Rewrote Networking and Base Lobby Created

- Rewrote networking based on tutorials from MLAPI Demo Project and
  Dapper Dino
- Created Lobby UI based on the turorial from Dapper Dino
- Linked Existing UI into using the new networking
- Modified Lobby Settings to only allow 3 players
- Added Field for players to enter their player name

Assets/Scripts/Network/ServerGameNetPortal.cs

@@ -0,0 +1,241 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Text;
+using MLAPI;
+using MLAPI.SceneManagement;
+using MLAPI.Spawning;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+
+public class ServerGameNetPortal : MonoBehaviour {
+
+    [Header("Settings")]
+    [SerializeField] private int maxPlayers = 3;
+
+    public static ServerGameNetPortal Instance => instance;
+    private static ServerGameNetPortal instance;
+
+    private Dictionary<string, PlayerData> clientData;
+    private Dictionary<ulong, string> clientIdToGuid;
+    private Dictionary<ulong, int> clientSceneMap;
+    private bool gameInProgress;
+
+    private const int MaxConnectionPayload = 1024;
+
+    private GameNetPortal gameNetPortal;
+
+    private void Awake()
+    {
+        if (instance != null && instance != this)
+        {
+            Destroy(gameObject);
+            return;
+        }
+
+        instance = this;
+        DontDestroyOnLoad(gameObject);
+    }
+
+    private void Start()
+    {
+        gameNetPortal = GetComponent<GameNetPortal>();
+        gameNetPortal.OnNetworkReadied += HandleNetworkReadied;
+
+        NetworkManager.Singleton.ConnectionApprovalCallback += ApprovalCheck;
+        NetworkManager.Singleton.OnServerStarted += HandleServerStarted;
+
+        clientData = new Dictionary<string, PlayerData>();
+        clientIdToGuid = new Dictionary<ulong, string>();
+        clientSceneMap = new Dictionary<ulong, int>();
+    }
+
+    private void OnDestroy()
+    {
+        if (gameNetPortal == null) { return; }
+
+        gameNetPortal.OnNetworkReadied -= HandleNetworkReadied;
+
+        if (NetworkManager.Singleton == null) { return; }
+
+        NetworkManager.Singleton.ConnectionApprovalCallback -= ApprovalCheck;
+        NetworkManager.Singleton.OnServerStarted -= HandleServerStarted;
+    }
+
+    public PlayerData? GetPlayerData(ulong clientId)
+    {
+        if (clientIdToGuid.TryGetValue(clientId, out string clientGuid))
+        {
+            if (clientData.TryGetValue(clientGuid, out PlayerData playerData))
+            {
+                return playerData;
+            }
+            else
+            {
+                Debug.LogWarning($"No player data found for client id: {clientId}");
+            }
+        }
+        else
+        {
+            Debug.LogWarning($"No client guid found for client id: {clientId}");
+        }
+
+        return null;
+    }
+
+    public void StartGame()
+    {
+        gameInProgress = true;
+
+        NetworkSceneManager.SwitchScene("Game");
+    }
+
+    public void EndRound()
+    {
+        gameInProgress = false;
+
+        NetworkSceneManager.SwitchScene("Lobby");
+    }
+
+    private void HandleNetworkReadied()
+    {
+        if (!NetworkManager.Singleton.IsServer) { return; }
+
+        gameNetPortal.OnUserDisconnectRequested += HandleUserDisconnectRequested;
+        NetworkManager.Singleton.OnClientDisconnectCallback += HandleClientDisconnect;
+        gameNetPortal.OnClientSceneChanged += HandleClientSceneChanged;
+
+        NetworkSceneManager.SwitchScene("Lobby");
+
+        if (NetworkManager.Singleton.IsHost)
+        {
+            clientSceneMap[NetworkManager.Singleton.LocalClientId] = SceneManager.GetActiveScene().buildIndex;
+        }
+    }
+
+    private void HandleClientDisconnect(ulong clientId)
+    {
+        clientSceneMap.Remove(clientId);
+
+        if (clientIdToGuid.TryGetValue(clientId, out string guid))
+        {
+            clientIdToGuid.Remove(clientId);
+
+            if (clientData[guid].ClientId == clientId)
+            {
+                clientData.Remove(guid);
+            }
+        }
+
+        if (clientId == NetworkManager.Singleton.LocalClientId)
+        {
+            gameNetPortal.OnUserDisconnectRequested -= HandleUserDisconnectRequested;
+            NetworkManager.Singleton.OnClientDisconnectCallback -= HandleClientDisconnect;
+            gameNetPortal.OnClientSceneChanged -= HandleClientSceneChanged;
+        }
+    }
+
+    private void HandleClientSceneChanged(ulong clientId, int sceneIndex)
+    {
+        clientSceneMap[clientId] = sceneIndex;
+    }
+
+    private void HandleUserDisconnectRequested()
+    {
+        HandleClientDisconnect(NetworkManager.Singleton.LocalClientId);
+
+        NetworkManager.Singleton.StopHost();
+
+        ClearData();
+
+        SceneManager.LoadScene("TitleScene");
+    }
+
+    private void HandleServerStarted()
+    {
+        if (!NetworkManager.Singleton.IsHost) { return; }
+
+        string clientGuid = Guid.NewGuid().ToString();
+        string playerName = PlayerPrefs.GetString("PlayerName", "Missing Name");
+
+        clientData.Add(clientGuid, new PlayerData(playerName, NetworkManager.Singleton.LocalClientId));
+        clientIdToGuid.Add(NetworkManager.Singleton.LocalClientId, clientGuid);
+    }
+
+    private void ClearData()
+    {
+        clientData.Clear();
+        clientIdToGuid.Clear();
+        clientSceneMap.Clear();
+
+        gameInProgress = false;
+    }
+
+    private void ApprovalCheck(byte[] connectionData, ulong clientId, NetworkManager.ConnectionApprovedDelegate callback)
+    {
+        if (connectionData.Length > MaxConnectionPayload)
+        {
+            callback(false, 0, false, null, null);
+            return;
+        }
+
+        string payload = Encoding.UTF8.GetString(connectionData);
+        var connectionPayload = JsonUtility.FromJson<ConnectionPayload>(payload);
+
+        ConnectStatus gameReturnStatus = ConnectStatus.Success;
+
+        // This stops us from running multiple standalone builds since 
+        // they disconnect eachother when trying to join
+        //
+        // if (clientData.ContainsKey(connectionPayload.clientGUID))
+        // {
+        //     ulong oldClientId = clientData[connectionPayload.clientGUID].ClientId;
+        //     StartCoroutine(WaitToDisconnectClient(oldClientId, ConnectStatus.LoggedInAgain));
+        // }
+
+        if (gameInProgress)
+        {
+            gameReturnStatus = ConnectStatus.GameInProgress;
+        }
+        else if (clientData.Count >= maxPlayers)
+        {
+            gameReturnStatus = ConnectStatus.ServerFull;
+        }
+
+        if (gameReturnStatus == ConnectStatus.Success)
+        {
+            clientSceneMap[clientId] = connectionPayload.clientScene;
+            clientIdToGuid[clientId] = connectionPayload.clientGUID;
+            clientData[connectionPayload.clientGUID] = new PlayerData(connectionPayload.playerName, clientId);
+        }
+
+        callback(false, 0, true, null, null);
+
+        gameNetPortal.ServerToClientConnectResult(clientId, gameReturnStatus);
+
+        if (gameReturnStatus != ConnectStatus.Success)
+        {
+            StartCoroutine(WaitToDisconnectClient(clientId, gameReturnStatus));
+        }
+    }
+
+    private IEnumerator WaitToDisconnectClient(ulong clientId, ConnectStatus reason)
+    {
+        gameNetPortal.ServerToClientSetDisconnectReason(clientId, reason);
+
+        yield return new WaitForSeconds(0);
+
+        KickClient(clientId);
+    }
+
+    private void KickClient(ulong clientId)
+    {
+        NetworkObject networkObject = NetworkSpawnManager.GetPlayerNetworkObject(clientId);
+        if (networkObject != null)
+        {
+            networkObject.Despawn(true);
+        }
+
+        NetworkManager.Singleton.DisconnectClient(clientId);
+    }
+}