package blake2

import (
	// Standard
	"crypto/subtle"
	"encoding/hex"

	// Standard Extended
	"golang.org/x/crypto/blake2b"
)

// Check Hash
func (algorithm Algorithm) CheckHash(data []byte, hashToCheck string) (bool, error) {
	// Hasher
	hasher, err := blake2b.New(algorithm.size, nil)
	// Handle Error
	if err != nil {
		return false, err
	}
	// Write To Hasher
	_, err = hasher.Write(data)
	// Handle Error
	if err != nil {
		return false, err
	}
	// Decode Hash To Check
	decodedHashToCheck, err := hex.DecodeString(hashToCheck)
	// Handle Error
	if err != nil {
		return false, err
	}
	// Return Match
	return subtle.ConstantTimeCompare(hasher.Sum(nil), decodedHashToCheck) == 1, err
}