///
/// Copyright (c) 2021 Sensus Slovensko a.s.
///
using System;
using System.Diagnostics;
using log4net;
using Dirichlet.Numerics;

namespace TBF.Rig.ControlBoard.Uni
{
    public static class OutputMessage
    {
        private static readonly ILog log = LogManager.GetLogger(typeof(OutputMessage));

        public const int PayloadLen = 38;
        public const byte MessageCode = (byte)' ';


        static Action arguments = new Action();
        /// 
        static void FetchArguments(Action combinedAction)
        {
            foreach (var aId in (ActionID[])Enum.GetValues(typeof(ActionID)))
            {
                if ((combinedAction.ActionId & aId) != 0) arguments.SetArgs(combinedAction, aId);
            }
        }


        public static byte[] GetMessage(Action action, short config, ulong bitsToInvert)
        {
            FetchArguments(action);

            byte[] message = new byte[PayloadLen + 5];      /// headed 3 bytes, checksum 2 bytes

            /// Header + message code (4 bytes)
            message[0] = Const.STX;
            message[1] = 1;                                 /// Control board addres
            message[2] = (byte)PayloadLen;                  /// Payload length
            message[3] = MessageCode;

            /// Command
            message[4] = GetCommand(action);
            message[5] = action.IsStart() ? GetStartParams(action) : action.IsStop() ? GetStopParams(action) : (byte)0;
            message[6] = (arguments.DivId <= 0) ? (byte)0 : (byte)(arguments.DivId - 1);

            int totalPulsesCount = (arguments.TotalPulsesCount < 0) ? 0 : arguments.TotalPulsesCount;
            message[7] = (byte)(totalPulsesCount & 0xFF);
            message[8] = (byte)((totalPulsesCount >> 8) & 0xFF);
            message[9] = (byte)((totalPulsesCount >> 16) & 0xFF);

            int massPulsesCount = (arguments.MassPulsesCount < 0) ? 0 : arguments.MassPulsesCount;
            message[10] = (byte)(massPulsesCount & 0xFF);
            message[11] = (byte)((massPulsesCount >> 8) & 0xFF);
            message[12] = (byte)((massPulsesCount >> 16) & 0xFF);

            message[13] = 0;

            message[14] = (byte)(config & 0xff);
            message[15] = (byte)((config >> 8) & 0xff);

            /// Route
            ulong routeOut = arguments.Route ^ bitsToInvert;
            message[16] = ((action.ActionId & ActionID.ChangeRoute) != 0) ? (byte)1 : (byte)0;  /// Route change flag
            message[17] = (byte)(routeOut & 0xFF);
            message[18] = (byte)((routeOut >> 8) & 0xFF);
            message[19] = (byte)((routeOut >> 16) & 0xFF);
            message[20] = (byte)((routeOut >> 24) & 0xFF);
            message[21] = (byte)((routeOut >> 32) & 0xFF);
            message[22] = (byte)((routeOut >> 40) & 0xFF);
            message[23] = (byte)((routeOut >> 48) & 0xFF);
            message[24] = (byte)((routeOut >> 56) & 0xFF);

            /// DA2
            message[25] = 0;
            message[26] = 0;

            /// Regulation valve
            message[27] = (action.RegVId < 0) ? (byte)0 : (byte)(action.RegVId | (int)action.RegVMode);
            message[28] = (byte)(action.RVMovePar1 & 0xFF);
            message[29] = (byte)((action.RVMovePar1 >> 8) & 0xFF);
            message[30] = (byte)(action.RVMovePar2 & 0xFF);
            message[31] = (byte)((action.RVMovePar2 >> 8) & 0xFF);
            message[32] = GetRVStopParam(action);
            
            /// DA1
            message[33] = 0;    /// PrudParL
            message[34] = 0;    /// PrudParH

            message[35] = (byte)Math.Max(1, Math.Min(255, arguments.PID));         /// PIDRV
            message[36] = 0;    // (byte)Math.Max(4, Math.Min(255, action.TolerRV));     /// TolerRV (4..20 mA reg.valve only)
            message[37] = (byte)Math.Max(0, Math.Min(255, arguments.StabTime));    /// StabRV
            message[38] = (byte)((arguments.DivThreshold >> 2) & 0xFF);

            message[39] = 0;
            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;
        }


        static byte GetCommand(Action action)
        {
            if (action.StartStop == Command.DelayStartOrStop)
            {
                return (byte)Command.None;
            }
            else if (action.StartStop == Command.Start && action.IsProlonged)
            {
                return (byte)(Command.Start | Command.ProlongedFlag);
            }
            else
            {
                return (byte)action.StartStop;
            }
        }

        static byte GetStartParams(Action action)
        {
            int param = action.FlowMId & (int)StartParam.EtalonMask;
            
            if (action.IsDivUsed)    param |= (int)StartParam.DiverterStart;
            if (action.IsSyncMethod) param |= (int)StartParam.SynchroMethod;
            if (action.IsStartStop)  param |= (int)StartParam.StartStopMethod;

            return (byte)param;
        }

        static byte GetStopParams(Action action)
        {
            return (byte)StopDevs.All;
        }

        static byte GetRVStopParam(Action action)
        {
            if (action.IsStop())                              return (byte)0x20;
            if ((action.ActionId & ActionID.RegVlvStop) != 0) return (byte)0x20;
            return (byte)0;
        }
    }


    public enum Command : byte
    {
        None = 0,                       /// Request data only
        Start = 1,
        Stop = 2,
        GetDiverterTransitionData = 4,
        GetScopeAnalyzerData = 7,
        ResetScopeAnalyzer = 8,
        GetSwitchCounterData = 9,
        /// 
        ProlongedFlag = 0x10,           /// Not a command of its own, a valid command is (byte)(Command.Start | Command.ProlongedFlag)
        DelayStartOrStop = 255,         /// Prevents other start or stop command, results in Command.None when creating a message
    }

    public enum StartParam : byte
    {
        EtalonMask      = 0x07,
        DiverterStart   = 0x08,
        SynchroMethod   = 0x10,
        DirectGateStart = 0x20,         /// ???
        StartStopMethod = 0x40,
        CalibrationMode = 0x80,
    }

    public enum StopDevs : byte
    {
        None = 0,
        Reference = 0x01,	            /// bit 0
        Diverter = 0x02,	            /// bit 1
        GatePulse = 0x08,	            /// bit 3
        TimeMeasurement = 0x10,	        /// bit 4
        BypassDevCoupled2Div = 0x20,	/// bit 5
        RegValveRegulation = 0x80,	    /// bit 7
        All = 0x9B,
    }

    public enum ValveChgFlag : byte
    {
        DoNotChange = 0,
        Change = 1,
        SendPressureMeterAddresses = 2,
    }

    public enum RegValveMode : byte
    {
        None = 0,
        TargetFrequency = 0x10,     /// Low and high frequency limits (0..2000Hz,0..2200Hz) are specified
        TargetPosition = 0x20,      /// Low and high position (=DAC value) limits (0..100%) are specified
        Stop = 0x30,                /// Stop regulation
        PulseWidth = 0x40,          /// Pulse width 0.05 .. 2 sec. ... opening and closing (opening=0x40, closing=0xC0)
        NegPulseWidth = 0x80,       /// Pulse width 0.05 .. 2 sec. ... closing (closing=0xC0)
    }

    public enum RegValveState : byte
    {
        Idle = 0,
        PwOrFreqRegul = 2,
        DacValueRegul = 3,
    }
}