Add basic login.
[wolnelektury.git] / src / catalogue / models / book.py
1 # This file is part of Wolne Lektury, licensed under GNU Affero GPLv3 or later.
2 # Copyright © Fundacja Wolne Lektury. See NOTICE for more information.
3 #
4 from collections import OrderedDict
5 import json
6 from datetime import date, timedelta
7 from random import randint
8 import os.path
9 import re
10 from urllib.request import urlretrieve
11 from django.apps import apps
12 from django.conf import settings
13 from django.db import connection, models, transaction
14 import django.dispatch
15 from django.contrib.contenttypes.fields import GenericRelation
16 from django.template.loader import render_to_string
17 from django.urls import reverse
18 from django.utils.translation import gettext_lazy as _, get_language
19 from fnpdjango.storage import BofhFileSystemStorage
20 from lxml import html
21 from librarian.cover import WLCover
22 from librarian.html import transform_abstrakt
23 from librarian.builders import builders
24 from newtagging import managers
25 from catalogue import constants
26 from catalogue import fields
27 from catalogue.models import Tag, Fragment, BookMedia
28 from catalogue.utils import create_zip, gallery_url, gallery_path, split_tags, get_random_hash
29 from catalogue.models.tag import prefetched_relations
30 from catalogue import app_settings
31 from wolnelektury.utils import makedirs, cached_render, clear_cached_renders
32
33 bofh_storage = BofhFileSystemStorage()
34
35
36 class Book(models.Model):
37     """Represents a book imported from WL-XML."""
38     title = models.CharField('tytuł', max_length=32767)
39     sort_key = models.CharField('klucz sortowania', max_length=120, db_index=True, editable=False)
40     sort_key_author = models.CharField(
41         'klucz sortowania wg autora', max_length=120, db_index=True, editable=False, default='')
42     slug = models.SlugField('slug', max_length=120, db_index=True, unique=True)
43     common_slug = models.SlugField('wspólny slug', max_length=120, db_index=True)
44     language = models.CharField('kod języka', max_length=3, db_index=True, default=app_settings.DEFAULT_LANGUAGE)
45     description = models.TextField('opis', blank=True)
46     abstract = models.TextField('abstrakt', blank=True)
47     toc = models.TextField('spis treści', blank=True)
48     created_at = models.DateTimeField('data utworzenia', auto_now_add=True, db_index=True)
49     changed_at = models.DateTimeField('data motyfikacji', auto_now=True, db_index=True)
50     parent_number = models.IntegerField('numer w ramach rodzica', default=0)
51     extra_info = models.TextField('dodatkowe informacje', default='{}')
52     gazeta_link = models.CharField(blank=True, max_length=240)
53     wiki_link = models.CharField(blank=True, max_length=240)
54     print_on_demand = models.BooleanField('druk na żądanie', default=False)
55     recommended = models.BooleanField('polecane', default=False)
56     audio_length = models.CharField('długość audio', blank=True, max_length=8)
57     preview = models.BooleanField('prapremiera', default=False)
58     preview_until = models.DateField('prapremiera do', blank=True, null=True)
59     preview_key = models.CharField(max_length=32, blank=True, null=True)
60     findable = models.BooleanField('wyszukiwalna', default=True, db_index=True)
61
62     # files generated during publication
63     xml_file = fields.XmlField(storage=bofh_storage, with_etag=False)
64     html_file = fields.HtmlField(storage=bofh_storage)
65     fb2_file = fields.Fb2Field(storage=bofh_storage)
66     txt_file = fields.TxtField(storage=bofh_storage)
67     epub_file = fields.EpubField(storage=bofh_storage)
68     mobi_file = fields.MobiField(storage=bofh_storage)
69     pdf_file = fields.PdfField(storage=bofh_storage)
70
71     cover = fields.CoverField('okładka', storage=bofh_storage)
72     # Cleaner version of cover for thumbs
73     cover_clean = fields.CoverCleanField('czysta okładka')
74     cover_thumb = fields.CoverThumbField('miniatura okładki')
75     cover_api_thumb = fields.CoverApiThumbField(
76         'mniaturka okładki dla aplikacji')
77     simple_cover = fields.SimpleCoverField('okładka dla aplikacji')
78     cover_ebookpoint = fields.CoverEbookpointField(
79         'okładka dla Ebookpoint')
80
81     ebook_formats = constants.EBOOK_FORMATS
82     formats = ebook_formats + ['html', 'xml']
83
84     parent = models.ForeignKey('self', models.CASCADE, blank=True, null=True, related_name='children')
85     ancestor = models.ManyToManyField('self', blank=True, editable=False, related_name='descendant', symmetrical=False)
86
87     cached_author = models.CharField(blank=True, max_length=240, db_index=True)
88     has_audience = models.BooleanField(default=False)
89
90     objects = models.Manager()
91     tagged = managers.ModelTaggedItemManager(Tag)
92     tags = managers.TagDescriptor(Tag)
93     tag_relations = GenericRelation(Tag.intermediary_table_model)
94     translators = models.ManyToManyField(Tag, blank=True)
95
96     html_built = django.dispatch.Signal()
97     published = django.dispatch.Signal()
98
99     SORT_KEY_SEP = '$'
100
101     is_book = True
102
103     class AlreadyExists(Exception):
104         pass
105
106     class Meta:
107         ordering = ('sort_key_author', 'sort_key')
108         verbose_name = 'książka'
109         verbose_name_plural = 'książki'
110         app_label = 'catalogue'
111
112     def __str__(self):
113         return self.title
114
115     def get_extra_info_json(self):
116         return json.loads(self.extra_info or '{}')
117
118     def get_initial(self):
119         try:
120             return re.search(r'\w', self.title, re.U).group(0)
121         except AttributeError:
122             return ''
123
124     def authors(self):
125         return self.tags.filter(category='author')
126
127     def epochs(self):
128         return self.tags.filter(category='epoch')
129
130     def genres(self):
131         return self.tags.filter(category='genre')
132
133     def kinds(self):
134         return self.tags.filter(category='kind')
135
136     def tag_unicode(self, category):
137         relations = prefetched_relations(self, category)
138         if relations:
139             return ', '.join(rel.tag.name for rel in relations)
140         else:
141             return ', '.join(self.tags.filter(category=category).values_list('name', flat=True))
142
143     def tags_by_category(self):
144         return split_tags(self.tags.exclude(category__in=('set', 'theme')))
145
146     def author_unicode(self):
147         return self.cached_author
148
149     def kind_unicode(self):
150         return self.tag_unicode('kind')
151
152     def epoch_unicode(self):
153         return self.tag_unicode('epoch')
154
155     def genre_unicode(self):
156         return self.tag_unicode('genre')
157
158     def translator(self):
159         translators = self.get_extra_info_json().get('translators')
160         if not translators:
161             return None
162         if len(translators) > 3:
163             translators = translators[:2]
164             others = ' i inni'
165         else:
166             others = ''
167         return ', '.join('\xa0'.join(reversed(translator.split(', ', 1))) for translator in translators) + others
168
169     def cover_source(self):
170         return self.get_extra_info_json().get('cover_source', self.parent.cover_source() if self.parent else '')
171
172     @property
173     def isbn_pdf(self):
174         return self.get_extra_info_json().get('isbn_pdf')
175
176     @property
177     def isbn_epub(self):
178         return self.get_extra_info_json().get('isbn_epub')
179
180     @property
181     def isbn_mobi(self):
182         return self.get_extra_info_json().get('isbn_mobi')
183
184     def is_accessible_to(self, user):
185         if not self.preview:
186             return True
187         if not user.is_authenticated:
188             return False
189         Membership = apps.get_model('club', 'Membership')
190         if Membership.is_active_for(user):
191             return True
192         Funding = apps.get_model('funding', 'Funding')
193         if Funding.objects.filter(user=user, offer__book=self):
194             return True
195         return False
196
197     def save(self, force_insert=False, force_update=False, **kwargs):
198         from sortify import sortify
199
200         self.sort_key = sortify(self.title)[:120]
201         self.title = str(self.title)  # ???
202
203         try:
204             author = self.authors().first().sort_key
205         except AttributeError:
206             author = ''
207         self.sort_key_author = author
208
209         self.cached_author = self.tag_unicode('author')
210         self.has_audience = 'audience' in self.get_extra_info_json()
211
212         if self.preview and not self.preview_key:
213             self.preview_key = get_random_hash(self.slug)[:32]
214
215         ret = super(Book, self).save(force_insert, force_update, **kwargs)
216
217         return ret
218
219     def get_absolute_url(self):
220         return reverse('book_detail', args=[self.slug])
221
222     def gallery_path(self):
223         return gallery_path(self.slug)
224
225     def gallery_url(self):
226         return gallery_url(self.slug)
227
228     def get_first_text(self):
229         if self.html_file:
230             return self
231         child = self.children.all().order_by('parent_number').first()
232         if child is not None:
233             return child.get_first_text()
234
235     def get_last_text(self):
236         if self.html_file:
237             return self
238         child = self.children.all().order_by('parent_number').last()
239         if child is not None:
240             return child.get_last_text()
241
242     def get_prev_text(self):
243         if not self.parent:
244             return None
245         sibling = self.parent.children.filter(parent_number__lt=self.parent_number).order_by('-parent_number').first()
246         if sibling is not None:
247             return sibling.get_last_text()
248
249         if self.parent.html_file:
250             return self.parent
251
252         return self.parent.get_prev_text()
253
254     def get_next_text(self, inside=True):
255         if inside:
256             child = self.children.order_by('parent_number').first()
257             if child is not None:
258                 return child.get_first_text()
259
260         if not self.parent:
261             return None
262         sibling = self.parent.children.filter(parent_number__gt=self.parent_number).order_by('parent_number').first()
263         if sibling is not None:
264             return sibling.get_first_text()
265         return self.parent.get_next_text(inside=False)
266
267     def get_child_audiobook(self):
268         BookMedia = apps.get_model('catalogue', 'BookMedia')
269         if not BookMedia.objects.filter(book__ancestor=self).exists():
270             return None
271         for child in self.children.order_by('parent_number').all():
272             if child.has_mp3_file():
273                 return child
274             child_sub = child.get_child_audiobook()
275             if child_sub is not None:
276                 return child_sub
277
278     def get_siblings(self):
279         if not self.parent:
280             return []
281         return self.parent.children.all().order_by('parent_number')
282
283     def get_children(self):
284         return self.children.all().order_by('parent_number')
285
286     @property
287     def name(self):
288         return self.title
289
290     def language_code(self):
291         return constants.LANGUAGES_3TO2.get(self.language, self.language)
292
293     def language_name(self):
294         return dict(settings.LANGUAGES).get(self.language_code(), "")
295
296     def is_foreign(self):
297         return self.language_code() != settings.LANGUAGE_CODE
298
299     def set_audio_length(self):
300         length = self.get_audio_length()
301         if length > 0:
302             self.audio_length = self.format_audio_length(length)
303             self.save()
304
305     @staticmethod
306     def format_audio_length(seconds):
307         """
308         >>> Book.format_audio_length(1)
309         '0:01'
310         >>> Book.format_audio_length(3661)
311         '1:01:01'
312         """
313         if seconds < 60*60:
314             minutes = seconds // 60
315             seconds = seconds % 60
316             return '%d:%02d' % (minutes, seconds)
317         else:
318             hours = seconds // 3600
319             minutes = seconds % 3600 // 60
320             seconds = seconds % 60
321             return '%d:%02d:%02d' % (hours, minutes, seconds)
322
323     def get_audio_length(self):
324         total = 0
325         for media in self.get_mp3() or ():
326             total += app_settings.GET_MP3_LENGTH(media.file.path)
327         return int(total)
328
329     def get_time(self):
330         return round(self.xml_file.size / 1000 * 40)
331     
332     def has_media(self, type_):
333         if type_ in Book.formats:
334             return bool(getattr(self, "%s_file" % type_))
335         else:
336             return self.media.filter(type=type_).exists()
337
338     def has_audio(self):
339         return self.has_media('mp3')
340
341     def get_media(self, type_):
342         if self.has_media(type_):
343             if type_ in Book.formats:
344                 return getattr(self, "%s_file" % type_)
345             else:
346                 return self.media.filter(type=type_)
347         else:
348             return None
349
350     def get_mp3(self):
351         return self.get_media("mp3")
352
353     def get_odt(self):
354         return self.get_media("odt")
355
356     def get_ogg(self):
357         return self.get_media("ogg")
358
359     def get_daisy(self):
360         return self.get_media("daisy")
361
362     def get_audio_epub(self):
363         return self.get_media("audio.epub")
364
365     def media_url(self, format_):
366         media = self.get_media(format_)
367         if media:
368             if self.preview:
369                 return reverse('embargo_link', kwargs={'key': self.preview_key, 'slug': self.slug, 'format_': format_})
370             else:
371                 return media.url
372         else:
373             return None
374
375     def html_url(self):
376         return self.media_url('html')
377
378     def pdf_url(self):
379         return self.media_url('pdf')
380
381     def epub_url(self):
382         return self.media_url('epub')
383
384     def mobi_url(self):
385         return self.media_url('mobi')
386
387     def txt_url(self):
388         return self.media_url('txt')
389
390     def fb2_url(self):
391         return self.media_url('fb2')
392
393     def xml_url(self):
394         return self.media_url('xml')
395
396     def has_description(self):
397         return len(self.description) > 0
398     has_description.short_description = 'opis'
399     has_description.boolean = True
400
401     def has_mp3_file(self):
402         return self.has_media("mp3")
403     has_mp3_file.short_description = 'MP3'
404     has_mp3_file.boolean = True
405
406     def has_ogg_file(self):
407         return self.has_media("ogg")
408     has_ogg_file.short_description = 'OGG'
409     has_ogg_file.boolean = True
410
411     def has_daisy_file(self):
412         return self.has_media("daisy")
413     has_daisy_file.short_description = 'DAISY'
414     has_daisy_file.boolean = True
415
416     def has_sync_file(self):
417         return settings.FEATURE_SYNCHRO and self.has_media("sync")
418
419     def get_sync(self):
420         with self.get_media('sync').first().file.open('r') as f:
421             sync = f.read().split('\n')
422         offset = float(sync[0])
423         items = []
424         for line in sync[1:]:
425             if not line:
426                 continue
427             start, end, elid = line.split()
428             items.append([elid, float(start) + offset])
429         return json.dumps(items)
430     
431     def has_audio_epub_file(self):
432         return self.has_media("audio.epub")
433
434     @property
435     def media_daisy(self):
436         return self.get_media('daisy')
437
438     @property
439     def media_audio_epub(self):
440         return self.get_media('audio.epub')
441
442     def get_audiobooks(self):
443         ogg_files = {}
444         for m in self.media.filter(type='ogg').order_by().iterator():
445             ogg_files[m.name] = m
446
447         audiobooks = []
448         projects = set()
449         total_duration = 0
450         for mp3 in self.media.filter(type='mp3').iterator():
451             # ogg files are always from the same project
452             meta = mp3.get_extra_info_json()
453             project = meta.get('project')
454             if not project:
455                 # temporary fallback
456                 project = 'CzytamySłuchając'
457
458             projects.add((project, meta.get('funded_by', '')))
459             total_duration += mp3.duration or 0
460
461             media = {'mp3': mp3}
462
463             ogg = ogg_files.get(mp3.name)
464             if ogg:
465                 media['ogg'] = ogg
466             audiobooks.append(media)
467
468         projects = sorted(projects)
469         total_duration = '%d:%02d' % (
470             total_duration // 60,
471             total_duration % 60
472         )
473         return audiobooks, projects, total_duration
474
475     def wldocument(self, parse_dublincore=True, inherit=True):
476         from catalogue.import_utils import ORMDocProvider
477         from librarian.parser import WLDocument
478
479         if inherit and self.parent:
480             meta_fallbacks = self.parent.cover_info()
481         else:
482             meta_fallbacks = None
483
484         return WLDocument.from_file(
485             self.xml_file.path,
486             provider=ORMDocProvider(self),
487             parse_dublincore=parse_dublincore,
488             meta_fallbacks=meta_fallbacks)
489
490     def wldocument2(self):
491         from catalogue.import_utils import ORMDocProvider
492         from librarian.document import WLDocument
493         doc = WLDocument(
494             self.xml_file.path,
495             provider=ORMDocProvider(self)
496         )
497         doc.meta.update(self.cover_info())
498         return doc
499
500
501     @staticmethod
502     def zip_format(format_):
503         def pretty_file_name(book):
504             return "%s/%s.%s" % (
505                 book.get_extra_info_json()['author'],
506                 book.slug,
507                 format_)
508
509         field_name = "%s_file" % format_
510         field = getattr(Book, field_name)
511         books = Book.objects.filter(parent=None).exclude(**{field_name: ""}).exclude(preview=True).exclude(findable=False)
512         paths = [(pretty_file_name(b), getattr(b, field_name).path) for b in books.iterator()]
513         return create_zip(paths, field.ZIP)
514
515     def zip_audiobooks(self, format_):
516         bm = BookMedia.objects.filter(book=self, type=format_)
517         paths = map(lambda bm: (bm.get_nice_filename(), bm.file.path), bm)
518         licenses = set()
519         for m in bm:
520             license = constants.LICENSES.get(
521                 m.get_extra_info_json().get('license'), {}
522             ).get('locative')
523             if license:
524                 licenses.add(license)
525         readme = render_to_string('catalogue/audiobook_zip_readme.txt', {
526             'licenses': licenses,
527             'meta': self.wldocument2().meta,
528         })
529         return create_zip(paths, "%s_%s" % (self.slug, format_), {'informacje.txt': readme})
530
531     def search_index(self, index=None):
532         if not self.findable:
533             return
534         from search.index import Index
535         Index.index_book(self)
536
537     # will make problems in conjunction with paid previews
538     def download_pictures(self, remote_gallery_url):
539         # This is only needed for legacy relative image paths.
540         gallery_path = self.gallery_path()
541         # delete previous files, so we don't include old files in ebooks
542         if os.path.isdir(gallery_path):
543             for filename in os.listdir(gallery_path):
544                 file_path = os.path.join(gallery_path, filename)
545                 os.unlink(file_path)
546         ilustr_elements = list(self.wldocument().edoc.findall('//ilustr'))
547         if ilustr_elements:
548             makedirs(gallery_path)
549             for ilustr in ilustr_elements:
550                 ilustr_src = ilustr.get('src')
551                 if '/' in ilustr_src:
552                     continue
553                 ilustr_path = os.path.join(gallery_path, ilustr_src)
554                 urlretrieve('%s/%s' % (remote_gallery_url, ilustr_src), ilustr_path)
555
556     def load_abstract(self):
557         abstract = self.wldocument(parse_dublincore=False).edoc.getroot().find('.//abstrakt')
558         if abstract is not None:
559             self.abstract = transform_abstrakt(abstract)
560         else:
561             self.abstract = ''
562
563     def load_toc(self):
564         self.toc = ''
565         if self.html_file:
566             parser = html.HTMLParser(encoding='utf-8')
567             tree = html.parse(self.html_file.path, parser=parser)
568             toc = tree.find('//div[@id="toc"]/ol')
569             if toc is None or not len(toc):
570                 return
571             html_link = reverse('book_text', args=[self.slug])
572             for a in toc.findall('.//a'):
573                 a.attrib['href'] = html_link + a.attrib['href']
574             self.toc = html.tostring(toc, encoding='unicode')
575             # div#toc
576
577     @classmethod
578     def from_xml_file(cls, xml_file, **kwargs):
579         from django.core.files import File
580         from librarian import dcparser
581
582         # use librarian to parse meta-data
583         book_info = dcparser.parse(xml_file)
584
585         if not isinstance(xml_file, File):
586             xml_file = File(open(xml_file))
587
588         try:
589             return cls.from_text_and_meta(xml_file, book_info, **kwargs)
590         finally:
591             xml_file.close()
592
593     @classmethod
594     def from_text_and_meta(cls, raw_file, book_info, overwrite=False, dont_build=None, search_index=True,
595                            remote_gallery_url=None, days=0, findable=True, logo=None, logo_mono=None, logo_alt=None):
596         from catalogue import tasks
597
598         if dont_build is None:
599             dont_build = set()
600         dont_build = set.union(set(dont_build), set(app_settings.DONT_BUILD))
601
602         # check for parts before we do anything
603         children = []
604         if hasattr(book_info, 'parts'):
605             for part_url in book_info.parts:
606                 try:
607                     children.append(Book.objects.get(slug=part_url.slug))
608                 except Book.DoesNotExist:
609                     raise Book.DoesNotExist('Książka "%s" nie istnieje.' % part_url.slug)
610
611         # Read book metadata
612         book_slug = book_info.url.slug
613         if re.search(r'[^a-z0-9-]', book_slug):
614             raise ValueError('Invalid characters in slug')
615         book, created = Book.objects.get_or_create(slug=book_slug)
616
617         if created:
618             book_shelves = []
619             old_cover = None
620             book.preview = bool(days)
621             if book.preview:
622                 book.preview_until = date.today() + timedelta(days)
623         else:
624             if not overwrite:
625                 raise Book.AlreadyExists('Książka %s już istnieje' % book_slug)
626             # Save shelves for this book
627             book_shelves = list(book.tags.filter(category='set'))
628             old_cover = book.cover_info()
629
630         # Save XML file
631         book.xml_file.save('%s.xml' % book.slug, raw_file, save=False)
632         if book.preview:
633             book.xml_file.set_readable(False)
634
635         book.findable = findable
636         book.language = book_info.language
637         book.title = book_info.title
638         if book_info.variant_of:
639             book.common_slug = book_info.variant_of.slug
640         else:
641             book.common_slug = book.slug
642         extra = book_info.to_dict()
643         if logo:
644             extra['logo'] = logo
645         if logo_mono:
646             extra['logo_mono'] = logo_mono
647         if logo_alt:
648             extra['logo_alt'] = logo_alt
649         book.extra_info = json.dumps(extra)
650         book.load_abstract()
651         book.load_toc()
652         book.save()
653
654         meta_tags = Tag.tags_from_info(book_info)
655
656         just_tags = [t for (t, rel) in meta_tags if not rel]
657         book.tags = set(just_tags + book_shelves)
658         book.save()  # update sort_key_author
659
660         book.translators.set([t for (t, rel) in meta_tags if rel == 'translator'])
661
662         cover_changed = old_cover != book.cover_info()
663         obsolete_children = set(b for b in book.children.all()
664                                 if b not in children)
665         notify_cover_changed = []
666         for n, child_book in enumerate(children):
667             new_child = child_book.parent != book
668             child_book.parent = book
669             child_book.parent_number = n
670             child_book.save()
671             if new_child or cover_changed:
672                 notify_cover_changed.append(child_book)
673         # Disown unfaithful children and let them cope on their own.
674         for child in obsolete_children:
675             child.parent = None
676             child.parent_number = 0
677             child.save()
678             if old_cover:
679                 notify_cover_changed.append(child)
680
681         cls.repopulate_ancestors()
682         tasks.update_counters.delay()
683
684         if remote_gallery_url:
685             book.download_pictures(remote_gallery_url)
686
687         # No saves beyond this point.
688
689         # Build cover.
690         if 'cover' not in dont_build:
691             book.cover.build_delay()
692             book.cover_clean.build_delay()
693             book.cover_thumb.build_delay()
694             book.cover_api_thumb.build_delay()
695             book.simple_cover.build_delay()
696             book.cover_ebookpoint.build_delay()
697
698         # Build HTML and ebooks.
699         book.html_file.build_delay()
700         if not children:
701             for format_ in constants.EBOOK_FORMATS_WITHOUT_CHILDREN:
702                 if format_ not in dont_build:
703                     getattr(book, '%s_file' % format_).build_delay()
704         for format_ in constants.EBOOK_FORMATS_WITH_CHILDREN:
705             if format_ not in dont_build:
706                 getattr(book, '%s_file' % format_).build_delay()
707
708         if not settings.NO_SEARCH_INDEX and search_index and findable:
709             tasks.index_book.delay(book.id)
710
711         for child in notify_cover_changed:
712             child.parent_cover_changed()
713
714         book.update_popularity()
715         tasks.update_references.delay(book.id)
716
717         cls.published.send(sender=cls, instance=book)
718         return book
719
720     def update_references(self):
721         Entity = apps.get_model('references', 'Entity')
722         doc = self.wldocument2()
723         doc._compat_assign_section_ids()
724         doc._compat_assign_ordered_ids()
725         refs = {}
726         for ref_elem in doc.references():
727             uri = ref_elem.attrib.get('href', '')
728             if not uri:
729                 continue
730             if uri in refs:
731                 ref = refs[uri]
732             else:
733                 entity, entity_created = Entity.objects.get_or_create(uri=uri)
734                 if entity_created:
735                     try:
736                         entity.populate()
737                     except:
738                         pass
739                     else:
740                         entity.save()
741                 ref, ref_created = entity.reference_set.get_or_create(book=self)
742                 refs[uri] = ref
743                 if not ref_created:
744                     ref.occurence_set.all().delete()
745             sec = ref_elem.get_link()
746             m = re.match(r'sec(\d+)', sec)
747             assert m is not None
748             sec = int(m.group(1))
749             snippet = ref_elem.get_snippet()
750             b = builders['html-snippet']()
751             for s in snippet:
752                 s.html_build(b)
753             html = b.output().get_bytes().decode('utf-8')
754
755             ref.occurence_set.create(
756                 section=sec,
757                 html=html
758             )
759         self.reference_set.exclude(entity__uri__in=refs).delete()
760
761     @property
762     def references(self):
763         return self.reference_set.all().select_related('entity')
764
765     @classmethod
766     @transaction.atomic
767     def repopulate_ancestors(cls):
768         """Fixes the ancestry cache."""
769         # TODO: table names
770         cursor = connection.cursor()
771         if connection.vendor == 'postgres':
772             cursor.execute("TRUNCATE catalogue_book_ancestor")
773             cursor.execute("""
774                 WITH RECURSIVE ancestry AS (
775                     SELECT book.id, book.parent_id
776                     FROM catalogue_book AS book
777                     WHERE book.parent_id IS NOT NULL
778                     UNION
779                     SELECT ancestor.id, book.parent_id
780                     FROM ancestry AS ancestor, catalogue_book AS book
781                     WHERE ancestor.parent_id = book.id
782                         AND book.parent_id IS NOT NULL
783                     )
784                 INSERT INTO catalogue_book_ancestor
785                     (from_book_id, to_book_id)
786                     SELECT id, parent_id
787                     FROM ancestry
788                     ORDER BY id;
789                 """)
790         else:
791             cursor.execute("DELETE FROM catalogue_book_ancestor")
792             for b in cls.objects.exclude(parent=None):
793                 parent = b.parent
794                 while parent is not None:
795                     b.ancestor.add(parent)
796                     parent = parent.parent
797
798     @property
799     def ancestors(self):
800         if self.parent:
801             for anc in self.parent.ancestors:
802                 yield anc
803             yield self.parent
804         else:
805             return []
806
807     def clear_cache(self):
808         clear_cached_renders(self.mini_box)
809         clear_cached_renders(self.mini_box_nolink)
810
811     def cover_info(self, inherit=True):
812         """Returns a dictionary to serve as fallback for BookInfo.
813
814         For now, the only thing inherited is the cover image.
815         """
816         need = False
817         info = {}
818         for field in ('cover_url', 'cover_by', 'cover_source'):
819             val = self.get_extra_info_json().get(field)
820             if val:
821                 info[field] = val
822             else:
823                 need = True
824         if inherit and need and self.parent is not None:
825             parent_info = self.parent.cover_info()
826             parent_info.update(info)
827             info = parent_info
828         return info
829
830     def related_themes(self):
831         return Tag.objects.usage_for_queryset(
832             Fragment.objects.filter(models.Q(book=self) | models.Q(book__ancestor=self)),
833             counts=True).filter(category='theme').order_by('-count')
834
835     def parent_cover_changed(self):
836         """Called when parent book's cover image is changed."""
837         if not self.cover_info(inherit=False):
838             if 'cover' not in app_settings.DONT_BUILD:
839                 self.cover.build_delay()
840                 self.cover_clean.build_delay()
841                 self.cover_thumb.build_delay()
842                 self.cover_api_thumb.build_delay()
843                 self.simple_cover.build_delay()
844                 self.cover_ebookpoint.build_delay()
845             for format_ in constants.EBOOK_FORMATS_WITH_COVERS:
846                 if format_ not in app_settings.DONT_BUILD:
847                     getattr(self, '%s_file' % format_).build_delay()
848             for child in self.children.all():
849                 child.parent_cover_changed()
850
851     def other_versions(self):
852         """Find other versions (i.e. in other languages) of the book."""
853         return type(self).objects.filter(common_slug=self.common_slug, findable=True).exclude(pk=self.pk)
854
855     def parents(self):
856         books = []
857         parent = self.parent
858         while parent is not None:
859             books.insert(0, parent)
860             parent = parent.parent
861         return books
862
863     def pretty_title(self, html_links=False):
864         names = [(tag.name, tag.get_absolute_url()) for tag in self.authors().only('name', 'category', 'slug')]
865         books = self.parents() + [self]
866         names.extend([(b.title, b.get_absolute_url()) for b in books])
867
868         if html_links:
869             names = ['<a href="%s">%s</a>' % (tag[1], tag[0]) for tag in names]
870         else:
871             names = [tag[0] for tag in names]
872         return ', '.join(names)
873
874     def publisher(self):
875         publisher = self.get_extra_info_json()['publisher']
876         if isinstance(publisher, str):
877             return publisher
878         elif isinstance(publisher, list):
879             return ', '.join(publisher)
880
881     @classmethod
882     def tagged_top_level(cls, tags):
883         """ Returns top-level books tagged with `tags`.
884
885         It only returns those books which don't have ancestors which are
886         also tagged with those tags.
887
888         """
889         objects = cls.tagged.with_all(tags)
890         return objects.filter(findable=True).exclude(ancestor__in=objects)
891
892     @classmethod
893     def book_list(cls, book_filter=None):
894         """Generates a hierarchical listing of all books.
895
896         Books are optionally filtered with a test function.
897
898         """
899
900         books_by_parent = {}
901         books = cls.objects.filter(findable=True).order_by('parent_number', 'sort_key').only('title', 'parent', 'slug', 'extra_info')
902         if book_filter:
903             books = books.filter(book_filter).distinct()
904
905             book_ids = set(b['pk'] for b in books.values("pk").iterator())
906             for book in books.iterator():
907                 parent = book.parent_id
908                 if parent not in book_ids:
909                     parent = None
910                 books_by_parent.setdefault(parent, []).append(book)
911         else:
912             for book in books.iterator():
913                 books_by_parent.setdefault(book.parent_id, []).append(book)
914
915         orphans = []
916         books_by_author = OrderedDict()
917         for tag in Tag.objects.filter(category='author').iterator():
918             books_by_author[tag] = []
919
920         for book in books_by_parent.get(None, ()):
921             authors = list(book.authors().only('pk'))
922             if authors:
923                 for author in authors:
924                     books_by_author[author].append(book)
925             else:
926                 orphans.append(book)
927
928         return books_by_author, orphans, books_by_parent
929
930     _audiences_pl = {
931         "SP": (1, "szkoła podstawowa"),
932         "SP1": (1, "szkoła podstawowa"),
933         "SP2": (1, "szkoła podstawowa"),
934         "SP3": (1, "szkoła podstawowa"),
935         "P": (1, "szkoła podstawowa"),
936         "G": (2, "gimnazjum"),
937         "L": (3, "liceum"),
938         "LP": (3, "liceum"),
939     }
940
941     def audiences_pl(self):
942         audiences = self.get_extra_info_json().get('audiences', [])
943         audiences = sorted(set([self._audiences_pl.get(a, (99, a)) for a in audiences]))
944         return [a[1] for a in audiences]
945
946     def stage_note(self):
947         stage = self.get_extra_info_json().get('stage')
948         if stage and stage < '0.4':
949             return (_('Ten utwór wymaga uwspółcześnienia'),
950                     reverse('infopage', args=['wymagajace-uwspolczesnienia']))
951         else:
952             return None, None
953
954     def choose_fragments(self, number):
955         fragments = self.fragments.order_by()
956         fragments_count = fragments.count()
957         if not fragments_count and self.children.exists():
958             fragments = Fragment.objects.filter(book__ancestor=self).order_by()
959             fragments_count = fragments.count()
960         if fragments_count:
961             if fragments_count > number:
962                 offset = randint(0, fragments_count - number)
963             else:
964                 offset = 0
965             return fragments[offset : offset + number]
966         elif self.parent:
967             return self.parent.choose_fragments(number)
968         else:
969             return []
970
971     def choose_fragment(self):
972         fragments = self.choose_fragments(1)
973         if fragments:
974             return fragments[0]
975         else:
976             return None
977
978     def fragment_data(self):
979         fragment = self.choose_fragment()
980         if fragment:
981             return {
982                 'title': fragment.book.pretty_title(),
983                 'html': re.sub('</?blockquote[^>]*>', '', fragment.get_short_text()),
984             }
985         else:
986             return None
987
988     def update_popularity(self):
989         count = self.tags.filter(category='set').values('user').order_by('user').distinct().count()
990         try:
991             pop = self.popularity
992             pop.count = count
993             pop.save()
994         except BookPopularity.DoesNotExist:
995             BookPopularity.objects.create(book=self, count=count)
996
997     def ridero_link(self):
998         return 'https://ridero.eu/%s/books/wl_%s/' % (get_language(), self.slug.replace('-', '_'))
999
1000     def like(self, user):
1001         from social.utils import likes, get_set, set_sets
1002         if not likes(user, self):
1003             tag = get_set(user, '')
1004             set_sets(user, self, [tag])
1005
1006     def unlike(self, user):
1007         from social.utils import likes, set_sets
1008         if likes(user, self):
1009             set_sets(user, self, [])
1010
1011     def full_sort_key(self):
1012         return self.SORT_KEY_SEP.join((self.sort_key_author, self.sort_key, str(self.id)))
1013
1014     def cover_color(self):
1015         return WLCover.epoch_colors.get(self.get_extra_info_json().get('epoch'), '#000000')
1016
1017     @cached_render('catalogue/book_mini_box.html')
1018     def mini_box(self):
1019         return {
1020             'book': self
1021         }
1022
1023     @cached_render('catalogue/book_mini_box.html')
1024     def mini_box_nolink(self):
1025         return {
1026             'book': self,
1027             'no_link': True,
1028         }
1029
1030
1031 class BookPopularity(models.Model):
1032     book = models.OneToOneField(Book, models.CASCADE, related_name='popularity')
1033     count = models.IntegerField(default=0, db_index=True)