From 9ce817511d63deb05f039bbb3e3ed3c3b57f7c9c Mon Sep 17 00:00:00 2001
From: Olaoluwa Osuntokun <laolu32@gmail.com>
Date: Thu, 19 Jan 2023 20:31:31 -0800
Subject: [PATCH] contractcourt: update chain watcher to understand the taproot
 pkscript

In this commit, we update the chain watcher to be able to generate the
correct pkScript so it can register for confirmation and spend
notifications for taproot channels.
---
 contractcourt/chain_watcher.go | 38 +++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 10 deletions(-)

diff --git a/contractcourt/chain_watcher.go b/contractcourt/chain_watcher.go
index 7fd45e1c2..39d160538 100644
--- a/contractcourt/chain_watcher.go
+++ b/contractcourt/chain_watcher.go
@@ -287,17 +287,32 @@ func (c *chainWatcher) Start() error {
 		}
 	}
 
-	localKey := chanState.LocalChanCfg.MultiSigKey.PubKey.SerializeCompressed()
-	remoteKey := chanState.RemoteChanCfg.MultiSigKey.PubKey.SerializeCompressed()
-	multiSigScript, err := input.GenMultiSigScript(
-		localKey, remoteKey,
+	localKey := chanState.LocalChanCfg.MultiSigKey.PubKey
+	remoteKey := chanState.RemoteChanCfg.MultiSigKey.PubKey
+
+	var (
+		pkScript []byte
+		err      error
 	)
-	if err != nil {
-		return err
-	}
-	pkScript, err := input.WitnessScriptHash(multiSigScript)
-	if err != nil {
-		return err
+	if chanState.ChanType.IsTaproot() {
+		pkScript, _, err = input.GenTaprootFundingScript(
+			localKey, remoteKey, 0,
+		)
+		if err != nil {
+			return err
+		}
+	} else {
+		multiSigScript, err := input.GenMultiSigScript(
+			localKey.SerializeCompressed(),
+			remoteKey.SerializeCompressed(),
+		)
+		if err != nil {
+			return err
+		}
+		pkScript, err = input.WitnessScriptHash(multiSigScript)
+		if err != nil {
+			return err
+		}
 	}
 
 	spendNtfn, err := c.cfg.notifier.RegisterSpendNtfn(
@@ -833,6 +848,9 @@ func (c *chainWatcher) handlePossibleBreach(commitSpend *chainntnfs.SpendDetail,
 	}
 
 	// Create an AnchorResolution for the breached state.
+	//
+	// TODO(roasbeef): make keyring for taproot chans to pass in instead of
+	// nil
 	anchorRes, err := lnwallet.NewAnchorResolution(
 		c.cfg.chanState, commitSpend.SpendingTx, nil,
 	)