Implement more violation checks and extract common code into a function

Implement check for overlapping AK slots in the same room
Implement check for overlapping AK slots by the same owner triggered by changing the slot

AKScheduling/models.py

@@ -5,6 +5,35 @@ from AKModel.availability.models import Availability
 from AKModel.models import AK, AKSlot, Room, Event, AKOwner, ConstraintViolation
 
 
+def update_constraint_violations(new_violations, existing_violations_to_check):
+    """
+    Update existing constraint violations (subset for which new violations were computed) based on these new violations.
+    This will add all new violations without a match, preserve the matching ones
+    and delete the obsolete ones (those without a match from the newly calculated violations).
+
+    :param new_violations: list of new (not yet saved) violations that exist after the last change
+    :type new_violations: list[ConstraintViolation]
+    :param existing_violations_to_check: list of related violations currently in the db
+    :type existing_violations_to_check: list[ConstraintViolation]
+    """
+    for new_violation in new_violations:
+        found_match = False
+        for existing_violation in existing_violations_to_check:
+            if existing_violation.matches(new_violation):
+                # Remove from existing violations set since it should stay in db
+                existing_violations_to_check.remove(existing_violation)
+                found_match = True
+                break
+
+        # Only save new violation if no match was found
+        if not found_match:
+            new_violation.save()
+
+    # Cleanup obsolete violations (ones without matches computed under current conditions)
+    for outdated_violation in existing_violations_to_check:
+        outdated_violation.delete()
+
+
 @receiver(post_save, sender=AK)
 def ak_changed_handler(sender, instance: AK, **kwargs):
     # Changes might affect: Owner(s), Requirements, Conflicts, Prerequisites, Category, Interest
@@ -59,30 +88,78 @@ def ak_changed_handler(sender, instance: AK, action: str, **kwargs):
     # belonging to the AK that was recently changed (important!)
     existing_violations_to_check = list(instance.constraintviolation_set.filter(type=violation_type))
     # print(existing_violations_to_check)
-
-    for new_violation in new_violations:
-        found_match = False
-        for existing_violation in existing_violations_to_check:
-            if existing_violation.matches(new_violation):
-                # Remove from existing violations set since it should stay in db
-                existing_violations_to_check.remove(existing_violation)
-                found_match = True
-                break
-
-        # Only save new violation if no match was found
-        if not found_match:
-            new_violation.save()
-
-    # Cleanup obsolete violations (ones without matches computed under current conditions)
-    for outdated_violation in existing_violations_to_check:
-        outdated_violation.delete()
+    update_constraint_violations(new_violations, existing_violations_to_check)
 
 
 @receiver(post_save, sender=AKSlot)
-def akslot_changed_handler(sender, instance, **kwargs):
+def akslot_changed_handler(sender, instance: AKSlot, **kwargs):
     # Changes might affect: Duplicate parallel, Two in room, Resodeadline
     print(f"{sender} changed")
-    # TODO Replace with real handling
+    event = instance.event
+
+    # == Check for two parallel slots by one of the owners ==
+
+    violation_type = ConstraintViolation.ViolationType.OWNER_TWO_SLOTS
+    new_violations = []
+
+    # For all owners (after recent change)...
+    for owner in instance.ak.owners.all():
+        # ...find other slots that might be overlapping...
+
+        for ak in owner.ak_set.all():
+            # ...find overlapping slots...
+            if ak != instance.ak:
+                for other_slot in ak.akslot_set.filter(start__isnull=False):
+                    if instance.overlaps(other_slot):
+                        # ...and create a temporary violation if necessary...
+                        c = ConstraintViolation(
+                            type=violation_type,
+                            level=ConstraintViolation.ViolationLevel.VIOLATION,
+                            event=event,
+                            ak_owner=owner
+                        )
+                        c.aks_tmp.add(instance.ak)
+                        c.aks_tmp.add(other_slot.ak)
+                        c.ak_slots_tmp.add(instance)
+                        c.ak_slots_tmp.add(other_slot)
+                        new_violations.append(c)
+
+        print(f"{owner} has the following conflicts: {new_violations}")
+
+    # ... and compare to/update list of existing violations of this type
+    # belonging to the AK that was recently changed (important!)
+    existing_violations_to_check = list(instance.constraintviolation_set.filter(type=violation_type))
+    print(existing_violations_to_check)
+    update_constraint_violations(new_violations, existing_violations_to_check)
+
+    # == Check for two aks in the same room at the same time ==
+
+    violation_type = ConstraintViolation.ViolationType.ROOM_TWO_SLOTS
+    new_violations = []
+
+    # For all slots in this room...
+    for other_slot in instance.room.akslot_set.all():
+        if other_slot != instance:
+            # ... find overlapping slots...
+            if instance.overlaps(other_slot):
+                # ...and create a temporary violation if necessary...
+                c = ConstraintViolation(
+                    type=violation_type,
+                    level=ConstraintViolation.ViolationLevel.WARNING,
+                    event=event,
+                    room=instance.room
+                )
+                c.ak_slots_tmp.add(instance)
+                c.ak_slots_tmp.add(other_slot)
+                new_violations.append(c)
+
+    print(f"Multiple slots in room {instance.room}: {new_violations}")
+
+    # ... and compare to/update list of existing violations of this type
+    # belonging to the AK that was recently changed (important!)
+    existing_violations_to_check = list(instance.room.constraintviolation_set.filter(type=violation_type))
+    print(existing_violations_to_check)
+    update_constraint_violations(new_violations, existing_violations_to_check)
 
 
 @receiver(post_save, sender=Room)