using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Autodesk.Revit.UI;
using Autodesk.Revit.UI.Events;

namespace ShrlAlgoToolkit.Revit.Assists
{
    /// <summary>
    /// UiApplication.PostCommand 结束事件监视器
    /// </summary>
    ///<example>
    /// <c>RevitCommandEndedMonitor revitCommandEndedMonitor = new RevitCommandEndedMonitor(UiApplication);
    /// revitCommandEndedMonitor.CommandEnded += OnCommandEnded;
    /// var command = RevitCommandId.LookupPostableCommandId(PostableCommand.TypeProperties);
    /// UiApplication.PostCommand(command);</c>
    /// </example>
    internal class RevitCommandEndedMonitor
    {
        private readonly UIApplication _revitUiApplication;

        private bool _initializingCommandMonitor;

        public event EventHandler CommandEnded;

        public RevitCommandEndedMonitor(UIApplication revituiApplication)
        {
            _revitUiApplication = revituiApplication;

            _initializingCommandMonitor = true;

            _revitUiApplication.Idling += OnRevitUiApplicationIdling;
        }

        private void OnRevitUiApplicationIdling(object sender, IdlingEventArgs idlingEventArgs)
        {
            if (_initializingCommandMonitor)
            {
                _initializingCommandMonitor = false;
                return;
            }

            _revitUiApplication.Idling -= OnRevitUiApplicationIdling;

            OnCommandEnded();
        }

        protected virtual void OnCommandEnded()
        {
            CommandEnded?.Invoke(this, EventArgs.Empty);
        }
    }
}