paymentsdb: implement InitPayment for sql backend

Author: ziggie1984

payments/db/sql_store.go

@@ -627,3 +627,106 @@ func (s *SQLStore) DeleteFailedAttempts(paymentHash lntypes.Hash) error {
 
 	return nil
 }
+
+// InitPayment initializes a payment.
+//
+// This is part of the DB interface.
+func (s *SQLStore) InitPayment(paymentHash lntypes.Hash,
+	paymentCreationInfo *PaymentCreationInfo) error {
+
+	ctx := context.TODO()
+
+	// Create the payment in the database.
+	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
+		existingPayment, err := s.db.FetchPayment(ctx, paymentHash[:])
+		if err == nil {
+			completePayment, err := s.fetchPaymentWithCompleteData(
+				ctx, s.db, existingPayment,
+			)
+			if err != nil {
+				return fmt.Errorf("failed to fetch payment "+
+					"with complete data: %w", err)
+			}
+
+			// Check if the payment is initializable otherwise
+			// we'll return early.
+			err = completePayment.Status.initializable()
+			if err != nil {
+				return err
+			}
+		} else if !errors.Is(err, sql.ErrNoRows) {
+			// Some other error occurred
+			return fmt.Errorf("failed to check existing "+
+				"payment: %w", err)
+		}
+
+		// If payment exists and is failed, delete it first.
+		if existingPayment.Payment.ID != 0 {
+			err := db.DeletePayment(ctx, existingPayment.Payment.ID)
+			if err != nil {
+				return fmt.Errorf("failed to delete "+
+					"payment: %w", err)
+			}
+		}
+
+		var intentID *int64
+		if len(paymentCreationInfo.PaymentRequest) > 0 {
+			//nolint:ll
+			intentIDValue, err := db.InsertPaymentIntent(ctx,
+				sqlc.InsertPaymentIntentParams{
+					IntentType:    int16(PaymentIntentTypeBolt11),
+					IntentPayload: paymentCreationInfo.PaymentRequest,
+				})
+			if err != nil {
+				return fmt.Errorf("failed to initialize "+
+					"payment intent: %w", err)
+			}
+			intentID = &intentIDValue
+		}
+
+		// Only set the intent ID if it's not nil.
+		var intentIDParam sql.NullInt64
+		if intentID != nil {
+			intentIDParam = sqldb.SQLInt64(*intentID)
+		}
+
+		err = db.InsertPayment(ctx, sqlc.InsertPaymentParams{
+			IntentID:          intentIDParam,
+			AmountMsat:        int64(paymentCreationInfo.Value),
+			CreatedAt:         paymentCreationInfo.CreationTime.UTC(),
+			PaymentIdentifier: paymentHash[:],
+		})
+		if err != nil {
+			return fmt.Errorf("failed to insert payment: %w", err)
+		}
+
+		// Get the payment ID from the inserted payment
+		// We need to fetch the payment we just inserted to get its ID
+		insertedPayment, err := db.FetchPayment(ctx, paymentHash[:])
+		if err != nil {
+			return fmt.Errorf("failed to fetch inserted payment: %w", err)
+		}
+
+		for key, value := range paymentCreationInfo.FirstHopCustomRecords {
+			err = db.InsertPaymentFirstHopCustomRecord(ctx,
+				sqlc.InsertPaymentFirstHopCustomRecordParams{
+					PaymentID: insertedPayment.Payment.ID,
+					Key:       int64(key),
+					Value:     value,
+				})
+			if err != nil {
+				return fmt.Errorf("failed to insert "+
+					"payment first hop custom "+
+					"record: %w", err)
+			}
+		}
+
+		return nil
+	}, func() {
+	})
+	if err != nil {
+		return fmt.Errorf("failed to initialize payment: %w", err)
+	}
+
+	return nil
+}