using CPF.Mac.Foundation;
using System.Collections.Generic;

namespace CPF.Mac.AppKit
{
	internal static class OneShotTracker
	{
		[Register("__MonoMac_OnEndTrackerDispatch")]
		internal class Dispatcher : NSObject
		{
			private NSAction action;

			public Dispatcher(NSAction action)
			{
				this.action = action;
			}

			[Export("xamarinApplySelector")]
			[Preserve(Conditional = true)]
			public void Apply()
			{
				try
				{
					action();
				}
				finally
				{
					pendingInvokes.Remove(this);
				}
			}
		}

		private static List<NSObject> pendingInvokes = new List<NSObject>();

		public static NSObject Create(NSAction action)
		{
			Dispatcher dispatcher = new Dispatcher(action);
			pendingInvokes.Add(dispatcher);
			return dispatcher;
		}
	}
}