evm/aave/lendingpool.go
2021-11-15 14:09:43 +04:00

122 lines
4.7 KiB
Go

package aave
import (
"context"
"math/big"
"time"
"git.lehouerou.net/laurent/evm"
"git.lehouerou.net/laurent/evm/aave/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 (
SECONDSPERYEAR = 31536000
)
type LendingPool struct {
client evm.Client
contract *contracts.LendingPool
}
func NewLendingPool(client evm.Client, address common.Address) (*LendingPool, error) {
contract, err := contracts.NewLendingPool(address, client)
if err != nil {
return nil, errors.Wrap(err, "init contract")
}
return &LendingPool{
client: client,
contract: contract,
}, nil
}
type UserAccountData struct {
TotalCollateralETH decimal.Decimal
TotalDebtETH decimal.Decimal
AvailableBorrowsETH decimal.Decimal
CurrentLiquidationThreshold decimal.Decimal
CurrentLtv decimal.Decimal
MaxLtv decimal.Decimal
HealthFactor decimal.Decimal
}
func (uad UserAccountData) BorrowAmountToLtv(ltv decimal.Decimal) decimal.Decimal {
return uad.TotalCollateralETH.Mul(ltv).Div(decimal.NewFromInt(100)).Sub(uad.TotalDebtETH)
}
func (lp *LendingPool) UserAccountDataForAddress(address common.Address) (UserAccountData, error) {
uad, err := lp.contract.GetUserAccountData(&bind.CallOpts{}, address)
if err != nil {
return UserAccountData{}, errors.Wrap(err, "calling contract")
}
res := UserAccountData{
TotalCollateralETH: decimal.NewFromBigInt(uad.TotalCollateralETH, -8),
TotalDebtETH: decimal.NewFromBigInt(uad.TotalDebtETH, -8),
AvailableBorrowsETH: decimal.NewFromBigInt(uad.AvailableBorrowsETH, -8),
CurrentLiquidationThreshold: decimal.NewFromBigInt(uad.CurrentLiquidationThreshold, -2),
MaxLtv: decimal.NewFromBigInt(uad.Ltv, -2),
HealthFactor: decimal.NewFromBigInt(uad.HealthFactor, -18),
}
res.CurrentLtv = res.TotalDebtETH.Div(res.TotalCollateralETH).Mul(decimal.NewFromInt(100))
return res, nil
}
type ReserveData struct {
LiquidityIndex decimal.Decimal
VariableBorrowIndex decimal.Decimal
CurrentLiquidityRate decimal.Decimal
CurrentVariableBorrowRate decimal.Decimal
CurrentStableBorrowRate decimal.Decimal
LastUpdateTimestamp time.Time
ATokenAddress common.Address
StableDebtTokenAddress common.Address
VariableDebtTokenAddress common.Address
InterestRateStrategyAddress common.Address
Id uint8
}
func (lp *LendingPool) ReserveData(asset evm.Token) (ReserveData, error) {
rd, err := lp.contract.GetReserveData(&bind.CallOpts{}, asset.Address())
if err != nil {
return ReserveData{}, errors.Wrap(err, "calling contract")
}
res := ReserveData{
LiquidityIndex: decimal.NewFromBigInt(rd.LiquidityIndex, -27),
VariableBorrowIndex: decimal.NewFromBigInt(rd.VariableBorrowIndex, -27),
CurrentLiquidityRate: decimal.NewFromBigInt(rd.CurrentLiquidityRate, -27),
CurrentVariableBorrowRate: decimal.NewFromBigInt(rd.CurrentVariableBorrowRate, -27),
CurrentStableBorrowRate: decimal.NewFromBigInt(rd.CurrentStableBorrowRate, -27),
LastUpdateTimestamp: time.Unix(rd.LastUpdateTimestamp.Int64(), 0),
ATokenAddress: rd.ATokenAddress,
StableDebtTokenAddress: rd.StableDebtTokenAddress,
VariableDebtTokenAddress: rd.VariableDebtTokenAddress,
InterestRateStrategyAddress: rd.InterestRateStrategyAddress,
Id: rd.Id,
}
return res, nil
}
func (lp *LendingPool) Borrow(ctx context.Context, asset evm.Token, amount decimal.Decimal, opts ...evm.ExecutionOption) (evm.Transaction, error) {
return lp.client.Execute(ctx, func(ctx context.Context, opts *evm.TransactOpts) (*types.Transaction, error) {
return lp.contract.Borrow(opts.TransactOpts, asset.Address(), asset.ValueToBigInt(amount), big.NewInt(2), 0, lp.client.PublicAddress())
}, opts...)
}
func (lp *LendingPool) Repay(ctx context.Context, asset evm.Token, amount decimal.Decimal, opts ...evm.ExecutionOption) (evm.Transaction, error) {
balance, err := asset.Balance()
if err != nil {
return nil, errors.Wrap(err, "getting token balance")
}
if balance.LessThan(amount) {
return nil, errors.Wrapf(err, "balance of %s insufficient. need %s have %s", asset.Symbol(), amount, balance)
}
return lp.client.Execute(ctx, func(ctx context.Context, opts *evm.TransactOpts) (*types.Transaction, error) {
return lp.contract.Repay(opts.TransactOpts, asset.Address(), asset.ValueToBigInt(amount), big.NewInt(2), lp.client.PublicAddress())
}, opts...)
}