namespace System.Threading.Tasks;

public static class PolyfillTaskExtensions // Polyfill for < .NET 6
{
	public static Task WaitAsync(this Task task, int millisecondsTimeout) =>
		  WaitAsync(task, TimeSpan.FromMilliseconds(millisecondsTimeout), default);

	public static Task WaitAsync(this Task task, TimeSpan timeout) =>
		WaitAsync(task, timeout, default);

	public static async Task WaitAsync(this Task task, CancellationToken cancellationToken)
	{
		var tcs = new TaskCompletionSource();
		using (cancellationToken.Register(s => ((TaskCompletionSource)s).TrySetCanceled(), tcs))
		{
			await (await Task.WhenAny(task, tcs.Task).ConfigureAwait(false)).ConfigureAwait(false);
		}
	}

	public static async Task WaitAsync(this Task task, TimeSpan timeout, CancellationToken cancellationToken)
	{
		var tcs = new TaskCompletionSource<bool>();
		using (new Timer(s => ((TaskCompletionSource<bool>)s).TrySetException(new TimeoutException()), tcs, timeout, Timeout.InfiniteTimeSpan))
		using (cancellationToken.Register(s => ((TaskCompletionSource<bool>)s).TrySetCanceled(), tcs))
		{
			await (await Task.WhenAny(task, tcs.Task).ConfigureAwait(false)).ConfigureAwait(false);
		}
	}

	public static Task<TResult> WaitAsync<TResult>(this Task<TResult> task, int millisecondsTimeout) =>
		WaitAsync(task, TimeSpan.FromMilliseconds(millisecondsTimeout), default);

	public static Task<TResult> WaitAsync<TResult>(this Task<TResult> task, TimeSpan timeout) =>
		WaitAsync(task, timeout, default);

	public static async Task<TResult> WaitAsync<TResult>(this Task<TResult> task, CancellationToken cancellationToken)
	{
		var tcs = new TaskCompletionSource<TResult>();
		using (cancellationToken.Register(s => ((TaskCompletionSource<TResult>)s).TrySetCanceled(), tcs))
		{
			return await (await Task.WhenAny(task, tcs.Task).ConfigureAwait(false)).ConfigureAwait(false);
		}
	}

	public static async Task<TResult> WaitAsync<TResult>(this Task<TResult> task, TimeSpan timeout, CancellationToken cancellationToken)
	{
		var tcs = new TaskCompletionSource<TResult>();
		using (new Timer(s => ((TaskCompletionSource<TResult>)s).TrySetException(new TimeoutException()), tcs, timeout, Timeout.InfiniteTimeSpan))
		using (cancellationToken.Register(s => ((TaskCompletionSource<TResult>)s).TrySetCanceled(), tcs))
		{
			return await (await Task.WhenAny(task, tcs.Task).ConfigureAwait(false)).ConfigureAwait(false);
		}
	}
}