fix diff update/delete on schedule change; fix match algorithms

aircox/signals.py

@@ -1,9 +1,12 @@
-from django.db.models.signals import post_save, pre_save, pre_delete, m2m_changed
-from django.contrib.auth.models import User, Group, Permission
+import pytz
 
-from django.dispatch import receiver
-from django.utils.translation import ugettext as _, ugettext_lazy
+from django.contrib.auth.models import User, Group, Permission
 from django.contrib.contenttypes.models import ContentType
+from django.db.models import F
+from django.db.models.signals import post_save, pre_save, pre_delete, m2m_changed
+from django.dispatch import receiver
+from django.utils import timezone as tz
+from django.utils.translation import ugettext as _, ugettext_lazy
 
 import aircox.models as models
 import aircox.utils as utils
@@ -36,9 +39,10 @@ def user_default_groups(sender, instance, created, *args, **kwargs):
 
 # FIXME: avoid copy of the code in schedule_post_saved and
 #        schedule_pre_delete
+
 @receiver(post_save, sender=models.Schedule)
 def schedule_post_saved(sender, instance, created, *args, **kwargs):
-    # TODO: case instance.program has changed
+    # TODO: case instance.program | instance.frequency has changed
     if not instance.program.sync:
         return
 
@@ -46,29 +50,28 @@ def schedule_post_saved(sender, instance, created, *args, **kwargs):
     if not initial or not instance.changed(['date','duration', 'frequency']):
         return
 
-    if not initial.get('date') or not initial.get('duration') or not initial.get('frequency'):
+    if not initial.get('date') or not initial.get('duration') \
+            or not initial.get('frequency'):
         return
 
     # old schedule and timedelta
-    old_sched = models.Schedule(
-        program = instance.program,
-        date = initial['date'],
-        duration = initial['duration'],
-        frequency = initial['frequency'],
-    )
-    delta = instance.date - old_sched.date
+    old = models.Schedule(**{ key: initial.get(key)
+        for key in ('date','timezone','duration','frequency')
+    })
+    start_delta = instance.local_date - old.local_date
 
-    # update diffusions...
-    qs = models.Diffusion.objects.after(
+    old.date = old.local_date.astimezone(pytz.UTC)
+
+    qs = models.Diffusion.objects.station(
         instance.program.station,
-        program = instance.program
     )
-    for diff in qs:
-        if not old_sched.match(diff.date):
-            continue
-        diff.start += delta
-        diff.end = diff.start + utils.to_timedelta(instance.duration)
-        diff.save()
+
+    pks = [ item.pk for item in qs if old.match(item.date) ]
+    qs.filter(pk__in = pks).update(
+        start = F('start') + start_delta,
+        end = F('start') + start_delta + utils.to_timedelta(instance.duration)
+    )
+    return
 
 @receiver(pre_delete, sender=models.Schedule)
 def schedule_pre_delete(sender, instance, *args, **kwargs):
@@ -79,17 +82,14 @@ def schedule_pre_delete(sender, instance, *args, **kwargs):
     if not initial or not instance.changed(['date','duration', 'frequency']):
         return
 
-    old_sched = models.Schedule(
-        date = initial['date'],
-        duration = initial['duration'],
-        frequency = initial['frequency'],
+    old = models.Schedule(**{ key: initial.get(key)
+        for key in ('date','timezone','duration','frequency')
+    })
+
+    qs = models.Diffusion.objects.station(
+        instance.program.station,
     )
 
-    qs = models.Diffusion.objects.after(instance.program.station).filter(
-        program = instance.program
-    )
-    for diff in qs:
-        if not old_sched.match(diff.date):
-            continue
-        diff.delete()
+    pks = [ item.pk for item in qs if old.match(item.date) ]
+    qs.filter(pk__in = pks).delete()