package verify

import (
	"testing"

	"github.com/ethereum/go-ethereum/accounts"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/stretchr/testify/assert"
)

func VerifySig(from, sigHex string, msg []byte) bool {
	sig, err := hexutil.Decode(sigHex)
	if err != nil {
		return false
	}

	msg = accounts.TextHash(msg)

	sig[crypto.RecoveryIDOffset] -= 27

	pub, err := crypto.SigToPub(msg, sig)
	if err != nil {
		return false
	}

	addr := crypto.PubkeyToAddress(*pub)
	givenAddr := common.HexToAddress(from)
	return addr == givenAddr
}

func TestVerifySig(t *testing.T) {
	from := "0x925a0ffacd6f5336d07ad01bef4717cb67064c98"
	sigHex := "0xdce77c911b3b4062be94110f392ffc040cb43600fad3b8483319fb9e7fa6241e14321efa7b7865d4841548f27be41124ec57ecbb5daf1bf30571e629d445c8511b"
	msg := []byte("0x8c386d0f0125c77139c8")

	assert.True(t, VerifySig(from, sigHex, msg))
}