BookParkingDialogChainPart1.cs

 public class BookParkingDialogChain : IDialog<object>
    {
        private string selectedName, selectedEmail, selectedPhoneNumber;
        private string selectedLicensePlate;
        private ParkingAreaDetails selectedParkingLocationDetails;
        private DateTime arrivalDateTime, departureDateTime;
        private ParkingLotDetails selectedParkingLot;
        ParkAroundBot.Data.ReserveTravelResponse result;
        private bool finalConfirmation;

        public async Task StartAsync(IDialogContext context)
        {
            context.Wait<string>(conversationStarted);
        }

        private async Task conversationStarted(IDialogContext context, IAwaitable<string> s)
        {
            await context.PostAsync(StringMessages.Welcome);
            var dialog = CreateChain();
            context.Call(dialog, ProcessFinished);
        }

       private IDialog<bool> CreateChain()
        {
            var dialog = Chain.From(() => new ParkingAreaSelectionDialog())
                .ContinueWith<ParkingAreaDetails, DateTime>
                (async (ctx, parkinglocationdetails) =>
                {
                    selectedParkingLocationDetails = await parkinglocationdetails;
                    return new DateTimeInputDialog(null, selectedParkingLocationDetails);
                })
                .ContinueWith<DateTime, DateTime>
                (async (ctx, dt) =>
                {
                    arrivalDateTime = await dt;
                    return new DateTimeInputDialog(arrivalDateTime, selectedParkingLocationDetails);
                })
                .ContinueWith<DateTime, ParkingLotDetails>
                (async (ctx, dt) =>
                {
                    departureDateTime = await dt;
                    return new ParkingLotSelectionDialog
                    (selectedParkingLocationDetails, arrivalDateTime, departureDateTime);
                })
                .LoopWhile(async (ctx, parkingLot) =>
                {
                    if ((await parkingLot) == null)
                        return true;
                    else
                        return false;
                })
                .ContinueWith<ParkingLotDetails, string>
                (async (ctx, parkingLot) =>
                {
                    selectedParkingLot = await parkingLot;
                    return new FullnameInputDialog();
                })
                .ContinueWith<string, string>
                (async (ctx, username) =>
                {
                    selectedName = await username;

                    var emailDialog = CustomTextInputDialog.CreateCustomTextInputDialog
                    (StringMessages.EnterEmail, StringMessages.EnterEmail, new EmailCustomInputValidator());
                    return emailDialog;
                })
                .ContinueWith<string, string>
                (async (ctx, email) =>
                {
                    selectedEmail = await email;
                    var phoneDialog = CustomTextInputDialog.CreateCustomTextInputDialog
                  (StringMessages.PhoneNumber, StringMessages.PhoneNumber, new PhoneCustomInputValidator());
                    return phoneDialog;
                })
             .ContinueWith<string, string>
                (async (ctx, phoneNumber) =>
                {
                    selectedPhoneNumber = await phoneNumber;
                    var licensePlateDialog = CustomTextInputDialog.CreateCustomTextInputDialog
                     (StringMessages.EnterLicensePlate, StringMessages.EnterCorrectLicensePlate, new TextCustomInputValidator(2, 10));
                    return licensePlateDialog;
                })
                 .ContinueWith<string, bool>
                (async (ctx, licenseplate) =>
                {
                    selectedLicensePlate = await licenseplate;
                    var confirmationDialog = new ConfirmBookingDialog(selectedParkingLot.parkingLotName, selectedParkingLot.Price, selectedEmail, selectedParkingLot.Image, arrivalDateTime.ToShortDateString(), departureDateTime.ToShortDateString());
                    return confirmationDialog;
                }).ContinueWith<bool, bool>
                (async (ctx, confirmation) =>
                {
                    finalConfirmation = await confirmation;
                    return Chain.Return(finalConfirmation);
                });
            return dialog;
        }

      }