///
/// Copyright (c) 2015 Sensus Metering Systems
/// Author: Milan Hanajik
///
using System;
using log4net;
using TBF.Boxes;

namespace TBF.BenchControl.MettlerToledo.Multi
{
	/// <summary>
	/// Operation to read more mass values and average them to obtain a more accurate result.
	/// </summary>
	public class ReadStableMassOp : IOperation
	{
		private static readonly ILog log = LogManager.GetLogger(typeof(ReadStableMassOp));
		public override string ToString() { return string.Format("ReadStableMassOp(.,{0},.)", totalReadingsCount); }

		/// Operation specific
		float[] massReadings;
		int currentReadingsCount;

		/// Set by the constructor
		BalanceDev balanceDev;
		int totalReadingsCount;
        FloatBox result;

		bool started;

		/// <summary>
		/// Events:  BalanceDone, Error
		/// </summary>
		/// <param name="balanceDev">Balance device instance</param>
		/// <param name="result">Reference to the measured mass in kg</param>
		/// <param name="readingsCount">Required mass readings count (>= 3)</param>
        public ReadStableMassOp(BalanceDev balanceDev, ref FloatBox result, int readingsCount)
        {
			if (balanceDev == null) throw new ArgumentNullException("balanceDev");
			this.balanceDev = balanceDev;

			if (readingsCount < 3) throw new ArgumentOutOfRangeException("requiredReadingsCount");
			this.totalReadingsCount = readingsCount;

			this.result = result;

			log.Debug(this.ToString());
        }


		/// <summary>Start this operation</summary>
		public void Start()
        {
			started = false;
			currentReadingsCount = 0;
			massReadings = new float[totalReadingsCount];
			started = BalanceDev.GetImmediateMassMeasurement(balanceDev.IdNr, balanceDev.Name);
		}

		/// <summary>Run this operation</summary>
		/// <returns>
		///		Event.None
		///		Event.BalanceDone
		///		Event.Error . . . . . Current.Tick == null
		/// </returns>
		public Event Run()
		{
			if (currentReadingsCount >= totalReadingsCount) return Event.BalanceDone;	/// Mass has already been calculated
																					
			if (balanceDev.MsrmntState == MsrmntState.Busy) return Event.None;

			if (balanceDev.MsrmntState == MsrmntState.Valid)
			{
				massReadings[currentReadingsCount++] = balanceDev.Mass;

				if (currentReadingsCount == totalReadingsCount)
				{
					/// calculate the average
					float calcMass = 0;
					Array.Sort(massReadings);
					for (int i = 1; i < totalReadingsCount - 1; i++) calcMass += massReadings[i];
					calcMass = (calcMass / (totalReadingsCount - 2));

                    log.InfoFormat("ReadStableMassOp.Run() ... valid mass={0} ... returning Event.BalanceDone", calcMass);

					result.Val = calcMass;
					return Event.BalanceDone;       /// Mass has just been calculated
				}
			}

			BalanceDev.GetImmediateMassMeasurement(balanceDev.IdNr, balanceDev.Name);
			return Event.None;
		}

		/// <summary>Stop this operation</summary>
		public void Stop()
		{
		}
	}
}