// createCoinbaseTx returns a coinbase transaction paying an appropriate subsidy
// based on the passed block height to the provided address.  When the address
// is nil, the coinbase transaction will instead be redeemable by anyone.
//
// See the comment for NewBlockTemplate for more information about why the nil
// address handling is useful.
func createCoinbaseTx(params *chaincfg.Params, coinbaseScript []byte, nextBlockHeight int32, addr btcutil.Address) (*btcutil.Tx, error) {
	// Create the script to pay to the provided payment address if one was
	// specified.  Otherwise create a script that allows the coinbase to be
	// redeemable by anyone.
	var pkScript []byte
	if addr != nil {
		var err error
		pkScript, err = txscript.PayToAddrScript(addr)
		if err != nil {
			return nil, err
		}
	} else {
		var err error
		scriptBuilder := txscript.NewScriptBuilder()
		pkScript, err = scriptBuilder.AddOp(txscript.OP_TRUE).Script()
		if err != nil {
			return nil, err
		}
	}

	tx := wire.NewMsgTx(wire.TxVersion)
	tx.AddTxIn(&wire.TxIn{
		// Coinbase transactions have no inputs, so previous outpoint is
		// zero hash and max index.
		PreviousOutPoint: *wire.NewOutPoint(&chainhash.Hash{},
			wire.MaxPrevOutIndex),
		SignatureScript: coinbaseScript,
		Sequence:        wire.MaxTxInSequenceNum,
	})
	tx.AddTxOut(&wire.TxOut{
		Value:    blockchain.CalcBlockSubsidy(nextBlockHeight, params),
		PkScript: pkScript,
	})
	return btcutil.NewTx(tx), nil
}

// TestTxSerialize tests MsgTx serialize and deserialize.
func TestTxSerialize(t *testing.T) {
	noTx := wire.NewMsgTx()
	noTx.Version = 1
	noTxEncoded := []byte{
		0x01, 0x00, 0x00, 0x00, // Version
		0x00,                   // Varint for number of input transactions
		0x00,                   // Varint for number of output transactions
		0x00, 0x00, 0x00, 0x00, // Lock time
	}

	tests := []struct {
		in  *wire.MsgTx // Message to encode
		out *wire.MsgTx // Expected decoded message
		buf []byte      // Serialized data
	}{
		// No transactions.
		{
			noTx,
			noTx,
			noTxEncoded,
		},

		// Multiple transactions.
		{
			multiTx,
			multiTx,
			multiTxEncoded,
		},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Serialize the transaction.
		var buf bytes.Buffer
		err := test.in.Serialize(&buf)
		if err != nil {
			t.Errorf("Serialize #%d error %v", i, err)
			continue
		}
		if !bytes.Equal(buf.Bytes(), test.buf) {
			t.Errorf("Serialize #%d\n got: %s want: %s", i,
				spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
			continue
		}

		// Deserialize the transaction.
		var tx wire.MsgTx
		rbuf := bytes.NewReader(test.buf)
		err = tx.Deserialize(rbuf)
		if err != nil {
			t.Errorf("Deserialize #%d error %v", i, err)
			continue
		}
		if !reflect.DeepEqual(&tx, test.out) {
			t.Errorf("Deserialize #%d\n got: %s want: %s", i,
				spew.Sdump(&tx), spew.Sdump(test.out))
			continue
		}
	}
}

// GetTx takes a txid and returns the transaction.  If we have it.
func (ts *TxStore) GetAllTxs() ([]*wire.MsgTx, error) {
	var rtxs []*wire.MsgTx

	err := ts.StateDB.View(func(btx *bolt.Tx) error {
		txns := btx.Bucket(BKTTxns)
		if txns == nil {
			return fmt.Errorf("no transactions in db")
		}

		return txns.ForEach(func(k, v []byte) error {
			tx := wire.NewMsgTx()
			buf := bytes.NewBuffer(v)
			err := tx.Deserialize(buf)
			if err != nil {
				return err
			}
			rtxs = append(rtxs, tx)
			return nil
		})
	})
	if err != nil {
		return nil, err
	}
	return rtxs, nil
}

// TestTxSerializeSize performs tests to ensure the serialize size for various
// transactions is accurate.
func TestTxSerializeSize(t *testing.T) {
	// Empty tx message.
	noTx := wire.NewMsgTx()
	noTx.Version = 1

	tests := []struct {
		in   *wire.MsgTx // Tx to encode
		size int         // Expected serialized size
	}{
		// No inputs or outpus.
		{noTx, 10},

		// Transcaction with an input and an output.
		{multiTx, 134},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		serializedSize := test.in.SerializeSize()
		if serializedSize != test.size {
			t.Errorf("MsgTx.SerializeSize: #%d got: %d, want: %d", i,
				serializedSize, test.size)
			continue
		}
	}
}

// CreateTxChain creates a chain of zero-fee transactions (each subsequent
// transaction spends the entire amount from the previous one) with the first
// one spending the provided outpoint.  Each transaction spends the entire
// amount of the previous one and as such does not include any fees.
func (p *poolHarness) CreateTxChain(firstOutput spendableOutput, numTxns uint32) ([]*btcutil.Tx, error) {
	txChain := make([]*btcutil.Tx, 0, numTxns)
	prevOutPoint := firstOutput.outPoint
	spendableAmount := firstOutput.amount
	for i := uint32(0); i < numTxns; i++ {
		// Create the transaction using the previous transaction output
		// and paying the full amount to the payment address associated
		// with the harness.
		tx := wire.NewMsgTx(wire.TxVersion)
		tx.AddTxIn(&wire.TxIn{
			PreviousOutPoint: prevOutPoint,
			SignatureScript:  nil,
			Sequence:         wire.MaxTxInSequenceNum,
		})
		tx.AddTxOut(&wire.TxOut{
			PkScript: p.payScript,
			Value:    int64(spendableAmount),
		})

		// Sign the new transaction.
		sigScript, err := txscript.SignatureScript(tx, 0, p.payScript,
			txscript.SigHashAll, p.signKey, true)
		if err != nil {
			return nil, err
		}
		tx.TxIn[0].SignatureScript = sigScript

		txChain = append(txChain, btcutil.NewTx(tx))

		// Next transaction uses outputs from this one.
		prevOutPoint = wire.OutPoint{Hash: tx.TxHash(), Index: 0}
	}

	return txChain, nil
}

func main() {
	// Pull the required arguments off of the command line.
	reqArgs := getArgs()

	// Get the bitcoin tx from blockchain.info's api
	rawFundingTx := lookupTxid(reqArgs.txid)

	// Get the parameters we need from the funding transaction
	oldTxOut, outpoint := getFundingParams(rawFundingTx, reqArgs.vout)

	// Formulate a new transaction from the provided parameters
	tx := wire.NewMsgTx()

	// Create the TxIn
	txin := createTxIn(outpoint)
	tx.AddTxIn(txin)

	// Create the TxOut
	txout := createTxOut(oldTxOut.Value, reqArgs.toAddress)
	txrem := createTxRemainder(oldTxOut.Value)
	tx.AddTxOut(txout)
	tx.AddTxOut(txrem)

	// Generate a signature over the whole tx.
	sig := generateSig(tx, reqArgs.privKey, oldTxOut.PkScript)
	tx.TxIn[0].SignatureScript = sig

	// Dump the bytes to stdout
	dumpHex(tx)

	// Send the transaction to the network
	broadcastTx(tx)
}

// CreateTransaction returns a fully signed transaction paying to the specified
// outputs while observing the desired fee rate. The passed fee rate should be
// expressed in satoshis-per-byte.
//
// This function is safe for concurrent access.
func (m *memWallet) CreateTransaction(outputs []*wire.TxOut, feeRate btcutil.Amount) (*wire.MsgTx, error) {
	m.Lock()
	defer m.Unlock()

	tx := wire.NewMsgTx()

	// Tally up the total amount to be sent in order to perform coin
	// selection shortly below.
	var outputAmt btcutil.Amount
	for _, output := range outputs {
		outputAmt += btcutil.Amount(output.Value)
		tx.AddTxOut(output)
	}

	// Attempt to fund the transaction with spendable utxos.
	if err := m.fundTx(tx, outputAmt, btcutil.Amount(feeRate)); err != nil {
		return nil, err
	}

	// Populate all the selected inputs with valid sigScript for spending.
	// Along the way record all outputs being spent in order to avoid a
	// potential double spend.
	spentOutputs := make([]*utxo, 0, len(tx.TxIn))
	for i, txIn := range tx.TxIn {
		outPoint := txIn.PreviousOutPoint
		utxo := m.utxos[outPoint]

		extendedKey, err := m.hdRoot.Child(utxo.keyIndex)
		if err != nil {
			return nil, err
		}

		privKey, err := extendedKey.ECPrivKey()
		if err != nil {
			return nil, err
		}

		sigScript, err := txscript.SignatureScript(tx, i, utxo.pkScript,
			txscript.SigHashAll, privKey, true)
		if err != nil {
			return nil, err
		}

		txIn.SignatureScript = sigScript

		spentOutputs = append(spentOutputs, utxo)
	}

	// As these outputs are now being spent by this newly created
	// transaction, mark the outputs are "locked". This action ensures
	// these outputs won't be double spent by any subsequent transactions.
	// These locked outputs can be freed via a call to UnlockOutputs.
	for _, utxo := range spentOutputs {
		utxo.isLocked = true
	}

	return tx, nil
}

// NewTransaction create transaction,
// utxos is an interface which need to be a slice type, and each item
// of the slice is an UtxoWithPrivkey interface.
// outAddrs is the output address array.
// using the api of blockchain.info to get the raw trasaction info of txid.
func NewTransaction(utxos interface{}, outAddrs []TxOut) (*Transaction, error) {
	s := reflect.ValueOf(utxos)
	if s.Kind() != reflect.Slice {
		return nil, errors.New("error utxo type")
	}

	ret := make([]interface{}, s.Len())
	for i := 0; i < s.Len(); i++ {
		ret[i] = s.Index(i).Interface()
	}

	tx := wire.NewMsgTx()
	oldTxOuts := make([]*wire.TxOut, len(ret))
	for i, r := range ret {
		utxo := r.(UtxoWithkey)
		txid, err := chainhash.NewHashFromStr(utxo.GetTxid())
		if err != nil {
			return nil, err
		}
		rawFundingTx, err := lookupTxid(txid)
		if err != nil {
			return nil, err
		}
		oldTxOut, outpoint, err := getFundingParams(rawFundingTx, utxo.GetVout())
		if err != nil {
			return nil, err
		}
		oldTxOuts[i] = oldTxOut

		txin := createTxIn(outpoint)
		tx.AddTxIn(txin)
	}

	if len(outAddrs) > 2 {
		return nil, errors.New("out address more than 2")
	}

	for _, out := range outAddrs {
		addr, err := btcutil.DecodeAddress(out.Addr, &chaincfg.MainNetParams)
		if err != nil {
			return nil, fmt.Errorf("decode address %s, faild, %s", out.Addr, err)
		}
		txout := createTxOut(out.Value, addr)
		tx.AddTxOut(txout)
	}

	// sign the transaction
	for i, r := range ret {
		utxo := r.(UtxoWithkey)
		sig, err := signRawTx(&Transaction{*tx}, i, utxo.GetPrivKey(), oldTxOuts[i].PkScript)
		if err != nil {
			return nil, err
		}
		tx.TxIn[i].SignatureScript = sig
	}
	return &Transaction{*tx}, nil
}

// CreateRawTx create bitcoin raw transaction.
func (btc Bitcoin) CreateRawTx(txIns []coin.TxIn, txOuts interface{}) (string, error) {
	tx := wire.NewMsgTx()
	oldTxOuts := make([]*wire.TxOut, len(txIns))
	for i, in := range txIns {
		txid, err := chainhash.NewHashFromStr(in.Txid)
		// txid, err := chainhash.NewShaHashFromStr(in.Txid)
		if err != nil {
			return "", err
		}
		rawFundingTx, err := lookupTxid(txid)
		if err != nil {
			return "", err
		}
		oldTxOut, outpoint, err := getFundingParams(rawFundingTx, in.Vout)
		if err != nil {
			return "", err
		}
		oldTxOuts[i] = oldTxOut

		txin := createTxIn(outpoint)
		tx.AddTxIn(txin)
	}

	s := reflect.ValueOf(txOuts)
	if s.Kind() != reflect.Slice {
		return "", errors.New("error tx out type")
	}

	outs := make([]interface{}, s.Len())
	for i := 0; i < s.Len(); i++ {
		outs[i] = s.Index(i).Interface()
	}

	if len(outs) > 2 {
		return "", errors.New("out address more than 2")
	}

	for _, o := range outs {
		out := o.(TxOut)
		addr, err := btcutil.DecodeAddress(out.Addr, &chaincfg.MainNetParams)
		if err != nil {
			return "", err
		}
		txout := createTxOut(out.Value, addr)
		tx.AddTxOut(txout)
	}

	t := Transaction{*tx}
	d, err := t.Serialize()
	if err != nil {
		return "", err
	}
	return hex.EncodeToString(d), nil
}

// createSpendTx generates a basic spending transaction given the passed
// signature and public key scripts.
func createSpendingTx(sigScript, pkScript []byte) *wire.MsgTx {
	coinbaseTx := wire.NewMsgTx()

	outPoint := wire.NewOutPoint(&wire.ShaHash{}, ^uint32(0))
	txIn := wire.NewTxIn(outPoint, []byte{OP_0, OP_0})
	txOut := wire.NewTxOut(0, pkScript)
	coinbaseTx.AddTxIn(txIn)
	coinbaseTx.AddTxOut(txOut)

	spendingTx := wire.NewMsgTx()
	coinbaseTxSha := coinbaseTx.TxSha()
	outPoint = wire.NewOutPoint(&coinbaseTxSha, 0)
	txIn = wire.NewTxIn(outPoint, sigScript)
	txOut = wire.NewTxOut(0, nil)

	spendingTx.AddTxIn(txIn)
	spendingTx.AddTxOut(txOut)

	return spendingTx
}

// createSpendTx generates a basic spending transaction given the passed
// signature and public key scripts.
func createSpendingTx(sigScript, pkScript []byte) *wire.MsgTx {
	coinbaseTx := wire.NewMsgTx(wire.TxVersion)

	outPoint := wire.NewOutPoint(&chainhash.Hash{}, ^uint32(0))
	txIn := wire.NewTxIn(outPoint, []byte{OP_0, OP_0})
	txOut := wire.NewTxOut(0, pkScript)
	coinbaseTx.AddTxIn(txIn)
	coinbaseTx.AddTxOut(txOut)

	spendingTx := wire.NewMsgTx(wire.TxVersion)
	coinbaseTxHash := coinbaseTx.TxHash()
	outPoint = wire.NewOutPoint(&coinbaseTxHash, 0)
	txIn = wire.NewTxIn(outPoint, sigScript)
	txOut = wire.NewTxOut(0, nil)

	spendingTx.AddTxIn(txIn)
	spendingTx.AddTxOut(txOut)

	return spendingTx
}

// TestCalcSignatureHash runs the Bitcoin Core signature hash calculation tests
// in sighash.json.
// https://github.com/bitcoin/bitcoin/blob/master/src/test/data/sighash.json
func TestCalcSignatureHash(t *testing.T) {
	file, err := ioutil.ReadFile("data/sighash.json")
	if err != nil {
		t.Errorf("TestCalcSignatureHash: %v\n", err)
		return
	}

	var tests [][]interface{}
	err = json.Unmarshal(file, &tests)
	if err != nil {
		t.Errorf("TestCalcSignatureHash couldn't Unmarshal: %v\n",
			err)
		return
	}

	for i, test := range tests {
		if i == 0 {
			// Skip first line -- contains comments only.
			continue
		}
		if len(test) != 5 {
			t.Fatalf("TestCalcSignatureHash: Test #%d has "+
				"wrong length.", i)
		}
		tx := wire.NewMsgTx()
		rawTx, _ := hex.DecodeString(test[0].(string))
		err := tx.Deserialize(bytes.NewReader(rawTx))
		if err != nil {
			t.Errorf("TestCalcSignatureHash failed test #%d: "+
				"Failed to parse transaction: %v", i, err)
			continue
		}

		subScript, _ := hex.DecodeString(test[1].(string))
		parsedScript, err := TstParseScript(subScript)
		if err != nil {
			t.Errorf("TestCalcSignatureHash failed test #%d: "+
				"Failed to parse sub-script: %v", i, err)
			continue
		}

		hashType := SigHashType(testVecF64ToUint32(test[3].(float64)))
		hash := TstCalcSignatureHash(parsedScript, hashType, tx,
			int(test[2].(float64)))

		expectedHash, _ := wire.NewShaHashFromStr(test[4].(string))
		if !bytes.Equal(hash, expectedHash.Bytes()) {
			t.Errorf("TestCalcSignatureHash failed test #%d: "+
				"Signature hash mismatch.", i)
		}
	}
}

// TestTxSha tests the ability to generate the hash of a transaction accurately.
func TestTxSha(t *testing.T) {
	// Hash of first transaction from block 113875.
	hashStr := "f051e59b5e2503ac626d03aaeac8ab7be2d72ba4b7e97119c5852d70d52dcb86"
	wantHash, err := wire.NewShaHashFromStr(hashStr)
	if err != nil {
		t.Errorf("NewShaHashFromStr: %v", err)
		return
	}

	// First transaction from block 113875.
	msgTx := wire.NewMsgTx()
	txIn := wire.TxIn{
		PreviousOutPoint: wire.OutPoint{
			Hash:  wire.ShaHash{},
			Index: 0xffffffff,
		},
		SignatureScript: []byte{0x04, 0x31, 0xdc, 0x00, 0x1b, 0x01, 0x62},
		Sequence:        0xffffffff,
	}
	txOut := wire.TxOut{
		Value: 5000000000,
		PkScript: []byte{
			0x41, // OP_DATA_65
			0x04, 0xd6, 0x4b, 0xdf, 0xd0, 0x9e, 0xb1, 0xc5,
			0xfe, 0x29, 0x5a, 0xbd, 0xeb, 0x1d, 0xca, 0x42,
			0x81, 0xbe, 0x98, 0x8e, 0x2d, 0xa0, 0xb6, 0xc1,
			0xc6, 0xa5, 0x9d, 0xc2, 0x26, 0xc2, 0x86, 0x24,
			0xe1, 0x81, 0x75, 0xe8, 0x51, 0xc9, 0x6b, 0x97,
			0x3d, 0x81, 0xb0, 0x1c, 0xc3, 0x1f, 0x04, 0x78,
			0x34, 0xbc, 0x06, 0xd6, 0xd6, 0xed, 0xf6, 0x20,
			0xd1, 0x84, 0x24, 0x1a, 0x6a, 0xed, 0x8b, 0x63,
			0xa6, // 65-byte signature
			0xac, // OP_CHECKSIG
		},
	}
	msgTx.AddTxIn(&txIn)
	msgTx.AddTxOut(&txOut)
	msgTx.LockTime = 0

	// Ensure the hash produced is expected.
	txHash, err := msgTx.TxSha()
	if err != nil {
		t.Errorf("TxSha: %v", err)
	}
	if !txHash.IsEqual(wantHash) {
		t.Errorf("TxSha: wrong hash - got %v, want %v",
			spew.Sprint(txHash), spew.Sprint(wantHash))
	}
}

// toMsgTx generates a btcwire.MsgTx with this tx's inputs and outputs.
func (tx *withdrawalTx) toMsgTx() *wire.MsgTx {
	msgtx := wire.NewMsgTx(wire.TxVersion)
	for _, o := range tx.outputs {
		msgtx.AddTxOut(wire.NewTxOut(int64(o.amount), o.pkScript()))
	}

	if tx.hasChange() {
		msgtx.AddTxOut(tx.changeOutput)
	}

	for _, i := range tx.inputs {
		msgtx.AddTxIn(wire.NewTxIn(&i.OutPoint, []byte{}))
	}
	return msgtx
}

// NewMsgTxWithInputCoins takes the coins in the CoinSet and makes them
// the inputs to a new wire.MsgTx which is returned.
func NewMsgTxWithInputCoins(txVersion int32, inputCoins Coins) *wire.MsgTx {
	msgTx := wire.NewMsgTx(txVersion)
	coins := inputCoins.Coins()
	msgTx.TxIn = make([]*wire.TxIn, len(coins))
	for i, coin := range coins {
		msgTx.TxIn[i] = &wire.TxIn{
			PreviousOutPoint: wire.OutPoint{
				Hash:  *coin.Hash(),
				Index: coin.Index(),
			},
			SignatureScript: nil,
			Sequence:        wire.MaxTxInSequenceNum,
		}
	}
	return msgTx
}

// CreateSignedTx creates a new signed transaction that consumes the provided
// inputs and generates the provided number of outputs by evenly splitting the
// total input amount.  All outputs will be to the payment script associated
// with the harness and all inputs are assumed to do the same.
func (p *poolHarness) CreateSignedTx(inputs []spendableOutput, numOutputs uint32) (*btcutil.Tx, error) {
	// Calculate the total input amount and split it amongst the requested
	// number of outputs.
	var totalInput btcutil.Amount
	for _, input := range inputs {
		totalInput += input.amount
	}
	amountPerOutput := int64(totalInput) / int64(numOutputs)
	remainder := int64(totalInput) - amountPerOutput*int64(numOutputs)

	tx := wire.NewMsgTx(wire.TxVersion)
	for _, input := range inputs {
		tx.AddTxIn(&wire.TxIn{
			PreviousOutPoint: input.outPoint,
			SignatureScript:  nil,
			Sequence:         wire.MaxTxInSequenceNum,
		})
	}
	for i := uint32(0); i < numOutputs; i++ {
		// Ensure the final output accounts for any remainder that might
		// be left from splitting the input amount.
		amount := amountPerOutput
		if i == numOutputs-1 {
			amount = amountPerOutput + remainder
		}
		tx.AddTxOut(&wire.TxOut{
			PkScript: p.payScript,
			Value:    amount,
		})
	}

	// Sign the new transaction.
	for i := range tx.TxIn {
		sigScript, err := txscript.SignatureScript(tx, i, p.payScript,
			txscript.SigHashAll, p.signKey, true)
		if err != nil {
			return nil, err
		}
		tx.TxIn[i].SignatureScript = sigScript
	}

	return btcutil.NewTx(tx), nil
}

// GetTx takes a txid and returns the transaction.  If we have it.
func (ts *TxStore) GetTx(txid *wire.ShaHash) (*wire.MsgTx, error) {
	rtx := wire.NewMsgTx()

	err := ts.StateDB.View(func(btx *bolt.Tx) error {
		txns := btx.Bucket(BKTTxns)
		if txns == nil {
			return fmt.Errorf("no transactions in db")
		}
		txbytes := txns.Get(txid.Bytes())
		if txbytes == nil {
			return fmt.Errorf("tx %x not in db", txid.String())
		}
		buf := bytes.NewBuffer(txbytes)
		return rtx.Deserialize(buf)
	})
	if err != nil {
		return nil, err
	}
	return rtx, nil
}

// createCommitTx...
// TODO(roasbeef): fix inconsistency of 32 vs 20 byte revocation hashes everywhere...
func createCommitTx(fundingOutput *wire.TxIn, selfKey, theirKey *btcec.PublicKey,
	revokeHash []byte, csvTimeout uint32, amountToSelf,
	amountToThem btcutil.Amount) (*wire.MsgTx, error) {

	// First, we create the script for the delayed "pay-to-self" output.
	ourRedeemScript, err := commitScriptToSelf(csvTimeout, selfKey, theirKey,
		revokeHash)
	if err != nil {
		return nil, err
	}
	payToUsScriptHash, err := scriptHashPkScript(ourRedeemScript)
	if err != nil {
		return nil, err
	}

	// Next, we create the script paying to them. This is just a regular
	// P2PKH-like output, without any added CSV delay. However, we instead
	// use P2SH.
	theirRedeemScript, err := commitScriptUnencumbered(theirKey)
	if err != nil {
		return nil, err
	}
	payToThemScriptHash, err := scriptHashPkScript(theirRedeemScript)
	if err != nil {
		return nil, err
	}

	// Now that both output scripts have been created, we can finally create
	// the transaction itself.
	commitTx := wire.NewMsgTx()
	commitTx.AddTxIn(fundingOutput)
	// TODO(roasbeef): we default to blocks, make configurable as part of
	// channel reservation.
	commitTx.TxIn[0].Sequence = lockTimeToSequence(false, csvTimeout)
	commitTx.AddTxOut(wire.NewTxOut(int64(amountToSelf), payToUsScriptHash))
	commitTx.AddTxOut(wire.NewTxOut(int64(amountToThem), payToThemScriptHash))

	return commitTx, nil
}

// createCommitTx...
// TODO(roasbeef): fix inconsistency of 32 vs 20 byte revocation hashes everywhere...
func createCommitTx(fundingOutput *wire.TxIn, selfKey, theirKey *btcec.PublicKey,
	revokeHash []byte, csvTimeout uint32, amountToSelf,
	amountToThem btcutil.Amount) (*wire.MsgTx, error) {

	// First, we create the script for the delayed "pay-to-self" output.
	ourRedeemScript, err := commitScriptToSelf(csvTimeout, selfKey, theirKey,
		revokeHash)
	if err != nil {
		return nil, err
	}
	payToUsScriptHash, err := scriptHashPkScript(ourRedeemScript)
	if err != nil {
		return nil, err
	}

	// Next, we create the script paying to them. This is just a regular
	// P2PKH-like output, without any added CSV delay. However, we instead
	// use P2SH.
	theirRedeemScript, err := commitScriptUnencumbered(theirKey)
	if err != nil {
		return nil, err
	}
	payToThemScriptHash, err := scriptHashPkScript(theirRedeemScript)
	if err != nil {
		return nil, err
	}

	// Now that both output scripts have been created, we can finally create
	// the transaction itself. We use a transaction version of 2 since CSV
	// will fail unless the tx version is >= 2.
	commitTx := wire.NewMsgTx()
	commitTx.Version = 2
	commitTx.AddTxIn(fundingOutput)
	commitTx.AddTxOut(wire.NewTxOut(int64(amountToSelf), payToUsScriptHash))
	commitTx.AddTxOut(wire.NewTxOut(int64(amountToThem), payToThemScriptHash))

	return commitTx, nil
}

// createCoinbaseTx returns a coinbase transaction paying an appropriate
// subsidy based on the passed block height to the provided address.
func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int32,
	addr btcutil.Address, net *chaincfg.Params) (*btcutil.Tx, error) {

	// Create the script to pay to the provided payment address.
	pkScript, err := txscript.PayToAddrScript(addr)
	if err != nil {
		return nil, err
	}

	tx := wire.NewMsgTx()
	tx.AddTxIn(&wire.TxIn{
		// Coinbase transactions have no inputs, so previous outpoint is
		// zero hash and max index.
		PreviousOutPoint: *wire.NewOutPoint(&chainhash.Hash{},
			wire.MaxPrevOutIndex),
		SignatureScript: coinbaseScript,
		Sequence:        wire.MaxTxInSequenceNum,
	})
	tx.AddTxOut(&wire.TxOut{
		Value:    blockchain.CalcBlockSubsidy(nextBlockHeight, net),
		PkScript: pkScript,
	})
	return btcutil.NewTx(tx), nil
}