// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the Apache 2.0 License.
// See the LICENSE file in the project root for more information. 

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

namespace System.Reactive.Disposables
{
    public sealed class CancellationAsyncDisposable : IAsyncDisposable
    {
        private readonly CancellationTokenSource _cts;

        public CancellationAsyncDisposable()
            : this(new CancellationTokenSource())
        {
        }

        public CancellationAsyncDisposable(CancellationTokenSource cts)
        {
            if (cts == null)
                throw new ArgumentNullException(nameof(cts));

            _cts = cts;
        }

        public CancellationToken Token => _cts.Token;

        public Task DisposeAsync()
        {
            _cts.Cancel();

            return Task.CompletedTask;
        }
    }
}