staticaddr: deposit timeout fsm actions

Author: hieblmi

staticaddr/actions.go

@@ -0,0 +1,95 @@
+package staticaddr
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/btcsuite/btcd/wire"
+	"github.com/lightninglabs/lndclient"
+	"github.com/lightninglabs/loop/fsm"
+	"github.com/lightninglabs/loop/staticaddr/script"
+)
+
+const (
+	defaultConfTarget = 3
+)
+
+// SweepExpiredDepositAction ...
+func (f *FSM) SweepExpiredDepositAction(
+	eventCtx fsm.EventContext) fsm.EventType {
+
+	depoCtx, ok := eventCtx.(*DepositContext)
+	if !ok {
+		return f.HandleError(fsm.ErrInvalidContextType)
+	}
+	f.Debugf("SweepExpiredDepositAction: %v", depoCtx)
+
+	msgTx := wire.NewMsgTx(2)
+
+	msgTx.AddTxIn(&wire.TxIn{
+		PreviousOutPoint: f.deposit.OutPoint,
+		Sequence:         f.addressParameters.Expiry,
+		SignatureScript:  nil,
+	})
+
+	// Estimate the fee rate of an expiry spend transaction.
+	feeRateEstimator, err := f.cfg.WalletKit.EstimateFeeRate(
+		f.ctx, defaultConfTarget,
+	)
+	if err != nil {
+		return f.HandleError(fmt.Errorf("timeout sweep fee "+
+			"estimation failed: %v", err))
+	}
+
+	weight := script.ExpirySpendWeight()
+
+	fee := feeRateEstimator.FeeForWeight(weight)
+
+	// We cap the fee at 20% of the deposit value.
+	if fee > f.deposit.Value/5 {
+		return f.HandleError(errors.New("fee is higher than 20% of " +
+			"deposit value"))
+	}
+
+	output := &wire.TxOut{
+		Value:    int64(f.deposit.Value - fee),
+		PkScript: f.deposit.TimeOutSweepPkScript,
+	}
+	msgTx.AddTxOut(output)
+
+	signDesc, err := f.SignDescriptor()
+	if err != nil {
+		return f.HandleError(err)
+	}
+
+	txOut := &wire.TxOut{
+		Value:    int64(f.deposit.Value),
+		PkScript: f.addressParameters.PkScript,
+	}
+
+	prevOut := []*wire.TxOut{txOut}
+
+	rawSigs, err := f.cfg.Signer.SignOutputRaw(
+		f.ctx, msgTx, []*lndclient.SignDescriptor{&signDesc}, prevOut,
+	)
+	if err != nil {
+		return f.HandleError(err)
+	}
+
+	sig := rawSigs[0]
+	msgTx.TxIn[0].Witness, err = f.staticAddress.GenTimeoutWitness(sig)
+	if err != nil {
+		return f.HandleError(err)
+	}
+
+	err = f.cfg.WalletKit.PublishTransaction(
+		f.ctx, msgTx, f.deposit.OutPoint.Hash.String()+"-close-sweep",
+	)
+	if err != nil {
+		return f.HandleError(err)
+	}
+
+	f.Debugf("publishing timeout sweep with txid: %v", msgTx.TxHash())
+
+	return OnSwept
+}