FISLib_Old/Vinno.FIS.Sonopost/Features/Oled/MessageReceiver.cs

using System;
using System.Text;

namespace Vinno.FIS.Sonopost.Features.Oled
{
    public class MessageReceiver
    {
        public static OKResult OK = new OKResult();
        public static WrongHeaderResult WrongHeader = new WrongHeaderResult();
        public static ErrorResult Error = new ErrorResult();
        public static CommonErrorResult CommonError = new CommonErrorResult();

        public static IReceiveResult Parse(byte[] data, byte command)
        {
            if (ParseHeader(data, command))
            {
                if (command == (byte)MessageType.SearchPage)
                {
                    return ParseSearchCommand(data);
                }
                return ParseNormalCommand(data);
            }

            return WrongHeader;
        }

        private static IReceiveResult ParseNormalCommand(byte[] data)
        {
            int dataLength = data[3];
            var returnValue = new byte[dataLength];
            Buffer.BlockCopy(data, 4, returnValue, 0, dataLength);
            var result = Encoding.UTF8.GetString(returnValue);
            if (result == "OK")
            {
                return OK;
            }

            return Error;
        }

        private static IReceiveResult ParseSearchCommand(byte[] data)
        {
            int dataLength = data[3];
            var pageCount = data[4];
            var returnValue = new byte[dataLength - 1];
            Buffer.BlockCopy(data, 5, returnValue, 0, dataLength - 1);
            var result = Encoding.UTF8.GetString(returnValue);
            if (result == "OK")
            {
                return new SearchPageResult(pageCount);
            }
            return Error;
        }

        private static bool ParseHeader(byte[] data, byte command)
        {
            return data[0] == 0XAA && data[1] == command && data[2] == 0xff;
        }
    }
}