namespace Correlator.Util
{
    public static class CrcCodeHub
    {
        #region CRC-16校验的高位字节表

        private static readonly byte[] HiCrcTable =
        {
            0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41, 0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40,
            0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40, 0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41,
            0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40, 0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41,
            0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41, 0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40,
            0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40, 0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41,
            0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41, 0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40,
            0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41, 0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40,
            0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40, 0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41,
            0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40, 0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41,
            0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41, 0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40,
            0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41, 0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40,
            0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40, 0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41,
            0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41, 0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40,
            0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40, 0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41,
            0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40, 0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41,
            0X00, 0XC1, 0X81, 0X40, 0X01, 0XC0, 0X80, 0X41, 0X01, 0XC0, 0X80, 0X41, 0X00, 0XC1, 0X81, 0X40
        };

        #endregion

        #region CRC-16校验的低位字节表

        private static readonly byte[] LoCrcTable =
        {
            0X00, 0XC0, 0XC1, 0X01, 0XC3, 0X03, 0X02, 0XC2, 0XC6, 0X06, 0X07, 0XC7, 0X05, 0XC5, 0XC4, 0X04,
            0XCC, 0X0C, 0X0D, 0XCD, 0X0F, 0XCF, 0XCE, 0X0E, 0X0A, 0XCA, 0XCB, 0X0B, 0XC9, 0X09, 0X08, 0XC8,
            0XD8, 0X18, 0X19, 0XD9, 0X1B, 0XDB, 0XDA, 0X1A, 0X1E, 0XDE, 0XDF, 0X1F, 0XDD, 0X1D, 0X1C, 0XDC,
            0X14, 0XD4, 0XD5, 0X15, 0XD7, 0X17, 0X16, 0XD6, 0XD2, 0X12, 0X13, 0XD3, 0X11, 0XD1, 0XD0, 0X10,
            0XF0, 0X30, 0X31, 0XF1, 0X33, 0XF3, 0XF2, 0X32, 0X36, 0XF6, 0XF7, 0X37, 0XF5, 0X35, 0X34, 0XF4,
            0X3C, 0XFC, 0XFD, 0X3D, 0XFF, 0X3F, 0X3E, 0XFE, 0XFA, 0X3A, 0X3B, 0XFB, 0X39, 0XF9, 0XF8, 0X38,
            0X28, 0XE8, 0XE9, 0X29, 0XEB, 0X2B, 0X2A, 0XEA, 0XEE, 0X2E, 0X2F, 0XEF, 0X2D, 0XED, 0XEC, 0X2C,
            0XE4, 0X24, 0X25, 0XE5, 0X27, 0XE7, 0XE6, 0X26, 0X22, 0XE2, 0XE3, 0X23, 0XE1, 0X21, 0X20, 0XE0,
            0XA0, 0X60, 0X61, 0XA1, 0X63, 0XA3, 0XA2, 0X62, 0X66, 0XA6, 0XA7, 0X67, 0XA5, 0X65, 0X64, 0XA4,
            0X6C, 0XAC, 0XAD, 0X6D, 0XAF, 0X6F, 0X6E, 0XAE, 0XAA, 0X6A, 0X6B, 0XAB, 0X69, 0XA9, 0XA8, 0X68,
            0X78, 0XB8, 0XB9, 0X79, 0XBB, 0X7B, 0X7A, 0XBA, 0XBE, 0X7E, 0X7F, 0XBF, 0X7D, 0XBD, 0XBC, 0X7C,
            0XB4, 0X74, 0X75, 0XB5, 0X77, 0XB7, 0XB6, 0X76, 0X72, 0XB2, 0XB3, 0X73, 0XB1, 0X71, 0X70, 0XB0,
            0X50, 0X90, 0X91, 0X51, 0X93, 0X53, 0X52, 0X92, 0X96, 0X56, 0X57, 0X97, 0X55, 0X95, 0X94, 0X54,
            0X9C, 0X5C, 0X5D, 0X9D, 0X5F, 0X9F, 0X9E, 0X5E, 0X5A, 0X9A, 0X9B, 0X5B, 0X99, 0X59, 0X58, 0X98,
            0X88, 0X48, 0X49, 0X89, 0X4B, 0X8B, 0X8A, 0X4A, 0X4E, 0X8E, 0X8F, 0X4F, 0X8D, 0X4D, 0X4C, 0X8C,
            0X44, 0X84, 0X85, 0X45, 0X87, 0X47, 0X46, 0X86, 0X82, 0X42, 0X43, 0X83, 0X41, 0X81, 0X80, 0X40
        };

        #endregion

        public static uint GenerateCrc16Code(byte[] source)
        {
            uint crc16 = 0xFFFF;
            foreach (var t in source)
            {
                crc16 ^= t;
                for (var j = 0; j < 8; j++)
                {
                    if ((crc16 & 0x01) == 1)
                    {
                        crc16 = (crc16 >> 1) ^ 0xA001;
                    }
                    else
                    {
                        crc16 >>= 1;
                    }
                }
            }

            return crc16;
        }
    }
}