using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AIK.Common.AIKProtocol
{
    public static class ProtocolHelper
    {
        public static ushort CalculateCRC16(IEnumerable<byte> data)
        {
            if (data == null || !data.Any())
                return 0;

            ushort crc = 0;
            foreach (byte b in data)
            {
                crc ^= (ushort)(b << 8);
                for (int i = 0; i < 8; i++)
                {
                    if ((crc & 0x8000) != 0)
                    {
                        crc = (ushort)((crc << 1) ^ 0x1021);
                    }
                    else
                    {
                        crc = (ushort)(crc << 1);
                    }
                }
            }
            return crc;
        }
    }
}