Handle existing amends on LessonEvents

aleksis/apps/untis/util/mysql/importers/absences.py

@@ -21,6 +21,7 @@ from ..util import (
     move_weekday_to_range,
     run_default_filter,
     untis_date_to_date,
+    update_or_create_lesson_event,
 )
 
 logger = logging.getLogger(__name__)
@@ -151,7 +152,7 @@ def import_absences(
 
             for affected_event in affected_events:
                 ref_object = affected_event["REFERENCE_OBJECT"]
-                amending_event, __ = LessonEvent.objects.update_or_create(
+                amending_event = update_or_create_lesson_event(
                     amends=ref_object,
                     datetime_start=affected_event["DTSTART"].dt,
                     datetime_end=affected_event["DTEND"].dt,
@@ -159,6 +160,7 @@ def import_absences(
                 )
                 amending_event.extended_data["cancelled_by_absence_untis"] = import_ref
                 amending_event.save()
+
                 logging.info(
                     f"  Cancel lesson event {ref_object.id} from {affected_event['DTSTART'].dt} "
                     f"to {affected_event['DTEND'].dt} with event {amending_event.id}"

aleksis/apps/untis/util/mysql/importers/substitutions.py

@@ -15,6 +15,7 @@ from ..util import (
     run_default_filter,
     untis_date_to_date,
     untis_split_first,
+    update_or_create_lesson_event,
 )
 
 logger = logging.getLogger(__name__)
@@ -156,30 +157,21 @@ def import_substitutions(
                 datetime_start = lesson.slot_start.get_datetime_start(date)
                 datetime_end = lesson.slot_end.get_datetime_end(date)
 
-                (
-                    substitution,
-                    created,
-                ) = (
-                    LessonEvent.objects.select_related(None)
-                    .prefetch_related(None)
-                    .update_or_create(
-                        amends=lesson.lesson_event,
-                        extended_data__substitution_ref_untis=sub_id,
-                        defaults={
-                            "datetime_start": datetime_start,
-                            "datetime_end": datetime_end,
-                            "subject": subject_new,
-                            "cancelled": cancelled,
-                            "comment": comment,
-                            "slot_number_start": lesson.slot_start.period,
-                            "slot_number_end": lesson.slot_end.period,
-                        },
-                    )
+                substitution = update_or_create_lesson_event(
+                    amends=lesson.lesson_event,
+                    datetime_start=datetime_start,
+                    datetime_end=datetime_end,
+                    defaults={
+                        "datetime_start": datetime_start,
+                        "datetime_end": datetime_end,
+                        "subject": subject_new,
+                        "cancelled": cancelled,
+                        "comment": comment,
+                        "slot_number_start": lesson.slot_start.period,
+                        "slot_number_end": lesson.slot_end.period,
+                    },
                 )
 
-                if created:
-                    logger.info("  Substitution created")
-
                 # Sync teachers
                 substitution.teachers.set(teachers)
                 substitution.rooms.set(rooms)

aleksis/apps/untis/util/mysql/util.py

@@ -6,7 +6,9 @@ from typing import Any, Callable, Optional, Sequence, Type, Union
 
 from django.db.models import Model, QuerySet
 
+from aleksis.apps.chronos.models import LessonEvent
 from aleksis.apps.lesrooster.models import ValidityRange
+from aleksis.core.models import CalendarEvent
 
 DB_NAME = "untis"
 UNTIS_DATE_FORMAT = "%Y%m%d"
@@ -215,3 +217,29 @@ def move_weekday_to_range(time_periods_ref: dict, weekday: int) -> int:
         weekday = last_weekday
 
     return weekday
+
+
+def update_or_create_lesson_event(amends: CalendarEvent, datetime_start, datetime_end, defaults):
+    try:
+        existing_event = CalendarEvent.objects.get(
+            amends=amends, datetime_start=datetime_start, datetime_end=datetime_end
+        )
+        existing_event.amends = None
+        existing_event.save()
+    except CalendarEvent.DoesNotExist:
+        existing_event = None
+
+    amending_event, __ = (
+        LessonEvent.objects.select_related(None)
+        .prefetch_related(None)
+        .update_or_create(
+            amends=amends,
+            datetime_start=datetime_start,
+            datetime_end=datetime_end,
+            defaults=defaults,
+        )
+    )
+    if existing_event:
+        existing_event.amends = amending_event
+        existing_event.save()
+    return amending_event