// 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.
 
#nullable disable
 
using System;
using System.Threading;
using Microsoft.CodeAnalysis;
 
namespace Roslyn.Test.Utilities;
 
public sealed class AsynchronousOperationBlocker : IDisposable
{
    private readonly ManualResetEvent _waitHandle;
    private readonly object _lockObj = new();
    private bool _blocking;
    private bool _disposed;
 
    public AsynchronousOperationBlocker()
    {
        _waitHandle = new ManualResetEvent(false);
        _blocking = true;
    }
 
    public bool IsBlockingOperations
    {
        get
        {
            lock (_lockObj)
            {
                return _blocking;
            }
        }
 
        private set
        {
            lock (_lockObj)
            {
                if (_blocking == value)
                {
                    return;
                }
 
                _blocking = value;
                if (!_disposed)
                {
                    if (_blocking)
                    {
                        _waitHandle.Reset();
                    }
                    else
                    {
                        _waitHandle.Set();
                    }
                }
            }
        }
    }
 
    public void BlockOperations()
        => this.IsBlockingOperations = true;
 
    public void UnblockOperations()
        => this.IsBlockingOperations = false;
 
    public bool WaitIfBlocked(TimeSpan timeout)
    {
        if (_disposed)
        {
            FailFast.Fail("Badness");
        }
 
        return _waitHandle.WaitOne(timeout);
    }
 
    public void Dispose()
    {
        if (!_disposed)
        {
            _disposed = true;
            _waitHandle.Dispose();
        }
    }
}