namespace System.Threading;

public struct CancellationToken
{
	private static readonly WaitHandle InfiniteWaitHandle = new ManualResetEvent(initialState: false);

	private CancellationTokenSource? source;

	public bool IsCancellationRequested => source?.IsCancellationRequested ?? false;

	public WaitHandle WaitHandle => source?.WaitHandle ?? InfiniteWaitHandle;

	internal CancellationToken(CancellationTokenSource source)
	{
		this.source = source;
	}

	public CancellationTokenRegistration Register(Action action)
	{
		return source?.Register(action) ?? default(CancellationTokenRegistration);
	}

	public override bool Equals(object? obj)
	{
		if (obj is CancellationToken cancellationToken)
		{
			return Equals(cancellationToken);
		}
		return false;
	}

	public bool Equals(CancellationToken cancellationToken)
	{
		return source == cancellationToken.source;
	}

	public override int GetHashCode()
	{
		return source?.GetHashCode() ?? 0;
	}

	public static bool operator ==(CancellationToken left, CancellationToken right)
	{
		return left.Equals(right);
	}

	public static bool operator !=(CancellationToken left, CancellationToken right)
	{
		return !(left == right);
	}
}