multi: base sweep fee estimate on actually used address type

Author: joostjager

client.go

@@ -359,9 +359,20 @@ func (s *Client) LoopOutQuote(ctx context.Context,
 		request.Amount, terms.SwapFeeBase, terms.SwapFeeRate,
 	)
 
+	// Generate dummy p2wsh address for fee estimation. The p2wsh address
+	// type is chosen because it adds the most weight of all output types
+	// and we want the quote to return a worst case value.
+	wsh := [32]byte{}
+	p2wshAddress, err := btcutil.NewAddressWitnessScriptHash(
+		wsh[:], s.lndServices.ChainParams,
+	)
+	if err != nil {
+		return nil, err
+	}
+
 	minerFee, err := s.sweeper.GetSweepFee(
 		ctx, swap.QuoteHtlc.AddSuccessToEstimator,
-		request.SweepConfTarget,
+		p2wshAddress, request.SweepConfTarget,
 	)
 	if err != nil {
 		return nil, err

loopin.go

@@ -584,7 +584,8 @@ func (s *loopInSwap) publishTimeoutTx(ctx context.Context,
 
 	// Calculate sweep tx fee
 	fee, err := s.sweeper.GetSweepFee(
-		ctx, s.htlc.AddTimeoutToEstimator, TimeoutTxConfTarget,
+		ctx, s.htlc.AddTimeoutToEstimator, s.timeoutAddr,
+		TimeoutTxConfTarget,
 	)
 	if err != nil {
 		return err

loopout.go

@@ -602,7 +602,7 @@ func (s *loopOutSwap) sweep(ctx context.Context,
 		confTarget = DefaultSweepConfTarget
 	}
 	fee, err := s.sweeper.GetSweepFee(
-		ctx, s.htlc.AddSuccessToEstimator, confTarget,
+		ctx, s.htlc.AddSuccessToEstimator, s.DestAddr, confTarget,
 	)
 	if err != nil {
 		return err

sweep/sweeper.go

@@ -91,7 +91,7 @@ func (s *Sweeper) CreateSweepTx(
 // estimator.
 func (s *Sweeper) GetSweepFee(ctx context.Context,
 	addInputEstimate func(*input.TxWeightEstimator),
-	sweepConfTarget int32) (
+	destAddr btcutil.Address, sweepConfTarget int32) (
 	btcutil.Amount, error) {
 
 	// Get fee estimate from lnd.
@@ -102,7 +102,19 @@ func (s *Sweeper) GetSweepFee(ctx context.Context,
 
 	// Calculate weight for this tx.
 	var weightEstimate input.TxWeightEstimator
-	weightEstimate.AddP2WKHOutput()
+	switch destAddr.(type) {
+	case *btcutil.AddressWitnessScriptHash:
+		weightEstimate.AddP2WSHOutput()
+	case *btcutil.AddressWitnessPubKeyHash:
+		weightEstimate.AddP2WKHOutput()
+	case *btcutil.AddressScriptHash:
+		weightEstimate.AddP2SHOutput()
+	case *btcutil.AddressPubKeyHash:
+		weightEstimate.AddP2PKHOutput()
+	default:
+		return 0, fmt.Errorf("unknown adress type %T", destAddr)
+	}
+
 	addInputEstimate(&weightEstimate)
 	weight := weightEstimate.Weight()