using System.Net;
using System.Net.Sockets;

using var listener = new Socket(SocketType.Stream, ProtocolType.Tcp);
listener.Bind(new IPEndPoint(IPAddress.Loopback, 9000));

Console.WriteLine($"Listening on {listener.LocalEndPoint}");

listener.Listen();

while (true)
{
  var connection = await listener.AcceptAsync();

  _ = Task.Run(async () =>
    {

      var buffer = new byte[4096];
      try
      {
        while (true)
        {
          int read = await connection.ReceiveAsync(buffer, SocketFlags.None);
          if (read == 0) break;

          var message = System.Text.Encoding.Default.GetString(buffer[..read]);

          Console.WriteLine($"Received new message: {message}");

          await connection.SendAsync(buffer[..read], SocketFlags.None);
        }
      }
      finally
      {
        connection.Dispose();
      }
    }
  );
}