Random optimizations.

[wolnelektury.git] / apps / social / templatetags / social_tags.py

diff --git a/apps/social/templatetags/social_tags.py b/apps/social/templatetags/social_tags.py
index e78f20f..d6d3f71 100755 (executable)
--- a/apps/social/templatetags/social_tags.py
+++ b/apps/social/templatetags/social_tags.py
@@ -2,6 +2,7 @@
 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
 #
+from random import randint
 from django import template
 from catalogue.models import Book
 from social.models import Cite
@@ -12,20 +13,47 @@ register = template.Library()
 register.filter('likes', likes)
 
 
+@register.assignment_tag(takes_context=True)
+def choose_cite(context, ctx=None):
+    """Choose a cite for main page, for book or for set of tags."""
+    try:
+        request = context['request']
+        assert request.user.is_staff
+        assert 'choose_cite' in request.GET
+        cite = Cite.objects.get(pk=request.GET['choose_cite'])
+    except AssertionError, Cite.DoesNotExist:
+        if ctx is None:
+            cites = Cite.objects.all()
+        elif isinstance(ctx, Book):
+            cites = ctx.cite_set.all()
+            if not cites.exists():
+                cites = cites_for_tags([ctx.book_tag()])
+        else:
+            cites = cites_for_tags(ctx)
+        stickies = cites.filter(sticky=True)
+        count = stickies.count()
+        if count:
+            cite = stickies[randint(0, count - 1)]
+        else:
+            count = cites.count()
+            if count:
+                cite = cites[randint(0, count - 1)]
+            else:
+                cite = None
+    return cite
+
+
 @register.inclusion_tag('social/cite_promo.html')
-def cite_promo(ctx=None, fallback=False):
-    """Choose"""
-    if ctx is None:
-        cites = Cite.objects.all()
-    elif isinstance(ctx, Book):
-        cites = ctx.cite_set.all()
-        if not cites.exists():
-            cites = cites_for_tags([ctx.book_tag()])
-    else:
-        cites = cites_for_tags(ctx)
+def render_cite(cite):
+    return {
+        'cite': cite,
+    }
+
 
+@register.inclusion_tag('social/cite_promo.html', takes_context=True)
+def cite_promo(context, ctx=None, fallback=False):
     return {
-        'cite': cites.order_by('?')[0] if cites.exists() else None,
+        'cite': choose_cite(context, ctx),
         'fallback': fallback,
         'ctx': ctx,
     }