package mutations

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

	"github.com/pkg/errors"

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

type Transfer struct {
	Amount              string `graphql:"amountAsString:amount"`
	Nonce               int    `graphql:"nonce"`
	SenderVaultId       int    `graphql:"senderVaultId"`
	Token               string `graphql:"token"`
	ReceiverVaultId     int    `graphql:"receiverVaultId"`
	ReceiverPublicKey   string `graphql:"receiverPublicKey"`
	ExpirationTimestamp int    `graphql:"expirationTimestamp"`
	Condition           string `graphql:"condition"`
	FeeInfoUser         *struct {
		FeeLimit      string `graphql:"feeLimit"`
		TokenId       string `graphql:"tokenId"`
		SourceVaultId int    `graphql:"sourceVaultId"`
	}
}

func (t Transfer) hash() (string, error) {
	token := t.Token
	if strings.HasPrefix(token, "0x") {
		token = token[2:]
	}
	receiverPublicKey := t.ReceiverPublicKey
	if strings.HasPrefix(receiverPublicKey, "0x") {
		receiverPublicKey = receiverPublicKey[2:]
	}
	condition := t.Condition
	if strings.HasPrefix(condition, "0x") {
		condition = condition[2:]
	}
	amountInt, err := strconv.ParseInt(t.Amount, 10, 64)
	if err != nil {
		return "", errors.Wrap(err, "parsing amount")
	}
	amountBn := big.NewInt(amountInt)
	nonceBn := big.NewInt(int64(t.Nonce))
	senderVaultIdBn := big.NewInt(int64(t.SenderVaultId))
	receiverVaultIdBn := big.NewInt(int64(t.ReceiverVaultId))
	expirationTimestampBn := big.NewInt(int64(t.ExpirationTimestamp))
	if t.FeeInfoUser != nil {
		feeVaultIdBn := big.NewInt(int64(t.FeeInfoUser.SourceVaultId))
		feeLimitInt, err := strconv.ParseInt(t.FeeInfoUser.FeeLimit, 10, 64)
		if err != nil {
			return "", errors.Wrap(err, "parsing feeLimit")
		}
		feeLimitBn := big.NewInt(feeLimitInt)
		feeToken := t.FeeInfoUser.TokenId
		if strings.HasPrefix(feeToken, "0x") {
			feeToken = feeToken[2:]
		}
		instructionType := big.NewInt(4)
		if t.Condition != "" {
			instructionType = big.NewInt(5)
		}

		return hashTransferWithFee(
			instructionType,
			senderVaultIdBn,
			receiverVaultIdBn,
			amountBn,
			nonceBn,
			expirationTimestampBn,
			token,
			receiverPublicKey,
			feeToken,
			feeVaultIdBn,
			feeLimitBn,
			condition,
		)
	} else {
		instructionType := big.NewInt(1)
		if t.Condition != "" {
			instructionType = big.NewInt(2)
		}
		return hashMsg(
			instructionType,
			senderVaultIdBn,
			receiverVaultIdBn,
			amountBn,
			big.NewInt(0),
			nonceBn,
			expirationTimestampBn,
			token,
			receiverPublicKey,
			condition,
		)
	}

}

func hashMsg(
	instructionType *big.Int,
	senderVaultId *big.Int,
	receiverVaultId *big.Int,
	amount0 *big.Int,
	amount1 *big.Int,
	nonce *big.Int,
	expirationTimestamp *big.Int,
	transferToken string,
	reveiverPublicKey string,
	condition string) (string, error) {

	packedMessage1 := big.NewInt(0).Set(instructionType)
	packedMessage1.Lsh(packedMessage1, 31)
	packedMessage1.Add(packedMessage1, senderVaultId)
	packedMessage1.Lsh(packedMessage1, 31)
	packedMessage1.Add(packedMessage1, receiverVaultId)
	packedMessage1.Lsh(packedMessage1, 63)
	packedMessage1.Add(packedMessage1, amount0)
	packedMessage1.Lsh(packedMessage1, 63)
	packedMessage1.Add(packedMessage1, amount1)
	packedMessage1.Lsh(packedMessage1, 31)
	packedMessage1.Add(packedMessage1, nonce)
	packedMessage1.Lsh(packedMessage1, 22)
	packedMessage1.Add(packedMessage1, expirationTimestamp)

	transferTokenBn, ok := big.NewInt(0).SetString(transferToken, 16)
	if !ok {
		return "", errors.Errorf("transferToken is not a hex string: %s", transferToken)
	}
	reveiverPublicKeyBn, ok := big.NewInt(0).SetString(reveiverPublicKey, 16)
	if !ok {
		return "", errors.Errorf("reveiverPublicKey is not a hex string: %s", reveiverPublicKey)
	}
	if condition == "" {
		return starkware.PedersenHash(
			starkware.PedersenHash(transferTokenBn.String(), reveiverPublicKeyBn.String()),
			packedMessage1.String(),
		), nil
	}
	conditionBn, ok := big.NewInt(0).SetString(condition, 16)
	if !ok {
		return "", errors.Errorf("condition is not a hex string: %s", condition)
	}
	return starkware.PedersenHash(
		starkware.PedersenHash(
			starkware.PedersenHash(
				transferTokenBn.String(),
				reveiverPublicKeyBn.String(),
			),
			conditionBn.String(),
		),
		packedMessage1.String(),
	), nil
}

func hashTransferWithFee(
	instructionType *big.Int,
	senderVaultId *big.Int,
	receiverVaultId *big.Int,
	amount *big.Int,
	nonce *big.Int,
	expirationTimestamp *big.Int,
	transferToken string,
	reveiverPublicKey string,
	feeToken string,
	feeVaultId *big.Int,
	feeLimit *big.Int,
	condition string) (string, error) {

	packedMessage1 := big.NewInt(0).Set(senderVaultId)
	packedMessage1.Lsh(packedMessage1, 64)
	packedMessage1.Add(packedMessage1, receiverVaultId)
	packedMessage1.Lsh(packedMessage1, 64)
	packedMessage1.Add(packedMessage1, feeVaultId)
	packedMessage1.Lsh(packedMessage1, 32)
	packedMessage1.Add(packedMessage1, nonce)

	packedMessage2 := big.NewInt(0).Set(instructionType)
	packedMessage2.Lsh(packedMessage2, 64)
	packedMessage2.Add(packedMessage2, amount)
	packedMessage2.Lsh(packedMessage2, 64)
	packedMessage2.Add(packedMessage2, feeLimit)
	packedMessage2.Lsh(packedMessage2, 32)
	packedMessage2.Add(packedMessage2, expirationTimestamp)
	packedMessage2.Lsh(packedMessage2, 81)
	packedMessage2.Add(packedMessage2, big.NewInt(0))

	transferTokenBn, ok := big.NewInt(0).SetString(transferToken, 16)
	if !ok {
		return "", errors.Errorf("transferToken is not a hex string: %s", transferToken)
	}
	reveiverPublicKeyBn, ok := big.NewInt(0).SetString(reveiverPublicKey, 16)
	if !ok {
		return "", errors.Errorf("reveiverPublicKey is not a hex string: %s", reveiverPublicKey)
	}
	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(transferTokenBn.String(), feeTokenbn.String()),
		reveiverPublicKeyBn.String(),
	)
	if condition == "" {
		return starkware.PedersenHash(
			starkware.PedersenHash(tmpHash, packedMessage1.String()),
			packedMessage2.String(),
		), nil
	}
	conditionBn, ok := big.NewInt(0).SetString(condition, 16)
	if !ok {
		return "", errors.Errorf("condition is not a hex string: %s", condition)
	}
	return starkware.PedersenHash(
		starkware.PedersenHash(
			starkware.PedersenHash(tmpHash, conditionBn.String()), packedMessage1.String()),
		packedMessage2.String(),
	), nil
}