SerialOperation.cs

using System;
using System.Collections.Generic;
using System.IO.Ports;
using System.Text;
using Xamarin.Forms;

namespace My_Climate_App
{
    enum ResponseStatus
    {
        SUCCESS,
        FAILURE
    }
    class SerialOperation
    {
        protected ISerial _serialDevice;
        protected string _response = "";
        public SerialOperation() { }

        public (ResponseStatus, string) Run()
        {
            _serialDevice = DependencyService.Get<ISerial>();
            if (_serialDevice != null)
            {
                try
                {
                    SendCommand();
                    _response = _serialDevice.ReadLine();
                }
                catch (InvalidOperationException e)
                {
                    System.Diagnostics.Debug.WriteLine($"USBSerialService InvalidOperationException occured: {e.Message}");
                }
                catch (TimeoutException e)
                {
                    System.Diagnostics.Debug.WriteLine($"USBSerialService TimeoutException occured: {e.Message}");
                }

                if (Valid(_response))
                {
                    return (ResponseStatus.SUCCESS, Parse(_response));
                }
                else
                {
                    return (ResponseStatus.FAILURE, "Invalid Response, Unknown");
                }
            }
            else
            {
                throw new Exception("platform not implemented");
            }
        }

        virtual protected void SendCommand()
        {
            throw new Exception();
        }

        virtual protected bool Valid(string response)
        {
            throw new Exception();
        }

        virtual protected string Parse(string response)
        {
            return "";
        }
    }

    class GetFirmwareVersionOperation : SerialOperation
    {
        const string GET_FIRMWARE_REVISION = "GR";
        const string RESPONSE_FIRMWARE_REVISION = "RR,";
        override protected void SendCommand()
        {
            _serialDevice.WriteLine(GET_FIRMWARE_REVISION);
        }

        override protected bool Valid(string response)
        {
            return response.Contains(RESPONSE_FIRMWARE_REVISION);
        }

        override protected string Parse(string serialResponse)
        {
           return serialResponse.Replace(RESPONSE_FIRMWARE_REVISION, "");
        }
    }

    class SetHelpLightOperation : SerialOperation
    {
        private string _value;
        public SetHelpLightOperation(string value = "") : base()
        {
            _value = value;
        }
        override protected void SendCommand()
        {
            _serialDevice.WriteLine($"SL4,{_value}");
        }

        override protected bool Valid(string response)
        {
            return response.Contains("AL4,1");
        }
    }

    
    class UseIt
    {
        public UseIt()
        {
            (ResponseStatus status, string message) response;
            response = new GetFirmwareVersionOperation().Run();

            if (response.status != ResponseStatus.SUCCESS)
            {
                // toast - firmware revision unavailable
            }
            else
            {
                return response.message;
            }
        }
    }
}