From dd600af5b2a357d0a6dbb101d127b6033c2a46b1 Mon Sep 17 00:00:00 2001
From: Stefan Kostic <skostic9242@gmail.com>
Date: Fri, 4 Mar 2022 20:05:59 +0100
Subject: [PATCH] Refactor send payment sync a bit to reduce code duplication

---
 lib/service/invoices.go | 61 +++++++++++++++++++++++++++++------------
 lib/service/ln.go       | 51 ----------------------------------
 2 files changed, 43 insertions(+), 69 deletions(-)

diff --git a/lib/service/invoices.go b/lib/service/invoices.go
index b4acc5e..330dc94 100644
--- a/lib/service/invoices.go
+++ b/lib/service/invoices.go
@@ -2,6 +2,7 @@ package service
 
 import (
 	"context"
+	"crypto/sha256"
 	"encoding/hex"
 	"errors"
 	"math/rand"
@@ -98,29 +99,15 @@ func (svc *LndhubService) SendInternalPayment(ctx context.Context, invoice *mode
 }
 
 func (svc *LndhubService) SendPaymentSync(ctx context.Context, invoice *models.Invoice) (SendPaymentResponse, error) {
-	if invoice.KeySend {
-		return svc.KeySendPaymentSync(ctx, invoice)
-	}
 	sendPaymentResponse := SendPaymentResponse{}
-	// TODO: set dynamic fee limit
-	feeLimit := lnrpc.FeeLimit{
-		//Limit: &lnrpc.FeeLimit_Percent{
-		//	Percent: 2,
-		//},
-		Limit: &lnrpc.FeeLimit_Fixed{
-			Fixed: 300,
-		},
-	}
 
-	// Prepare the LNRPC call
-	sendPaymentRequest := lnrpc.SendRequest{
-		PaymentRequest: invoice.PaymentRequest,
-		Amt:            invoice.Amount,
-		FeeLimit:       &feeLimit,
+	sendPaymentRequest, err := createLnRpcSendRequest(invoice)
+	if err != nil {
+		return sendPaymentResponse, err
 	}
 
 	// Execute the payment
-	sendPaymentResult, err := svc.LndClient.SendPaymentSync(ctx, &sendPaymentRequest)
+	sendPaymentResult, err := svc.LndClient.SendPaymentSync(ctx, sendPaymentRequest)
 	if err != nil {
 		return sendPaymentResponse, err
 	}
@@ -140,6 +127,44 @@ func (svc *LndhubService) SendPaymentSync(ctx context.Context, invoice *models.I
 	return sendPaymentResponse, nil
 }
 
+func createLnRpcSendRequest(invoice *models.Invoice) (*lnrpc.SendRequest, error) {
+	// TODO: set dynamic fee limit
+	feeLimit := lnrpc.FeeLimit{
+		//Limit: &lnrpc.FeeLimit_Percent{
+		//	Percent: 2,
+		//},
+		Limit: &lnrpc.FeeLimit_Fixed{
+			Fixed: 300,
+		},
+	}
+
+	if !invoice.KeySend {
+		return &lnrpc.SendRequest{
+			PaymentRequest: invoice.PaymentRequest,
+			Amt:            invoice.Amount,
+			FeeLimit:       &feeLimit,
+		}, nil
+	}
+
+	preImage := makePreimageHex()
+	pHash := sha256.New()
+	pHash.Write(preImage)
+	// Prepare the LNRPC call
+	//See: https://github.com/hsjoberg/blixt-wallet/blob/9fcc56a7dc25237bc14b85e6490adb9e044c009c/src/lndmobile/index.ts#L251-L270
+	destBytes, err := hex.DecodeString(invoice.DestinationPubkeyHex)
+	if err != nil {
+		return nil, err
+	}
+	return &lnrpc.SendRequest{
+		Dest:              destBytes,
+		Amt:               invoice.Amount,
+		PaymentHash:       pHash.Sum(nil),
+		FeeLimit:          &feeLimit,
+		DestFeatures:      []lnrpc.FeatureBit{lnrpc.FeatureBit_TLV_ONION_REQ},
+		DestCustomRecords: map[uint64][]byte{KEYSEND_CUSTOM_RECORD: preImage, TLV_WHATSAT_MESSAGE: []byte(invoice.Memo)},
+	}, nil
+}
+
 func (svc *LndhubService) PayInvoice(ctx context.Context, invoice *models.Invoice) (*SendPaymentResponse, error) {
 	userId := invoice.UserID
 
diff --git a/lib/service/ln.go b/lib/service/ln.go
index bce08a7..f139e2b 100644
--- a/lib/service/ln.go
+++ b/lib/service/ln.go
@@ -2,11 +2,7 @@ package service
 
 import (
 	"context"
-	"crypto/sha256"
-	"encoding/hex"
-	"errors"
 
-	"github.com/getAlby/lndhub.go/db/models"
 	"github.com/lightningnetwork/lnd/lnrpc"
 )
 
@@ -20,50 +16,3 @@ const (
 func (svc *LndhubService) GetInfo(ctx context.Context) (*lnrpc.GetInfoResponse, error) {
 	return svc.LndClient.GetInfo(ctx, &lnrpc.GetInfoRequest{})
 }
-
-func (svc *LndhubService) KeySendPaymentSync(ctx context.Context, invoice *models.Invoice) (result SendPaymentResponse, err error) {
-	sendPaymentResponse := SendPaymentResponse{}
-	// TODO: set dynamic fee limit
-	feeLimit := lnrpc.FeeLimit{
-		Limit: &lnrpc.FeeLimit_Fixed{
-			Fixed: 300,
-		},
-	}
-	preImage := makePreimageHex()
-	pHash := sha256.New()
-	pHash.Write(preImage)
-	// Prepare the LNRPC call
-	//See: https://github.com/hsjoberg/blixt-wallet/blob/9fcc56a7dc25237bc14b85e6490adb9e044c009c/src/lndmobile/index.ts#L251-L270
-	destBytes, err := hex.DecodeString(invoice.DestinationPubkeyHex)
-	if err != nil {
-		return sendPaymentResponse, err
-	}
-	sendPaymentRequest := lnrpc.SendRequest{
-		Dest:              destBytes,
-		Amt:               invoice.Amount,
-		PaymentHash:       pHash.Sum(nil),
-		FeeLimit:          &feeLimit,
-		DestFeatures:      []lnrpc.FeatureBit{lnrpc.FeatureBit_TLV_ONION_REQ},
-		DestCustomRecords: map[uint64][]byte{KEYSEND_CUSTOM_RECORD: preImage, TLV_WHATSAT_MESSAGE: []byte(invoice.Memo)},
-	}
-
-	// Execute the payment
-	sendPaymentResult, err := svc.LndClient.SendPaymentSync(ctx, &sendPaymentRequest)
-	if err != nil {
-		return sendPaymentResponse, err
-	}
-
-	// If there was a payment error we return an error
-	if sendPaymentResult.GetPaymentError() != "" || sendPaymentResult.GetPaymentPreimage() == nil {
-		return sendPaymentResponse, errors.New(sendPaymentResult.GetPaymentError())
-	}
-
-	preimage := sendPaymentResult.GetPaymentPreimage()
-	sendPaymentResponse.PaymentPreimage = preimage
-	sendPaymentResponse.PaymentPreimageStr = hex.EncodeToString(preimage[:])
-	paymentHash := sendPaymentResult.GetPaymentHash()
-	sendPaymentResponse.PaymentHash = paymentHash
-	sendPaymentResponse.PaymentHashStr = hex.EncodeToString(paymentHash[:])
-	sendPaymentResponse.PaymentRoute = &Route{TotalAmt: sendPaymentResult.PaymentRoute.TotalAmt, TotalFees: sendPaymentResult.PaymentRoute.TotalFees}
-	return sendPaymentResponse, nil
-}