fallback missing Telegram city topics

src/utils/telegram_push.py

@@ -1733,6 +1733,7 @@ def _process_airport_city(
     # Send to all target chats
     sent = False
     for chat_id in chat_ids:
+        thread_id = 0
         try:
             kwargs = {}
             thread_id = _resolve_thread_id(chat_id, city)
@@ -1741,6 +1742,25 @@ def _process_airport_city(
             _rate_limited_send(bot, chat_id, message, **kwargs)
             sent = True
         except Exception as exc:
+            if thread_id and "message thread not found" in str(exc).lower():
+                logger.warning(
+                    "airport push thread missing; retrying main chat city={} chat_id={} thread_id={}",
+                    city,
+                    chat_id,
+                    thread_id,
+                )
+                try:
+                    _rate_limited_send(bot, chat_id, message)
+                    sent = True
+                    continue
+                except Exception as fallback_exc:
+                    logger.warning(
+                        "airport push main chat fallback failed city={} chat_id={}: {}",
+                        city,
+                        chat_id,
+                        fallback_exc,
+                    )
+                    continue
             logger.warning("airport push failed city={} chat_id={}: {}", city, chat_id, exc)
 
     if sent:

tests/test_telegram_hashtags.py

@@ -405,6 +405,48 @@ def test_airport_push_rejects_observation_older_than_last_push(monkeypatch):
     assert result is None
 
 
+def test_airport_push_retries_main_chat_when_forum_thread_is_missing(monkeypatch):
+    import src.utils.telegram_push as telegram_push
+
+    calls = []
+
+    monkeypatch.setattr(
+        telegram_push,
+        "_load_airport_city_weather_for_push",
+        lambda _city: {
+            "local_time": "15:22",
+            "current": {"temp": 30.0},
+            "deb": {"prediction": 31.0},
+            "airport_primary": {
+                "temp": 30.0,
+                "obs_time": "2026-06-11T07:52:00+00:00",
+            },
+        },
+    )
+    monkeypatch.setattr(telegram_push, "_resolve_thread_id", lambda _chat, _city: 99)
+
+    def fake_send(_bot, chat_id, _message, **kwargs):
+        calls.append((chat_id, kwargs))
+        if kwargs.get("message_thread_id"):
+            raise RuntimeError("Bad Request: message thread not found")
+
+    monkeypatch.setattr(telegram_push, "_rate_limited_send", fake_send)
+
+    result = telegram_push._process_airport_city(
+        "shenzhen",
+        now_ts=1781164400,
+        last_city={},
+        chat_ids=["chat-1"],
+        bot=object(),
+    )
+
+    assert result is not None
+    assert calls == [
+        ("chat-1", {"message_thread_id": 99}),
+        ("chat-1", {}),
+    ]
+
+
 def test_high_freq_airport_push_workers_default_to_one_for_shared_cpu(monkeypatch):
     source = Path("src/utils/telegram_push.py").read_text(encoding="utf-8")
     assert 'TELEGRAM_AIRPORT_PUSH_MAX_WORKERS", 1' in source