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     return tag
  56
  57
  58 def set_sets(user, work, sets):
  59     """Set tags used for given work by a given user."""
  60
  61     old_sets = list(work.tags.filter(category='set', user=user))
  62
  63     work.tags = sets + list(
  64             work.tags.filter(~Q(category='set') | ~Q(user=user)))
  65
  66     for shelf in [shelf for shelf in old_sets if shelf not in sets]:
  67         touch_tag(shelf)
  68     for shelf in [shelf for shelf in sets if shelf not in old_sets]:
  69         touch_tag(shelf)
  70
  71     # delete empty tags
  72     Tag.objects.filter(category='set', user=user, items=None).delete()
  73
  74     if isinstance(work, Book):
  75         work.update_popularity()
  76
  77
  78 def cites_for_tags(tags):
  79     """Returns a QuerySet with all Cites for books with given tags."""
  80     return Cite.objects.filter(book__in=Book.tagged.with_all(tags))
  81
  82
  83 # tag_ids is never used
  84 def choose_cite(book_id=None, tag_ids=None):
  85     """Choose a cite for main page, for book or for set of tags."""
  86     if book_id is not None:
  87         cites = Cite.objects.filter(Q(book=book_id) | Q(book__ancestor=book_id))
  88     elif tag_ids is not None:
  89         tags = Tag.objects.filter(pk__in=tag_ids)
  90         cites = cites_for_tags(tags)
  91     else:
  92         cites = Cite.objects.all()
  93     stickies = cites.filter(sticky=True)
  94     count = len(stickies)
  95     if count:
  96         cites = stickies
  97     else:
  98         count = len(cites)
  99     if count:
 100         cite = cites[randint(0, count - 1)]
 101     else:
 102         cite = None
 103     return cite
 104
 105
 106 def get_or_choose_cite(request, book_id=None, tag_ids=None):
 107     try:
 108         assert request.user.is_staff
 109         assert 'choose_cite' in request.GET
 110         return Cite.objects.get(pk=request.GET['choose_cite'])
 111     except (AssertionError, Cite.DoesNotExist):
 112         return choose_cite(book_id, tag_ids)