// 
// Timeout.cs
//  
// Author:
//       Carlos Alberto Cortez <calberto.cortez@gmail.com>
// 
// Copyright (c) 2011 Carlos Alberto Cortez
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

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

using System.Windows;
using System.Windows.Threading;

namespace Xwt.WPFBackend
{
	static class Timeout
	{
		public static uint Add (Func<bool> action, TimeSpan interval, Dispatcher dispatcher)
		{
			var timer = new DispatcherTimer (DispatcherPriority.Normal, dispatcher);
			timer.Interval = interval;
			timer.Tick += delegate {
				if (!action ())
					timer.IsEnabled = false;
			};

			uint id = RegisterTimer (timer);
			timer.IsEnabled = true;

			return id;
		}

		public static void CancelTimeout (uint id)
		{
			var timer = UnregisterTimer (id);
			if (timer != null)
				timer.IsEnabled = false;
		}

		static uint RegisterTimer (DispatcherTimer timer)
		{
			lock (locker) {
				while (timers.ContainsKey (counter))
					counter++;

				timers [counter] = timer;
				return counter++;
			}
		}

		static DispatcherTimer UnregisterTimer (uint id)
		{
			lock (locker) {
				if (!timers.ContainsKey (id))
					return null;

				var timer = timers [id];
				timers.Remove (id);

				return timer;
			}
		}

		static Dictionary<uint, DispatcherTimer> timers = new Dictionary<uint, DispatcherTimer> ();
		static uint counter;
		static object locker = new object ();
	}
}