namespace Obfuz.Encryption
{
    public class BitRotateInstruction : EncryptInstructionBase
    {
        private readonly int _rotateBitNum;
        private readonly int _opKeyIndex;

        public BitRotateInstruction(int rotateBitNum, int opKeyIndex)
        {
            _rotateBitNum = rotateBitNum;
            _opKeyIndex = opKeyIndex;
        }

        public override int Encrypt(int value, int[] secretKey, int salt)
        {
            uint part1 = (uint)value << _rotateBitNum;
            uint part2 = (uint)value >> (32 - _rotateBitNum);
            return ((int)(part1 | part2) ^ secretKey[_opKeyIndex]) + salt;
        }

        public override int Decrypt(int value, int[] secretKey, int salt)
        {
            uint value2 = (uint)((value - salt) ^ secretKey[_opKeyIndex]);
            uint part1 = value2 >> _rotateBitNum;
            uint part2 = value2 << (32 - _rotateBitNum);
            return (int)(part1 | part2);
        }
    }
}