using System;
using System.Threading;
using System.Threading.Tasks;

namespace GISTech.GISDataDownloader
{
	internal static class TaskCancellationInternals
	{
		public static async Task<T> CancelWithInternal<T>(Task<T> task, CancellationToken cancellationToken, bool swallowCancellationException = false)
		{
			TaskCompletionSource<bool> taskCompletionSource = new TaskCompletionSource<bool>();
			using (cancellationToken.Register(delegate(object s)
			{
				((TaskCompletionSource<bool>)s).TrySetResult(result: true);
			}, taskCompletionSource))
			{
				if (task != await Task.WhenAny(task, taskCompletionSource.Task))
				{
					if (!swallowCancellationException)
					{
						throw new OperationCanceledException(cancellationToken);
					}
					return default(T);
				}
			}
			return await task;
		}

		public static async Task<T> CancelWithInternal<T>(Task<T> task, CancellationToken cancellationToken, string message, bool swallowCancellationException = false)
		{
			TaskCompletionSource<bool> taskCompletionSource = new TaskCompletionSource<bool>();
			using (cancellationToken.Register(delegate(object s)
			{
				((TaskCompletionSource<bool>)s).TrySetResult(result: true);
			}, taskCompletionSource))
			{
				if (task != await Task.WhenAny(task, taskCompletionSource.Task))
				{
					if (!swallowCancellationException)
					{
						throw new OperationCanceledException(message, cancellationToken);
					}
					return default(T);
				}
			}
			return await task;
		}

		public static async Task CancelWithInternal(Task task, CancellationToken cancellationToken, bool swallowCancellationException = false)
		{
			TaskCompletionSource<bool> taskCompletionSource = new TaskCompletionSource<bool>();
			using (cancellationToken.Register(delegate(object s)
			{
				((TaskCompletionSource<bool>)s).TrySetResult(result: true);
			}, taskCompletionSource))
			{
				if (task != await Task.WhenAny(task, taskCompletionSource.Task))
				{
					if (swallowCancellationException)
					{
						throw new OperationCanceledException(cancellationToken);
					}
					return;
				}
			}
			await task;
		}

		public static async Task CancelWithInternal(Task task, CancellationToken cancellationToken, string message, bool swallowCancellationException = false)
		{
			TaskCompletionSource<bool> taskCompletionSource = new TaskCompletionSource<bool>();
			using (cancellationToken.Register(delegate(object s)
			{
				((TaskCompletionSource<bool>)s).TrySetResult(result: true);
			}, taskCompletionSource))
			{
				if (task != await Task.WhenAny(task, taskCompletionSource.Task))
				{
					if (!swallowCancellationException)
					{
						throw new OperationCanceledException(message, cancellationToken);
					}
					return;
				}
			}
			await task;
		}
	}
}