neo-go/pkg/rpc/client/nep17.go
2020-11-27 21:47:08 +03:00

236 lines
7.5 KiB
Go

package client
import (
"errors"
"fmt"
"github.com/nspcc-dev/neo-go/pkg/core/transaction"
"github.com/nspcc-dev/neo-go/pkg/encoding/address"
"github.com/nspcc-dev/neo-go/pkg/io"
"github.com/nspcc-dev/neo-go/pkg/rpc/response/result"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/util"
"github.com/nspcc-dev/neo-go/pkg/vm/emit"
"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
"github.com/nspcc-dev/neo-go/pkg/wallet"
)
// TransferTarget represents target address and token amount for transfer.
type TransferTarget struct {
Token util.Uint160
Address util.Uint160
Amount int64
}
// NEP17Decimals invokes `decimals` NEP17 method on a specified contract.
func (c *Client) NEP17Decimals(tokenHash util.Uint160) (int64, error) {
result, err := c.InvokeFunction(tokenHash, "decimals", []smartcontract.Parameter{}, nil)
if err != nil {
return 0, err
}
err = getInvocationError(result)
if err != nil {
return 0, fmt.Errorf("failed to get NEP17 decimals: %w", err)
}
return topIntFromStack(result.Stack)
}
// NEP17Symbol invokes `symbol` NEP17 method on a specified contract.
func (c *Client) NEP17Symbol(tokenHash util.Uint160) (string, error) {
result, err := c.InvokeFunction(tokenHash, "symbol", []smartcontract.Parameter{}, nil)
if err != nil {
return "", err
}
err = getInvocationError(result)
if err != nil {
return "", fmt.Errorf("failed to get NEP17 symbol: %w", err)
}
return topStringFromStack(result.Stack)
}
// NEP17TotalSupply invokes `totalSupply` NEP17 method on a specified contract.
func (c *Client) NEP17TotalSupply(tokenHash util.Uint160) (int64, error) {
result, err := c.InvokeFunction(tokenHash, "totalSupply", []smartcontract.Parameter{}, nil)
if err != nil {
return 0, err
}
err = getInvocationError(result)
if err != nil {
return 0, fmt.Errorf("failed to get NEP17 total supply: %w", err)
}
return topIntFromStack(result.Stack)
}
// NEP17BalanceOf invokes `balanceOf` NEP17 method on a specified contract.
func (c *Client) NEP17BalanceOf(tokenHash, acc util.Uint160) (int64, error) {
result, err := c.InvokeFunction(tokenHash, "balanceOf", []smartcontract.Parameter{{
Type: smartcontract.Hash160Type,
Value: acc,
}}, nil)
if err != nil {
return 0, err
}
err = getInvocationError(result)
if err != nil {
return 0, fmt.Errorf("failed to get NEP17 balance: %w", err)
}
return topIntFromStack(result.Stack)
}
// NEP17TokenInfo returns full NEP17 token info.
func (c *Client) NEP17TokenInfo(tokenHash util.Uint160) (*wallet.Token, error) {
cs, err := c.GetContractStateByHash(tokenHash)
if err != nil {
return nil, err
}
symbol, err := c.NEP17Symbol(tokenHash)
if err != nil {
return nil, err
}
decimals, err := c.NEP17Decimals(tokenHash)
if err != nil {
return nil, err
}
return wallet.NewToken(tokenHash, cs.Manifest.Name, symbol, decimals), nil
}
// CreateNEP17TransferTx creates an invocation transaction for the 'transfer'
// method of a given contract (token) to move specified amount of NEP17 assets
// (in FixedN format using contract's number of decimals) to given account and
// returns it. The returned transaction is not signed.
func (c *Client) CreateNEP17TransferTx(acc *wallet.Account, to util.Uint160, token util.Uint160, amount int64, gas int64) (*transaction.Transaction, error) {
return c.CreateNEP17MultiTransferTx(acc, gas, TransferTarget{
Token: token,
Address: to,
Amount: amount,
})
}
// CreateNEP17MultiTransferTx creates an invocation transaction for performing NEP17 transfers
// from a single sender to multiple recipients.
func (c *Client) CreateNEP17MultiTransferTx(acc *wallet.Account, gas int64, recipients ...TransferTarget) (*transaction.Transaction, error) {
from, err := address.StringToUint160(acc.Address)
if err != nil {
return nil, fmt.Errorf("bad account address: %w", err)
}
w := io.NewBufBinWriter()
for i := range recipients {
emit.AppCallWithOperationAndArgs(w.BinWriter, recipients[i].Token, "transfer", from,
recipients[i].Address, recipients[i].Amount, nil)
emit.Opcodes(w.BinWriter, opcode.ASSERT)
}
accAddr, err := address.StringToUint160(acc.Address)
if err != nil {
return nil, fmt.Errorf("bad account address: %v", err)
}
return c.CreateTxFromScript(w.Bytes(), acc, -1, gas, transaction.Signer{
Account: accAddr,
Scopes: transaction.CalledByEntry,
})
}
// CreateTxFromScript creates transaction and properly sets cosigners and NetworkFee.
// If sysFee <= 0, it is determined via result of `invokescript` RPC. You should
// initialize network magic with Init before calling CreateTxFromScript.
func (c *Client) CreateTxFromScript(script []byte, acc *wallet.Account, sysFee, netFee int64,
cosigners ...transaction.Signer) (*transaction.Transaction, error) {
from, err := address.StringToUint160(acc.Address)
if err != nil {
return nil, fmt.Errorf("bad account address: %v", err)
}
signers := getSigners(from, cosigners)
if sysFee < 0 {
result, err := c.InvokeScript(script, signers)
if err != nil {
return nil, fmt.Errorf("can't add system fee to transaction: %w", err)
}
if result.State != "HALT" {
return nil, fmt.Errorf("can't add system fee to transaction: bad vm state: %s due to an error: %s", result.State, result.FaultException)
}
sysFee = result.GasConsumed
}
if !c.initDone {
return nil, errNetworkNotInitialized
}
tx := transaction.New(c.GetNetwork(), script, sysFee)
tx.Signers = signers
tx.ValidUntilBlock, err = c.CalculateValidUntilBlock()
if err != nil {
return nil, fmt.Errorf("failed to add validUntilBlock to transaction: %w", err)
}
err = c.AddNetworkFee(tx, netFee, acc)
if err != nil {
return nil, fmt.Errorf("failed to add network fee: %w", err)
}
return tx, nil
}
// TransferNEP17 creates an invocation transaction that invokes 'transfer' method
// on a given token to move specified amount of NEP17 assets (in FixedN format
// using contract's number of decimals) to given account and sends it to the
// network returning just a hash of it.
func (c *Client) TransferNEP17(acc *wallet.Account, to util.Uint160, token util.Uint160, amount int64, gas int64) (util.Uint256, error) {
tx, err := c.CreateNEP17TransferTx(acc, to, token, amount, gas)
if err != nil {
return util.Uint256{}, err
}
if err := acc.SignTx(tx); err != nil {
return util.Uint256{}, fmt.Errorf("can't sign tx: %w", err)
}
return c.SendRawTransaction(tx)
}
// MultiTransferNEP17 is similar to TransferNEP17, buf allows to have multiple recipients.
func (c *Client) MultiTransferNEP17(acc *wallet.Account, gas int64, recipients ...TransferTarget) (util.Uint256, error) {
tx, err := c.CreateNEP17MultiTransferTx(acc, gas, recipients...)
if err != nil {
return util.Uint256{}, err
}
if err := acc.SignTx(tx); err != nil {
return util.Uint256{}, fmt.Errorf("can't sign tx: %w", err)
}
return c.SendRawTransaction(tx)
}
func topIntFromStack(st []stackitem.Item) (int64, error) {
index := len(st) - 1 // top stack element is last in the array
bi, err := st[index].TryInteger()
if err != nil {
return 0, err
}
return bi.Int64(), nil
}
func topStringFromStack(st []stackitem.Item) (string, error) {
index := len(st) - 1 // top stack element is last in the array
bs, err := st[index].TryBytes()
if err != nil {
return "", err
}
return string(bs), nil
}
// getInvocationError returns an error in case of bad VM state or empty stack.
func getInvocationError(result *result.Invoke) error {
if result.State != "HALT" {
return fmt.Errorf("invocation failed: %s", result.FaultException)
}
if len(result.Stack) == 0 {
return errors.New("result stack is empty")
}
return nil
}