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

using System.Reactive.Disposables;

namespace System.Reactive.Concurrency
{
    internal sealed class UserWorkItem<TState> : IDisposable
    {
        private SingleAssignmentDisposableValue _cancelRunDisposable;
        private SingleAssignmentDisposableValue _cancelQueueDisposable;

        private readonly TState _state;
        private readonly IScheduler _scheduler;
        private readonly Func<IScheduler, TState, IDisposable> _action;

        public UserWorkItem(IScheduler scheduler, TState state, Func<IScheduler, TState, IDisposable> action)
        {
            _state = state;
            _action = action;
            _scheduler = scheduler;
        }

        public void Run()
        {
            if (!_cancelRunDisposable.IsDisposed)
            {
                _cancelRunDisposable.Disposable = _action(_scheduler, _state);
            }
        }

        public IDisposable CancelQueueDisposable
        {
            set => _cancelQueueDisposable.Disposable = value;
        }

        public void Dispose()
        {
            _cancelQueueDisposable.Dispose();
            _cancelRunDisposable.Dispose();
        }
    }
}