public async Task SubmitPayment()

in src/Modules/SimplCommerce.Module.PaymentNganLuong/Areas/PaymentNganLuong/Controllers/NganLuongController.cs [62:129]
62 lines of code
5 McCabe index (conditional complexity)

        public async Task<IActionResult> SubmitPayment(string paymentOption, string bankCode)
        {
            var currentUser = await _workContext.GetCurrentUser();
            var cart = await _cartService.GetActiveCartDetails(currentUser.Id);
            if (cart == null)
            {
                return NotFound();
            }

            var orderCreateResult = await _orderService.CreateOrder(cart.Id, "NganLuong", 0, OrderStatus.PendingPayment);

            if (!orderCreateResult.Success)
            {
                TempData["Error"] = orderCreateResult.Error;
                return Redirect("~/checkout/payment");
            }

            var order = orderCreateResult.Value;

            var rootUrl = Request.GetFullHostingUrlRoot();
            var paymentSubmitRequest = new PaymentSubmitRequest
            {
                MerchantId = _setting.Value.MerchantId,
                MerchantPassword = _setting.Value.MerchantPassword,
                ReceiverEmail =  _setting.Value.ReceiverEmail,
                OrderCode = order.Id.ToString(),
                TotalAmount = (int)order.OrderTotal,
                PaymentMethod = paymentOption,
                BankCode = bankCode,
                ReturnUrl = $"{rootUrl}/ngan-luong/result",
                CancelUrl = $"{rootUrl}/ngan-luong/cancel?orderCode={order.Id}",
                BuyerFullname = currentUser.FullName,
                BuyerEmail = currentUser.Email,
                BuyerMobile = currentUser.PhoneNumber
            };

            var httpClient = _httpClientFactory.CreateClient();
            var nganLuongUrl = _setting.Value.IsSandbox ? "https://sandbox.nganluong.vn:8088/nl35/checkout.api.nganluong.post.php" : "https://www.nganluong.vn/checkout.api.nganluong.post.php";
            var requestMesage = new HttpRequestMessage(HttpMethod.Post, nganLuongUrl)
            {
                Content = paymentSubmitRequest.MakePostContent()
            };
            var response = await httpClient.SendAsync(requestMesage);
            response.EnsureSuccessStatusCode();
            var contentString = await response.Content.ReadAsStringAsync();
            contentString = contentString.Replace("&", "&amp;");
            var xdoc = XDocument.Parse(contentString);
            var paymentSubmitResponse = xdoc.Descendants("result").Select(x => new PaymentSubmitResponse
            {
                ErrorCode = x.Element("error_code").Value,
                Token = x.Element("token").Value,
                Description = x.Element("description").Value,
                TimeLimit = x.Element("time_limit").Value,
                CheckoutUrl = x.Element("checkout_url").Value
            }).First();

            if(paymentSubmitResponse.ErrorCode == "00")
            {
                return Redirect(paymentSubmitResponse.CheckoutUrl);
            }
            else
            {
                string errorMessage = $"Error code: {paymentSubmitResponse.ErrorCode}, Description: {paymentSubmitResponse.Description}";
                await UpdatePaymentStatusError(order, errorMessage, paymentSubmitResponse.Token);
                TempData["Error"] = errorMessage;
                return Redirect($"~/checkout/error?orderId={order.Id}");
            }
        }