Update app.py

app.py

@@ -397,6 +397,63 @@ def unified_push_message(game_id, msg_obj):
 
 # ---------------------------
 # Push a new score to leaderboard
+def sync_firebase_leaderboard_to_csv():
+    """
+    Sync Firebase /leaderboard → local CSV.
+    Runs only in Online mode.
+    Prevents duplicate entries.
+    """
+
+    mode = st.session_state.get("mode_selection", "Offline")
+    if mode != "Online":
+        return
+
+    ok, msg = init_firebase_if_needed()
+    if not ok:
+        return
+
+    try:
+        # Fetch from Firebase
+        fb_data = fb_get("/leaderboard") or {}
+
+        if isinstance(fb_data, dict):
+            fb_rows = list(fb_data.values())
+        elif isinstance(fb_data, list):
+            fb_rows = fb_data
+        else:
+            fb_rows = []
+
+        if not fb_rows:
+            return
+
+        # Load existing CSV
+        if os.path.exists(LEADERBOARD_FILE):
+            csv_df = pd.read_csv(LEADERBOARD_FILE)
+        else:
+            csv_df = pd.DataFrame()
+
+        fb_df = pd.DataFrame(fb_rows)
+
+        # If CSV empty → just save
+        if csv_df.empty:
+            fb_df.to_csv(LEADERBOARD_FILE, index=False)
+            return
+
+        # Merge & remove duplicates
+        combined = pd.concat([csv_df, fb_df], ignore_index=True)
+
+        # Remove duplicates using unique combo
+        combined.drop_duplicates(
+            subset=["name", "game_id", "timestamp"],
+            keep="last",
+            inplace=True
+        )
+
+        combined.to_csv(LEADERBOARD_FILE, index=False)
+
+    except Exception as e:
+        st.warning(f"Leaderboard sync failed: {e}")
+
 # ---------------------------
 def unified_push_leaderboard(row):
     """