Add weekend availability view

Closes: #130

agenda/data.py

@@ -287,9 +287,10 @@ async def time_function(
     return name, result, end_time - start_time, exception
 
 
-def gap_list(
+def get_busy_events(
     today: date, config: flask.config.Config, trips: list[Trip]
-) -> list[StrDict]:
+) -> list[Event]:
+    """Find busy events from a year ago to two years in the future."""
     last_year = today - timedelta(days=365)
     next_year = today + timedelta(days=2 * 365)
 
@@ -311,6 +312,7 @@ def gap_list(
                 url=flask.url_for("trip_page", start=trip.start.isoformat()),
             )
         )
+    # pprint(events)
 
     busy_events = [
         e
@@ -318,7 +320,41 @@ def gap_list(
         if e.as_date > today and e.as_date < next_year and busy_event(e)
     ]
 
-    return find_gaps(busy_events)
+    return busy_events
+
+
+def weekends(busy_events: list[Event]) -> typing.Sequence[StrDict]:
+    """Next ten weekends."""
+    today = datetime.today()
+    weekday = today.weekday()
+
+    # Calculate the difference to the next or previous Saturday
+    if weekday == 6:  # Sunday
+        start_date = (today - timedelta(days=1)).date()
+    else:
+        start_date = (today + timedelta(days=(5 - weekday))).date()
+
+    weekends_info = []
+    for i in range(52):
+        saturday = start_date + timedelta(weeks=i)
+        sunday = saturday + timedelta(days=1)
+
+        saturday_events = [
+            event
+            for event in busy_events
+            if event.end_date and event.as_date <= saturday <= event.end_as_date
+        ]
+        sunday_events = [
+            event
+            for event in busy_events
+            if event.end_date and event.as_date <= sunday <= event.end_as_date
+        ]
+
+        weekends_info.append(
+            {"date": saturday, "saturday": saturday_events, "sunday": sunday_events}
+        )
+
+    return weekends_info
 
 
 async def get_data(