status-im/status-go

package pathprocessor

import (
    "context"
    "math/big"
    "strings"

    "github.com/ethereum/go-ethereum"
    "github.com/ethereum/go-ethereum/accounts/abi"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/common/hexutil"
    ethTypes "github.com/ethereum/go-ethereum/core/types"
    "github.com/status-im/status-go/account"
    "github.com/status-im/status-go/contracts/ierc20"
    statusErrors "github.com/status-im/status-go/errors"
    "github.com/status-im/status-go/eth-node/types"
    "github.com/status-im/status-go/rpc"
    "github.com/status-im/status-go/transactions"
)

type TransferProcessor struct {
    rpcClient  *rpc.Client
    transactor transactions.TransactorIface
}

func NewTransferProcessor(rpcClient *rpc.Client, transactor transactions.TransactorIface) *TransferProcessor {
    return &TransferProcessor{rpcClient: rpcClient, transactor: transactor}
}

func (s *TransferProcessor) Name() string {
    return ProcessorTransferName
}

func (s *TransferProcessor) AvailableFor(params ProcessorInputParams) (bool, error) {
    if params.FromChain == nil || params.ToChain == nil {
        return false, ErrNoChainSet
    }
    if params.FromToken == nil {
        return false, ErrNoTokenSet
    }
    if params.ToToken != nil {
        return false, ErrToTokenShouldNotBeSet
    }
    return params.FromChain.ChainID == params.ToChain.ChainID, nil
}

func (s *TransferProcessor) CalculateFees(params ProcessorInputParams) (*big.Int, *big.Int, error) {
    return ZeroBigIntValue, ZeroBigIntValue, nil
}

func (s *TransferProcessor) PackTxInputData(params ProcessorInputParams) ([]byte, error) {
    if params.FromToken.IsNative() {
        return []byte("eth_sendRawTransaction"), nil
    } else {
        abi, err := abi.JSON(strings.NewReader(ierc20.IERC20ABI))
        if err != nil {
            return []byte{}, statusErrors.CreateErrorResponseFromError(err)
        }
        return abi.Pack("transfer",
            params.ToAddr,
            params.AmountIn,
        )
    }
}

func (s *TransferProcessor) EstimateGas(params ProcessorInputParams) (uint64, error) {
    if params.TestsMode {
        if params.TestEstimationMap != nil {
            if val, ok := params.TestEstimationMap[s.Name()]; ok {
                return val, nil
            }
        }
        return 0, ErrNoEstimationFound
    }

    estimation := uint64(0)
    var err error

    input, err := s.PackTxInputData(params)
    if err != nil {
        return 0, statusErrors.CreateErrorResponseFromError(err)
    }

    if params.FromToken.IsNative() {
        estimation, err = s.transactor.EstimateGas(params.FromChain, params.FromAddr, params.ToAddr, params.AmountIn, input)
        if err != nil {
            return 0, statusErrors.CreateErrorResponseFromError(err)
        }
    } else {
        ethClient, err := s.rpcClient.EthClient(params.FromChain.ChainID)
        if err != nil {
            return 0, statusErrors.CreateErrorResponseFromError(err)
        }

        ctx := context.Background()

        msg := ethereum.CallMsg{
            From: params.FromAddr,
            To:   &params.FromToken.Address,
            Data: input,
        }

        estimation, err = ethClient.EstimateGas(ctx, msg)
        if err != nil {
            return 0, statusErrors.CreateErrorResponseFromError(err)
        }

    }

    increasedEstimation := float64(estimation) * IncreaseEstimatedGasFactor
    return uint64(increasedEstimation), nil
}

func (s *TransferProcessor) BuildTx(params ProcessorInputParams) (*ethTypes.Transaction, error) {
    toAddr := types.Address(params.ToAddr)
    if params.FromToken.IsNative() {
        sendArgs := &MultipathProcessorTxArgs{
            TransferTx: &transactions.SendTxArgs{
                From:  types.Address(params.FromAddr),
                To:    &toAddr,
                Value: (*hexutil.Big)(params.AmountIn),
                Data:  types.HexBytes("0x0"),
            },
            ChainID: params.FromChain.ChainID,
        }

        return s.BuildTransaction(sendArgs)
    }
    abi, err := abi.JSON(strings.NewReader(ierc20.IERC20ABI))
    if err != nil {
        return nil, statusErrors.CreateErrorResponseFromError(err)
    }
    input, err := abi.Pack("transfer",
        params.ToAddr,
        params.AmountIn,
    )
    if err != nil {
        return nil, statusErrors.CreateErrorResponseFromError(err)
    }
    sendArgs := &MultipathProcessorTxArgs{
        TransferTx: &transactions.SendTxArgs{
            From:  types.Address(params.FromAddr),
            To:    &toAddr,
            Value: (*hexutil.Big)(ZeroBigIntValue),
            Data:  input,
        },
        ChainID: params.FromChain.ChainID,
    }

    return s.BuildTransaction(sendArgs)
}

func (s *TransferProcessor) Send(sendArgs *MultipathProcessorTxArgs, verifiedAccount *account.SelectedExtKey) (types.Hash, error) {
    return s.transactor.SendTransactionWithChainID(sendArgs.ChainID, *sendArgs.TransferTx, verifiedAccount)
}

func (s *TransferProcessor) BuildTransaction(sendArgs *MultipathProcessorTxArgs) (*ethTypes.Transaction, error) {
    return s.transactor.ValidateAndBuildTransaction(sendArgs.ChainID, *sendArgs.TransferTx)
}

func (s *TransferProcessor) CalculateAmountOut(params ProcessorInputParams) (*big.Int, error) {
    return params.AmountIn, nil
}

func (s *TransferProcessor) GetContractAddress(params ProcessorInputParams) (common.Address, error) {
    return common.Address{}, nil
}