using System;

namespace CSNetwork
{
    public static class Helper
    {
        public static byte[] HexStringToByteArray(string hex)
        {
            if (hex.Length % 2 == 1)
                throw new ArgumentException("Hex string must have an even number of digits.");

            int numberChars = hex.Length;
            byte[] bytes = new byte[numberChars / 2];
            for (int i = 0; i < numberChars; i += 2)
            {
                try
                {
                    bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
                }
                catch (FormatException ex)
                {
                    throw new ArgumentException(
                        $"Invalid hex character found at position {i}: '{hex.Substring(i, 2)}'",
                        ex
                    );
                }
            }
            return bytes;
        }

        public static string ByteToHexString(byte[] bytes)
        {
            return BitConverter.ToString(bytes).Replace("-", "");
        }
    }
}