From 0477c80732c8b6c66fa471ec1bbc8b561603d630 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@lightning.engineering>
Date: Tue, 15 Sep 2020 12:43:20 -0400
Subject: [PATCH] watchtower/blob/type: add new FlagAnchorChannel

---
 watchtower/blob/type.go      | 18 ++++++++++++++++++
 watchtower/blob/type_test.go |  6 +++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/watchtower/blob/type.go b/watchtower/blob/type.go
index da83472c..f24b41f3 100644
--- a/watchtower/blob/type.go
+++ b/watchtower/blob/type.go
@@ -19,6 +19,11 @@ const (
 	// FlagCommitOutputs signals that the blob contains the information
 	// required to sweep commitment outputs.
 	FlagCommitOutputs Flag = 1 << 1
+
+	// FlagAnchorChannel signals that this blob is meant to spend an anchor
+	// channel, and therefore must expect a P2WSH-style to-remote output if
+	// one exists.
+	FlagAnchorChannel Flag = 1 << 2
 )
 
 // Type returns a Type consisting solely of this flag enabled.
@@ -33,6 +38,8 @@ func (f Flag) String() string {
 		return "FlagReward"
 	case FlagCommitOutputs:
 		return "FlagCommitOutputs"
+	case FlagAnchorChannel:
+		return "FlagAnchorChannel"
 	default:
 		return "FlagUnknown"
 	}
@@ -50,6 +57,11 @@ const (
 	// controlled by the user, and does not give the tower a reward.
 	TypeAltruistCommit = Type(FlagCommitOutputs)
 
+	// TypeAltruistAnchorCommit sweeps only commitment outputs from an
+	// anchor commitment to a sweep address controlled by the user, and does
+	// not give the tower a reward.
+	TypeAltruistAnchorCommit = Type(FlagCommitOutputs | FlagAnchorChannel)
+
 	// TypeRewardCommit sweeps only commitment outputs to a sweep address
 	// controlled by the user, and pays a negotiated reward to the tower.
 	TypeRewardCommit = Type(FlagCommitOutputs | FlagReward)
@@ -70,10 +82,16 @@ func TypeFromFlags(flags ...Flag) Type {
 	return typ
 }
 
+// IsAnchorChannel returns true if the blob type is for an anchor channel.
+func (t Type) IsAnchorChannel() bool {
+	return t.Has(FlagAnchorChannel)
+}
+
 // knownFlags maps the supported flags to their name.
 var knownFlags = map[Flag]struct{}{
 	FlagReward:        {},
 	FlagCommitOutputs: {},
+	FlagAnchorChannel: {},
 }
 
 // String returns a human readable description of a Type.
diff --git a/watchtower/blob/type_test.go b/watchtower/blob/type_test.go
index 95b01c01..a88965b2 100644
--- a/watchtower/blob/type_test.go
+++ b/watchtower/blob/type_test.go
@@ -18,17 +18,17 @@ var typeStringTests = []typeStringTest{
 	{
 		name:   "commit no-reward",
 		typ:    blob.TypeAltruistCommit,
-		expStr: "[FlagCommitOutputs|No-FlagReward]",
+		expStr: "[No-FlagAnchorChannel|FlagCommitOutputs|No-FlagReward]",
 	},
 	{
 		name:   "commit reward",
 		typ:    blob.TypeRewardCommit,
-		expStr: "[FlagCommitOutputs|FlagReward]",
+		expStr: "[No-FlagAnchorChannel|FlagCommitOutputs|FlagReward]",
 	},
 	{
 		name:   "unknown flag",
 		typ:    unknownFlag.Type(),
-		expStr: "0000000000010000[No-FlagCommitOutputs|No-FlagReward]",
+		expStr: "0000000000010000[No-FlagAnchorChannel|No-FlagCommitOutputs|No-FlagReward]",
 	},
 }