From 0433bee6f44f53e6f53c8429a4742c562716be29 Mon Sep 17 00:00:00 2001
From: ziggie <ziggie1984@protonmail.com>
Date: Wed, 22 Nov 2023 23:04:45 +0100
Subject: [PATCH] main: add dumphistoricalchannel command.

---
 cmd/chantools/dumphistoricalchannel.go | 174 +++++++++++++++++++++++++
 cmd/chantools/root.go                  |   1 +
 2 files changed, 175 insertions(+)
 create mode 100644 cmd/chantools/dumphistoricalchannel.go

diff --git a/cmd/chantools/dumphistoricalchannel.go b/cmd/chantools/dumphistoricalchannel.go
new file mode 100644
index 0000000..8b0697f
--- /dev/null
+++ b/cmd/chantools/dumphistoricalchannel.go
@@ -0,0 +1,174 @@
+package main
+
+import (
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/davecgh/go-spew/spew"
+	"github.com/lightninglabs/chantools/dump"
+	"github.com/lightninglabs/chantools/lnd"
+	"github.com/lightningnetwork/lnd/channeldb"
+	"github.com/lightningnetwork/lnd/lnrpc"
+	"github.com/spf13/cobra"
+)
+
+type summaryHTLC struct {
+	ChannelDB    string
+	ChannelPoint string
+
+	rootKey *rootKey
+	cmd     *cobra.Command
+}
+
+var errBadChanPoint = errors.New("expecting chan_point to be in format of: " +
+	"txid:index")
+
+func parseChanPoint(s string) (*lnrpc.ChannelPoint, error) {
+	split := strings.Split(s, ":")
+	if len(split) != 2 || len(split[0]) == 0 || len(split[1]) == 0 {
+		return nil, errBadChanPoint
+	}
+
+	index, err := strconv.ParseInt(split[1], 10, 64)
+	if err != nil {
+		return nil, fmt.Errorf("unable to decode output index: %v", err)
+	}
+
+	txid, err := chainhash.NewHashFromStr(split[0])
+	if err != nil {
+		return nil, fmt.Errorf("unable to parse hex string: %v", err)
+	}
+
+	return &lnrpc.ChannelPoint{
+		FundingTxid: &lnrpc.ChannelPoint_FundingTxidBytes{
+			FundingTxidBytes: txid[:],
+		},
+		OutputIndex: uint32(index),
+	}, nil
+}
+
+func dumphistoricalchan() *cobra.Command {
+	cc := &summaryHTLC{}
+	cc.cmd = &cobra.Command{
+		Use: "dumphistoricalchannel",
+		Short: "dump all information of a closed channel's last " +
+			"commitment state",
+		Long: `when a channel is closed we delete all the data from the
+			openchannel bkt and move the last commitment state to
+			the historical bkt. This command aims to dump all the
+			necessary data from that last state.`,
+		Example: `chantools dumphtlcsummary \
+	--channeldb ~/.lnd/data/graph/mainnet/channel.db`,
+		RunE: cc.Execute,
+	}
+	cc.cmd.Flags().StringVar(
+		&cc.ChannelDB, "channeldb", "", "lnd channel.db file to dump "+
+			"channels from",
+	)
+	cc.cmd.Flags().StringVar(
+		&cc.ChannelPoint, "chan_point", "", "",
+	)
+
+	cc.rootKey = newRootKey(cc.cmd, "deriving keys")
+
+	return cc.cmd
+}
+
+func (c *summaryHTLC) Execute(_ *cobra.Command, _ []string) error {
+	// Check that we have a channel DB.
+	if c.ChannelDB == "" {
+		return fmt.Errorf("channel DB is required")
+	}
+	db, err := lnd.OpenDB(c.ChannelDB, true)
+	if err != nil {
+		return fmt.Errorf("error opening rescue DB: %w", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	return dumpHistoricalChanInfos(db.ChannelStateDB(), c.ChannelPoint)
+}
+
+func dumpHistoricalChanInfos(chanDb *channeldb.ChannelStateDB, channel string) error {
+
+	chanPoint, err := parseChanPoint(channel)
+	if err != nil {
+		return err
+	}
+
+	//Open the Historical Bucket
+	fundingHash, err := chainhash.NewHash(chanPoint.GetFundingTxidBytes())
+
+	fmt.Println("Test", fundingHash.String())
+
+	if err != nil {
+		return err
+	}
+	outPoint := wire.NewOutPoint(fundingHash, chanPoint.OutputIndex)
+
+	dbChannel, err := chanDb.FetchHistoricalChannel(outPoint)
+	if err != nil {
+		return err
+	}
+
+	channels := []*channeldb.OpenChannel{
+		dbChannel,
+	}
+
+	dumpChannels, err := dump.OpenChannelDump(channels, chainParams)
+	if err != nil {
+		return fmt.Errorf("error converting to dump format: %w", err)
+	}
+
+	spew.Dump(dumpChannels)
+
+	// For the tests, also log as trace level which is disabled by default.
+	log.Tracef(spew.Sdump(dumpChannels))
+
+	// Go also through all the HTLCs and calculate the sha of the onionblob.
+	log.Debug("===========================================================")
+	local := dbChannel.LocalCommitment
+	remote := dbChannel.RemoteCommitment
+	log.Debugf("RemoteCommitment: height=%v", remote.CommitHeight)
+	log.Debugf("LocalCommitment: height=%v", local.CommitHeight)
+
+	remoteHtlcs := make(map[[32]byte]struct{})
+	for _, htlc := range remote.Htlcs {
+		log.Debugf("RemoteCommitment has htlc: id=%v, update=%v "+
+			"incoming=%v", htlc.HtlcIndex, htlc.LogIndex,
+			htlc.Incoming)
+
+		onionHash := sha256.Sum256(htlc.OnionBlob[:])
+		remoteHtlcs[onionHash] = struct{}{}
+
+	}
+
+	// as active if *we* know them as well.
+	activeHtlcs := make([]channeldb.HTLC, 0, len(remoteHtlcs))
+	for _, htlc := range local.Htlcs {
+		log.Debugf("LocalCommitment has htlc: id=%v, update=%v "+
+			"incoming=%v", htlc.HtlcIndex, htlc.LogIndex,
+			htlc.Incoming)
+
+		onionHash := sha256.Sum256(htlc.OnionBlob[:])
+		if _, ok := remoteHtlcs[onionHash]; !ok {
+			log.Debugf("Skipped htlc due to onion has not "+
+				"matched: id=%v, update=%v incoming=%v",
+				htlc.HtlcIndex, htlc.LogIndex, htlc.Incoming)
+
+			continue
+		}
+		activeHtlcs = append(activeHtlcs, htlc)
+	}
+
+	log.Debugf("Active htlcs on the local commitment when the channel " +
+		"closed")
+
+	spew.Dump(activeHtlcs)
+
+	return nil
+}
diff --git a/cmd/chantools/root.go b/cmd/chantools/root.go
index 39da6aa..62ef87a 100644
--- a/cmd/chantools/root.go
+++ b/cmd/chantools/root.go
@@ -128,6 +128,7 @@ func main() {
 		newVanityGenCommand(),
 		newWalletInfoCommand(),
 		newZombieRecoveryCommand(),
+		dumphistoricalchan(),
 	)
 
 	if err := rootCmd.Execute(); err != nil {