internal static Encoding SniffByteOrderMark()

in src/Model/Utilities.cs [89:112]

• 24 lines of code
• 29 McCabe index (conditional complexity)

        internal static Encoding SniffByteOrderMark(byte[] bytes, int len)
        {
            if (len >= 3 && bytes[0] == 0xef && bytes[1] == 0xbb && bytes[2] == 0xbf)
            {
                return Encoding.UTF8;
            }
            else if (len >= 4 && ((bytes[0] == 0x00 && bytes[1] == 0x00 && bytes[2] == 0xfe && bytes[3] == 0xff) || (bytes[0] == 0xfe && bytes[1] == 0xff && bytes[2] == 0xfe && bytes[3] == 0xff)))
            {
                return Encoding.GetEncoding(12001); // big endian UTF-32.
            }
            else if (len >= 4 && ((bytes[0] == 0xff && bytes[1] == 0xfe && bytes[2] == 0x00 && bytes[3] == 0x00) || (bytes[0] == 0xff && bytes[1] == 0xfe && bytes[2] == 0xff && bytes[3] == 0xfe)))
            {
                return Encoding.UTF32; // skip UTF-32 little endian BOM
            }
            else if (len >= 2 && bytes[0] == 0xff && bytes[1] == 0xfe)
            {
                return Encoding.Unicode; // skip UTF-16 little endian BOM
            }
            else if (len >= 2 && bytes[0] == 0xf2 && bytes[1] == 0xff)
            {
                return Encoding.BigEndianUnicode; // skip UTF-16 big endian BOM
            }
            return null;
        }