transaction.go

// Modifications Copyright 2018 The klaytn Authors
// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
//
// This file is derived from core/types/transaction.go (2018/06/04).
// Modified and improved for the klaytn development.

package types

import (
	"container/heap"
	"crypto/ecdsa"
	"encoding/json"
	"errors"
	"io"
	"math/big"
	"sync"
	"sync/atomic"

	"github.com/klaytn/klaytn/blockchain/types/accountkey"
	"github.com/klaytn/klaytn/common"
	"github.com/klaytn/klaytn/crypto"
	"github.com/klaytn/klaytn/kerrors"
	"github.com/klaytn/klaytn/rlp"
)

var (
	ErrInvalidSig                     = errors.New("invalid transaction v, r, s values")
	ErrInvalidSigSender               = errors.New("invalid transaction v, r, s values of the sender")
	ErrInvalidSigFeePayer             = errors.New("invalid transaction v, r, s values of the fee payer")
	errNoSigner                       = errors.New("missing signing methods")
	ErrInvalidTxTypeForAnchoredData   = errors.New("invalid transaction type for anchored data")
	errLegacyTransaction              = errors.New("should not be called by a legacy transaction")
	errNotImplementTxInternalDataFrom = errors.New("not implement TxInternalDataFrom")
	errNotFeeDelegationTransaction    = errors.New("not a fee delegation type transaction")
	errInvalidValueMap                = errors.New("tx fields should be filled with valid values")
)

// deriveSigner makes a *best* guess about which signer to use.
func deriveSigner(V *big.Int) Signer {
	return NewEIP155Signer(deriveChainId(V))
}

type Transaction struct {
	data TxInternalData
	// caches
	hash         atomic.Value
	size         atomic.Value
	from         atomic.Value
	feePayer     atomic.Value
	senderTxHash atomic.Value

	// validatedSender represents the sender of the transaction to be used for ApplyTransaction().
	// This value is set in AsMessageWithAccountKeyPicker().
	validatedSender common.Address
	// validatedFeePayer represents the fee payer of the transaction to be used for ApplyTransaction().
	// This value is set in AsMessageWithAccountKeyPicker().
	validatedFeePayer common.Address
	// validatedIntrinsicGas represents intrinsic gas of the transaction to be used for ApplyTransaction().
	// This value is set in AsMessageWithAccountKeyPicker().
	validatedIntrinsicGas uint64
	// The account's nonce is checked only if `checkNonce` is true.
	checkNonce bool
	// This value is set when the tx is invalidated in block tx validation, and is used to remove pending tx in txPool.
	markedUnexecutable int32

	// lock for protecting AsMessageWithAccountKeyPicker().
	mu sync.Mutex
}

// NewTransactionWithMap generates a tx from tx field values.
// One of the return value, retErr, is lastly updated when panic is occurred.
func NewTransactionWithMap(t TxType, values map[TxValueKeyType]interface{}) (tx *Transaction, retErr error) {
	defer func() {
		if err := recover(); err != nil {
			logger.Warn("Got panic and recovered", "panicErr", err)
			retErr = errInvalidValueMap
		}
	}()
	txdata, err := NewTxInternalDataWithMap(t, values)
	if err != nil {
		return nil, err
	}
	tx = &Transaction{data: txdata}
	return tx, retErr
}

func NewTransaction(nonce uint64, to common.Address, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
	return newTransaction(nonce, &to, amount, gasLimit, gasPrice, data)
}

func NewContractCreation(nonce uint64, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
	return newTransaction(nonce, nil, amount, gasLimit, gasPrice, data)
}

func newTransaction(nonce uint64, to *common.Address, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte) *Transaction {
	if len(data) > 0 {
		data = common.CopyBytes(data)
	}
	d := TxInternalDataLegacy{
		AccountNonce: nonce,
		Recipient:    to,
		Payload:      data,
		Amount:       new(big.Int),
		GasLimit:     gasLimit,
		Price:        new(big.Int),
		V:            new(big.Int),
		R:            new(big.Int),
		S:            new(big.Int),
	}
	if amount != nil {
		d.Amount.Set(amount)
	}
	if gasPrice != nil {
		d.Price.Set(gasPrice)
	}

	return &Transaction{data: &d}
}

// ChainId returns which chain id this transaction was signed for (if at all)
func (tx *Transaction) ChainId() *big.Int {
	return tx.data.ChainId()
}

// SenderTxHash returns (SenderTxHash, true) if the tx is a fee-delegated transaction.
// Otherwise, it returns (nil hash, false).
func (tx *Transaction) SenderTxHash() (common.Hash, bool) {
	if tx.Type().IsFeeDelegatedTransaction() == false {
		// Do not compute SenderTxHash for non-fee-delegated txs
		return common.Hash{}, false
	}
	if senderTxHash := tx.senderTxHash.Load(); senderTxHash != nil {
		return senderTxHash.(common.Hash), tx.Type().IsFeeDelegatedTransaction()
	}
	v := tx.data.SenderTxHash()
	tx.senderTxHash.Store(v)
	return v, tx.Type().IsFeeDelegatedTransaction()
}

// SenderTxHashAll returns SenderTxHash for all tx types.
// If it is not a fee-delegated tx, SenderTxHash and TxHash are the same.
func (tx *Transaction) SenderTxHashAll() common.Hash {
	if senderTxHash := tx.senderTxHash.Load(); senderTxHash != nil {
		return senderTxHash.(common.Hash)
	}
	v := tx.data.SenderTxHash()
	tx.senderTxHash.Store(v)
	return v
}

func validateSignature(v, r, s *big.Int) bool {
	// TODO-Klaytn: Need to consider the case v.BitLen() > 64.
	// Since ValidateSignatureValues receives v as type of byte, leave it as a future work.
	chainID := deriveChainId(v).Uint64()
	V := byte(v.Uint64() - 35 - 2*chainID)

	return crypto.ValidateSignatureValues(V, r, s, false)
}

func (tx *Transaction) Equal(tb *Transaction) bool {
	return tx.data.Equal(tb.data)
}

// EncodeRLP implements rlp.Encoder
func (tx *Transaction) EncodeRLP(w io.Writer) error {
	serializer := newTxInternalDataSerializerWithValues(tx.data)
	return rlp.Encode(w, serializer)
}

// DecodeRLP implements rlp.Decoder
func (tx *Transaction) DecodeRLP(s *rlp.Stream) error {
	serializer := newTxInternalDataSerializer()
	if err := s.Decode(serializer); err != nil {
		return err
	}

	if !serializer.tx.ValidateSignature() {
		return ErrInvalidSig
	}

	tx.data = serializer.tx
	tx.Size()

	return nil
}

// MarshalJSON encodes the web3 RPC transaction format.
func (tx *Transaction) MarshalJSON() ([]byte, error) {
	hash := tx.Hash()
	data := tx.data
	data.SetHash(&hash)
	serializer := newTxInternalDataSerializerWithValues(tx.data)
	return json.Marshal(serializer)
}

// UnmarshalJSON decodes the web3 RPC transaction format.
func (tx *Transaction) UnmarshalJSON(input []byte) error {
	serializer := newTxInternalDataSerializer()
	if err := json.Unmarshal(input, serializer); err != nil {
		return err
	}
	if !serializer.tx.ValidateSignature() {
		return ErrInvalidSig
	}
	*tx = Transaction{data: serializer.tx}
	return nil
}

func (tx *Transaction) Gas() uint64                           { return tx.data.GetGasLimit() }
func (tx *Transaction) GasPrice() *big.Int                    { return new(big.Int).Set(tx.data.GetPrice()) }
func (tx *Transaction) Value() *big.Int                       { return new(big.Int).Set(tx.data.GetAmount()) }
func (tx *Transaction) Nonce() uint64                         { return tx.data.GetAccountNonce() }
func (tx *Transaction) CheckNonce() bool                      { return tx.checkNonce }
func (tx *Transaction) Type() TxType                          { return tx.data.Type() }
func (tx *Transaction) IsLegacyTransaction() bool             { return tx.data.IsLegacyTransaction() }
func (tx *Transaction) ValidatedSender() common.Address       { return tx.validatedSender }
func (tx *Transaction) ValidatedFeePayer() common.Address     { return tx.validatedFeePayer }
func (tx *Transaction) ValidatedIntrinsicGas() uint64         { return tx.validatedIntrinsicGas }
func (tx *Transaction) MakeRPCOutput() map[string]interface{} { return tx.data.MakeRPCOutput() }
func (tx *Transaction) GetTxInternalData() TxInternalData     { return tx.data }

func (tx *Transaction) IntrinsicGas(currentBlockNumber uint64) (uint64, error) {
	return tx.data.IntrinsicGas(currentBlockNumber)
}

func (tx *Transaction) Validate(db StateDB, blockNumber uint64) error {
	return tx.data.Validate(db, blockNumber)
}

// ValidateMutableValue conducts validation of the sender's account key and additional validation for each transaction type.
func (tx *Transaction) ValidateMutableValue(db StateDB, signer Signer, currentBlockNumber uint64) error {
	// validate the sender's account key
	accKey := db.GetKey(tx.validatedSender)
	if tx.IsLegacyTransaction() {
		if !accKey.Type().IsLegacyAccountKey() {
			return ErrInvalidSigSender
		}
	} else {
		pubkey, err := SenderPubkey(signer, tx)
		if err != nil || accountkey.ValidateAccountKey(tx.validatedSender, accKey, pubkey, tx.GetRoleTypeForValidation()) != nil {
			return ErrInvalidSigSender
		}
	}

	// validate the fee payer's account key
	if tx.IsFeeDelegatedTransaction() {
		feePayerAccKey := db.GetKey(tx.validatedFeePayer)
		feePayerPubkey, err := SenderFeePayerPubkey(signer, tx)
		if err != nil || accountkey.ValidateAccountKey(tx.validatedFeePayer, feePayerAccKey, feePayerPubkey, accountkey.RoleFeePayer) != nil {
			return ErrInvalidSigFeePayer
		}
	}

	return tx.data.ValidateMutableValue(db, currentBlockNumber)
}

func (tx *Transaction) GetRoleTypeForValidation() accountkey.RoleType {
	return tx.data.GetRoleTypeForValidation()
}

func (tx *Transaction) Data() []byte {
	tp, ok := tx.data.(TxInternalDataPayload)
	if !ok {
		return []byte{}
	}

	return common.CopyBytes(tp.GetPayload())
}

// IsFeeDelegatedTransaction returns true if the transaction is a fee-delegated transaction.
// A fee-delegated transaction has an address of the fee payer which can be different from `from` of the tx.
func (tx *Transaction) IsFeeDelegatedTransaction() bool {
	_, ok := tx.data.(TxInternalDataFeePayer)

	return ok
}

// AnchoredData returns the anchored data of the chain data anchoring transaction.
// if the tx is not chain data anchoring transaction, it will return error.
func (tx *Transaction) AnchoredData() ([]byte, error) {
	switch tx.Type() {
	case TxTypeChainDataAnchoring:
		txData, ok := tx.data.(*TxInternalDataChainDataAnchoring)
		if ok {
			return txData.Payload, nil
		}
	case TxTypeFeeDelegatedChainDataAnchoring:
		txData, ok := tx.data.(*TxInternalDataFeeDelegatedChainDataAnchoring)
		if ok {
			return txData.Payload, nil
		}
	case TxTypeFeeDelegatedChainDataAnchoringWithRatio:
		txData, ok := tx.data.(*TxInternalDataFeeDelegatedChainDataAnchoringWithRatio)
		if ok {
			return txData.Payload, nil
		}
	}
	return []byte{}, ErrInvalidTxTypeForAnchoredData
}

// To returns the recipient address of the transaction.
// It returns nil if the transaction is a contract creation.
func (tx *Transaction) To() *common.Address {
	if tx.data.GetRecipient() == nil {
		return nil
	}
	to := *tx.data.GetRecipient()
	return &to
}

// From returns the from address of the transaction.
// Since a legacy transaction (TxInternalDataLegacy) does not have the field `from`,
// calling From() is failed for `TxInternalDataLegacy`.
func (tx *Transaction) From() (common.Address, error) {
	if tx.IsLegacyTransaction() {
		return common.Address{}, errLegacyTransaction
	}

	tf, ok := tx.data.(TxInternalDataFrom)
	if !ok {
		return common.Address{}, errNotImplementTxInternalDataFrom
	}

	return tf.GetFrom(), nil
}

// FeePayer returns the fee payer address.
// If the tx is a fee-delegated transaction, it returns the specified fee payer.
// Otherwise, it returns `from` of the tx.
func (tx *Transaction) FeePayer() (common.Address, error) {
	tf, ok := tx.data.(TxInternalDataFeePayer)
	if !ok {
		// if the tx is not a fee-delegated transaction, the fee payer is `from` of the tx.
		return tx.From()
	}

	return tf.GetFeePayer(), nil
}

// FeeRatio returns the fee ratio of a transaction and a boolean value indicating TxInternalDataFeeRatio implementation.
// If the transaction does not implement TxInternalDataFeeRatio,
// it returns MaxFeeRatio which means the fee payer will be paid all tx fee by default.
func (tx *Transaction) FeeRatio() (FeeRatio, bool) {
	tf, ok := tx.data.(TxInternalDataFeeRatio)
	if !ok {
		// default fee ratio is MaxFeeRatio.
		return MaxFeeRatio, ok
	}

	return tf.GetFeeRatio(), ok
}

// Hash hashes the RLP encoding of tx.
// It uniquely identifies the transaction.
func (tx *Transaction) Hash() common.Hash {
	if hash := tx.hash.Load(); hash != nil {
		return hash.(common.Hash)
	}
	v := rlpHash(tx)
	tx.hash.Store(v)
	return v
}

// Size returns the true RLP encoded storage size of the transaction, either by
// encoding and returning it, or returning a previsouly cached value.
func (tx *Transaction) Size() common.StorageSize {
	if size := tx.size.Load(); size != nil {
		return size.(common.StorageSize)
	}
	c := writeCounter(0)
	rlp.Encode(&c, &tx.data)
	tx.size.Store(common.StorageSize(c))
	return common.StorageSize(c)
}

// FillContractAddress fills contract address to receipt. This only works for types deploying a smart contract.
func (tx *Transaction) FillContractAddress(from common.Address, r *Receipt) {
	if filler, ok := tx.data.(TxInternalDataContractAddressFiller); ok {
		filler.FillContractAddress(from, r)
	}
}

// Execute performs execution of the transaction. This function will be called from StateTransition.TransitionDb().
// Since each transaction type performs different execution, this function calls TxInternalData.TransitionDb().
func (tx *Transaction) Execute(vm VM, stateDB StateDB, currentBlockNumber uint64, gas uint64, value *big.Int) ([]byte, uint64, error) {
	sender := NewAccountRefWithFeePayer(tx.validatedSender, tx.validatedFeePayer)
	return tx.data.Execute(sender, vm, stateDB, currentBlockNumber, gas, value)
}

// AsMessageWithAccountKeyPicker returns the transaction as a blockchain.Message.
//
// AsMessageWithAccountKeyPicker requires a signer to derive the sender and AccountKeyPicker.
//
// XXX Rename message to something less arbitrary?
// TODO-Klaytn: Message is removed and this function will return *Transaction.
func (tx *Transaction) AsMessageWithAccountKeyPicker(s Signer, picker AccountKeyPicker, currentBlockNumber uint64) (*Transaction, error) {
	intrinsicGas, err := tx.IntrinsicGas(currentBlockNumber)
	if err != nil {
		return nil, err
	}

	gasFrom, err := tx.ValidateSender(s, picker, currentBlockNumber)
	if err != nil {
		return nil, err
	}

	tx.checkNonce = true

	gasFeePayer := uint64(0)
	if tx.IsFeeDelegatedTransaction() {
		gasFeePayer, err = tx.ValidateFeePayer(s, picker, currentBlockNumber)
		if err != nil {
			return nil, err
		}
	}

	tx.mu.Lock()
	tx.validatedIntrinsicGas = intrinsicGas + gasFrom + gasFeePayer
	tx.mu.Unlock()

	return tx, err
}

// WithSignature returns a new transaction with the given signature.
// This signature needs to be formatted as described in the yellow paper (v+27).
func (tx *Transaction) WithSignature(signer Signer, sig []byte) (*Transaction, error) {
	r, s, v, err := signer.SignatureValues(sig)
	if err != nil {
		return nil, err
	}
	cpy := &Transaction{data: tx.data}
	cpy.data.SetSignature(TxSignatures{&TxSignature{v, r, s}})
	return cpy, nil
}

// WithFeePayerSignature returns a new transaction with the given fee payer signature.
func (tx *Transaction) WithFeePayerSignature(signer Signer, sig []byte) (*Transaction, error) {
	r, s, v, err := signer.SignatureValues(sig)
	if err != nil {
		return nil, err
	}
	feePayerSig := TxSignatures{&TxSignature{v, r, s}}
	if err := tx.SetFeePayerSignatures(feePayerSig); err != nil {
		return nil, err
	}
	return tx, nil
}

// Cost returns amount + gasprice * gaslimit.
func (tx *Transaction) Cost() *big.Int {
	total := tx.Fee()
	total.Add(total, tx.data.GetAmount())
	return total
}

func (tx *Transaction) Fee() *big.Int {
	return new(big.Int).Mul(tx.data.GetPrice(), new(big.Int).SetUint64(tx.data.GetGasLimit()))
}

// Sign signs the tx with the given signer and private key.
func (tx *Transaction) Sign(s Signer, prv *ecdsa.PrivateKey) error {
	h := s.Hash(tx)
	sig, err := NewTxSignatureWithValues(s, h, prv)
	if err != nil {
		return err
	}

	tx.SetSignature(TxSignatures{sig})
	return nil
}

// SignWithKeys signs the tx with the given signer and a slice of private keys.
func (tx *Transaction) SignWithKeys(s Signer, prv []*ecdsa.PrivateKey) error {
	h := s.Hash(tx)
	sig, err := NewTxSignaturesWithValues(s, h, prv)
	if err != nil {
		return err
	}

	tx.SetSignature(sig)
	return nil
}

// SignFeePayer signs the tx with the given signer and private key as a fee payer.
func (tx *Transaction) SignFeePayer(s Signer, prv *ecdsa.PrivateKey) error {
	h, err := s.HashFeePayer(tx)
	if err != nil {
		return err
	}
	sig, err := NewTxSignatureWithValues(s, h, prv)
	if err != nil {
		return err
	}

	if err := tx.SetFeePayerSignatures(TxSignatures{sig}); err != nil {
		return err
	}

	return nil
}

// SignFeePayerWithKeys signs the tx with the given signer and a slice of private keys as a fee payer.
func (tx *Transaction) SignFeePayerWithKeys(s Signer, prv []*ecdsa.PrivateKey) error {
	h, err := s.HashFeePayer(tx)
	if err != nil {
		return err
	}
	sig, err := NewTxSignaturesWithValues(s, h, prv)
	if err != nil {
		return err
	}

	if err := tx.SetFeePayerSignatures(sig); err != nil {
		return err
	}

	return nil
}

func (tx *Transaction) SetFeePayerSignatures(s TxSignatures) error {
	tf, ok := tx.data.(TxInternalDataFeePayer)
	if !ok {
		return errNotFeeDelegationTransaction
	}

	tf.SetFeePayerSignatures(s)

	return nil
}

// GetFeePayerSignatures returns fee payer signatures of the transaction.
func (tx *Transaction) GetFeePayerSignatures() (TxSignatures, error) {
	tf, ok := tx.data.(TxInternalDataFeePayer)
	if !ok {
		return nil, errNotFeeDelegationTransaction
	}
	return tf.GetFeePayerRawSignatureValues(), nil
}

func (tx *Transaction) SetSignature(signature TxSignatures) {
	tx.data.SetSignature(signature)
}

func (tx *Transaction) MarkUnexecutable(b bool) {
	v := int32(0)
	if b {
		v = 1
	}
	atomic.StoreInt32(&tx.markedUnexecutable, v)
}

func (tx *Transaction) IsMarkedUnexecutable() bool {
	return atomic.LoadInt32(&tx.markedUnexecutable) == 1
}

func (tx *Transaction) RawSignatureValues() TxSignatures {
	return tx.data.RawSignatureValues()
}

func (tx *Transaction) String() string {
	return tx.data.String()
}

// ValidateSender finds a sender from both legacy and new types of transactions.
// It returns the senders address and gas used for the tx validation.
func (tx *Transaction) ValidateSender(signer Signer, p AccountKeyPicker, currentBlockNumber uint64) (uint64, error) {
	if tx.IsLegacyTransaction() {
		addr, err := Sender(signer, tx)
		// Legacy transaction cannot be executed unless the account has a legacy key.
		if p.GetKey(addr).Type().IsLegacyAccountKey() == false {
			return 0, kerrors.ErrLegacyTransactionMustBeWithLegacyKey
		}
		if tx.validatedSender == (common.Address{}) {
			tx.validatedSender = addr
			tx.validatedFeePayer = addr
		}
		return 0, err
	}

	pubkey, err := SenderPubkey(signer, tx)
	if err != nil {
		return 0, err
	}
	txfrom, ok := tx.data.(TxInternalDataFrom)
	if !ok {
		return 0, errNotTxInternalDataFrom
	}
	from := txfrom.GetFrom()
	accKey := p.GetKey(from)

	gasKey, err := accKey.SigValidationGas(currentBlockNumber, tx.GetRoleTypeForValidation())
	if err != nil {
		return 0, err
	}

	if err := accountkey.ValidateAccountKey(from, accKey, pubkey, tx.GetRoleTypeForValidation()); err != nil {
		return 0, ErrInvalidSigSender
	}

	if tx.validatedSender == (common.Address{}) {
		tx.validatedSender = from
		tx.validatedFeePayer = from
	}

	return gasKey, nil
}

// ValidateFeePayer finds a fee payer from a transaction.
// If the transaction is not a fee-delegated transaction, it returns an error.
func (tx *Transaction) ValidateFeePayer(signer Signer, p AccountKeyPicker, currentBlockNumber uint64) (uint64, error) {
	tf, ok := tx.data.(TxInternalDataFeePayer)
	if !ok {
		return 0, errUndefinedTxType
	}

	pubkey, err := SenderFeePayerPubkey(signer, tx)
	if err != nil {
		return 0, err
	}

	feePayer := tf.GetFeePayer()
	accKey := p.GetKey(feePayer)

	gasKey, err := accKey.SigValidationGas(currentBlockNumber, accountkey.RoleFeePayer)
	if err != nil {
		return 0, err
	}

	if err := accountkey.ValidateAccountKey(feePayer, accKey, pubkey, accountkey.RoleFeePayer); err != nil {
		return 0, ErrInvalidSigFeePayer
	}

	if tx.validatedFeePayer == tx.validatedSender {
		tx.validatedFeePayer = feePayer
	}

	return gasKey, nil
}

// Transactions is a Transaction slice type for basic sorting.
type Transactions []*Transaction

// Len returns the length of s.
func (s Transactions) Len() int { return len(s) }

// Swap swaps the i'th and the j'th element in s.
func (s Transactions) Swap(i, j int) { s[i], s[j] = s[j], s[i] }

// GetRlp implements Rlpable and returns the i'th element of s in rlp.
func (s Transactions) GetRlp(i int) []byte {
	enc, _ := rlp.EncodeToBytes(s[i])
	return enc
}

// TxDifference returns a new set t which is the difference between a to b.
func TxDifference(a, b Transactions) (keep Transactions) {
	keep = make(Transactions, 0, len(a))

	remove := make(map[common.Hash]struct{})
	for _, tx := range b {
		remove[tx.Hash()] = struct{}{}
	}

	for _, tx := range a {
		if _, ok := remove[tx.Hash()]; !ok {
			keep = append(keep, tx)
		}
	}

	return keep
}

// TxByNonce implements the sort interface to allow sorting a list of transactions
// by their nonces. This is usually only useful for sorting transactions from a
// single account, otherwise a nonce comparison doesn't make much sense.
type TxByNonce Transactions

func (s TxByNonce) Len() int { return len(s) }
func (s TxByNonce) Less(i, j int) bool {
	return s[i].data.GetAccountNonce() < s[j].data.GetAccountNonce()
}
func (s TxByNonce) Swap(i, j int) { s[i], s[j] = s[j], s[i] }

// TxByPrice implements both the sort and the heap interface, making it useful
// for all at once sorting as well as individually adding and removing elements.
type TxByPrice Transactions

func (s TxByPrice) Len() int           { return len(s) }
func (s TxByPrice) Less(i, j int) bool { return s[i].data.GetPrice().Cmp(s[j].data.GetPrice()) > 0 }
func (s TxByPrice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }

func (s *TxByPrice) Push(x interface{}) {
	*s = append(*s, x.(*Transaction))
}

func (s *TxByPrice) Pop() interface{} {
	old := *s
	n := len(old)
	x := old[n-1]
	*s = old[0 : n-1]
	return x
}

// TransactionsByPriceAndNonce represents a set of transactions that can return
// transactions in a profit-maximizing sorted order, while supporting removing
// entire batches of transactions for non-executable accounts.
type TransactionsByPriceAndNonce struct {
	txs    map[common.Address]Transactions // Per account nonce-sorted list of transactions
	heads  TxByPrice                       // Next transaction for each unique account (price heap)
	signer Signer                          // Signer for the set of transactions
}

// ############ method for debug
func (t *TransactionsByPriceAndNonce) Count() (int, int) {
	var count int

	for _, tx := range t.txs {
		count += tx.Len()
	}

	return len(t.txs), count
}

func (t *TransactionsByPriceAndNonce) Txs() map[common.Address]Transactions {
	return t.txs
}

// NewTransactionsByPriceAndNonce creates a transaction set that can retrieve
// price sorted transactions in a nonce-honouring way.
//
// Note, the input map is reowned so the caller should not interact any more with
// if after providing it to the constructor.
func NewTransactionsByPriceAndNonce(signer Signer, txs map[common.Address]Transactions) *TransactionsByPriceAndNonce {
	// Initialize a price based heap with the head transactions
	heads := make(TxByPrice, 0, len(txs))
	for _, accTxs := range txs {
		heads = append(heads, accTxs[0])
		// Ensure the sender address is from the signer
		acc, _ := Sender(signer, accTxs[0])
		txs[acc] = accTxs[1:]
	}
	heap.Init(&heads)

	// Assemble and return the transaction set
	return &TransactionsByPriceAndNonce{
		txs:    txs,
		heads:  heads,
		signer: signer,
	}
}

// Peek returns the next transaction by price.
func (t *TransactionsByPriceAndNonce) Peek() *Transaction {
	if len(t.heads) == 0 {
		return nil
	}
	return t.heads[0]
}

// Shift replaces the current best head with the next one from the same account.
func (t *TransactionsByPriceAndNonce) Shift() {
	acc, _ := Sender(t.signer, t.heads[0])
	if txs, ok := t.txs[acc]; ok && len(txs) > 0 {
		t.heads[0], t.txs[acc] = txs[0], txs[1:]
		heap.Fix(&t.heads, 0)
	} else {
		heap.Pop(&t.heads)
	}
}

// Pop removes the best transaction, *not* replacing it with the next one from
// the same account. This should be used when a transaction cannot be executed
// and hence all subsequent ones should be discarded from the same account.
func (t *TransactionsByPriceAndNonce) Pop() {
	heap.Pop(&t.heads)
}

// NewMessage returns a `*Transaction` object with the given arguments.
func NewMessage(from common.Address, to *common.Address, nonce uint64, amount *big.Int, gasLimit uint64, gasPrice *big.Int, data []byte, checkNonce bool, intrinsicGas uint64) *Transaction {
	return &Transaction{
		data:                  newTxInternalDataLegacyWithValues(nonce, to, amount, gasLimit, gasPrice, data),
		validatedIntrinsicGas: intrinsicGas,
		validatedFeePayer:     from,
		validatedSender:       from,
		checkNonce:            checkNonce,
	}
}