Update project structure and build process

libwallet/submarineSwapV2.go

@@ -0,0 +1,66 @@
+package libwallet
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/btcsuite/btcutil"
+	"github.com/muun/libwallet/swaps"
+)
+
+type coinSubmarineSwapV2 struct {
+	Network             *chaincfg.Params
+	OutPoint            wire.OutPoint
+	Amount              btcutil.Amount
+	KeyPath             string
+	PaymentHash256      []byte
+	UserPublicKey       []byte
+	MuunPublicKey       []byte
+	ServerPublicKey     []byte
+	BlocksForExpiration int64
+	ServerSignature     []byte
+}
+
+func (c *coinSubmarineSwapV2) SignInput(index int, tx *wire.MsgTx, userKey *HDPrivateKey,
+	_ *HDPublicKey) error {
+
+	userKey, err := userKey.DeriveTo(c.KeyPath)
+	if err != nil {
+		return fmt.Errorf("failed to derive user key: %w", err)
+	}
+
+	if len(c.ServerSignature) == 0 {
+		return errors.New("swap server must provide signature")
+	}
+
+	witnessScript, err := swaps.CreateWitnessScriptSubmarineSwapV2(
+		c.PaymentHash256,
+		c.UserPublicKey,
+		c.MuunPublicKey,
+		c.ServerPublicKey,
+		c.BlocksForExpiration)
+	if err != nil {
+		return err
+	}
+
+	sig, err := signNativeSegwitInput(
+		index, tx, userKey, witnessScript, c.Amount)
+	if err != nil {
+		return err
+	}
+
+	txInput := tx.TxIn[index]
+	txInput.Witness = wire.TxWitness{
+		sig,
+		c.ServerSignature,
+		witnessScript,
+	}
+
+	return nil
+}
+
+func (c *coinSubmarineSwapV2) FullySignInput(index int, tx *wire.MsgTx, userKey, muunKey *HDPrivateKey) error {
+	return errors.New("cannot fully sign submarine swap transactions")
+}