signet-backend/utils/submission.go

package utils

import (
	"fmt"
	"math"

	"github.com/imosed/signet/client"
	. "github.com/imosed/signet/data"
	"github.com/stellar/go/clients/horizonclient"
	"github.com/stellar/go/keypair"
	"github.com/stellar/go/network"
	"github.com/stellar/go/protocols/horizon"
	"github.com/stellar/go/txnbuild"
	"github.com/stellar/go/xdr"
	"gorm.io/gorm/clause"
)

func getFraction(price float64) xdr.Price {
	factor := math.Pow(10, 8)
	return xdr.Price{N: xdr.Int32(price * factor), D: xdr.Int32(factor)}
}

func SubmitGroupFund(fundID uint) (bool, error) {
	var fund RewardFund
	Db.Preload(clause.Associations).Find(&fund, fundID)

	var err error

	source := keypair.MustParseFull(fund.FundSecret)
	sourceReq := horizonclient.AccountRequest{AccountID: source.Address()}
	var sourceAcct horizon.Account
	sourceAcct, err = client.SignetClient.AccountDetail(sourceReq)

	offerReq := horizonclient.OfferRequest{
		Seller:  fund.SellingWallet,
		Selling: fmt.Sprintf("%s:%s", fund.Asset, fund.IssuerWallet),
		Order:   horizonclient.OrderDesc,
	}

	if err, ok := FindOffer(offerReq, &fund); !ok {
		return false, err
	}

	var currentContributions = fund.Contributions
	var submissionAmount = sumContributions(currentContributions)

	tr := Db.Begin()
	tr.Table("contributions").
		Where("reward_fund_id = ? and submitted is null or submitted = false", fundID).
		Updates(Contribution{Submitted: true})

	var tx *txnbuild.Transaction
	tx, err = txnbuild.NewTransaction(
		txnbuild.TransactionParams{
			SourceAccount:        &sourceAcct,
			IncrementSequenceNum: true,
			Operations: []txnbuild.Operation{
				&txnbuild.ChangeTrust{
					Line: txnbuild.CreditAsset{
						Code:   fund.Asset,
						Issuer: fund.IssuerWallet,
					}.MustToChangeTrustAsset(),
					SourceAccount: fund.FundWallet,
				},
				&txnbuild.ManageBuyOffer{
					Selling: txnbuild.NativeAsset{},
					Buying: txnbuild.CreditAsset{
						Code:   fund.Asset,
						Issuer: fund.IssuerWallet,
					},
					Amount:        fmt.Sprintf("%f", submissionAmount),
					Price:         getFraction(fund.Price),
					OfferID:       0,
					SourceAccount: fund.FundWallet,
				},
			},
			BaseFee: txnbuild.MinBaseFee,
			Memo:    txnbuild.Memo(nil),
			Preconditions: txnbuild.Preconditions{
				TimeBounds: txnbuild.NewInfiniteTimeout(), // TODO: change from infinite
			},
		})
	if err != nil {
		tr.Rollback()
		return false, err
	}

	tx, err = tx.Sign(network.TestNetworkPassphrase, source)
	if err != nil {
		tr.Rollback()
		return false, err
	}

	_, err = client.SignetClient.SubmitTransaction(tx)
	if err != nil {
		tr.Rollback()
		return false, err
	}

	tr.Commit()
	return true, nil
}

func sumContributions(contributions []Contribution) float64 {
	var total float64 = 0
	for _, contribution := range contributions {
		if !contribution.Submitted {
			total += contribution.Amount
		}
	}
	return total
}