station_obscurum_unity/Assets/Scripts/Steam/SteamLobbyManager.cs

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Steamworks;
using Steamworks.Data;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.UI;


    public class SteamLobbyManager : MonoBehaviour
    {
        public static Lobby CurrentLobby;
        public static bool UserInLobby;
        public UnityEvent onLobbyCreated;
        public UnityEvent onLobbyJoined;
        public UnityEvent onLobbyLeave;


        public GameObject inLobbyFriend;
        public Transform content;

        public Dictionary<SteamId, GameObject> inLobby = new();

        private void Start()
        {
            DontDestroyOnLoad(this);

            SteamMatchmaking.OnLobbyCreated += OnLobbyCreatedCallBack;
            SteamMatchmaking.OnLobbyEntered += OnLobbyEntered;
            SteamMatchmaking.OnLobbyMemberJoined += OnLobbyMemberJoined;
            SteamMatchmaking.OnChatMessage += OnChatMessage;
            SteamMatchmaking.OnLobbyMemberDisconnected += OnLobbyMemberDisconnected;
            SteamMatchmaking.OnLobbyMemberLeave += OnLobbyMemberDisconnected;
            SteamMatchmaking.OnLobbyGameCreated += OnLobbyGameCreated;
            SteamFriends.OnGameLobbyJoinRequested += OnGameLobbyJoinRequest;
            SteamMatchmaking.OnLobbyInvite += OnLobbyInvite;
        }

        private void OnLobbyInvite(Friend friend, Lobby lobby)
        {
            Debug.Log($"{friend.Name} invited you to his lobby.");
        }


        private void OnLobbyGameCreated(Lobby lobby, uint ip, ushort port, SteamId id)
        {
        }

        private async void OnLobbyMemberJoined(Lobby lobby, Friend friend)
        {
            Debug.Log($"{friend.Name} joined the lobby");
            var obj = Instantiate(inLobbyFriend, content);
            obj.GetComponentInChildren<Text>().text = friend.Name;
            obj.GetComponentInChildren<RawImage>().texture =
                await SteamFriendsManager.GetTextureFromSteamIdAsync(friend.Id);
            inLobby.Add(friend.Id, obj);
        }

        private void OnLobbyMemberDisconnected(Lobby lobby, Friend friend)
        {
            Debug.Log($"{friend.Name} left the lobby");
            Debug.Log($"New lobby owner is {CurrentLobby.Owner}");
            if (inLobby.ContainsKey(friend.Id))
            {
                Destroy(inLobby[friend.Id]);
                inLobby.Remove(friend.Id);
            }
        }

        private void OnChatMessage(Lobby lobby, Friend friend, string message)
        {
            Debug.Log($"incoming chat message from {friend.Name} : {message}");
        }

        private async void OnGameLobbyJoinRequest(Lobby joinedLobby, SteamId id)
        {
            var joinedLobbySuccess = await joinedLobby.Join();
            if (joinedLobbySuccess != RoomEnter.Success)
                Debug.Log("failed to join lobby : " + joinedLobbySuccess);
            else
                CurrentLobby = joinedLobby;
        }

        private void OnLobbyCreatedCallBack(Result result, Lobby lobby)
        {
            if (result != Result.OK)
            {
                Debug.Log("lobby creation result not ok : " + result);
            }
            else
            {
                onLobbyCreated.Invoke();
                Debug.Log("lobby creation result ok");
            }
        }

        private async void OnLobbyEntered(Lobby lobby)
        {
            Debug.Log("Client joined the lobby");
            UserInLobby = true;
            foreach (var user in inLobby.Values) Destroy(user);
            inLobby.Clear();

            var obj = Instantiate(inLobbyFriend, content);
            obj.GetComponentInChildren<Text>().text = SteamClient.Name;
            obj.GetComponentInChildren<RawImage>().texture =
                await SteamFriendsManager.GetTextureFromSteamIdAsync(SteamClient.SteamId);

            inLobby.Add(SteamClient.SteamId, obj);

            foreach (var friend in CurrentLobby.Members)
                if (friend.Id != SteamClient.SteamId)
                {
                    var obj2 = Instantiate(inLobbyFriend, content);
                    obj2.GetComponentInChildren<Text>().text = friend.Name;
                    obj2.GetComponentInChildren<RawImage>().texture =
                        await SteamFriendsManager.GetTextureFromSteamIdAsync(friend.Id);

                    inLobby.Add(friend.Id, obj2);
                }

            onLobbyJoined.Invoke();
        }


        public async void CreateLobbyAsync()
        {
            var result = await CreateLobby();
            if (!result)
            {
                //Invoke a error message.
            }
        }

        public static async Task<bool> CreateLobby()
        {
            try
            {
                var createLobbyOutput = await SteamMatchmaking.CreateLobbyAsync();
                if (!createLobbyOutput.HasValue)
                {
                    Debug.Log("Lobby created but not correctly instantiated.");
                    return false;
                }

                CurrentLobby = createLobbyOutput.Value;

                CurrentLobby.SetPublic();
                //currentLobby.SetPrivate();
                CurrentLobby.SetJoinable(true);

                return true;
            }
            catch (Exception exception)
            {
                Debug.Log("Failed to create multiplayer lobby : " + exception);
                return false;
            }
        }

        public void LeaveLobby()
        {
            try
            {
                UserInLobby = false;
                CurrentLobby.Leave();
                onLobbyLeave.Invoke();
                foreach (var user in inLobby.Values) Destroy(user);
                inLobby.Clear();
            }
            catch
            {
            }
        }
    }