init

backend/app/services/sync.py

@@ -0,0 +1,48 @@
+from typing import Dict, Set
+from fastapi import WebSocket
+from uuid import UUID
+import json
+
+
+class ConnectionManager:
+    def __init__(self):
+        # room_id -> set of (websocket, user_id)
+        self.active_connections: Dict[UUID, Set[tuple[WebSocket, UUID]]] = {}
+
+    async def connect(self, websocket: WebSocket, room_id: UUID, user_id: UUID):
+        await websocket.accept()
+        if room_id not in self.active_connections:
+            self.active_connections[room_id] = set()
+        self.active_connections[room_id].add((websocket, user_id))
+
+    def disconnect(self, websocket: WebSocket, room_id: UUID, user_id: UUID):
+        if room_id in self.active_connections:
+            self.active_connections[room_id].discard((websocket, user_id))
+            if not self.active_connections[room_id]:
+                del self.active_connections[room_id]
+
+    async def broadcast_to_room(self, room_id: UUID, message: dict, exclude_user: UUID = None):
+        if room_id not in self.active_connections:
+            return
+
+        message_json = json.dumps(message, default=str)
+        disconnected = []
+
+        for websocket, user_id in self.active_connections[room_id]:
+            if exclude_user and user_id == exclude_user:
+                continue
+            try:
+                await websocket.send_text(message_json)
+            except Exception:
+                disconnected.append((websocket, user_id))
+
+        for conn in disconnected:
+            self.active_connections[room_id].discard(conn)
+
+    def get_room_user_count(self, room_id: UUID) -> int:
+        if room_id not in self.active_connections:
+            return 0
+        return len(self.active_connections[room_id])
+
+
+manager = ConnectionManager()