package mutations

import (
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"math/big"

	"github.com/pkg/errors"

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

type MangopayWalletTransfer struct {
	Amount           int    `graphql:"amount"`
	Currency         string `graphql:"currency"`
	MangopayWalletId string `graphql:"mangopayWalletId"`
	Nonce            int    `graphql:"nonce"`
	OperationHash    string `graphql:"operationHash"`
}

func (t MangopayWalletTransfer) hash() (string, error) {
	message := fmt.Sprintf(
		"%s:%s:%s:%d:%d",
		t.MangopayWalletId,
		t.OperationHash,
		t.Currency,
		t.Amount,
		t.Nonce,
	)
	return hashMessage(message)

}

func hashMessage(
	message string) (string, error) {
	if message == "" {
		return "", errors.New("message cannot be empty")
	}
	h := sha256.Sum256([]byte(message))
	hexH := hex.EncodeToString(h[:])

	if len(hexH) < 64 {
		return "", errors.New("invalid hash length")
	}
	hexH1Bn, ok := big.NewInt(0).SetString(hexH[:32], 16)
	if !ok {
		return "", errors.New("invalid hexH1")
	}
	hexH2Bn, ok := big.NewInt(0).SetString(hexH[32:], 16)
	if !ok {
		return "", errors.New("invalid hexH2")
	}

	return starkware.PedersenHash(hexH1Bn.String(), hexH2Bn.String()), nil
}