///
/// Copyright (c) 2021 Sensus Slovensko a.s.
///
using System;
using System.Diagnostics;

namespace TBF.Rig.ControlBoard.Uni
{
    class ValveMoveMsg
    {
        public int PayloadLen { get { return 38; } }
        public byte MessageCode { get { return 0x20; } }

        Command cmd;
        int regValveNr;

        public ValveMoveMsg(Command cmd, int regValveNr)
        {
            this.cmd = cmd;
            this.regValveNr = regValveNr;
        }

        public byte[] GetMessage()
        {
            byte[] message = new byte[PayloadLen + 5];      /// headed 3 bytes, checksum 2 bytes

            /// Header (3 bytes)
            message[0] = Const.STX;
            message[1] = 1;                         /// Control board addres
            message[2] = (byte)PayloadLen;          /// Payload length

            /// Command
            message[3] = MessageCode;
            message[4] = (byte)cmd;
            
            /// ...
            
            message[40] = 0;
            Debug.Assert(40 == PayloadLen + 2);

            /// Checksum (2 bytes)
            int checksum = 0;
            for (int i = 1; i < PayloadLen + 3; i++) checksum += message[i];
            message[PayloadLen + 3] = (byte)(checksum & 0xFF);
            message[PayloadLen + 4] = (byte)((checksum >> 8) & 0xFF);

            return message;
        }

        public override string ToString()
        {
            return string.Format("ValveMoveMsg : {0}", cmd);
        }
    }
}