Add interval support for direct debits

src/Cashier.Stripe/Controllers/StripeDirectDebitPaymentPageController.cs

@@ -114,7 +114,7 @@ protected Models.PaymentIntent UpdatePaymentIntent(string sessionId)
                 return paymentIntent;
             }
 
-            var ddPriceName = "Direct Debit - " + paymentIntent.Amount;
+            var ddPriceName = $"Direct Debit - {paymentIntent.DirectDebitFrequencyMonths} Month{(paymentIntent.DirectDebitFrequencyMonths > 1 ? "s" : "")} - {paymentIntent.Amount}";
 
             var productService = new ProductService();
             var product = productService.List().FirstOrDefault(p => p.Description == "Direct Debit");
@@ -142,6 +142,7 @@ protected Models.PaymentIntent UpdatePaymentIntent(string sessionId)
                     Recurring = new PriceRecurringOptions
                     {
                         Interval = "month",
+                        IntervalCount = paymentIntent.DirectDebitFrequencyMonths,
                         UsageType = "licensed"
                     }
                 });

src/Cashier.TestBed/Controllers/DonationFormSurfaceController.cs

@@ -59,7 +59,8 @@ public ActionResult HandleDonationForm(DonationFormModel model)
                     "a constituent ID",
                     model.Amount,
                     "gbp",
-                    DateTime.UtcNow,
+                    DateTime.UtcNow.AddHours(3),
+                    3, //three months
                     "craig@mentordigital.co.uk",
                     "craig@mentordigital.co.uk",
                     new CustomerAddress { AddressLines = "Street", City= "Bristol", Country = "United Kingdom", Postcode = "BS13 2xs" },

src/Cashier/CashierService.cs

@@ -48,6 +48,7 @@ public PaymentIntentCreated CreateNewPaymentIntent(PaymentIntentRequest request)
             if (request.PaymentIntentType == PaymentIntentType.DirectDebit)
             {
                 paymentIntent.DirectDebitStartDate = request.DirectDebitStartDate;
+                paymentIntent.DirectDebitFrequencyMonths = request.DirectDebitFrequencyMonths;
                 paymentIntent.CustomerAddressLines = request.CustomerAddress.AddressLines;
                 paymentIntent.CustomerCity = request.CustomerAddress.City;
                 paymentIntent.CustomerCountry = request.CustomerAddress.Country;

src/Cashier/Data/PaymentIntentRepository.cs

@@ -49,6 +49,16 @@ [CustomerUniqueReference] [nvarchar](max) NULL
 	                        ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
                         END
 
+                    IF NOT EXISTS (
+                      SELECT * 
+                      FROM   sys.columns 
+                      WHERE  object_id = OBJECT_ID(N'[dbo].[PaymentIntents]') 
+                             AND name = 'DirectDebitFrequencyMonths'
+                    )
+                        BEGIN
+                            ALTER TABLE PaymentIntents
+                            ADD [DirectDebitFrequencyMonths] INT
+                        END
 
                     ");
             }

src/Cashier/Models/PaymentIntent.cs

@@ -30,6 +30,7 @@ public class PaymentIntent
         public DateTime Updated { get; set; } = DateTime.Now;
         public string HandShake { get; set; }
         public string CustomerUniqueReference { get; set; }
+        public int DirectDebitFrequencyMonths { get; set; }
     }
 
     public enum PaymentIntentType 

src/Cashier/Models/PaymentIntentRequest.cs

@@ -17,6 +17,7 @@ public class PaymentIntentRequest
         public string CallbackUrl { get; set; }
         public string AdditionalData { get; set; }
         public DateTime DirectDebitStartDate { get; set; }
+        public int DirectDebitFrequencyMonths { get; private set; }
         public string CustomerEmail { get; set; }
         public string CustomerUniqueReference { get; set; }
         public CustomerAddress CustomerAddress { get; set; }
@@ -39,7 +40,7 @@ public static PaymentIntentRequest CreateCardPayment(string transactionReference
             return pi;
         }
 
-        public static PaymentIntentRequest CreateDirectDebit(string transactionReference, string description, double amount, string currency, DateTime directDebitStartDate, string customerEmail, string customerUniqueReference, CustomerAddress customerAddress, string confirmationPageUrl, string failurePageUrl, string callbackUrl, string additionalData)
+        public static PaymentIntentRequest CreateDirectDebit(string transactionReference, string description, double amount, string currency, DateTime directDebitStartDate, int directDebitFrequencyMonths, string customerEmail, string customerUniqueReference, CustomerAddress customerAddress, string confirmationPageUrl, string failurePageUrl, string callbackUrl, string additionalData)
         {
             var pi = new PaymentIntentRequest();
             pi.PaymentIntentType = PaymentIntentType.DirectDebit;
@@ -48,6 +49,7 @@ public static PaymentIntentRequest CreateDirectDebit(string transactionReference
             pi.TransactionReference = transactionReference;
             pi.Description = description;
             pi.DirectDebitStartDate = directDebitStartDate;
+            pi.DirectDebitFrequencyMonths = directDebitFrequencyMonths;
             pi.CustomerEmail = customerEmail;
             pi.CustomerUniqueReference = customerUniqueReference;
             pi.CustomerAddress = customerAddress;