Support intersecting terms

CHANGELOG.rst

@@ -14,6 +14,7 @@ Fixed
 
 * Importer failed sometimes on progressing absences.
 * Exam import failed sometimes when data provided through Untis were incomplete.
+* Importer now automatically fixes intersections of terms with previous terms.
 
 `2.3.2`_ - 2022-09-01
 ---------------------

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

 import logging
-from datetime import date
+from datetime import date, timedelta
 from typing import Dict, Optional
 
 from django.db.models import Max, OuterRef, Q, QuerySet, Subquery
@@ -71,7 +71,7 @@ def import_terms(
 
     if school_id is None:
         school_id = get_site_preferences()["untis_mysql__school_id"]
-    qs = qs.filter(school_id=school_id)
+    qs = qs.filter(school_id=school_id).order_by("datefrom")
 
     if version is None:
         # Select newest version per term / validity range
@@ -142,6 +142,7 @@ def import_terms(
             school_term.date_start = date_start
 
         school_term.save()
+        school_terms[school_year_id] = school_term
 
         try:
             validity_range = chronos_models.ValidityRange.objects.get(
@@ -151,13 +152,24 @@ def import_terms(
         except chronos_models.ValidityRange.DoesNotExist:
             try:
                 validity_range = chronos_models.ValidityRange.objects.within_dates(
-                    date_start, date_end
+                    date_start__gte=date_start, date_end__lte=date_end
                 ).get()
                 logger.info("  Validity range found by time.")
             except chronos_models.ValidityRange.DoesNotExist:
                 validity_range = chronos_models.ValidityRange()
                 logger.info("  Validity range created newly.")
 
+        # In Untis, you can set all the end dates of the terms to the same date
+        # and despite that, the terms still end if a new one starts.
+        # If this case occurs, we have to set the end date of the previous term
+        # to the start date of the next one.
+        validity_range_with_possible_intersection = chronos_models.ValidityRange.objects.filter(
+            date_end__gte=date_start, date_start__lt=date_start
+        ).first()
+        if validity_range_with_possible_intersection:
+            validity_range_with_possible_intersection.date_end = date_start - timedelta(days=1)
+            validity_range_with_possible_intersection.save()
+
         validity_range.import_ref_untis = term_id
         validity_range.date_start = date_start
         validity_range.date_end = date_end