--- a/gpp/forums/models.py	Wed Mar 16 02:13:38 2011 +0000
+++ b/gpp/forums/models.py	Thu Mar 17 01:20:23 2011 +0000
@@ -183,7 +183,7 @@
     sticky = models.BooleanField(blank=True, default=False)
     locked = models.BooleanField(blank=True, default=False)
     subscribers = models.ManyToManyField(User, related_name='subscriptions',
-            verbose_name='subscribers', blank=True, through='Subscription')
+            verbose_name='subscribers', blank=True)
     bookmarkers = models.ManyToManyField(User, related_name='favorite_topics',
             verbose_name='bookmarkers', blank=True)
 
@@ -392,12 +392,3 @@
     def __unicode__(self):
         return u'Post %d, %s' % (self.post.pk, self.embed.title)
 
-
-class Subscription(models.Model):
-    """
-    This model is a "through" table for the M2M relationshiop between forum
-    topics and users (subscribers).
-    """
-    topic = models.ForeignKey(Topic)
-    user = models.ForeignKey(User)
-    notify_date = models.DateTimeField(null=True)

--- a/gpp/forums/views/subscriptions.py	Wed Mar 16 02:13:38 2011 +0000
+++ b/gpp/forums/views/subscriptions.py	Thu Mar 17 01:20:23 2011 +0000
@@ -1,6 +1,4 @@
 """This module handles the subscriptions of users to forum topics."""
-import datetime
-
 from django.conf import settings
 from django.contrib.auth.decorators import login_required
 from django.contrib.sites.models import Site
@@ -14,48 +12,21 @@
 from django.template import RequestContext
 from django.views.decorators.http import require_POST
 
-from forums.models import Topic, TopicLastVisit, Subscription
+from forums.models import Topic
 from core.functions import send_mail
 from core.paginator import DiggPaginator
 
 
-# This constant is the minimum amount of time a user will be
-# notified of new posts in a topic. Currently it is set to 1 day.
-# Thus a user will be notified at most once per day of new posts.
-TOPIC_NOTIFY_DELAY = datetime.timedelta(days=1)
-
-
 def notify_topic_subscribers(post):
     """
     The argument post is a newly created post. Send out an email
     notification to all subscribers of the post's parent Topic.
-    The emails are throttled such that unless the user visits the topic,
-    only 1 email will be sent per TOPIC_NOTIFY_DELAY period.
-    Visiting the topic will reset this delay.
-
     """
     #TODO: consider moving this function of the HTTP request/response cycle.
 
     topic = post.topic
-    subscriptions = Subscription.objects.filter(topic=post.topic).exclude(
-            user=post.user).select_related()
-
-    if not subscriptions:
-        return
-
-    subscriber_ids = [sub.user.id for sub in subscriptions]
-    tlvs = dict(TopicLastVisit.objects.filter(topic=topic,
-            user__in=subscriber_ids).values_list('user', 'last_visit'))
-
-    recipients = []
-    for sub in subscriptions:
-        if (sub.notify_date is None or
-            post.creation_date - sub.notify_date > TOPIC_NOTIFY_DELAY or
-            tlvs.get(sub.user.id, datetime.datetime.min) > sub.notify_date):
-
-            recipients.append(sub.user.email)
-            sub.notify_date = post.creation_date
-            sub.save()
+    recipients = topic.subscribers.exclude(id=post.user.id).values_list(
+            'email', flat=True)
 
     if recipients:
         site = Site.objects.get_current()
@@ -80,11 +51,10 @@
     """Subscribe the user to the requested topic."""
     topic = get_object_or_404(Topic.objects.select_related(), id=topic_id)
     if topic.forum.category.can_access(request.user):
-        sub = Subscription(topic=topic, user=request.user)
-        sub.save()
+        topic.subscribers.add(request.user)
         return HttpResponseRedirect(
             reverse("forums-subscription_status", args=[topic.id]))
-    raise Http404   # TODO return HttpResponseForbidden instead
+    raise Http404
 
 
 @login_required
@@ -92,12 +62,7 @@
 def unsubscribe_topic(request, topic_id):
     """Unsubscribe the user to the requested topic."""
     topic = get_object_or_404(Topic, id=topic_id)
-    try:
-        sub = Subscription.objects.get(topic=topic, user=request.user)
-    except Subscription.DoesNotExist:
-        pass
-    else:
-        sub.delete()
+    topic.subscribers.remove(request.user)
     return HttpResponseRedirect(
         reverse("forums-subscription_status", args=[topic.id]))
 
@@ -121,7 +86,7 @@
     user = request.user
     if request.method == "POST":
         if request.POST.get('delete_all'):
-            Subscription.objects.filter(user=user).delete()
+            user.subscriptions.clear()
         else:
             delete_ids = request.POST.getlist('delete_ids')
             try:
@@ -129,7 +94,8 @@
             except ValueError:
                 raise Http404
 
-            Subscription.objects.filter(user=user, topic__in=delete_ids).delete()
+            for topic in user.subscriptions.filter(id__in=delete_ids):
+                user.subscriptions.remove(topic)
 
         return HttpResponseRedirect(reverse("forums-manage_subscriptions"))