/
estimate_coin_sell.go
77 lines (63 loc) 路 2.85 KB
/
estimate_coin_sell.go
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package api
import (
"fmt"
"github.com/MinterTeam/minter-go-node/core/commissions"
"github.com/MinterTeam/minter-go-node/core/transaction"
"github.com/MinterTeam/minter-go-node/core/types"
"github.com/MinterTeam/minter-go-node/formula"
"github.com/MinterTeam/minter-go-node/rpc/lib/types"
"math/big"
)
// EstimateCoinSellResponse returns an estimate of sell coin transaction
type EstimateCoinSellResponse struct {
WillGet string `json:"will_get"`
Commission string `json:"commission"`
}
// EstimateCoinSell returns an estimate of sell coin transaction
func EstimateCoinSell(coinToSell, coinToBuy string, valueToSell *big.Int, height int) (*EstimateCoinSellResponse, error) {
cState, err := GetStateForHeight(height)
if err != nil {
return nil, err
}
cState.RLock()
defer cState.RUnlock()
coinFrom := cState.Coins().GetCoinBySymbol(types.StrToCoinBaseSymbol(coinToSell), types.GetVersionFromSymbol(coinToSell))
if coinFrom == nil {
return nil, rpctypes.RPCError{Code: 404, Message: "Coin to sell not exists"}
}
coinTo := cState.Coins().GetCoinBySymbol(types.StrToCoinBaseSymbol(coinToBuy), types.GetVersionFromSymbol(coinToBuy))
if coinTo == nil {
return nil, rpctypes.RPCError{Code: 404, Message: "Coin to buy not exists"}
}
if coinFrom.ID() == coinTo.ID() {
return nil, rpctypes.RPCError{Code: 400, Message: "\"From\" coin equals to \"to\" coin"}
}
var result *big.Int
commissionInBaseCoin := big.NewInt(commissions.ConvertTx)
commissionInBaseCoin.Mul(commissionInBaseCoin, transaction.CommissionMultiplier)
commission := big.NewInt(0).Set(commissionInBaseCoin)
if !coinFrom.ID().IsBaseCoin() {
if coinFrom.Reserve().Cmp(commissionInBaseCoin) < 0 {
return nil, rpctypes.RPCError{Code: 400, Message: fmt.Sprintf("Coin reserve balance is not sufficient for transaction. Has: %s, required %s",
coinFrom.Reserve().String(), commissionInBaseCoin.String())}
}
if coinFrom.Volume().Cmp(valueToSell) < 0 {
return nil, rpctypes.RPCError{Code: 400, Message: fmt.Sprintf("Coin volume is not sufficient for transaction. Has: %s, required %s",
coinFrom.Volume().String(), valueToSell.String())}
}
commission = formula.CalculateSaleAmount(coinFrom.Volume(), coinFrom.Reserve(), coinFrom.Crr(), commissionInBaseCoin)
}
switch {
case coinFrom.ID().IsBaseCoin():
result = formula.CalculatePurchaseReturn(coinTo.Volume(), coinTo.Reserve(), coinTo.Crr(), valueToSell)
case coinTo.ID().IsBaseCoin():
result = formula.CalculateSaleReturn(coinFrom.Volume(), coinFrom.Reserve(), coinFrom.Crr(), valueToSell)
default:
basecoinValue := formula.CalculateSaleReturn(coinFrom.Volume(), coinFrom.Reserve(), coinFrom.Crr(), valueToSell)
result = formula.CalculatePurchaseReturn(coinTo.Volume(), coinTo.Reserve(), coinTo.Crr(), basecoinValue)
}
return &EstimateCoinSellResponse{
WillGet: result.String(),
Commission: commission.String(),
}, nil
}