src/social/utils.py

   1 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   2 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   3 #
   4 from collections import defaultdict
   5 from random import randint
   6
   7 from django.contrib.contenttypes.models import ContentType
   8 from django.db.models import Q
   9 from django.utils.functional import lazy
  10 from catalogue.models import Book, Tag
  11 from catalogue import utils
  12 from catalogue.tasks import touch_tag
  13 from social.models import Cite
  14
  15
  16 def likes(user, work, request=None):
  17     if not user.is_authenticated:
  18         return False
  19
  20     if request is None:
  21         return work.tags.filter(category='set', user=user).exists()
  22
  23     if not hasattr(request, 'social_likes'):
  24         # tuple: unchecked, checked, liked
  25         request.social_likes = defaultdict(lambda: (set(), set(), set()))
  26
  27     ct = ContentType.objects.get_for_model(type(work))
  28     likes_t = request.social_likes[ct.pk]
  29     if work.pk in likes_t[1]:
  30         return work.pk in likes_t[2]
  31     else:
  32         likes_t[0].add(work.pk)
  33
  34         def _likes():
  35             if likes_t[0]:
  36                 ids = tuple(likes_t[0])
  37                 likes_t[0].clear()
  38                 likes_t[2].update(Tag.intermediary_table_model.objects.filter(
  39                     content_type_id=ct.pk, tag__user_id=user.pk,
  40                     object_id__in=ids
  41                 ).distinct().values_list('object_id', flat=True))
  42                 likes_t[1].update(ids)
  43             return work.pk in likes_t[2]
  44         return lazy(_likes, bool)()
  45
  46
  47 def get_set(user, name):
  48     """Returns a tag for use by the user. Creates it, if necessary."""
  49     try:
  50         tag = Tag.objects.get(category='set', user=user, name=name)
  51     except Tag.DoesNotExist:
  52         tag = Tag.objects.create(
  53             category='set', user=user, name=name, slug=utils.get_random_hash(name), sort_key=name.lower())
  54     except Tag.MultipleObjectsReturned:
  55         # fix duplicated noname shelf
  56         tags = list(Tag.objects.filter(category='set', user=user, name=name))
  57         tag = tags[0]
  58         for other_tag in tags[1:]:
  59             for item in other_tag.items.all():
  60                 Tag.objects.remove_tag(item, other_tag)
  61                 Tag.objects.add_tag(item, tag)
  62             other_tag.delete()
  63     return tag
  64
  65
  66 def set_sets(user, work, sets):
  67     """Set tags used for given work by a given user."""
  68
  69     old_sets = list(work.tags.filter(category='set', user=user))
  70
  71     work.tags = sets + list(
  72             work.tags.filter(~Q(category='set') | ~Q(user=user)))
  73
  74     for shelf in [shelf for shelf in old_sets if shelf not in sets]:
  75         touch_tag(shelf)
  76     for shelf in [shelf for shelf in sets if shelf not in old_sets]:
  77         touch_tag(shelf)
  78
  79     # delete empty tags
  80     Tag.objects.filter(category='set', user=user, items=None).delete()
  81
  82     if isinstance(work, Book):
  83         work.update_popularity()
  84
  85
  86 def cites_for_tags(tags):
  87     """Returns a QuerySet with all Cites for books with given tags."""
  88     return Cite.objects.filter(book__in=Book.tagged.with_all(tags))
  89
  90
  91 # tag_ids is never used
  92 def choose_cite(book_id=None, tag_ids=None):
  93     """Choose a cite for main page, for book or for set of tags."""
  94     if book_id is not None:
  95         cites = Cite.objects.filter(Q(book=book_id) | Q(book__ancestor=book_id))
  96     elif tag_ids is not None:
  97         tags = Tag.objects.filter(pk__in=tag_ids)
  98         cites = cites_for_tags(tags)
  99     else:
 100         cites = Cite.objects.all()
 101     stickies = cites.filter(sticky=True)
 102     count = len(stickies)
 103     if count:
 104         cites = stickies
 105     else:
 106         count = len(cites)
 107     if count:
 108         cite = cites[randint(0, count - 1)]
 109     else:
 110         cite = None
 111     return cite
 112
 113
 114 def get_or_choose_cite(request, book_id=None, tag_ids=None):
 115     try:
 116         assert request.user.is_staff
 117         assert 'banner' in request.GET
 118         return Cite.objects.get(pk=request.GET['banner'])
 119     except (AssertionError, Cite.DoesNotExist):
 120         return choose_cite(book_id, tag_ids)