fix: register swap listeners before websocket subscribe (#2141)

* fix: register swap listeners before websocket subscribe

* fix: only pay swap invoice when lookup returns not found

Author: im-adithya

swaps/swaps_service.go

@@ -856,6 +856,11 @@ func (svc *swapsService) subscribePendingSwaps() {
 }
 
 func (svc *swapsService) startSwapInListener(swap *db.Swap) {
+	updateCh := make(chan boltz.SwapUpdate, 1)
+	svc.swapListenersLock.Lock()
+	svc.swapListeners[swap.SwapId] = updateCh
+	svc.swapListenersLock.Unlock()
+
 	for {
 		err := svc.boltzWs.Subscribe([]string{swap.SwapId})
 		if err != nil {
@@ -868,11 +873,6 @@ func (svc *swapsService) startSwapInListener(swap *db.Swap) {
 
 	logger.Logger.WithField("swapId", swap.SwapId).Info("Subscribed to boltz websocket")
 
-	updateCh := make(chan boltz.SwapUpdate)
-	svc.swapListenersLock.Lock()
-	svc.swapListeners[swap.SwapId] = updateCh
-	svc.swapListenersLock.Unlock()
-
 	var err error
 	defer func() {
 		svc.swapListenersLock.Lock()
@@ -1024,6 +1024,11 @@ func (svc *swapsService) startSwapInListener(swap *db.Swap) {
 }
 
 func (svc *swapsService) startSwapOutListener(swap *db.Swap) {
+	updateCh := make(chan boltz.SwapUpdate, 1)
+	svc.swapListenersLock.Lock()
+	svc.swapListeners[swap.SwapId] = updateCh
+	svc.swapListenersLock.Unlock()
+
 	for {
 		err := svc.boltzWs.Subscribe([]string{swap.SwapId})
 		if err != nil {
@@ -1036,11 +1041,6 @@ func (svc *swapsService) startSwapOutListener(swap *db.Swap) {
 
 	logger.Logger.WithField("swapId", swap.SwapId).Info("Subscribed to boltz websocket")
 
-	updateCh := make(chan boltz.SwapUpdate)
-	svc.swapListenersLock.Lock()
-	svc.swapListeners[swap.SwapId] = updateCh
-	svc.swapListenersLock.Unlock()
-
 	var err error
 	defer func() {
 		svc.swapListenersLock.Lock()
@@ -1163,10 +1163,14 @@ func (svc *swapsService) startSwapOutListener(swap *db.Swap) {
 				logger.Logger.WithField("swapId", swap.SwapId).Info("Paying the swap invoice")
 				go func() {
 					_, err := svc.transactionsService.LookupTransaction(svc.ctx, swap.PaymentHash, nil, svc.lnClient, nil)
-					if err == transactions.NewNotFoundError() {
+					if err == nil {
 						logger.Logger.WithField("swapId", swap.SwapId).Info("Already initiated swap invoice payment")
 						return
 					}
+					if !errors.Is(err, transactions.NewNotFoundError()) {
+						logger.Logger.WithError(err).WithField("swapId", swap.SwapId).Warn("Failed to lookup transaction")
+						return
+					}
 					metadata := map[string]interface{}{
 						"swap_id": swap.SwapId,
 					}