///
/// Copyright (c) 2013-2015 Sensus Metering Systems
///
using System;
using log4net;

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

		/// Set by the constructor
		BalanceNewDev scale;
		string serialNumber;
        bool activityStarted;

		/// <summary>
		/// Events:  BalanceDone, Error
		/// </summary>
		/// <param name="scale">Balance device instance</param>
		/// <param name="serialNumber">Reference to the serialNumber</param>
		public GetSerNumOp(BalanceNewDev scale, ref string serialNumber)
        {
			if (scale == null) throw new ArgumentNullException("balanceDev");
			this.scale = scale;
			this.serialNumber = serialNumber;

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

		/// <summary>Start this operation</summary>
		public void Start()
        {
            if (scale.Activity == Activity.Idle)
            {
                scale.SendGetSerialNumberCmd();
                activityStarted = true;
                scale.Activity = Activity.RunningOperation;
            }
            else
            {
                activityStarted = false;
            }
        }

		/// <summary>Run this operation</summary>
		/// <returns>
		///		Event.None
		///		Event.BalanceDone
		/// </returns>
		public Event Run()
		{
            if (!activityStarted && scale.Activity == Activity.Idle)
            {
                scale.SendGetSerialNumberCmd();
                activityStarted = true;
                scale.Activity = Activity.RunningOperation;
                return Event.Busy;
            }

            if (scale.MsrmntState == MsrmntState.Valid)
			{
				serialNumber = scale.SerialNumber;
				return Event.ScaleDone;				    /// S/N read successful
			}

            if (scale.MsrmntState == MsrmntState.Failed)
            {
                return Event.Error;	/// S/N read failed
            }

            return Event.Busy;								/// No result yet
		}

		/// <summary>Stop this operation</summary>
		public void Stop()
		{
            if (scale.MsrmntState == MsrmntState.Busy) scale.MsrmntState = MsrmntState.Failed;
            scale.Activity = Activity.Idle;
		}
	}
}