Added username validation

Auto hide enter/leave room
Username starts as UNNAMED now
Show roomnumber for connected room

PongGame/Hubs/PongHub.cs

@@ -21,7 +21,6 @@ public class PongHub : Hub<IPongClient> {
     public override Task OnConnectedAsync() {
         Player = Lobby.CreatePlayer();
         Player.Client = Clients.Client(Context.ConnectionId);
-        Player.Username = "Anon";
         return Task.CompletedTask;
     }
 
@@ -42,10 +41,10 @@ public class PongHub : Hub<IPongClient> {
         return Task.FromResult(room.ID);
     }
 
-    public Task<string> JoinRoom(string roomId) {
+    public async Task<string> JoinRoom(string roomId) {
         AssertNotInRoom();
-        var room = Lobby.JoinRoom(Player, roomId);
-        return Task.FromResult(room.ID);
+        var room = await Lobby.JoinRoom(Player, roomId);
+        return room.ID;
     }
 
     public Task MovePaddle(int dir) {
@@ -53,21 +52,14 @@ public class PongHub : Hub<IPongClient> {
         var direction = (PongPaddleDirection)dir;
         if (!Enum.IsDefined(direction))
             throw new HubException($"Invalid direction: {dir}!");
-        room.MovePaddle(Player, direction);
-        return Task.CompletedTask;
+        return room.MovePaddle(Player, direction);
     }
 
-    public Task LeaveRoom() {
-        Lobby.LeaveRoom(Player);
-        return Task.CompletedTask;
-    }
+    public Task LeaveRoom()
+        => Lobby.LeaveRoom(Player);
 
-    public Task RequestUsernameChange(string username) {
-        // TOOD: check this
-        Logger.LogInformation("Player {Player} requested username change to [{username}]", Player, username);
-        Player.Username = username;
-        return Task.CompletedTask;
-    }
+    public Task RequestUsernameChange(string username)
+        => Lobby.ChangeUsername(Player, username);
 
     public override Task OnDisconnectedAsync(Exception? exception) {
         Lobby.RemovePlayer(Player);

PongGame/Hubs/PongLobbyCollection.cs

@@ -1,4 +1,6 @@
-using Microsoft.AspNetCore.SignalR;
+using System.Numerics;
+using System.Text.RegularExpressions;
+using Microsoft.AspNetCore.SignalR;
 
 namespace PongGame.Hubs;
 
@@ -35,19 +37,24 @@ public class PongLobby {
         return room;
     }
 
-    public PongRoom JoinRoom(PongPlayer player, string roomId) {
+    public Task<PongRoom> JoinRoom(PongPlayer player, string roomId) {
         PongRoom? room;
         lock (PongRooms) {
             room = PongRooms.GetValueOrDefault(roomId);
         }
         if (room is null) throw new HubException($"Room [{roomId}] not found!");
         room.Join(player);
-        return room;
+        return Task.FromResult(room);
     }
 
-    public void LeaveRoom(PongPlayer player) {
-        if (player.ConnectedRoom is PongRoom room)
+    public Task LeaveRoom(PongPlayer player) {
+        if (player.ConnectedRoom is PongRoom room) {
             room.Leave(player);
+            if (room.IsEmpty)
+                lock (PongRooms)
+                    _ = PongRooms.Remove(room.ID);
+        }
+        return Task.CompletedTask;
     }
 
     private readonly Random random = new();
@@ -61,4 +68,28 @@ public class PongLobby {
         } while (PongRooms.ContainsKey(id));
         return id;
     }
+
+    public async Task ChangeUsername(PongPlayer player, string username) {
+        username = ValidateUsername(username);
+        if (player.Username == username) {
+            await player.Client.UsernameChanged(username);
+            return;
+        }
+        lock (connectedPlayers) {
+            // TODO: separate hashset for usernames
+            if (connectedPlayers.Select(i => i.Username).Contains(username))
+                throw new HubException($"Username {username} is already taken!");
+        }
+        Logger.LogInformation("Player {Player} requested username change to [{username}]", player, username);
+        player.Username = username;
+    }
+
+    private static readonly Regex UsernameRegex = new(@"^(?!.*[._ -]{2})[\w._ -]{3,20}$", RegexOptions.Compiled, TimeSpan.FromMilliseconds(200));
+
+    private static string ValidateUsername(string username) {
+        username = username.Trim();
+        if (!UsernameRegex.IsMatch(username))
+            throw new HubException($"At most 20 characters, no two consecutive symbols");
+        return username;
+    }
 }

PongGame/Hubs/PongPlayer.cs

@@ -4,7 +4,7 @@ namespace PongGame.Hubs;
 
 [DebuggerDisplay($"{{{nameof(ToString)}(),nq}}")]
 public class PongPlayer {
-    private string username = default!;
+    private string username = "UNNAMED";
 
     public PongRoom? ConnectedRoom { get; internal set; }
     public string Username {

PongGame/Hubs/PongRoom.cs

@@ -18,6 +18,8 @@ public class PongRoom {
 
     public PongPlayer? Player1 { get; private set; }
     public PongPlayer? Player2 { get; private set; }
+    public bool IsEmpty => Player1 is null && Player2 is null;
+
     private PongGameState State = PongGameState.Initial;
 
     public void Join(PongPlayer player) {
@@ -67,7 +69,7 @@ public class PongRoom {
         if (Player1 is PongPlayer player1 && Player2 is PongPlayer player2) {
             Logger.LogInformation("[{ID}] Pong game started: {player1} vs. {player2}", ID, player1, player2);
             ResumeGame();
-        } else if (Player1 is null && Player2 is null) {
+        } else if (IsEmpty) {
             CloseRoom();
         } else
             PauseGame();
@@ -84,16 +86,15 @@ public class PongRoom {
 
     public override string ToString() => $"[{ID}]";
 
-    public void MovePaddle(PongPlayer player, PongPaddleDirection direction) {
+    public Task MovePaddle(PongPlayer player, PongPaddleDirection direction) {
         if (Player1 == player) {
             State.Paddle1.Direction = direction;
             Logger.LogDebug(DIRECTION_LOG_TEMPLATE, ID, 1, player, direction);
-            return;
         } else if (Player2 == player) {
             State.Paddle2.Direction = direction;
             Logger.LogDebug(DIRECTION_LOG_TEMPLATE, ID, 2, player, direction);
-            return;
-        }
-        throw new InvalidOperationException("Player is not in this room, but moved! Assumably players room wasn't deleted.");
+        } else
+            throw new InvalidOperationException("Player is not in this room, but moved! Assumably players room wasn't deleted.");
+        return Task.CompletedTask;
     }
 }