set up scaffolding

controllers/bolt12.ctrl.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"net/http"
 
+	"github.com/getAlby/lndhub.go/lib/responses"
 	"github.com/getAlby/lndhub.go/lib/service"
 	"github.com/labstack/echo/v4"
 )
@@ -12,6 +13,11 @@ import (
 type Bolt12Controller struct {
 	svc *service.LndhubService
 }
+type FetchInvoiceRequestBody struct {
+	Amount int64  `json:"amt"` // amount in Satoshi
+	Memo   string `json:"memo"`
+	Offer  string `json:"offer"`
+}
 
 func NewBolt12Controller(svc *service.LndhubService) *Bolt12Controller {
 	return &Bolt12Controller{svc: svc}
@@ -26,3 +32,49 @@ func (controller *Bolt12Controller) Decode(c echo.Context) error {
 	}
 	return c.JSON(http.StatusOK, decoded)
 }
+
+// FetchInvoice: fetches an invoice from a bolt12 offer for a certain amount
+func (controller *Bolt12Controller) FetchInvoice(c echo.Context) error {
+	var body FetchInvoiceRequestBody
+
+	if err := c.Bind(&body); err != nil {
+		c.Logger().Errorf("Failed to load fetchinvoice request body: %v", err)
+		return c.JSON(http.StatusBadRequest, responses.BadArgumentsError)
+	}
+
+	if err := c.Validate(&body); err != nil {
+		c.Logger().Errorf("Invalid fetchinvoice request body: %v", err)
+		return c.JSON(http.StatusBadRequest, responses.BadArgumentsError)
+	}
+
+	invoice, err := controller.svc.FetchBolt12Invoice(context.TODO(), body.Offer, body.Memo, body.Amount)
+	if err != nil {
+		return err
+	}
+	return c.JSON(http.StatusOK, invoice)
+}
+
+// PayOffer: fetches an invoice from a bolt12 offer for a certain amount, and pays it
+func (controller *Bolt12Controller) PayOffer(c echo.Context) error {
+	var body FetchInvoiceRequestBody
+
+	if err := c.Bind(&body); err != nil {
+		c.Logger().Errorf("Failed to load fetchinvoice request body: %v", err)
+		return c.JSON(http.StatusBadRequest, responses.BadArgumentsError)
+	}
+
+	if err := c.Validate(&body); err != nil {
+		c.Logger().Errorf("Invalid fetchinvoice request body: %v", err)
+		return c.JSON(http.StatusBadRequest, responses.BadArgumentsError)
+	}
+
+	invoice, err := controller.svc.FetchBolt12Invoice(context.TODO(), body.Offer, body.Memo, body.Amount)
+	if err != nil {
+		return err
+	}
+	result, err := controller.svc.PayBolt12Invoice(context.TODO(), invoice.Invoice)
+	if err != nil {
+		return err
+	}
+	return c.JSON(http.StatusOK, result)
+}

lib/service/bolt12.go

@@ -0,0 +1,16 @@
+package service
+
+import (
+	"context"
+
+	"github.com/getAlby/lndhub.go/lnd"
+	"github.com/lightningnetwork/lnd/lnrpc"
+)
+
+func (svc *LndhubService) FetchBolt12Invoice(ctx context.Context, offer, memo string, amt int64) (result *lnd.Bolt12Invoice, err error) {
+	return nil, err
+}
+
+func (svc *LndhubService) PayBolt12Invoice(ctx context.Context, invoice string) (result *lnrpc.SendResponse, err error) {
+	return nil, err
+}

lnd/c-lightning.go

@@ -145,8 +145,8 @@ func (cl *CLNClient) SendPaymentSync(ctx context.Context, req *lnrpc.SendRequest
 		PaymentPreimage: []byte(result.Get("payment_preimage").String()),
 		PaymentHash:     []byte(result.Get("payment_hash").String()),
 		PaymentRoute: &lnrpc.Route{
-			TotalFees: result.Get("amount_sent_msat").Int() - result.Get("amount_msat").Int(),
-			TotalAmt:  result.Get("amount_sent_msat").Int(),
+			TotalFees: result.Get("msatoshi_sent").Int()/MSAT_PER_SAT - result.Get("msatoshi").Int()/MSAT_PER_SAT,
+			TotalAmt:  result.Get("msatoshi_sent").Int() / MSAT_PER_SAT,
 		},
 	}, nil
 }

lnd/interface.go

@@ -29,3 +29,7 @@ type Offer struct {
 	Vendor      string   `json:"vendor"`
 	Valid       bool     `json:"valid"`
 }
+
+type Bolt12Invoice struct {
+	Invoice string `json:"invoice"`
+}