package mutations

import (
	"math/big"
	"strconv"
	"strings"

	"github.com/pkg/errors"

	"git.lehouerou.net/laurent/sorare/starkware"
)

type LimitOrder struct {
	AmountBuy           string `json:"amountBuy"`
	AmountSell          string `json:"amountSell"`
	ExpirationTimestamp int    `json:"expirationTimestamp"`
	FeeInfo             *struct {
		FeeLimit      string `json:"feeLimit"`
		SourceVaultId int    `json:"sourceVaultId"`
		TokenId       string `json:"tokenId"`
	} `json:"feeInfo"`
	Nonce       int    `json:"nonce"`
	TokenBuy    string `json:"tokenBuy"`
	TokenSell   string `json:"tokenSell"`
	VaultIdBuy  int    `json:"vaultIdBuy"`
	VaultIdSell int    `json:"vaultIdSell"`
}

func (o LimitOrder) hash() (string, error) {
	vaultSellBn := big.NewInt(int64(o.VaultIdSell))
	vaultBuyBn := big.NewInt(int64(o.VaultIdBuy))
	amountSellInt, err := strconv.ParseInt(o.AmountSell, 10, 64)
	if err != nil {
		return "", errors.Wrap(err, "parsing amountSell")
	}
	amountSellBn := big.NewInt(amountSellInt)
	amountBuyInt, err := strconv.ParseInt(o.AmountBuy, 10, 64)
	if err != nil {
		return "", errors.Wrap(err, "parsing amountBuy")
	}
	amountBuyBn := big.NewInt(amountBuyInt)
	nonceBn := big.NewInt(int64(o.Nonce))
	expirationTimestampBn := big.NewInt(int64(o.ExpirationTimestamp))

	tokenSell := o.TokenSell
	if strings.HasPrefix(tokenSell, "0x") {
		tokenSell = tokenSell[2:]
	}
	tokenBuy := o.TokenBuy
	if strings.HasPrefix(tokenBuy, "0x") {
		tokenBuy = tokenBuy[2:]
	}

	if o.FeeInfo != nil {
		feeVaultIdBn := big.NewInt(int64(o.FeeInfo.SourceVaultId))
		feeLimitInt, err := strconv.ParseInt(o.FeeInfo.FeeLimit, 10, 64)
		if err != nil {
			return "", errors.Wrap(err, "parsing feeLimit")
		}
		feeLimitBn := big.NewInt(feeLimitInt)
		feeToken := o.FeeInfo.TokenId
		if strings.HasPrefix(feeToken, "0x") {
			feeToken = feeToken[2:]
		}

		return hashLimitOrderWithFee(
			big.NewInt(3),
			vaultSellBn,
			vaultBuyBn,
			amountSellBn,
			amountBuyBn,
			nonceBn,
			expirationTimestampBn,
			tokenSell,
			tokenBuy,
			feeToken,
			feeVaultIdBn,
			feeLimitBn,
		)
	} else {
		return hashLimitOrder(
			big.NewInt(0),
			vaultSellBn,
			vaultBuyBn,
			amountSellBn,
			amountBuyBn,
			nonceBn,
			expirationTimestampBn,
			tokenSell,
			tokenBuy,
		)
	}

}

func hashLimitOrderWithFee(
	instructionType *big.Int,
	vaultSell *big.Int,
	vaultBuy *big.Int,
	amountSell *big.Int,
	amountBuy *big.Int,
	nonce *big.Int,
	expirationTimestamp *big.Int,
	tokenSell string,
	tokenBuy string,
	feeToken string,
	feeVaultId *big.Int,
	feeLimit *big.Int) (string, error) {

	packedMessage1 := big.NewInt(0).Set(amountSell)
	packedMessage1.Lsh(packedMessage1, 64)
	packedMessage1.Add(packedMessage1, amountBuy)
	packedMessage1.Lsh(packedMessage1, 64)
	packedMessage1.Add(packedMessage1, feeLimit)
	packedMessage1.Lsh(packedMessage1, 32)
	packedMessage1.Add(packedMessage1, nonce)

	packedMessage2 := big.NewInt(0).Set(instructionType)
	packedMessage2.Lsh(packedMessage2, 64)
	packedMessage2.Add(packedMessage2, feeVaultId)
	packedMessage2.Lsh(packedMessage2, 64)
	packedMessage2.Add(packedMessage2, vaultSell)
	packedMessage2.Lsh(packedMessage2, 64)
	packedMessage2.Add(packedMessage2, vaultBuy)
	packedMessage2.Lsh(packedMessage2, 32)
	packedMessage2.Add(packedMessage2, expirationTimestamp)
	packedMessage2.Lsh(packedMessage2, 17)
	packedMessage2.Add(packedMessage2, big.NewInt(0))

	tokenSellbn, ok := big.NewInt(0).SetString(tokenSell, 16)
	if !ok {
		return "", errors.Errorf("token0 is not a hex string: %s", tokenSell)
	}
	tokenBuybn, ok := big.NewInt(0).SetString(tokenBuy, 16)
	if !ok {
		return "", errors.Errorf("token1 is not a hex string: %s", tokenBuy)
	}
	feeTokenbn, ok := big.NewInt(0).SetString(feeToken, 16)
	if !ok {
		return "", errors.Errorf("feeToken is not a hex string: %s", feeToken)
	}

	tmpHash := starkware.PedersenHash(
		starkware.PedersenHash(tokenSellbn.String(), tokenBuybn.String()),
		feeTokenbn.String(),
	)
	return starkware.PedersenHash(
		starkware.PedersenHash(tmpHash, packedMessage1.String()),
		packedMessage2.String(),
	), nil
}

func hashLimitOrder(
	instructionType *big.Int,
	vaultSell *big.Int,
	vaultBuy *big.Int,
	amountSell *big.Int,
	amountBuy *big.Int,
	nonce *big.Int,
	expirationTimestamp *big.Int,
	tokenSell string,
	tokenBuy string,
) (string, error) {
	packedMessage := big.NewInt(0).Set(instructionType)
	packedMessage.Lsh(packedMessage, 31)
	packedMessage.Add(packedMessage, vaultSell)
	packedMessage.Lsh(packedMessage, 31)
	packedMessage.Add(packedMessage, vaultBuy)
	packedMessage.Lsh(packedMessage, 63)
	packedMessage.Add(packedMessage, amountSell)
	packedMessage.Lsh(packedMessage, 63)
	packedMessage.Add(packedMessage, amountBuy)
	packedMessage.Lsh(packedMessage, 31)
	packedMessage.Add(packedMessage, nonce)
	packedMessage.Lsh(packedMessage, 22)
	packedMessage.Add(packedMessage, expirationTimestamp)

	tokenSellbn, ok := big.NewInt(0).SetString(tokenSell, 16)
	if !ok {
		return "", errors.Errorf("tokenSell is not a hex string: %s", tokenSell)
	}
	tokenBuybn, ok := big.NewInt(0).SetString(tokenBuy, 16)
	if !ok {
		return "", errors.Errorf("tokenBuy is not a hex string: %s", tokenBuy)
	}

	return starkware.PedersenHash(
		starkware.PedersenHash(tokenSellbn.String(), tokenBuybn.String()),
		packedMessage.String(),
	), nil
}