1package eth
  2
  3import (
  4	"context"
  5	"fmt"
  6	"math/big"
  7	"time"
  8
  9	"github.com/ethereum/go-ethereum/accounts"
 10	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 11	ethKeystore "github.com/ethereum/go-ethereum/accounts/keystore"
 12	ethCommon "github.com/ethereum/go-ethereum/common"
 13	"github.com/ethereum/go-ethereum/core/types"
 14	"github.com/ethereum/go-ethereum/ethclient"
 15	"github.com/hermeznetwork/hermez-node/common"
 16	HEZ "github.com/hermeznetwork/hermez-node/eth/contracts/tokenHEZ"
 17	"github.com/hermeznetwork/hermez-node/log"
 18	"github.com/hermeznetwork/tracerr"
 19)
 20
 21// ERC20Consts are the constants defined in a particular ERC20 Token instance
 22type ERC20Consts struct {
 23	Name     string
 24	Symbol   string
 25	Decimals uint64
 26}
 27
 28// EthereumInterface is the interface to Ethereum
 29type EthereumInterface interface {
 30	EthLastBlock() (int64, error)
 31	// EthHeaderByNumber(context.Context, *big.Int) (*types.Header, error)
 32	EthBlockByNumber(context.Context, int64) (*common.Block, error)
 33	EthAddress() (*ethCommon.Address, error)
 34	EthTransactionReceipt(context.Context, ethCommon.Hash) (*types.Receipt, error)
 35
 36	EthERC20Consts(ethCommon.Address) (*ERC20Consts, error)
 37}
 38
 39var (
 40	// ErrAccountNil is used when the calls can not be made because the account is nil
 41	ErrAccountNil = fmt.Errorf("Authorized calls can't be made when the account is nil")
 42	// ErrReceiptStatusFailed is used when receiving a failed transaction
 43	ErrReceiptStatusFailed = fmt.Errorf("receipt status is failed")
 44	// ErrReceiptNotReceived is used when unable to retrieve a transaction
 45	ErrReceiptNotReceived = fmt.Errorf("receipt not available")
 46	// ErrBlockHashMismatchEvent is used when there's a block hash mismatch
 47	// beetween different events of the same block
 48	ErrBlockHashMismatchEvent = fmt.Errorf("block hash mismatch in event log")
 49)
 50
 51const (
 52	errStrDeploy      = "deployment of %s failed: %w"
 53	errStrWaitReceipt = "wait receipt of %s deploy failed: %w"
 54
 55	// default values
 56	defaultCallGasLimit        = 300000
 57	defaultDeployGasLimit      = 1000000
 58	defaultGasPriceDiv         = 100
 59	defaultReceiptTimeout      = 60
 60	defaultIntervalReceiptLoop = 200
 61)
 62
 63// EthereumConfig defines the configuration parameters of the EthereumClient
 64type EthereumConfig struct {
 65	CallGasLimit        uint64
 66	DeployGasLimit      uint64
 67	GasPriceDiv         uint64
 68	ReceiptTimeout      time.Duration // in seconds
 69	IntervalReceiptLoop time.Duration // in milliseconds
 70}
 71
 72// EthereumClient is an ethereum client to call Smart Contract methods and check blockchain information.
 73type EthereumClient struct {
 74	client         *ethclient.Client
 75	account        *accounts.Account
 76	ks             *ethKeystore.KeyStore
 77	ReceiptTimeout time.Duration
 78	config         *EthereumConfig
 79}
 80
 81// NewEthereumClient creates a EthereumClient instance.  The account is not mandatory (it can
 82// be nil).  If the account is nil, CallAuth will fail with ErrAccountNil.
 83func NewEthereumClient(client *ethclient.Client, account *accounts.Account, ks *ethKeystore.KeyStore, config *EthereumConfig) *EthereumClient {
 84	if config == nil {
 85		config = &EthereumConfig{
 86			CallGasLimit:        defaultCallGasLimit,
 87			DeployGasLimit:      defaultDeployGasLimit,
 88			GasPriceDiv:         defaultGasPriceDiv,
 89			ReceiptTimeout:      defaultReceiptTimeout,
 90			IntervalReceiptLoop: defaultIntervalReceiptLoop,
 91		}
 92	}
 93	return &EthereumClient{client: client, account: account, ks: ks, ReceiptTimeout: config.ReceiptTimeout * time.Second, config: config}
 94}
 95
 96// BalanceAt retieves information about the default account
 97func (c *EthereumClient) BalanceAt(addr ethCommon.Address) (*big.Int, error) {
 98	return c.client.BalanceAt(context.TODO(), addr, nil)
 99}
100
101// Account returns the underlying ethereum account
102func (c *EthereumClient) Account() *accounts.Account {
103	return c.account
104}
105
106// EthAddress returns the ethereum address of the account loaded into the EthereumClient
107func (c *EthereumClient) EthAddress() (*ethCommon.Address, error) {
108	if c.account == nil {
109		return nil, tracerr.Wrap(ErrAccountNil)
110	}
111	return &c.account.Address, nil
112}
113
114// CallAuth performs a Smart Contract method call that requires authorization.
115// This call requires a valid account with Ether that can be spend during the
116// call.
117func (c *EthereumClient) CallAuth(gasLimit uint64,
118	fn func(*ethclient.Client, *bind.TransactOpts) (*types.Transaction, error)) (*types.Transaction, error) {
119	if c.account == nil {
120		return nil, tracerr.Wrap(ErrAccountNil)
121	}
122
123	gasPrice, err := c.client.SuggestGasPrice(context.Background())
124	if err != nil {
125		return nil, tracerr.Wrap(err)
126	}
127	inc := new(big.Int).Set(gasPrice)
128	inc.Div(inc, new(big.Int).SetUint64(c.config.GasPriceDiv))
129	gasPrice.Add(gasPrice, inc)
130	log.Debugw("Transaction metadata", "gasPrice", gasPrice)
131
132	auth, err := bind.NewKeyStoreTransactor(c.ks, *c.account)
133	if err != nil {
134		return nil, tracerr.Wrap(err)
135	}
136	auth.Value = big.NewInt(0) // in wei
137	if gasLimit == 0 {
138		auth.GasLimit = c.config.CallGasLimit // in units
139	} else {
140		auth.GasLimit = gasLimit // in units
141	}
142	auth.GasPrice = gasPrice
143
144	tx, err := fn(c.client, auth)
145	if tx != nil {
146		log.Debugw("Transaction", "tx", tx.Hash().Hex(), "nonce", tx.Nonce())
147	}
148	return tx, tracerr.Wrap(err)
149}
150
151// ContractData contains the contract data
152type ContractData struct {
153	Address ethCommon.Address
154	Tx      *types.Transaction
155	Receipt *types.Receipt
156}
157
158// Deploy a smart contract.  `name` is used to log deployment information.  fn
159// is a wrapper to the deploy function generated by abigen.  In case of error,
160// the returned `ContractData` may have some parameters filled depending on the
161// kind of error that occurred.
162func (c *EthereumClient) Deploy(name string,
163	fn func(c *ethclient.Client, auth *bind.TransactOpts) (ethCommon.Address, *types.Transaction, interface{}, error)) (ContractData, error) {
164	var contractData ContractData
165	log.Infow("Deploying", "contract", name)
166	tx, err := c.CallAuth(
167		c.config.DeployGasLimit,
168		func(client *ethclient.Client, auth *bind.TransactOpts) (*types.Transaction, error) {
169			addr, tx, _, err := fn(client, auth)
170			if err != nil {
171				return nil, tracerr.Wrap(err)
172			}
173			contractData.Address = addr
174			return tx, nil
175		},
176	)
177	if err != nil {
178		return contractData, tracerr.Wrap(fmt.Errorf(errStrDeploy, name, err))
179	}
180	log.Infow("Waiting receipt", "tx", tx.Hash().Hex(), "contract", name)
181	contractData.Tx = tx
182	receipt, err := c.WaitReceipt(tx)
183	if err != nil {
184		return contractData, tracerr.Wrap(fmt.Errorf(errStrWaitReceipt, name, err))
185	}
186	contractData.Receipt = receipt
187	return contractData, nil
188}
189
190// Call performs a read only Smart Contract method call.
191func (c *EthereumClient) Call(fn func(*ethclient.Client) error) error {
192	return fn(c.client)
193}
194
195// WaitReceipt will block until a transaction is confirmed.  Internally it
196// polls the state every 200 milliseconds.
197func (c *EthereumClient) WaitReceipt(tx *types.Transaction) (*types.Receipt, error) {
198	return c.waitReceipt(context.TODO(), tx, c.ReceiptTimeout)
199}
200
201// GetReceipt will check if a transaction is confirmed and return
202// immediately, waiting at most 1 second and returning error if the transaction
203// is still pending.
204func (c *EthereumClient) GetReceipt(tx *types.Transaction) (*types.Receipt, error) {
205	ctx, cancel := context.WithTimeout(context.TODO(), 1*time.Second)
206	defer cancel()
207	return c.waitReceipt(ctx, tx, 0)
208}
209
210// EthTransactionReceipt returns the transaction receipt of the given txHash
211func (c *EthereumClient) EthTransactionReceipt(ctx context.Context, txHash ethCommon.Hash) (*types.Receipt, error) {
212	return c.client.TransactionReceipt(ctx, txHash)
213}
214
215func (c *EthereumClient) waitReceipt(ctx context.Context, tx *types.Transaction, timeout time.Duration) (*types.Receipt, error) {
216	var err error
217	var receipt *types.Receipt
218
219	txHash := tx.Hash()
220	log.Debugw("Waiting for receipt", "tx", txHash.Hex())
221
222	start := time.Now()
223	for {
224		receipt, err = c.client.TransactionReceipt(ctx, txHash)
225		if receipt != nil || time.Since(start) >= timeout {
226			break
227		}
228		time.Sleep(c.config.IntervalReceiptLoop * time.Millisecond)
229	}
230
231	if receipt != nil && receipt.Status == types.ReceiptStatusFailed {
232		log.Errorw("Failed transaction", "tx", txHash.Hex())
233		return receipt, tracerr.Wrap(ErrReceiptStatusFailed)
234	}
235
236	if receipt == nil {
237		log.Debugw("Pendingtransaction / Wait receipt timeout", "tx", txHash.Hex(), "lasterr", err)
238		return receipt, tracerr.Wrap(ErrReceiptNotReceived)
239	}
240	log.Debugw("Successful transaction", "tx", txHash.Hex())
241
242	return receipt, tracerr.Wrap(err)
243}
244
245// EthLastBlock returns the last block number in the blockchain
246func (c *EthereumClient) EthLastBlock() (int64, error) {
247	ctx, cancel := context.WithTimeout(context.TODO(), 1*time.Second)
248	defer cancel()
249	header, err := c.client.HeaderByNumber(ctx, nil)
250	if err != nil {
251		return 0, tracerr.Wrap(err)
252	}
253	return header.Number.Int64(), nil
254}
255
256// EthHeaderByNumber internally calls ethclient.Client HeaderByNumber
257// func (c *EthereumClient) EthHeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error) {
258// 	return c.client.HeaderByNumber(ctx, number)
259// }
260
261// EthBlockByNumber internally calls ethclient.Client BlockByNumber and returns
262// *common.Block.  If number == -1, the latests known block is returned.
263func (c *EthereumClient) EthBlockByNumber(ctx context.Context, number int64) (*common.Block, error) {
264	blockNum := big.NewInt(number)
265	if number == -1 {
266		blockNum = nil
267	}
268	block, err := c.client.BlockByNumber(ctx, blockNum)
269	if err != nil {
270		return nil, tracerr.Wrap(err)
271	}
272	b := &common.Block{
273		Num:        block.Number().Int64(),
274		Timestamp:  time.Unix(int64(block.Time()), 0),
275		ParentHash: block.ParentHash(),
276		Hash:       block.Hash(),
277	}
278	return b, nil
279}
280
281// EthERC20Consts returns the constants defined for a particular ERC20 Token instance.
282func (c *EthereumClient) EthERC20Consts(tokenAddress ethCommon.Address) (*ERC20Consts, error) {
283	// We use the HEZ token smart contract interfacehere because it's an
284	// ERC20, which allows us to access the standard ERC20 constants.
285	instance, err := HEZ.NewHEZ(tokenAddress, c.client)
286	if err != nil {
287		return nil, tracerr.Wrap(err)
288	}
289	name, err := instance.Name(nil)
290	if err != nil {
291		return nil, tracerr.Wrap(err)
292	}
293
294	symbol, err := instance.Symbol(nil)
295	if err != nil {
296		return nil, tracerr.Wrap(err)
297	}
298
299	decimals, err := instance.Decimals(nil)
300	if err != nil {
301		return nil, tracerr.Wrap(err)
302	}
303	return &ERC20Consts{
304		Name:     name,
305		Symbol:   symbol,
306		Decimals: uint64(decimals),
307	}, nil
308}
309
310// Client returns the internal ethclient.Client
311func (c *EthereumClient) Client() *ethclient.Client {
312	return c.client
313}