evm/pancakeswap/masterchef.go

package pancakeswap

import (
	"context"
	"math/big"

	"git.lehouerou.net/laurent/evm"
	"git.lehouerou.net/laurent/evm/pancakeswap/contracts"
	"github.com/ethereum/go-ethereum/accounts/abi/bind"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/pkg/errors"
	"github.com/shopspring/decimal"
)

const MasterChefAddress = "0x73feaa1eE314F8c655E354234017bE2193C9E24E"

type MasterChef struct {
	client   evm.Client
	contract *contracts.MasterChef

	cake evm.Token
}

func NewMasterChef(client evm.Client) (*MasterChef, error) {
	c, err := contracts.NewMasterChef(common.HexToAddress(MasterChefAddress), client)
	if err != nil {
		return nil, errors.Wrap(err, "init contract")
	}
	cake, err := client.TokenService().TokenBySymbol("CAKE")
	if err != nil {
		return nil, errors.Wrap(err, "finding cake token")
	}
	return &MasterChef{
		contract: c,
		client:   client,
		cake:     cake,
	}, nil
}

func (m *MasterChef) PendingCake(pid int64) (decimal.Decimal, error) {
	return m.PendingCakeOfAddress(pid, m.client.PublicAddress())
}

func (m *MasterChef) PendingCakeOfAddress(pid int64, address common.Address) (decimal.Decimal, error) {
	raw, err := m.contract.PendingCake(&bind.CallOpts{}, big.NewInt(pid), address)
	if err != nil {
		return decimal.Zero, errors.Wrap(err, "calling contract")
	}
	return m.cake.ValueFromBigInt(raw), nil
}

func (m *MasterChef) EnterStaking(ctx context.Context, amount decimal.Decimal, opts ...evm.ExecutionOption) (evm.Transaction, error) {
	return m.client.Execute(ctx, func(ctx context.Context, opts *evm.TransactOpts) (*types.Transaction, error) {
		return m.contract.EnterStaking(opts.TransactOpts, m.cake.ValueToBigInt(amount))
	}, opts...)
}

func (m *MasterChef) CompoundAndAddCakeBalance(ctx context.Context, opts ...evm.ExecutionOption) (evm.Transaction, error) {
	pending, err := m.PendingCake(0)
	if err != nil {
		return nil, errors.Wrap(err, "getting pending cake reward")
	}
	balance, err := m.cake.Balance()
	if err != nil {
		return nil, errors.Wrap(err, "getting cake balance")
	}
	return m.EnterStaking(ctx, pending.Add(balance), opts...)
}