website

aircox/models/signals.py

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+import pytz
+
+from django.contrib.auth.models import User, Group, Permission
+from django.db.models import F, signals
+from django.dispatch import receiver
+from django.utils import timezone as tz
+
+from .. import settings, utils
+from . import Diffusion, Episode, Program, Schedule
+
+
+# Add a default group to a user when it is created. It also assigns a list
+# of permissions to the group if it is created.
+#
+# - group name: settings.AIRCOX_DEFAULT_USER_GROUP
+# - group permissions: settings.AIRCOX_DEFAULT_USER_GROUP_PERMS
+#
+@receiver(signals.post_save, sender=User)
+def user_default_groups(sender, instance, created, *args, **kwargs):
+    """
+    Set users to different default groups
+    """
+    if not created or instance.is_superuser:
+        return
+
+    for groupName, permissions in settings.AIRCOX_DEFAULT_USER_GROUPS.items():
+        if instance.groups.filter(name=groupName).count():
+            continue
+
+        group, created = Group.objects.get_or_create(name=groupName)
+        if created and permissions:
+            for codename in permissions:
+                permission = Permission.objects.filter(
+                    codename=codename).first()
+                if permission:
+                    group.permissions.add(permission)
+            group.save()
+        instance.groups.add(group)
+
+
+@receiver(signals.post_save, sender=Program)
+def program_post_save(sender, instance, created, *args, **kwargs):
+    """
+    Clean-up later diffusions when a program becomes inactive
+    """
+    if not instance.active:
+        Diffusion.objects.program(instance).after().delete()
+        Episode.object.program(instance).filter(diffusion__isnull=True) \
+               .delete()
+
+
+@receiver(signals.pre_save, sender=Schedule)
+def schedule_pre_save(sender, instance, *args, **kwargs):
+    if getattr(instance, 'pk') is not None:
+        instance._initial = Schedule.objects.get(pk=instance.pk)
+
+
+# TODO
+@receiver(signals.post_save, sender=Schedule)
+def schedule_post_save(sender, instance, created, *args, **kwargs):
+    """
+    Handles Schedule's time, duration and timezone changes and update
+    corresponding diffusions accordingly.
+    """
+    initial = getattr(instance, '_initial', None)
+    if not initial or ((instance.time, instance.duration, instance.timezone) ==
+                       (initial.time, initial.duration, initial.timezone)):
+        return
+
+    today = tz.datetime.today()
+    delta = instance.normalize(today) - initial.normalize(today)
+
+    qs = Diffusion.objects.program(instance.program).after()
+    pks = [d.pk for d in qs if initial.match(d.date)]
+    qs.filter(pk__in=pks).update(
+        start=F('start') + delta,
+        end=F('start') + delta + utils.to_timedelta(instance.duration)
+    )
+
+
+@receiver(signals.pre_delete, sender=Schedule)
+def schedule_pre_delete(sender, instance, *args, **kwargs):
+    """
+    Delete later corresponding diffusion to a changed schedule.
+    """
+    if not instance.program.sync:
+        return
+
+    qs = Diffusion.objects.program(instance.program).after()
+    pks = [d.pk for d in qs if instance.match(d.date)]
+    qs.filter(pk__in=pks).delete()
+
+
+@receiver(signals.post_delete, sender=Diffusion)
+def diffusion_post_delete(sender, instance, *args, **kwargs):
+    Episode.objects.filter(diffusion__isnull=True, content_isnull=True,
+                           sound__isnull=True) \
+                   .delete()
+
+