using System;
using log4net;
using TBF.Boxes;

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

		bool done;

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

		/// <summary>
		/// Events:  BalanceDone, Error
		/// </summary>
		/// <param name="balanceDev">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 balanceDev, ref FloatBox result)
        {
			if (balanceDev == null) throw new ArgumentNullException("balanceDev");
			this.balanceDev = balanceDev;

			this.result = result;

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

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

		/// <summary>Run this operation</summary>
		/// <returns>
		///		Event.None
		///		Event.BalanceDone
		///		Event.Error . . . . . Current.Tick == null
		/// </returns>
		public Event Run()
		{
            if (balanceDev.MsrmntState == MsrmntState.Valid)
            {
                result.Val = balanceDev.Mass;
                done = true;
                log.InfoFormat("ReadMassOp.Run() ... mass={0} ... returning Event.BalanceDone", balanceDev.Mass);
                balanceDev.GetImmediateMassMeasurement();	/// Start another measurement
                return Event.BalanceDone;				    /// Mass read OK
            }
            else if (done)
            {
                return Event.BalanceDone;			        /// Mass has already been read (at least once)
            }
            else
            {
                return Event.None;
            }
		}

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