NatTypeTester/STUN/StunServer.cs

using System.Diagnostics.CodeAnalysis;
using System.Net;
using System.Net.Sockets;

namespace STUN;

public class StunServer
{
	public string Hostname { get; }
	public ushort Port { get; }

	private const ushort DefaultPort = 3478;

	public StunServer()
	{
		Hostname = @"stun.syncthing.net";
		Port = DefaultPort;
	}

	private StunServer(string hostname, ushort port)
	{
		Hostname = hostname;
		Port = port;
	}

	public static bool TryParse(string s, [NotNullWhen(true)] out StunServer? result)
	{
		if (!HostnameEndpoint.TryParse(s, out var host, DefaultPort))
		{
			result = null;
			return false;
		}

		result = new StunServer(host.Hostname, host.Port);
		return true;
	}

	public override string ToString()
	{
		if (Port is DefaultPort)
		{
			return Hostname;
		}
		if (IPAddress.TryParse(Hostname, out var ip) && ip.AddressFamily is AddressFamily.InterNetworkV6)
		{
			return $@"[{ip}]:{Port}";
		}
		return $@"{Hostname}:{Port}";
	}
}