///
/// Copyright (c) 2013-2017 Sensus Metering Systems
///
using System;
using log4net;
using TBF.Boxes;

namespace TBF.BenchControl.MettlerToledo.Standard
{
	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("balanceDev");
			this.scale = scale;

			this.result = result;

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

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

		/// <summary>Run this operation</summary>
		/// <returns>
		///		Event.None
		///		Event.BalanceDone
		///		Event.Error . . . . . Current.Tick == null
		/// </returns>
		public Event Run()
		{
            scale.MsrmntTime++;

			if (!started)
			{
				scale.GetImmediateMassMeasurement();
				started = true;
				done = false;
				return Event.Busy;
			}
            else if (started && scale.MsrmntState == MsrmntState.Busy)
            {
                /// Measurement is in progress
                
                if (scale.MsrmntTime >= 2)
                {
                    /// Timeout - no response from the scale within 2 seconds - send command again
                    scale.GetImmediateMassMeasurement();
                    started = true;
                    done = false;
                }

                return Event.Busy;
            }
            else
            {
                /// Measurement completed or failed: (started == true) && (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.BalanceDone;				    /// Mass read OK
            }
		}

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