public IActionResult AddToCart(int productId)
{
//Ürünü çek
Product product = _productService.GetById(productId);
var cart = _cartSessionHelper.GetCart("cart");
_cartService.AddToCart(cart, product);
_cartSessionHelper.SetCard("cart", cart);
TempData.Add("message", product.ProductName + " sepete eklendi.");
return(RedirectToAction("Index", "Product"));
}