///
/// Copyright (c) 2018 Sensus Slovensko a.s.
///
using System;
using System.Collections.Generic;
using Common;
using log4net;
using TBF.Rig.Generic;
using TBF.Rig.GenericDevices;
using TBF.Boxes;
using TBF.Rig.Hart.Common;
using TBF.Resources;

namespace TBF.Rig.Hart.Nivotrack
{
    /// <summary>
	/// Root component for Modbus communication via serial port (RS485)
	/// </summary>
    public class Nivotrack : ComponentBase, IDevice, ILevelMeter, IOperation, GenericDevices.IHasCalendarEvents
    {
        const int StableReadingsCount = 9;

		private static readonly ILog log = LogManager.GetLogger(typeof(Nivotrack));
        public override string ToString() { return string.Format("{0}({1})", ClassName, Cfg.ToString(-1)); }

		readonly NivotrackCfg nivotrackCfg;
		readonly IHart hart;

        public double Level { get { return ReadLevel(); } }

		double rawLevel_mm;
        bool isRawLevelValid;

        /// For stable measurement calculation
        double maxSDev;
        double[] levelReadings;
        double[] sortedLevelReadings;
        int currentReadingsCount;

        bool measurementCompleted;      /// stableMeasurementCompleted

        DoubleBox levelBox;
        /// 
        enum CurrentOp
		{
			None,
			ReadLevel,
            ReadStableLevel,
        }
		CurrentOp currentOp;


		public Nivotrack() { }

		/// <summary>
		/// Ambient temperature / humidity / pressure meter 'Greco' connected via serial interface (RS232)
		/// Connection settings: 19200 Bd 8-bits No-parity 1-stop-bit Flow control: none or hardware.
		/// </summary>
		public Nivotrack(Generic.IComponentCfg cfg, IList<Generic.IComponent> components)
            : base(cfg)
        {
			nivotrackCfg = cfg as NivotrackCfg;

			hart = (IHart)TbfComponents.FindComponent(cfg.ParentName, components);
			if (hart == null) throw new Exception("Cannot find " + Name + " parent");
		}

        public override void Initialize()
        {
            levelReadings = new double[StableReadingsCount];
            sortedLevelReadings = new double[StableReadingsCount];
            rawLevel_mm = 0;
            isRawLevelValid = false;
            log.FatalFormat("{0} initialized: {1}", Name, this);
        }

        /// 
        /// Calendar support
        ///
        public IList<Config.CalendarEvent.ICalendarEvent> GetCalendarEvents()
        {
            DateTime calibrationDue = nivotrackCfg.CalibValidDate;
            IList<Config.CalendarEvent.ICalendarEvent> calendarEvents = new List<Config.CalendarEvent.ICalendarEvent>();

            if (calibrationDue > TBF.UI.Constants.MinDate)
            {
                /// Calibration due date calendar event
                calendarEvents.Add(new TBF.UI.Calendar.CalibrationDueDateEvent(calibrationDue.Date, Name,
                                                                               string.Format(Strings.Calibration_due_date_is_0,
                                                                                             calibrationDue.Date.ToString(TBF.UI.Constants.DateFormat))));
                if (DateTime.Now.Date <= calibrationDue.AddDays(-7))
                {
                    /// Weekly reminders (last 5 weeks)
                    calendarEvents.Add(new TBF.UI.Calendar.CalibrationReminderEvent(calibrationDue.Date.AddDays(-35), Name,
                                                                                    string.Format(Strings.Calibration_due_date_is_0,
                                                                                                  calibrationDue.Date.ToString(TBF.UI.Constants.DateFormat)),
                                                                                    false));
                }
                if (DateTime.Now.Date <= calibrationDue.Date)
                {
                    /// Daily reminders (last 5 days)
                    calendarEvents.Add(new TBF.UI.Calendar.CalibrationReminderEvent(calibrationDue.AddDays(-5), Name,
                                                                                    string.Format(Strings.Calibration_due_date_is_0,
                                                                                                  calibrationDue.Date.ToString(TBF.UI.Constants.DateFormat)),
                                                                                    true));
                }
            }
            return calendarEvents;
        }


		void Detect()
		{
			byte bcnt = (byte)0;		/// block count

			byte[] data = new byte[5];
			data[0] = (byte)Mark.ShortFrameMaster2Slave;
			data[1] = (byte)((int)Master.Primary + (byte)nivotrackCfg.Address);
			data[2] = (byte)Cmd.ReadUniqueID;
			data[3] = bcnt;
			data[4] = 0;				/// reserved for chehcksum

			hart.SendMessage(5, data);
		}


		void RequestProcessValue()
		{
			byte bcnt    = (byte)0;		/// block count

			byte[] data = new byte[5];
			data[0] = (byte)Mark.ShortFrameMaster2Slave;
			data[1] = (byte)((int)Master.Primary + (byte)nivotrackCfg.Address);
			data[2] = (byte)Cmd.ReadPrimaryVar;
			data[3] = bcnt;
			data[4] = 0;				/// reserved for chehcksum

			hart.SendMessage(5, data);
		}


		/// <summary>Run this device</summary>
		public void RunDeviceBefore()
		{
			if (nivotrackCfg.DebugLevel == DebugMode.Simulate) return;

			if (hart.ReceivedTelegrams[nivotrackCfg.Address].Count > 0)
			{
				byte[] data = hart.ReceivedTelegrams[nivotrackCfg.Address].Dequeue();

				if ((data.Length == 12) && (data[0] == (byte)Mark.ShortFrameSlave2Master)
										&& (data[2] == (byte)Cmd.ReadPrimaryVar)
										&& (data[3] == 7))
				{
					///
					/// A frame with a status and a primary variable
					///
					ushort state = (ushort)(256 * data[4] + data[5]);
					byte unitsID = data[6];
					byte[] floatData = new byte[] { data[10], data[9], data[8], data[7] };
                    rawLevel_mm = System.BitConverter.ToSingle(floatData, 0);
					isRawLevelValid = true;
                    log.InfoFormat("{0} : Received water level = {1} mm, State = {2}", Name, rawLevel_mm, state.ToString("X4"));
				}
				else if ((data.Length == 7) && (data[0] == (byte)Mark.ShortFrameSlave2Master) 
											&& (data[2] == (byte)Cmd.ReadPrimaryVar)
											&& (data[3] == 2))
				{
					///
					/// A frame with a status only
					///
					ushort state = (ushort)(256 * data[4] + data[5]);
                    isRawLevelValid = false;
                    log.InfoFormat("{0} : State = {1}", Name, state.ToString("X4"));
				}
			}
		}

		public void RunDeviceAfter()
		{
			if (nivotrackCfg.DebugLevel == DebugMode.Simulate) return;

			if ((StateMachine.Time % 2) == (nivotrackCfg.Address % 2))
			{
				RequestProcessValue();
			}
		}

		public void StopDevice() { }
		public void StopDevice2() { }


        /// <summary>
        /// Gets the most recent raw level measurement and applies correction table
        /// </summary>
        /// <returns></returns>
		public double ReadLevel()
		{
            return Config.Entities.MeasurementCorrection.CorrectedValue(rawLevel_mm, Corrections);
		}

		/// <returns>Reference to the operation</returns>
		public IOperation ReadLevelOp(ref DoubleBox levelBox)
		{
			if (currentOp != CurrentOp.None) throw new Exception("Sequence error");
			this.levelBox = levelBox;
			currentOp = CurrentOp.ReadLevel;
			return this;
		}

        /// <returns>Reference to the operation</returns>
        public IOperation ReadStableLevelOp(ref DoubleBox levelBox, double maxSDev)
        {
            if (currentOp != CurrentOp.None) throw new Exception("Sequence error");
            this.levelBox = levelBox;
            this.maxSDev = maxSDev;
            currentOp = CurrentOp.ReadStableLevel;

            return this;
        }

		/// <summary>Start this operation</summary>
		public void Start()
		{
            if (currentOp == CurrentOp.ReadLevel)
            {
                if (isRawLevelValid && (levelBox != null)) levelBox.Val = ReadLevel();
            }
            else if (currentOp == CurrentOp.ReadStableLevel)
            {
                currentReadingsCount = 0;
                measurementCompleted = false;
                if (isRawLevelValid)
                {
                    levelReadings[currentReadingsCount++] = ReadLevel();
                }
            }
		}

		/// <summary>Run this operation</summary>
		/// <returns>Event.ResultsPrinted</returns>
		public Event Run()
		{
            if (measurementCompleted)
            {
                if ((currentOp == CurrentOp.ReadLevel) && (levelBox != null)) levelBox.Val = ReadLevel();
                return Event.LevelDone;
            }

            if ((currentOp == CurrentOp.ReadLevel) && isRawLevelValid)
            {
                if (levelBox != null) levelBox.Val = ReadLevel();
                measurementCompleted = true;
                return Event.LevelDone;
            }
            else if ((currentOp == CurrentOp.ReadStableLevel) && isRawLevelValid)
            {
                ///
                /// Read new level and put it into a FIFO buffer
                ///
                if (currentReadingsCount < StableReadingsCount)
                {
                    levelReadings[currentReadingsCount++] = ReadLevel();
                }
                else
                {
                    /// Shift data in the (already full) buffer, save the mass into the last buffer item
                    for (int i = 1; i < StableReadingsCount; i++)
                    {
                        levelReadings[i - 1] = levelReadings[i];
                    }
                    levelReadings[StableReadingsCount - 1] = ReadLevel();
                }

                ///
                /// Evaluate reading stability
                ///
                if (currentReadingsCount >= StableReadingsCount)
                {
                    Array.Copy(levelReadings, sortedLevelReadings, StableReadingsCount);
                    Array.Sort(sortedLevelReadings);

                    if (true)
                    {
                        /// Spread of values (except of the largest and the smalles value) must be <= maxSDev

                        if ((sortedLevelReadings[StableReadingsCount - 2] - sortedLevelReadings[1]) <= maxSDev)
                        {
                            double massSum = 0;
                            for (int i = 1; i < StableReadingsCount - 1; i++) massSum += sortedLevelReadings[i];
                            double ave = massSum / (StableReadingsCount - 2);
                            if (levelBox != null) levelBox.Val = ave;
                            measurementCompleted = true;
                            log.InfoFormat("ReadStableLevelOp.Run() ... valid level={0} ... returning LevelDone", ave);
                            return Event.LevelDone;
                        }
                    }
                    else
                    {
                        /// Standard deviation (except of the largest and the smalles value) must be <= maxSDev
                        double massSum = 0;
                        for (int i = 1; i < StableReadingsCount - 1; i++) massSum += sortedLevelReadings[i];
                        double ave = massSum / (StableReadingsCount - 2);
                        double sdev = 0;
                        for (int i = 1; i < StableReadingsCount - 1; i++) sdev += ((sortedLevelReadings[i] - ave) * (sortedLevelReadings[i] - ave));

                        if (Math.Sqrt(sdev / (StableReadingsCount - 2)) <= maxSDev)
                        {
                            if (levelBox != null) levelBox.Val = ave;
                            measurementCompleted = true;
                            log.InfoFormat("ReadStableMassOp.Run() ... valid mass={0} ... returning Event.BalanceDone", ave);
                            return Event.LevelDone;
                        }
                    }
                }
            }

            return Event.Busy;
        }

		/// <summary>Stop this operation</summary>
		public void Stop()
		{
			currentOp = CurrentOp.None;
		}
	}
}