public IActionResult Index(OrderViewModel model)
 {
     if (ModelState.IsValid)
     {
         var discount          = _discountProcessor.ProcessDiscount(model);
         var checkoutViewModel = new CheckoutViewModel(model, discount);
         return(RedirectToAction("Checkout", checkoutViewModel));
     }
     else
     {
         return(View(model));
     }
 }
 public IActionResult Index(OrderViewModel model)
 {
     if (ModelState.IsValid)
     {
         var discounts         = _discountProcessor.ProcessDiscount(model);
         var checkoutViewModel = new CheckoutViewModel(model, discounts);
         return(RedirectToAction("Checkout", checkoutViewModel));
     }
     else
     {
         _logWriter.LogWarning("Model is not valid");
         return(View(model));
     }
 }