity not available\');</script>';
             echo '<script>window.location.href=\'?controller=pages&action=shop\';</script>';
         }
     } else {
         echo '<script>window.location.href=\'?controller=pages&action=login\';</script>';
     }
 }
 public function testQuantity()
 {
     $this->assertSame($this->entity, $this->entity->setQuantity(5));
     $this->assertSame(5, $this->entity->getQuantity());
 }