///
/// Copyright (c) 2015-2016 Sensus Metering Systems
///
using System;
using log4net;
using TBF.Boxes;

namespace TBF.Rig.MettlerToledo.Multi
{
	public class ReadMassOp : IOperation
	{
		private static readonly ILog log = LogManager.GetLogger(typeof(ReadMassOp));
		public override string ToString() { return string.Format("ReadMassOp(.,.)"); }

		bool started;
		bool done;

		/// Set by the constructor
		BalanceDev scale;
		DoubleBox result;

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

			this.result = result;

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

		/// <summary>Start this operation</summary>
		public void Start()
        {
			done = false;
			started = BalanceDev.GetImmediateMassMeasurement(scale.IdNr, scale.Name);
		}

		/// <summary>Run this operation</summary>
		/// <returns>
		///		Event.None
		///		Event.BalanceDone
		///		Event.Error . . . . . Current.Tick == null
		/// </returns>
		public Event Run()
		{
			if (!started)
			{
				started = BalanceDev.GetImmediateMassMeasurement(scale.IdNr, scale.Name);
				if (!done)
					return Event.Busy;
				else
					return Event.ScaleDone;
			}
			else if (started && scale.MsrmntState != MsrmntState.Busy)
			{
				if (scale.MsrmntState == MsrmntState.Valid) result.Val = scale.Mass;
				log.InfoFormat("ReadMassOp.Run() ... state={0}, mass={1} ... returning Event.BalanceDone",
							   scale.MsrmntState, scale.Mass);
				done = true;
				started = false;
				return Event.ScaleDone;				    /// Mass read OK
			}
            else
            {
                return Event.Busy;
            }
		}

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