Various improvements

agenda/data.py

@@ -3,13 +3,13 @@
 import asyncio
 import os
 import typing
-from datetime import date, datetime, timedelta
+from datetime import date, datetime, timedelta, timezone
 from time import time
 
 import dateutil.rrule
 import dateutil.tz
 import flask
-import lxml
+import lxml  # type: ignore[import-untyped]
 import pytz
 
 from . import (
@@ -68,7 +68,7 @@ async def n_somerset_waste_collection_events(
     html = await n_somerset_waste.get_html(data_dir, postcode, uprn, force_cache)
     root = lxml.html.fromstring(html)
     events = n_somerset_waste.parse(root)
-    return events
+    return typing.cast(list[Event], events)
 
 
 async def bristol_waste_collection_events(
@@ -76,7 +76,9 @@ async def bristol_waste_collection_events(
 ) -> list[Event]:
     """Waste colllection events."""
     cache = "force" if force_cache else "recent"
-    return await bristol_waste.get(start_date, data_dir, uprn, cache)
+    return typing.cast(
+        list[Event], await bristol_waste.get(start_date, data_dir, uprn, cache)
+    )
 
 
 def find_events_during_stay(
@@ -168,6 +170,14 @@ def rocket_launch_events(rockets: list[thespacedevs.Summary]) -> list[Event]:
     return events
 
 
+def event_sort_datetime(event: Event) -> datetime:
+    """Return a timezone-normalized datetime suitable for sorting events."""
+    dt = typing.cast(datetime, event.as_datetime)
+    if dt.tzinfo is None or dt.utcoffset() is None:
+        return dt
+    return dt.astimezone(timezone.utc).replace(tzinfo=None)
+
+
 async def get_data(now: datetime, config: flask.config.Config) -> AgendaData:
     """Get data to display on agenda dashboard."""
     data_dir = config["DATA_DIR"]
@@ -290,7 +300,7 @@ async def get_data(now: datetime, config: flask.config.Config) -> AgendaData:
     # at the top of the list for today. This is achieved by sorting first by
     # the datetime attribute, and then ensuring that events with the name
     # "today" are ordered before others on the same date.
-    events.sort(key=lambda e: (e.as_datetime, e.name != "today"))
+    events.sort(key=lambda e: (event_sort_datetime(e), e.name != "today"))
 
     reply["gaps"] = gaps