✨ Chat room subscribe

DysonNetwork.Sphere/Connection/WebSocketService.cs

@@ -17,6 +17,31 @@ public class WebSocketService
         (WebSocket Socket, CancellationTokenSource Cts)
     > ActiveConnections = new();
 
+    private static readonly ConcurrentDictionary<string, string> ActiveSubscriptions = new(); // deviceId -> chatRoomId
+
+    public void SubscribeToChatRoom(string chatRoomId, string deviceId)
+    {
+        ActiveSubscriptions[deviceId] = chatRoomId;
+    }
+
+    public void UnsubscribeFromChatRoom(string deviceId)
+    {
+        ActiveSubscriptions.TryRemove(deviceId, out _);
+    }
+
+    public bool IsUserSubscribedToChatRoom(Guid accountId, string chatRoomId)
+    {
+        var userDeviceIds = ActiveConnections.Keys.Where(k => k.AccountId == accountId).Select(k => k.DeviceId);
+        foreach (var deviceId in userDeviceIds)
+        {
+            if (ActiveSubscriptions.TryGetValue(deviceId, out var subscribedChatRoomId) && subscribedChatRoomId == chatRoomId)
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
     public bool TryAdd(
         (Guid AccountId, string DeviceId) key,
         WebSocket socket,
@@ -39,6 +64,7 @@ public class WebSocketService
         );
         data.Cts.Cancel();
         ActiveConnections.TryRemove(key, out _);
+        UnsubscribeFromChatRoom(key.DeviceId);
     }
 
     public bool GetAccountIsConnected(Guid accountId)