Update project structure and build process

recovery_tool/sweeper.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+
+	"github.com/muun/recovery/electrum"
+	"github.com/muun/recovery/scanner"
+
+	"github.com/btcsuite/btcd/chaincfg"
+
+	"github.com/btcsuite/btcd/wire"
+	"github.com/btcsuite/btcutil"
+	"github.com/muun/libwallet"
+)
+
+var (
+	chainParams = chaincfg.MainNetParams
+)
+
+type Sweeper struct {
+	UserKey      *libwallet.HDPrivateKey
+	MuunKey      *libwallet.HDPrivateKey
+	Birthday     int
+	SweepAddress btcutil.Address
+}
+
+func (s *Sweeper) GetSweepTxAmountAndWeightInBytes(utxos []*scanner.Utxo) (outputAmount int64, weightInBytes int64, err error) {
+	// we build a sweep tx with 0 fee with the only purpose of checking its signed size
+	zeroFeeSweepTx, err := s.BuildSweepTx(utxos, 0)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	outputAmount = zeroFeeSweepTx.TxOut[0].Value
+	weightInBytes = int64(zeroFeeSweepTx.SerializeSize())
+
+	return outputAmount, weightInBytes, nil
+}
+
+func (s *Sweeper) BuildSweepTx(utxos []*scanner.Utxo, fee int64) (*wire.MsgTx, error) {
+	derivedMuunKey, err := s.MuunKey.DeriveTo("m/1'/1'")
+	if err != nil {
+		return nil, err
+	}
+	sweepTx, err := buildSweepTx(utxos, s.SweepAddress, fee)
+	if err != nil {
+		return nil, err
+	}
+
+	return buildSignedTx(utxos, sweepTx, s.UserKey, derivedMuunKey)
+}
+
+func (s *Sweeper) BroadcastTx(tx *wire.MsgTx) error {
+	// Connect to an Electurm server using a fresh client and provider pair:
+	sp := electrum.NewServerProvider(electrum.PublicServers) // TODO create servers module, for provider and pool
+	client := electrum.NewClient(true)
+
+	for !client.IsConnected() {
+		client.Connect(sp.NextServer())
+	}
+
+	// Encode the transaction for broadcast:
+	txBytes := new(bytes.Buffer)
+
+	err := tx.BtcEncode(txBytes, wire.ProtocolVersion, wire.WitnessEncoding)
+	if err != nil {
+		return fmt.Errorf("error while encoding tx: %w", err)
+	}
+
+	txHex := hex.EncodeToString(txBytes.Bytes())
+
+	// Do the thing!
+	_, err = client.Broadcast(txHex)
+	if err != nil {
+		return fmt.Errorf("error while broadcasting: %w", err)
+	}
+
+	return nil
+}