internal class InternalListener : PausableFtpService, IListenerService
    {
        private readonly Channel<TcpClient> channels = System.Threading.Channels.Channel.CreateBounded<TcpClient>(1);
        private CancellationTokenSource cts;
        private TcpClient client;

        public InternalListener(CancellationTokenSource cts, TcpClient client) : base(cts.Token)
        {
            this.cts = cts;
            this.client = client;
        }

        public ChannelReader<TcpClient> Channel => channels;
        public CancellationToken Token => cts.Token;
        public bool IsCancellationRequested => cts.IsCancellationRequested;
        public event EventHandler<ListenerStartedEventArgs> ListenerStarted;

        public void Cancel(bool throwOnFirstException)
        {
            cts.Cancel(throwOnFirstException);
        }

        public void Dispose()
        {
            cts.Cancel();
            cts.Dispose();
        }

        protected override async Task ExecuteAsync(CancellationToken cancellationToken)
        {
            try
            {
                ListenerStarted?.Invoke(this, new ListenerStartedEventArgs((client.Client.LocalEndPoint as IPEndPoint).Port));
                await channels.Writer.WriteAsync(client, cancellationToken).ConfigureAwait(false);
            }
            catch (Exception ex) when (ex is OperationCanceledException)
            {
                // Ignore - everything is fine
            }
        }
    }