task for updating collection metadata

apps/bandwagon/models.py

@@ -56,6 +56,8 @@ class Collection(amo.models.ModelBase):
     upvotes = models.PositiveIntegerField(default=0)
     downvotes = models.PositiveIntegerField(default=0)
     rating = models.FloatField(default=0)
+    all_personas = models.BooleanField(default=False,
+        help_text='Does this collection only contain personas?')
 
     addons = models.ManyToManyField(Addon, through='CollectionAddon',
                                     related_name='collections')

apps/bandwagon/tasks.py

@@ -8,8 +8,9 @@ from celery.decorators import task
 # from easy_thumbnails import processors
 # from PIL import Image
 
+import amo
 from . import cron  # Pull in tasks run through cron.
-from .models import Collection, CollectionVote
+from .models import Collection, CollectionAddon, CollectionVote
 
 log = logging.getLogger('z.task')
 
@@ -35,3 +36,18 @@ def collection_votes(*ids):
 #        os.remove(src)
 #    except Exception, e:
 #        log.error("Error saving collection icon: %s" % e)
+
+
+@task
+def collection_meta(*ids):
+    log.info('[%s@%s] Updating collection metadata.' %
+             (len(ids), collection_meta.rate_limit))
+    qs = (CollectionAddon.objects.filter(collection__in=ids)
+          .values_list('collection'))
+    counts = dict(qs.annotate(Count('id')))
+    persona_counts = dict(qs.filter(addon__type=amo.ADDON_PERSONA)
+                          .annotate(Count('id')))
+    for c in Collection.objects.filter(id__in=ids):
+        c.addon_count = counts.get(c.id, 0)
+        c.all_personas = c.addon_count == persona_counts.get(c.id, None)
+        c.save()

migrations/56-collections-personas.sql

@@ -0,0 +1,2 @@
+ALTER TABLE `collections`
+    ADD `all_personas` bool DEFAULT False;