src/social/utils.py

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