public async Task Review()

in Hands-on lab/lab-files/src/Contoso Sports League/Contoso.Apps.SportsLeague.Web/Controllers/CheckoutController.cs [80:192]
76 lines of code
9 McCabe index (conditional complexity)

        public async Task<ActionResult> Review(CheckoutModel data)
        {
            if (ModelState.IsValid)
            {
                try
                {
                    var gatewayCaller = new NVPAPICaller(_config, HttpContext);

                    var token = string.Empty;
                    var decoder = new NVPCodec();

                    // Call the gateway payment authorization API:
                    bool ret = gatewayCaller.DoCheckoutAuth(data.Order, ref token, ref decoder);

                    // If authorizaton is successful:
                    if (ret)
                    {
                        // Hydrate a new Order model from our OrderModel.
                        var myOrder = _mapper.Map<Data.Models.Order>(data.Order);
                        // Timestamp with a UTC date.
                        myOrder.OrderDate = DateTime.UtcNow;

                        // Add order to DB.
                        _db.Orders.Add(myOrder);
                        await _db.SaveChangesAsync();

                        // Get the shopping cart items and process them.
                        var usersShoppingCart = new ShoppingCartActions(_db, CartId);
                        
                        List<CartItem> myOrderList = usersShoppingCart.GetCartItems();

                        // Add OrderDetail information to the DB for each product purchased.
                        for (int i = 0; i < myOrderList.Count; i++)
                        {
                            // Create a new OrderDetail object.
                            var myOrderDetail = new OrderDetail();
                            myOrderDetail.OrderId = myOrder.OrderId;
                            myOrderDetail.ProductId = myOrderList[i].ProductId;
                            myOrderDetail.Quantity = myOrderList[i].Quantity;
                            myOrderDetail.UnitPrice = myOrderList[i].Product.UnitPrice;

                            // Add OrderDetail to DB.
                            _db.OrderDetails.Add(myOrderDetail);
                            _db.SaveChanges();
                        }

                        // Set OrderId.
                        HttpContext.Session.SetInt32("currentOrderId", myOrder.OrderId);
                        HttpContext.Session.SetString("Token", token);

                        // Report successful event to Application Insights.
                        var eventProperties = new Dictionary<string, string>();
                        eventProperties.Add("CustomerEmail", data.Order.Email);
                        eventProperties.Add("NumberOfItems", myOrderList.Count.ToString());
                        eventProperties.Add("OrderTotal", data.Order.Total.ToString("C2"));
                        eventProperties.Add("OrderId", myOrder.OrderId.ToString());
                        TelemetryHelper.TrackEvent("SuccessfulPaymentAuth", eventProperties);

                        data.Order.OrderId = myOrder.OrderId;
                        if (data.Order.CreditCardNumber.Length > 4)
                        {
                            // Only show the last 4 digits of the credit card number:
                            data.Order.CreditCardNumber = "xxxxxxxxxxx" + data.Order.CreditCardNumber.Substring(data.Order.CreditCardNumber.Length - 4);
                        }

                    }
                    else
                    {
                        var error = gatewayCaller.PopulateGatewayErrorModel(decoder);

                        // Report failed event to Application Insights.
                        Exception ex = new Exception(error.ToString());
                        ex.Source = "Contoso.Apps.SportsLeague.Web.CheckoutController.cs";
                        TelemetryHelper.TrackException(ex);

                        // Redirect to the checkout error view:
                        return RedirectToAction("Error", error);
                    }
                }
                catch (WebException wex)
                {
                    ExceptionUtility.LogException(wex, "CheckoutController.cs Complete Action");

                    var error = new CheckoutErrorModel
                    {
                        ErrorCode = wex.Message
                    };

                    if (wex.Response != null && wex.Response.GetType() == typeof(HttpWebResponse))
                    {
                        // Extract the response body from the WebException's HttpWebResponse:
                        error.LongMessage = ((HttpWebResponse)wex.Response).StatusDescription;
                    }

                    // Redirect to the checkout error view:
                    return RedirectToAction("Error", error);
                }
                catch (Exception ex)
                {
                    ExceptionUtility.LogException(ex, "CheckoutController.cs Review Action");

                    var error = new CheckoutErrorModel
                    {
                        ErrorCode = ex.Message
                    };

                    // Redirect to the checkout error view:
                    return RedirectToAction("Error", error);
                }
            }

            return View(data);
        }