From 710ae777509ebd374b2fe198bbc906180071be5e Mon Sep 17 00:00:00 2001
From: Joost Jager <joost.jager@gmail.com>
Date: Tue, 14 Apr 2020 14:35:56 +0200
Subject: [PATCH] loopout: log in-flight htlc status

---
 lndclient/router_client.go | 33 +++++++++++++++++++++++++++++----
 loopout.go                 |  3 +--
 2 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/lndclient/router_client.go b/lndclient/router_client.go
index ae827b7..fb8a4d6 100644
--- a/lndclient/router_client.go
+++ b/lndclient/router_client.go
@@ -34,10 +34,22 @@ type RouterClient interface {
 
 // PaymentStatus describe the state of a payment.
 type PaymentStatus struct {
-	State    lnrpc.Payment_PaymentStatus
-	Preimage lntypes.Preimage
-	Fee      lnwire.MilliSatoshi
-	Value    lnwire.MilliSatoshi
+	State         lnrpc.Payment_PaymentStatus
+	Preimage      lntypes.Preimage
+	Fee           lnwire.MilliSatoshi
+	Value         lnwire.MilliSatoshi
+	InFlightAmt   lnwire.MilliSatoshi
+	InFlightHtlcs int
+}
+
+func (p PaymentStatus) String() string {
+	text := fmt.Sprintf("state=%v", p.State)
+	if p.State == lnrpc.Payment_IN_FLIGHT {
+		text += fmt.Sprintf(", inflight_htlcs=%v, inflight_amt=%v",
+			p.InFlightHtlcs, p.InFlightAmt)
+	}
+
+	return text
 }
 
 // SendPaymentRequest defines the payment parameters for a new payment.
@@ -227,6 +239,19 @@ func unmarshallPaymentStatus(rpcPayment *lnrpc.Payment) (
 		status.Value = lnwire.MilliSatoshi(rpcPayment.ValueMsat)
 	}
 
+	for _, htlc := range rpcPayment.Htlcs {
+		if htlc.Status != lnrpc.HTLCAttempt_IN_FLIGHT {
+			continue
+		}
+
+		status.InFlightHtlcs++
+
+		lastHop := htlc.Route.Hops[len(htlc.Route.Hops)-1]
+		status.InFlightAmt += lnwire.MilliSatoshi(
+			lastHop.AmtToForwardMsat,
+		)
+	}
+
 	return &status, nil
 }
 
diff --git a/loopout.go b/loopout.go
index a4dad22..82c3ecc 100644
--- a/loopout.go
+++ b/loopout.go
@@ -469,8 +469,7 @@ func (s *loopOutSwap) payInvoiceAsync(ctx context.Context,
 		select {
 		// Payment advanced to the next state.
 		case payState := <-payStatusChan:
-			s.log.Infof("Payment %v: state=%v",
-				hash, payState.State)
+			s.log.Infof("Payment %v: %v", hash, payState)
 
 			switch payState.State {
 			case lnrpc.Payment_SUCCEEDED: