Enhance leave request handling and improve error logging in RotaBuilder

rota/shifts.py

@@ -431,6 +431,8 @@ class RotaBuilder(object):
 
         self.exported_rota_file = None
 
+        self.enable_unavailabilities = True
+
         self.MAX_SHIFTS_PER_DAY = 2
 
     def set_rota_constraint(self, constraint: str, value: Any):
@@ -987,6 +989,10 @@ class RotaBuilder(object):
                                     f"Worker '{worker.name}' has a forced assignment for shift '{shift_name}' on week {week}, day {day} (date: {self.get_date_by_week_day(week, day)}), which conflicts with a leave request.",
                                 )
 
+        if not self.enable_unavailabilities:
+            self.unavailable_to_work = set()
+            self.unavailable_to_work_reason = {}
+
         def availability_init(model, wid, week, day):
             # This needs to be higher than the max number of possible shifts per day
             if (wid, week, day) in self.unavailable_to_work:
@@ -3462,7 +3468,14 @@ class RotaBuilder(object):
         return self.shifts_by_name[name].length
 
     def get_date_by_week_day(self, week: WeekInt, day: DayStr) -> datetime.date:
-        return self.week_day_date_map[(week, day)]
+        try:
+            return self.week_day_date_map[(week, day)]
+        except KeyError:
+            self.add_warning(
+                "Rota/week day date map",
+                f"Week {week}, Day {day} not found in week_day_date_map",
+            )
+            return datetime.date(1900, 1, 1)
 
     def get_weeks_by_date_range(self, start_date: datetime.date | None, end_date: datetime.date | None) -> list[WeekInt]:
         """Get a list of weeks that fall within a date range.