trade.go

package transform

import (
	"fmt"
	"math"
	"time"

	"github.com/guregu/null"
	"github.com/pkg/errors"

	"github.com/stellar/go/exp/orderbook"
	"github.com/stellar/go/ingest"
	"github.com/stellar/go/support/log"
	"github.com/stellar/go/xdr"
	"github.com/stellar/stellar-etl/internal/toid"
	"github.com/stellar/stellar-etl/internal/utils"
)

// TransformTrade converts a relevant operation from the history archive ingestion system into a form suitable for BigQuery
func TransformTrade(operationIndex int32, operationID int64, transaction ingest.LedgerTransaction, ledgerCloseTime time.Time) ([]TradeOutput, error) {
	operationResults, ok := transaction.Result.OperationResults()
	if !ok {
		return []TradeOutput{}, fmt.Errorf("could not get any results from this transaction")
	}

	if !transaction.Result.Successful() {
		return []TradeOutput{}, fmt.Errorf("transaction failed; no trades")
	}

	operation := transaction.Envelope.Operations()[operationIndex]
	// operation id is +1 incremented to stay in sync with ingest package
	outputOperationID := operationID + 1
	claimedOffers, BuyingOffer, sellerIsExact, err := extractClaimedOffers(operationResults, operationIndex, operation.Body.Type)
	if err != nil {
		return []TradeOutput{}, err
	}

	transformedTrades := []TradeOutput{}

	for claimOrder, claimOffer := range claimedOffers {
		outputOrder := int32(claimOrder)
		outputLedgerClosedAt := ledgerCloseTime

		var outputSellingAssetType, outputSellingAssetCode, outputSellingAssetIssuer string
		err = claimOffer.AssetSold().Extract(&outputSellingAssetType, &outputSellingAssetCode, &outputSellingAssetIssuer)
		if err != nil {
			return []TradeOutput{}, err
		}
		outputSellingAssetID := FarmHashAsset(outputSellingAssetCode, outputSellingAssetIssuer, outputSellingAssetType)

		outputSellingAmount := claimOffer.AmountSold()
		if outputSellingAmount < 0 {
			return []TradeOutput{}, fmt.Errorf("amount sold is negative (%d) for operation at index %d", outputSellingAmount, operationIndex)
		}

		var outputBuyingAssetType, outputBuyingAssetCode, outputBuyingAssetIssuer string
		err = claimOffer.AssetBought().Extract(&outputBuyingAssetType, &outputBuyingAssetCode, &outputBuyingAssetIssuer)
		if err != nil {
			return []TradeOutput{}, err
		}
		outputBuyingAssetID := FarmHashAsset(outputBuyingAssetCode, outputBuyingAssetIssuer, outputBuyingAssetType)

		outputBuyingAmount := int64(claimOffer.AmountBought())
		if outputBuyingAmount < 0 {
			return []TradeOutput{}, fmt.Errorf("amount bought is negative (%d) for operation at index %d", outputBuyingAmount, operationIndex)
		}

		if outputSellingAmount == 0 && outputBuyingAmount == 0 {
			log.Debugf("Both Selling and Buying amount are 0 for operation at index %d", operationIndex)
			continue
		}

		// Final price should be buy / sell
		outputPriceN, outputPriceD, err := findTradeSellPrice(transaction, operationIndex, claimOffer)
		if err != nil {
			return []TradeOutput{}, err
		}

		var outputSellingAccountAddress string
		var liquidityPoolID null.String
		var outputPoolFee, roundingSlippageBips null.Int
		var outputSellingOfferID, outputBuyingOfferID null.Int
		var tradeType int32
		if claimOffer.Type == xdr.ClaimAtomTypeClaimAtomTypeLiquidityPool {
			id := claimOffer.MustLiquidityPool().LiquidityPoolId
			liquidityPoolID = null.StringFrom(PoolIDToString(id))
			tradeType = int32(2)
			var fee uint32
			if fee, err = findPoolFee(transaction, operationIndex, id); err != nil {
				return []TradeOutput{}, fmt.Errorf("cannot parse fee for liquidity pool %v", liquidityPoolID)
			}
			outputPoolFee = null.IntFrom(int64(fee))

			change, err := liquidityPoolChange(transaction, operationIndex, claimOffer)
			if err != nil {
				return nil, err
			}
			if change != nil {
				roundingSlippageBips, err = roundingSlippage(transaction, operationIndex, claimOffer, change)
				if err != nil {
					return nil, err
				}
			}
		} else {
			outputSellingOfferID = null.IntFrom(int64(claimOffer.OfferId()))
			outputSellingAccountAddress = claimOffer.SellerId().Address()
			tradeType = int32(1)
		}

		if BuyingOffer != nil {
			outputBuyingOfferID = null.IntFrom(int64(BuyingOffer.OfferId))
		} else {
			outputBuyingOfferID = null.IntFrom(toid.EncodeOfferId(uint64(operationID)+1, toid.TOIDType))
		}

		var outputBuyingAccountAddress string
		if buyer := operation.SourceAccount; buyer != nil {
			accid := buyer.ToAccountId()
			outputBuyingAccountAddress = accid.Address()
		} else {
			sa := transaction.Envelope.SourceAccount().ToAccountId()
			outputBuyingAccountAddress = sa.Address()
		}

		trade := TradeOutput{
			Order:                  outputOrder,
			LedgerClosedAt:         outputLedgerClosedAt,
			SellingAccountAddress:  outputSellingAccountAddress,
			SellingAssetType:       outputSellingAssetType,
			SellingAssetCode:       outputSellingAssetCode,
			SellingAssetIssuer:     outputSellingAssetIssuer,
			SellingAssetID:         outputSellingAssetID,
			SellingAmount:          utils.ConvertStroopValueToReal(outputSellingAmount),
			BuyingAccountAddress:   outputBuyingAccountAddress,
			BuyingAssetType:        outputBuyingAssetType,
			BuyingAssetCode:        outputBuyingAssetCode,
			BuyingAssetIssuer:      outputBuyingAssetIssuer,
			BuyingAssetID:          outputBuyingAssetID,
			BuyingAmount:           utils.ConvertStroopValueToReal(xdr.Int64(outputBuyingAmount)),
			PriceN:                 outputPriceN,
			PriceD:                 outputPriceD,
			SellingOfferID:         outputSellingOfferID,
			BuyingOfferID:          outputBuyingOfferID,
			SellingLiquidityPoolID: liquidityPoolID,
			LiquidityPoolFee:       outputPoolFee,
			HistoryOperationID:     outputOperationID,
			TradeType:              tradeType,
			RoundingSlippage:       roundingSlippageBips,
			SellerIsExact:          sellerIsExact,
		}

		transformedTrades = append(transformedTrades, trade)
	}
	return transformedTrades, nil
}

func extractClaimedOffers(operationResults []xdr.OperationResult, operationIndex int32, operationType xdr.OperationType) (claimedOffers []xdr.ClaimAtom, BuyingOffer *xdr.OfferEntry, sellerIsExact null.Bool, err error) {
	if operationIndex >= int32(len(operationResults)) {
		err = fmt.Errorf("operation index of %d is out of bounds in result slice (len = %d)", operationIndex, len(operationResults))
		return
	}

	if operationResults[operationIndex].Tr == nil {
		err = fmt.Errorf("could not get result Tr for operation at index %d", operationIndex)
		return
	}

	operationTr, ok := operationResults[operationIndex].GetTr()
	if !ok {
		err = fmt.Errorf("could not get result Tr for operation at index %d", operationIndex)
		return
	}
	switch operationType {
	case xdr.OperationTypeManageBuyOffer:
		var buyOfferResult xdr.ManageBuyOfferResult
		if buyOfferResult, ok = operationTr.GetManageBuyOfferResult(); !ok {
			err = fmt.Errorf("could not get ManageBuyOfferResult for operation at index %d", operationIndex)
			return
		}
		if success, ok := buyOfferResult.GetSuccess(); ok {
			claimedOffers = success.OffersClaimed
			BuyingOffer = success.Offer.Offer
			return
		}

		err = fmt.Errorf("could not get ManageOfferSuccess for operation at index %d", operationIndex)

	case xdr.OperationTypeManageSellOffer:
		var sellOfferResult xdr.ManageSellOfferResult
		if sellOfferResult, ok = operationTr.GetManageSellOfferResult(); !ok {
			err = fmt.Errorf("could not get ManageSellOfferResult for operation at index %d", operationIndex)
			return
		}

		if success, ok := sellOfferResult.GetSuccess(); ok {
			claimedOffers = success.OffersClaimed
			BuyingOffer = success.Offer.Offer
			return
		}

		err = fmt.Errorf("could not get ManageOfferSuccess for operation at index %d", operationIndex)

	case xdr.OperationTypeCreatePassiveSellOffer:
		// KNOWN ISSUE: stellar-core creates results for CreatePassiveOffer operations
		// with the wrong result arm set.
		if operationTr.Type == xdr.OperationTypeManageSellOffer {
			passiveSellResult := operationTr.MustManageSellOfferResult().MustSuccess()
			claimedOffers = passiveSellResult.OffersClaimed
			BuyingOffer = passiveSellResult.Offer.Offer
			return
		} else {
			passiveSellResult := operationTr.MustCreatePassiveSellOfferResult().MustSuccess()
			claimedOffers = passiveSellResult.OffersClaimed
			BuyingOffer = passiveSellResult.Offer.Offer
			return
		}

	case xdr.OperationTypePathPaymentStrictSend:
		var pathSendResult xdr.PathPaymentStrictSendResult
		sellerIsExact = null.BoolFrom(false)
		if pathSendResult, ok = operationTr.GetPathPaymentStrictSendResult(); !ok {
			err = fmt.Errorf("could not get PathPaymentStrictSendResult for operation at index %d", operationIndex)
			return
		}

		success, ok := pathSendResult.GetSuccess()
		if ok {
			claimedOffers = success.Offers
			return
		}

		err = fmt.Errorf("could not get PathPaymentStrictSendSuccess for operation at index %d", operationIndex)

	case xdr.OperationTypePathPaymentStrictReceive:
		var pathReceiveResult xdr.PathPaymentStrictReceiveResult
		sellerIsExact = null.BoolFrom(true)
		if pathReceiveResult, ok = operationTr.GetPathPaymentStrictReceiveResult(); !ok {
			err = fmt.Errorf("could not get PathPaymentStrictReceiveResult for operation at index %d", operationIndex)
			return
		}

		if success, ok := pathReceiveResult.GetSuccess(); ok {
			claimedOffers = success.Offers
			return
		}

		err = fmt.Errorf("could not get GetPathPaymentStrictReceiveSuccess for operation at index %d", operationIndex)

	default:
		err = fmt.Errorf("operation of type %s at index %d does not result in trades", operationType, operationIndex)
		return
	}

	return
}

func findTradeSellPrice(t ingest.LedgerTransaction, operationIndex int32, trade xdr.ClaimAtom) (n, d int64, err error) {
	if trade.Type == xdr.ClaimAtomTypeClaimAtomTypeLiquidityPool {
		return int64(trade.AmountBought()), int64(trade.AmountSold()), nil
	}

	key := xdr.LedgerKey{}
	if err := key.SetOffer(trade.SellerId(), uint64(trade.OfferId())); err != nil {
		return 0, 0, errors.Wrap(err, "Could not create offer ledger key")
	}
	change, err := findLatestOperationChange(t, operationIndex, key)
	if err != nil {
		return 0, 0, errors.Wrap(err, "could not find change for trade offer")
	}

	return int64(change.Pre.Data.MustOffer().Price.N), int64(change.Pre.Data.MustOffer().Price.D), nil
}

func findLatestOperationChange(t ingest.LedgerTransaction, operationIndex int32, key xdr.LedgerKey) (ingest.Change, error) {
	changes, err := t.GetOperationChanges(uint32(operationIndex))
	if err != nil {
		return ingest.Change{}, errors.Wrap(err, "could not determine changes for operation")
	}

	var change ingest.Change
	// traverse through the slice in reverse order
	for i := len(changes) - 1; i >= 0; i-- {
		change = changes[i]
		if change.Pre != nil {
			preKey, err := change.Pre.LedgerKey()
			if err != nil {
				return ingest.Change{}, errors.Wrap(err, "could not determine ledger key for change")

			}
			if key.Equals(preKey) {
				return change, nil
			}
		}

	}
	return ingest.Change{}, errors.Errorf("could not find operation for key %v", key)
}

func findPoolFee(t ingest.LedgerTransaction, operationIndex int32, poolID xdr.PoolId) (fee uint32, err error) {
	key := xdr.LedgerKey{}
	if err := key.SetLiquidityPool(poolID); err != nil {
		return 0, errors.Wrap(err, "Could not create liquidity pool ledger key")
	}
	change, err := findLatestOperationChange(t, operationIndex, key)
	if err != nil {
		return 0, errors.Wrap(err, "could not find change for liquidity pool")
	}

	return uint32(change.Pre.Data.MustLiquidityPool().Body.MustConstantProduct().Params.Fee), nil
}

func liquidityPoolChange(t ingest.LedgerTransaction, operationIndex int32, trade xdr.ClaimAtom) (*ingest.Change, error) {
	if trade.Type != xdr.ClaimAtomTypeClaimAtomTypeLiquidityPool {
		return nil, nil
	}

	poolID := trade.LiquidityPool.LiquidityPoolId

	key := xdr.LedgerKey{}
	if err := key.SetLiquidityPool(poolID); err != nil {
		return nil, errors.Wrap(err, "Could not create liquidity pool ledger key")
	}

	change, err := findLatestOperationChange(t, operationIndex, key)
	if err != nil {
		return nil, errors.Wrap(err, "Could not find change for liquidity pool")
	}

	return &change, nil
}

func liquidityPoolReserves(trade xdr.ClaimAtom, change *ingest.Change) (int64, int64) {
	pre := change.Pre.Data.MustLiquidityPool().Body.ConstantProduct
	a := int64(pre.ReserveA)
	b := int64(pre.ReserveB)
	if !trade.AssetSold().Equals(pre.Params.AssetA) {
		a, b = b, a
	}

	return a, b
}

func roundingSlippage(t ingest.LedgerTransaction, operationIndex int32, trade xdr.ClaimAtom, change *ingest.Change) (null.Int, error) {
	disbursedReserves, depositedReserves := liquidityPoolReserves(trade, change)

	pre := change.Pre.Data.MustLiquidityPool().Body.ConstantProduct

	op, found := t.GetOperation(uint32(operationIndex))
	if !found {
		return null.Int{}, errors.New("Could not find operation")
	}

	amountDeposited := trade.AmountBought()
	amountDisbursed := trade.AmountSold()

	switch op.Body.Type {
	case xdr.OperationTypePathPaymentStrictReceive:
		// User specified the disbursed amount
		_, roundingSlippageBips, ok := orderbook.CalculatePoolPayout(
			xdr.Int64(depositedReserves),
			xdr.Int64(disbursedReserves),
			amountDisbursed,
			pre.Params.Fee,
			true,
		)
		if !ok {
			// This is a temporary workaround and will be addressed when
			// https://github.com/stellar/go/issues/4203 is closed
			roundingSlippageBips = xdr.Int64(math.MaxInt64)
		}
		return null.IntFrom(int64(roundingSlippageBips)), nil
	case xdr.OperationTypePathPaymentStrictSend:
		// User specified the deposited amount
		_, roundingSlippageBips, ok := orderbook.CalculatePoolPayout(
			xdr.Int64(depositedReserves),
			xdr.Int64(disbursedReserves),
			amountDeposited,
			pre.Params.Fee,
			true,
		)
		if !ok {
			// Temporary workaround for https://github.com/stellar/go/issues/4203
			// Given strict receives that would overflow here, minimum slippage
			// so they get excluded.
			roundingSlippageBips = xdr.Int64(math.MinInt64)
		}
		return null.IntFrom(int64(roundingSlippageBips)), nil
	default:
		return null.Int{}, fmt.Errorf("unexpected trade operation type: %v", op.Body.Type)
	}

}