Code layout change.

[wolnelektury.git] / src / social / utils.py

diff --git a/src/social/utils.py b/src/social/utils.py
new file mode 100755 (executable)
index 0000000..bf1c242
--- /dev/null
+++ b/src/social/utils.py
@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+# This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
+from collections import defaultdict
+from django.contrib.contenttypes.models import ContentType
+from django.db.models import Q
+from django.utils.functional import lazy
+from catalogue.models import Book, Tag
+from catalogue import utils
+from catalogue.tasks import touch_tag
+from social.models import Cite
+
+
+def likes(user, work, request=None):
+    if not user.is_authenticated():
+        return False
+
+    if request is None:
+        return work.tags.filter(category='set', user=user).exists()
+
+    if not hasattr(request, 'social_likes'):
+        # tuple: unchecked, checked, liked
+        request.social_likes = defaultdict(lambda:(set(), set(), set()))
+
+    ct = ContentType.objects.get_for_model(type(work))
+    likes_t = request.social_likes[ct.pk]
+    if work.pk in likes_t[1]:
+        return work.pk in likes_t[2]
+    else:
+        likes_t[0].add(work.pk)
+        def _likes():
+            if likes_t[0]:
+                ids = tuple(likes_t[0])
+                likes_t[0].clear()
+                likes_t[2].update(Tag.intermediary_table_model.objects.filter(
+                    content_type_id=ct.pk, tag__user_id=user.pk,
+                    object_id__in=ids
+                ).distinct().values_list('object_id', flat=True))
+                likes_t[1].update(ids)
+            return work.pk in likes_t[2]
+        return lazy(_likes, bool)()
+
+
+def get_set(user, name):
+    """Returns a tag for use by the user. Creates it, if necessary."""
+    try:
+        tag = Tag.objects.get(category='set', user=user, name=name)
+    except Tag.DoesNotExist:
+        tag = Tag.objects.create(category='set', user=user, name=name,
+                slug=utils.get_random_hash(name), sort_key=name.lower())
+    return tag
+
+
+def set_sets(user, work, sets):
+    """Set tags used for given work by a given user."""
+
+    old_sets = list(work.tags.filter(category='set', user=user))
+
+    work.tags = sets + list(
+            work.tags.filter(~Q(category='set') | ~Q(user=user)))
+
+    for shelf in [shelf for shelf in old_sets if shelf not in sets]:
+        touch_tag(shelf)
+    for shelf in [shelf for shelf in sets if shelf not in old_sets]:
+        touch_tag(shelf)
+
+    # delete empty tags
+    Tag.objects.filter(category='set', user=user, items=None).delete()
+
+
+def cites_for_tags(tags):
+    """Returns a QuerySet with all Cites for books with given tags."""
+    return Cite.objects.filter(book__in=Book.tagged.with_all(tags))