Limit weather API calls to cron only, increase cache TTL to 24h

Web view was calling the OpenWeatherMap API directly on every request
(home + all trip locations), causing >1000 calls/day. Now web_view.py
uses cache_only=True everywhere so it never triggers live API calls —
update.py (cron) is the sole API caller. Also warms home location cache
in update_weather(), and increases TTL from 6h to 24h.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

agenda/weather.py

@@ -14,7 +14,7 @@ def _cache_path(data_dir: str, lat: float, lon: float) -> str:
     return os.path.join(weather_dir, f"{lat:.2f}_{lon:.2f}.json")
 
 
-def _is_fresh(path: str, max_age_hours: int = 6) -> bool:
+def _is_fresh(path: str, max_age_hours: int = 24) -> bool:
     """Return True if the cache file exists and is recent enough."""
     if not os.path.exists(path):
         return False
@@ -22,14 +22,30 @@ def _is_fresh(path: str, max_age_hours: int = 6) -> bool:
     return age < max_age_hours * 3600
 
 
-def get_forecast(data_dir: str, api_key: str, lat: float, lon: float) -> list[dict]:
+def get_forecast(
-    """Return 8-day daily forecast for lat/lon, caching results for 6 hours."""
+    data_dir: str,
+    api_key: str,
+    lat: float,
+    lon: float,
+    cache_only: bool = False,
+) -> list[dict]:
+    """Return 8-day daily forecast for lat/lon, caching results for 24 hours.
+
+    If cache_only=True, return cached data if available (even if stale) and
+    never call the API. Returns [] if no cache exists.
+    """
     cache_file = _cache_path(data_dir, lat, lon)
 
     if _is_fresh(cache_file):
         with open(cache_file) as f:
             return json.load(f)  # type: ignore[no-any-return]
 
+    if cache_only:
+        if os.path.exists(cache_file):
+            with open(cache_file) as f:
+                return json.load(f)  # type: ignore[no-any-return]
+        return []
+
     owm = pyowm.OWM(api_key)
     mgr = owm.weather_manager()
     result = mgr.one_call(lat=lat, lon=lon)
@@ -67,17 +83,23 @@ def trip_latlon(trip: object) -> tuple[float, float] | None:
     return None
 
 
-def get_trip_weather(data_dir: str, api_key: str, trip: object) -> dict[str, dict]:
+def get_trip_weather(
+    data_dir: str,
+    api_key: str,
+    trip: object,
+    cache_only: bool = False,
+) -> dict[str, dict]:
     """Return forecast for a trip keyed by date ISO string.
 
     Returns an empty dict if no location is known or the API call fails.
+    If cache_only=True, never call the API (returns stale or empty data).
     """
     latlon = trip_latlon(trip)
     if not latlon:
         return {}
     lat, lon = latlon
     try:
-        forecasts = get_forecast(data_dir, api_key, lat, lon)
+        forecasts = get_forecast(data_dir, api_key, lat, lon, cache_only=cache_only)
     except Exception:
         return {}
     return {f["date"]: f for f in forecasts}

update.py

@@ -410,7 +410,7 @@ def update_gandi(config: flask.config.Config) -> None:
 
 
 def update_weather(config: flask.config.Config) -> None:
-    """Refresh weather cache for all upcoming trips."""
+    """Refresh weather cache for home and all upcoming trips."""
     from datetime import date, timedelta
 
     today = date.today()
@@ -425,6 +425,20 @@ def update_weather(config: flask.config.Config) -> None:
 
     seen: set[tuple[float, float]] = set()
     count = 0
+
+    # Always include home location
+    home_lat = config.get("HOME_LATITUDE")
+    home_lon = config.get("HOME_LONGITUDE")
+    if home_lat is not None and home_lon is not None:
+        seen.add((home_lat, home_lon))
+        try:
+            agenda.weather.get_forecast(
+                config["DATA_DIR"], config["OPENWEATHERMAP_API_KEY"], home_lat, home_lon
+            )
+            count += 1
+        except Exception as exc:
+            print(f"weather update failed for home {home_lat},{home_lon}: {exc}")
+
     for trip in upcoming:
         latlon = agenda.weather.trip_latlon(trip)
         if not latlon or latlon in seen:

web_view.py

@@ -627,6 +627,7 @@ def get_home_weather() -> list[StrDict]:
         app.config.get("OPENWEATHERMAP_API_KEY", ""),
         app.config["HOME_LATITUDE"],
         app.config["HOME_LONGITUDE"],
+        cache_only=True,
     )
     for f in forecasts:
         f["date_obj"] = date_type.fromisoformat(f["date"])
@@ -729,6 +730,7 @@ def trip_future_list() -> str:
             app.config["DATA_DIR"],
             app.config.get("OPENWEATHERMAP_API_KEY", ""),
             trip,
+            cache_only=True,
         )
         for trip in shown
     }
@@ -1049,6 +1051,7 @@ def trip_page(start: str) -> str:
         app.config["DATA_DIR"],
         app.config.get("OPENWEATHERMAP_API_KEY", ""),
         trip,
+        cache_only=True,
     )
 
     return flask.render_template(