WIP: EventDays rework

api/advent22_api/core/helpers.py

@@ -72,6 +72,61 @@ async def api_return_image(img: Image.Image) -> StreamingResponse:
     )
 
 
+class EventDays2:
+    """
+    Events in einem Ereigniszeitraum
+    """
+
+    __overall_duration: timedelta
+    __events: dict[int, date]
+
+    def first(self) -> date:
+        """Datum des ersten Ereignisses"""
+        return self.__events[min(self.__events.keys())]
+
+    def last(self) -> date:
+        """Datum des letzten Ereignisses"""
+        return self.__events[max(self.__events.keys())]
+
+    def end(self) -> date:
+        """Letztes Datum des Ereigniszeitraums"""
+        return self.__events[max(self.__events.keys())]
+
+    def __init__(
+        self,
+        *,
+        # current date
+        today: date,
+        # month/day when events begin
+        begin_month: int,
+        begin_day: int,
+        # events: e.g. a 2 means there is an event 2 days after begin
+        # -> assume sorted (asc)
+        events_after: list[int],
+        # countdown to closing begins after last event
+        closing_after: int,
+    ) -> None:
+        # account for the last event, then add closing period
+        self.__overall_duration = timedelta(days=events_after[-1] + closing_after)
+
+        # the events may begin last year, this year or next year
+        maybe_begin = (
+            datetime(today.year + year_diff, begin_month, begin_day).date()
+            for year_diff in (-1, 0, +1)
+        )
+
+        # find the first begin where the end date is in the future
+        begin = next(
+            begin for begin in maybe_begin if today <= (begin + self.__overall_duration)
+        )
+
+        # all event dates
+        self.__events = {
+            event_after: begin + timedelta(days=event_after - 1)
+            for event_after in events_after
+        }
+
+
 class EventDays(BaseModel):
     """
     Kenndaten eines Ereigniszeitraums: