Fixes #4001: TOC contains parent books, and add links to previous and next book.
[wolnelektury.git] / src / catalogue / models / book.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 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.conf import settings
12 from django.db import connection, models, transaction
13 import django.dispatch
14 from django.contrib.contenttypes.fields import GenericRelation
15 from django.urls import reverse
16 from django.utils.translation import ugettext_lazy as _, get_language
17 from django.utils.deconstruct import deconstructible
18 from fnpdjango.storage import BofhFileSystemStorage
19
20 from librarian.cover import WLCover
21 from librarian.html import transform_abstrakt
22 from newtagging import managers
23 from catalogue import constants
24 from catalogue.fields import EbookField
25 from catalogue.models import Tag, Fragment, BookMedia
26 from catalogue.utils import create_zip, gallery_url, gallery_path, split_tags, get_random_hash
27 from catalogue.models.tag import prefetched_relations
28 from catalogue import app_settings
29 from catalogue import tasks
30 from wolnelektury.utils import makedirs, cached_render, clear_cached_renders
31
32 bofh_storage = BofhFileSystemStorage()
33
34
35 @deconstructible
36 class UploadToPath(object):
37     def __init__(self, path):
38         self.path = path
39
40     def __call__(self, instance, filename):
41         return self.path % instance.slug
42
43
44 _cover_upload_to = UploadToPath('book/cover/%s.jpg')
45 _cover_thumb_upload_to = UploadToPath('book/cover_thumb/%s.jpg')
46 _cover_api_thumb_upload_to = UploadToPath('book/cover_api_thumb/%s.jpg')
47 _simple_cover_upload_to = UploadToPath('book/cover_simple/%s.jpg')
48 _cover_ebookpoint_upload_to = UploadToPath('book/cover_ebookpoint/%s.jpg')
49
50
51 def _ebook_upload_to(upload_path):
52     return UploadToPath(upload_path)
53
54
55 class Book(models.Model):
56     """Represents a book imported from WL-XML."""
57     title = models.CharField(_('title'), max_length=32767)
58     sort_key = models.CharField(_('sort key'), max_length=120, db_index=True, editable=False)
59     sort_key_author = models.CharField(
60         _('sort key by author'), max_length=120, db_index=True, editable=False, default='')
61     slug = models.SlugField(_('slug'), max_length=120, db_index=True, unique=True)
62     common_slug = models.SlugField(_('slug'), max_length=120, db_index=True)
63     language = models.CharField(_('language code'), max_length=3, db_index=True, default=app_settings.DEFAULT_LANGUAGE)
64     description = models.TextField(_('description'), blank=True)
65     abstract = models.TextField(_('abstract'), blank=True)
66     created_at = models.DateTimeField(_('creation date'), auto_now_add=True, db_index=True)
67     changed_at = models.DateTimeField(_('change date'), auto_now=True, db_index=True)
68     parent_number = models.IntegerField(_('parent number'), default=0)
69     extra_info = models.TextField(_('extra information'), default='{}')
70     gazeta_link = models.CharField(blank=True, max_length=240)
71     wiki_link = models.CharField(blank=True, max_length=240)
72     print_on_demand = models.BooleanField(_('print on demand'), default=False)
73     recommended = models.BooleanField(_('recommended'), default=False)
74     audio_length = models.CharField(_('audio length'), blank=True, max_length=8)
75     preview = models.BooleanField(_('preview'), default=False)
76     preview_until = models.DateField(_('preview until'), blank=True, null=True)
77     preview_key = models.CharField(max_length=32, blank=True, null=True)
78     findable = models.BooleanField(_('findable'), default=True, db_index=True)
79
80     # files generated during publication
81     cover = EbookField(
82         'cover', _('cover'),
83         null=True, blank=True,
84         upload_to=_cover_upload_to,
85         storage=bofh_storage, max_length=255)
86     cover_etag = models.CharField(max_length=255, editable=False, default='', db_index=True)
87     # Cleaner version of cover for thumbs
88     cover_thumb = EbookField(
89         'cover_thumb', _('cover thumbnail'),
90         null=True, blank=True,
91         upload_to=_cover_thumb_upload_to,
92         max_length=255)
93     cover_thumb_etag = models.CharField(max_length=255, editable=False, default='', db_index=True)
94     cover_api_thumb = EbookField(
95         'cover_api_thumb', _('cover thumbnail for mobile app'),
96         null=True, blank=True,
97         upload_to=_cover_api_thumb_upload_to,
98         max_length=255)
99     cover_api_thumb_etag = models.CharField(max_length=255, editable=False, default='', db_index=True)
100     simple_cover = EbookField(
101         'simple_cover', _('cover for mobile app'),
102         null=True, blank=True,
103         upload_to=_simple_cover_upload_to,
104         max_length=255)
105     simple_cover_etag = models.CharField(max_length=255, editable=False, default='', db_index=True)
106     cover_ebookpoint = EbookField(
107         'cover_ebookpoint', _('cover for Ebookpoint'),
108         null=True, blank=True,
109         upload_to=_cover_ebookpoint_upload_to,
110         max_length=255)
111     cover_ebookpoint_etag = models.CharField(max_length=255, editable=False, default='', db_index=True)
112     ebook_formats = constants.EBOOK_FORMATS
113     formats = ebook_formats + ['html', 'xml']
114
115     parent = models.ForeignKey('self', models.CASCADE, blank=True, null=True, related_name='children')
116     ancestor = models.ManyToManyField('self', blank=True, editable=False, related_name='descendant', symmetrical=False)
117
118     cached_author = models.CharField(blank=True, max_length=240, db_index=True)
119     has_audience = models.BooleanField(default=False)
120
121     objects = models.Manager()
122     tagged = managers.ModelTaggedItemManager(Tag)
123     tags = managers.TagDescriptor(Tag)
124     tag_relations = GenericRelation(Tag.intermediary_table_model)
125
126     html_built = django.dispatch.Signal()
127     published = django.dispatch.Signal()
128
129     SORT_KEY_SEP = '$'
130
131     class AlreadyExists(Exception):
132         pass
133
134     class Meta:
135         ordering = ('sort_key_author', 'sort_key')
136         verbose_name = _('book')
137         verbose_name_plural = _('books')
138         app_label = 'catalogue'
139
140     def __str__(self):
141         return self.title
142
143     def get_extra_info_json(self):
144         return json.loads(self.extra_info or '{}')
145
146     def get_initial(self):
147         try:
148             return re.search(r'\w', self.title, re.U).group(0)
149         except AttributeError:
150             return ''
151
152     def authors(self):
153         return self.tags.filter(category='author')
154
155     def epochs(self):
156         return self.tags.filter(category='epoch')
157
158     def genres(self):
159         return self.tags.filter(category='genre')
160
161     def kinds(self):
162         return self.tags.filter(category='kind')
163
164     def tag_unicode(self, category):
165         relations = prefetched_relations(self, category)
166         if relations:
167             return ', '.join(rel.tag.name for rel in relations)
168         else:
169             return ', '.join(self.tags.filter(category=category).values_list('name', flat=True))
170
171     def tags_by_category(self):
172         return split_tags(self.tags.exclude(category__in=('set', 'theme')))
173
174     def author_unicode(self):
175         return self.cached_author
176
177     def kind_unicode(self):
178         return self.tag_unicode('kind')
179
180     def epoch_unicode(self):
181         return self.tag_unicode('epoch')
182
183     def genre_unicode(self):
184         return self.tag_unicode('genre')
185
186     def translators(self):
187         translators = self.get_extra_info_json().get('translators') or []
188         return [
189             '\xa0'.join(reversed(translator.split(', ', 1))) for translator in translators
190         ]
191
192     def translator(self):
193         translators = self.get_extra_info_json().get('translators')
194         if not translators:
195             return None
196         if len(translators) > 3:
197             translators = translators[:2]
198             others = ' i inni'
199         else:
200             others = ''
201         return ', '.join('\xa0'.join(reversed(translator.split(', ', 1))) for translator in translators) + others
202
203     def cover_source(self):
204         return self.get_extra_info_json().get('cover_source', self.parent.cover_source() if self.parent else '')
205
206     @property
207     def isbn_pdf(self):
208         return self.get_extra_info_json().get('isbn_pdf')
209
210     @property
211     def isbn_epub(self):
212         return self.get_extra_info_json().get('isbn_epub')
213
214     @property
215     def isbn_mobi(self):
216         return self.get_extra_info_json().get('isbn_mobi')
217
218
219     def save(self, force_insert=False, force_update=False, **kwargs):
220         from sortify import sortify
221
222         self.sort_key = sortify(self.title)[:120]
223         self.title = str(self.title)  # ???
224
225         try:
226             author = self.authors().first().sort_key
227         except AttributeError:
228             author = ''
229         self.sort_key_author = author
230
231         self.cached_author = self.tag_unicode('author')
232         self.has_audience = 'audience' in self.get_extra_info_json()
233
234         if self.preview and not self.preview_key:
235             self.preview_key = get_random_hash(self.slug)[:32]
236
237         ret = super(Book, self).save(force_insert, force_update, **kwargs)
238
239         return ret
240
241     def get_absolute_url(self):
242         return reverse('book_detail', args=[self.slug])
243
244     def gallery_path(self):
245         return gallery_path(self.slug)
246
247     def gallery_url(self):
248         return gallery_url(self.slug)
249
250     def get_first_text(self):
251         if self.html_file:
252             return self
253         child = self.children.all().order_by('parent_number').first()
254         if child is not None:
255             return child.get_first_text()
256
257     def get_last_text(self):
258         if self.html_file:
259             return self
260         child = self.children.all().order_by('parent_number').last()
261         if child is not None:
262             return child.get_last_text()
263
264     def get_prev_text(self):
265         if not self.parent:
266             return None
267         sibling = self.parent.children.filter(parent_number__lt=self.parent_number).order_by('-parent_number').first()
268         if sibling is not None:
269             return sibling.get_last_text()
270         return self.parent.get_prev_text()
271
272     def get_next_text(self):
273         if not self.parent:
274             return None
275         sibling = self.parent.children.filter(parent_number__gt=self.parent_number).order_by('parent_number').first()
276         if sibling is not None:
277             return sibling.get_first_text()
278         return self.parent.get_next_text()
279
280     def get_siblings(self):
281         if not self.parent:
282             return []
283         return self.parent.children.all().order_by('parent_number')
284
285     @property
286     def name(self):
287         return self.title
288
289     def language_code(self):
290         return constants.LANGUAGES_3TO2.get(self.language, self.language)
291
292     def language_name(self):
293         return dict(settings.LANGUAGES).get(self.language_code(), "")
294
295     def is_foreign(self):
296         return self.language_code() != settings.LANGUAGE_CODE
297
298     def set_audio_length(self):
299         length = self.get_audio_length()
300         if length > 0:
301             self.audio_length = self.format_audio_length(length)
302             self.save()
303
304     @staticmethod
305     def format_audio_length(seconds):
306         """
307         >>> Book.format_audio_length(1)
308         '0:01'
309         >>> Book.format_audio_length(3661)
310         '1:01:01'
311         """
312         if seconds < 60*60:
313             minutes = seconds // 60
314             seconds = seconds % 60
315             return '%d:%02d' % (minutes, seconds)
316         else:
317             hours = seconds // 3600
318             minutes = seconds % 3600 // 60
319             seconds = seconds % 60
320             return '%d:%02d:%02d' % (hours, minutes, seconds)
321
322     def get_audio_length(self):
323         total = 0
324         for media in self.get_mp3() or ():
325             total += app_settings.GET_MP3_LENGTH(media.file.path)
326         return int(total)
327
328     def has_media(self, type_):
329         if type_ in Book.formats:
330             return bool(getattr(self, "%s_file" % type_))
331         else:
332             return self.media.filter(type=type_).exists()
333
334     def has_audio(self):
335         return self.has_media('mp3')
336
337     def get_media(self, type_):
338         if self.has_media(type_):
339             if type_ in Book.formats:
340                 return getattr(self, "%s_file" % type_)
341             else:
342                 return self.media.filter(type=type_)
343         else:
344             return None
345
346     def get_mp3(self):
347         return self.get_media("mp3")
348
349     def get_odt(self):
350         return self.get_media("odt")
351
352     def get_ogg(self):
353         return self.get_media("ogg")
354
355     def get_daisy(self):
356         return self.get_media("daisy")
357
358     def media_url(self, format_):
359         media = self.get_media(format_)
360         if media:
361             if self.preview:
362                 return reverse('embargo_link', kwargs={'key': self.preview_key, 'slug': self.slug, 'format_': format_})
363             else:
364                 return media.url
365         else:
366             return None
367
368     def html_url(self):
369         return self.media_url('html')
370
371     def pdf_url(self):
372         return self.media_url('pdf')
373
374     def epub_url(self):
375         return self.media_url('epub')
376
377     def mobi_url(self):
378         return self.media_url('mobi')
379
380     def txt_url(self):
381         return self.media_url('txt')
382
383     def fb2_url(self):
384         return self.media_url('fb2')
385
386     def xml_url(self):
387         return self.media_url('xml')
388
389     def has_description(self):
390         return len(self.description) > 0
391     has_description.short_description = _('description')
392     has_description.boolean = True
393
394     def has_mp3_file(self):
395         return self.has_media("mp3")
396     has_mp3_file.short_description = 'MP3'
397     has_mp3_file.boolean = True
398
399     def has_ogg_file(self):
400         return self.has_media("ogg")
401     has_ogg_file.short_description = 'OGG'
402     has_ogg_file.boolean = True
403
404     def has_daisy_file(self):
405         return self.has_media("daisy")
406     has_daisy_file.short_description = 'DAISY'
407     has_daisy_file.boolean = True
408
409     def get_audiobooks(self):
410         ogg_files = {}
411         for m in self.media.filter(type='ogg').order_by().iterator():
412             ogg_files[m.name] = m
413
414         audiobooks = []
415         projects = set()
416         for mp3 in self.media.filter(type='mp3').iterator():
417             # ogg files are always from the same project
418             meta = mp3.get_extra_info_json()
419             project = meta.get('project')
420             if not project:
421                 # temporary fallback
422                 project = 'CzytamySłuchając'
423
424             projects.add((project, meta.get('funded_by', '')))
425
426             media = {'mp3': mp3}
427
428             ogg = ogg_files.get(mp3.name)
429             if ogg:
430                 media['ogg'] = ogg
431             audiobooks.append(media)
432
433         projects = sorted(projects)
434         return audiobooks, projects
435
436     def wldocument(self, parse_dublincore=True, inherit=True):
437         from catalogue.import_utils import ORMDocProvider
438         from librarian.parser import WLDocument
439
440         if inherit and self.parent:
441             meta_fallbacks = self.parent.cover_info()
442         else:
443             meta_fallbacks = None
444
445         return WLDocument.from_file(
446             self.xml_file.path,
447             provider=ORMDocProvider(self),
448             parse_dublincore=parse_dublincore,
449             meta_fallbacks=meta_fallbacks)
450
451     @staticmethod
452     def zip_format(format_):
453         def pretty_file_name(book):
454             return "%s/%s.%s" % (
455                 book.get_extra_info_json()['author'],
456                 book.slug,
457                 format_)
458
459         field_name = "%s_file" % format_
460         books = Book.objects.filter(parent=None).exclude(**{field_name: ""}).exclude(preview=True).exclude(findable=False)
461         paths = [(pretty_file_name(b), getattr(b, field_name).path) for b in books.iterator()]
462         return create_zip(paths, app_settings.FORMAT_ZIPS[format_])
463
464     def zip_audiobooks(self, format_):
465         bm = BookMedia.objects.filter(book=self, type=format_)
466         paths = map(lambda bm: (None, bm.file.path), bm)
467         return create_zip(paths, "%s_%s" % (self.slug, format_))
468
469     def search_index(self, book_info=None, index=None, index_tags=True, commit=True):
470         if not self.findable:
471             return
472         if index is None:
473             from search.index import Index
474             index = Index()
475         try:
476             index.index_book(self, book_info)
477             if index_tags:
478                 index.index_tags()
479             if commit:
480                 index.index.commit()
481         except Exception as e:
482             index.index.rollback()
483             raise e
484
485     # will make problems in conjunction with paid previews
486     def download_pictures(self, remote_gallery_url):
487         gallery_path = self.gallery_path()
488         # delete previous files, so we don't include old files in ebooks
489         if os.path.isdir(gallery_path):
490             for filename in os.listdir(gallery_path):
491                 file_path = os.path.join(gallery_path, filename)
492                 os.unlink(file_path)
493         ilustr_elements = list(self.wldocument().edoc.findall('//ilustr'))
494         if ilustr_elements:
495             makedirs(gallery_path)
496             for ilustr in ilustr_elements:
497                 ilustr_src = ilustr.get('src')
498                 ilustr_path = os.path.join(gallery_path, ilustr_src)
499                 urlretrieve('%s/%s' % (remote_gallery_url, ilustr_src), ilustr_path)
500
501     def load_abstract(self):
502         abstract = self.wldocument(parse_dublincore=False).edoc.getroot().find('.//abstrakt')
503         if abstract is not None:
504             self.abstract = transform_abstrakt(abstract)
505         else:
506             self.abstract = ''
507
508     @classmethod
509     def from_xml_file(cls, xml_file, **kwargs):
510         from django.core.files import File
511         from librarian import dcparser
512
513         # use librarian to parse meta-data
514         book_info = dcparser.parse(xml_file)
515
516         if not isinstance(xml_file, File):
517             xml_file = File(open(xml_file))
518
519         try:
520             return cls.from_text_and_meta(xml_file, book_info, **kwargs)
521         finally:
522             xml_file.close()
523
524     @classmethod
525     def from_text_and_meta(cls, raw_file, book_info, overwrite=False, dont_build=None, search_index=True,
526                            search_index_tags=True, remote_gallery_url=None, days=0, findable=True):
527         if dont_build is None:
528             dont_build = set()
529         dont_build = set.union(set(dont_build), set(app_settings.DONT_BUILD))
530
531         # check for parts before we do anything
532         children = []
533         if hasattr(book_info, 'parts'):
534             for part_url in book_info.parts:
535                 try:
536                     children.append(Book.objects.get(slug=part_url.slug))
537                 except Book.DoesNotExist:
538                     raise Book.DoesNotExist(_('Book "%s" does not exist.') % part_url.slug)
539
540         # Read book metadata
541         book_slug = book_info.url.slug
542         if re.search(r'[^a-z0-9-]', book_slug):
543             raise ValueError('Invalid characters in slug')
544         book, created = Book.objects.get_or_create(slug=book_slug)
545
546         if created:
547             book_shelves = []
548             old_cover = None
549             book.preview = bool(days)
550             if book.preview:
551                 book.preview_until = date.today() + timedelta(days)
552         else:
553             if not overwrite:
554                 raise Book.AlreadyExists(_('Book %s already exists') % book_slug)
555             # Save shelves for this book
556             book_shelves = list(book.tags.filter(category='set'))
557             old_cover = book.cover_info()
558
559         # Save XML file
560         book.xml_file.save('%s.xml' % book.slug, raw_file, save=False)
561         if book.preview:
562             book.xml_file.set_readable(False)
563
564         book.findable = findable
565         book.language = book_info.language
566         book.title = book_info.title
567         if book_info.variant_of:
568             book.common_slug = book_info.variant_of.slug
569         else:
570             book.common_slug = book.slug
571         book.extra_info = json.dumps(book_info.to_dict())
572         book.load_abstract()
573         book.save()
574
575         meta_tags = Tag.tags_from_info(book_info)
576
577         for tag in meta_tags:
578             if not tag.for_books:
579                 tag.for_books = True
580                 tag.save()
581
582         book.tags = set(meta_tags + book_shelves)
583         book.save()  # update sort_key_author
584
585         cover_changed = old_cover != book.cover_info()
586         obsolete_children = set(b for b in book.children.all()
587                                 if b not in children)
588         notify_cover_changed = []
589         for n, child_book in enumerate(children):
590             new_child = child_book.parent != book
591             child_book.parent = book
592             child_book.parent_number = n
593             child_book.save()
594             if new_child or cover_changed:
595                 notify_cover_changed.append(child_book)
596         # Disown unfaithful children and let them cope on their own.
597         for child in obsolete_children:
598             child.parent = None
599             child.parent_number = 0
600             child.save()
601             if old_cover:
602                 notify_cover_changed.append(child)
603
604         cls.repopulate_ancestors()
605         tasks.update_counters.delay()
606
607         if remote_gallery_url:
608             book.download_pictures(remote_gallery_url)
609
610         # No saves beyond this point.
611
612         # Build cover.
613         if 'cover' not in dont_build:
614             book.cover.build_delay()
615             book.cover_thumb.build_delay()
616             book.cover_api_thumb.build_delay()
617             book.simple_cover.build_delay()
618             book.cover_ebookpoint.build_delay()
619
620         # Build HTML and ebooks.
621         book.html_file.build_delay()
622         if not children:
623             for format_ in constants.EBOOK_FORMATS_WITHOUT_CHILDREN:
624                 if format_ not in dont_build:
625                     getattr(book, '%s_file' % format_).build_delay()
626         for format_ in constants.EBOOK_FORMATS_WITH_CHILDREN:
627             if format_ not in dont_build:
628                 getattr(book, '%s_file' % format_).build_delay()
629
630         if not settings.NO_SEARCH_INDEX and search_index and findable:
631             tasks.index_book.delay(book.id, book_info=book_info, index_tags=search_index_tags)
632
633         for child in notify_cover_changed:
634             child.parent_cover_changed()
635
636         book.update_popularity()
637         cls.published.send(sender=cls, instance=book)
638         return book
639
640     @classmethod
641     @transaction.atomic
642     def repopulate_ancestors(cls):
643         """Fixes the ancestry cache."""
644         # TODO: table names
645         cursor = connection.cursor()
646         if connection.vendor == 'postgres':
647             cursor.execute("TRUNCATE catalogue_book_ancestor")
648             cursor.execute("""
649                 WITH RECURSIVE ancestry AS (
650                     SELECT book.id, book.parent_id
651                     FROM catalogue_book AS book
652                     WHERE book.parent_id IS NOT NULL
653                     UNION
654                     SELECT ancestor.id, book.parent_id
655                     FROM ancestry AS ancestor, catalogue_book AS book
656                     WHERE ancestor.parent_id = book.id
657                         AND book.parent_id IS NOT NULL
658                     )
659                 INSERT INTO catalogue_book_ancestor
660                     (from_book_id, to_book_id)
661                     SELECT id, parent_id
662                     FROM ancestry
663                     ORDER BY id;
664                 """)
665         else:
666             cursor.execute("DELETE FROM catalogue_book_ancestor")
667             for b in cls.objects.exclude(parent=None):
668                 parent = b.parent
669                 while parent is not None:
670                     b.ancestor.add(parent)
671                     parent = parent.parent
672
673     def clear_cache(self):
674         clear_cached_renders(self.mini_box)
675         clear_cached_renders(self.mini_box_nolink)
676
677     def cover_info(self, inherit=True):
678         """Returns a dictionary to serve as fallback for BookInfo.
679
680         For now, the only thing inherited is the cover image.
681         """
682         need = False
683         info = {}
684         for field in ('cover_url', 'cover_by', 'cover_source'):
685             val = self.get_extra_info_json().get(field)
686             if val:
687                 info[field] = val
688             else:
689                 need = True
690         if inherit and need and self.parent is not None:
691             parent_info = self.parent.cover_info()
692             parent_info.update(info)
693             info = parent_info
694         return info
695
696     def related_themes(self):
697         return Tag.objects.usage_for_queryset(
698             Fragment.objects.filter(models.Q(book=self) | models.Q(book__ancestor=self)),
699             counts=True).filter(category='theme')
700
701     def parent_cover_changed(self):
702         """Called when parent book's cover image is changed."""
703         if not self.cover_info(inherit=False):
704             if 'cover' not in app_settings.DONT_BUILD:
705                 self.cover.build_delay()
706                 self.cover_thumb.build_delay()
707                 self.cover_api_thumb.build_delay()
708                 self.simple_cover.build_delay()
709             for format_ in constants.EBOOK_FORMATS_WITH_COVERS:
710                 if format_ not in app_settings.DONT_BUILD:
711                     getattr(self, '%s_file' % format_).build_delay()
712             for child in self.children.all():
713                 child.parent_cover_changed()
714
715     def other_versions(self):
716         """Find other versions (i.e. in other languages) of the book."""
717         return type(self).objects.filter(common_slug=self.common_slug, findable=True).exclude(pk=self.pk)
718
719     def parents(self):
720         books = []
721         parent = self.parent
722         while parent is not None:
723             books.insert(0, parent)
724             parent = parent.parent
725         return books
726
727     def pretty_title(self, html_links=False):
728         names = [(tag.name, tag.get_absolute_url()) for tag in self.authors().only('name', 'category', 'slug')]
729         books = self.parents() + [self]
730         names.extend([(b.title, b.get_absolute_url()) for b in books])
731
732         if html_links:
733             names = ['<a href="%s">%s</a>' % (tag[1], tag[0]) for tag in names]
734         else:
735             names = [tag[0] for tag in names]
736         return ', '.join(names)
737
738     def publisher(self):
739         publisher = self.get_extra_info_json()['publisher']
740         if isinstance(publisher, str):
741             return publisher
742         elif isinstance(publisher, list):
743             return ', '.join(publisher)
744
745     @classmethod
746     def tagged_top_level(cls, tags):
747         """ Returns top-level books tagged with `tags`.
748
749         It only returns those books which don't have ancestors which are
750         also tagged with those tags.
751
752         """
753         objects = cls.tagged.with_all(tags)
754         return objects.filter(findable=True).exclude(ancestor__in=objects)
755
756     @classmethod
757     def book_list(cls, book_filter=None):
758         """Generates a hierarchical listing of all books.
759
760         Books are optionally filtered with a test function.
761
762         """
763
764         books_by_parent = {}
765         books = cls.objects.filter(findable=True).order_by('parent_number', 'sort_key').only('title', 'parent', 'slug', 'extra_info')
766         if book_filter:
767             books = books.filter(book_filter).distinct()
768
769             book_ids = set(b['pk'] for b in books.values("pk").iterator())
770             for book in books.iterator():
771                 parent = book.parent_id
772                 if parent not in book_ids:
773                     parent = None
774                 books_by_parent.setdefault(parent, []).append(book)
775         else:
776             for book in books.iterator():
777                 books_by_parent.setdefault(book.parent_id, []).append(book)
778
779         orphans = []
780         books_by_author = OrderedDict()
781         for tag in Tag.objects.filter(category='author').iterator():
782             books_by_author[tag] = []
783
784         for book in books_by_parent.get(None, ()):
785             authors = list(book.authors().only('pk'))
786             if authors:
787                 for author in authors:
788                     books_by_author[author].append(book)
789             else:
790                 orphans.append(book)
791
792         return books_by_author, orphans, books_by_parent
793
794     _audiences_pl = {
795         "SP": (1, "szkoła podstawowa"),
796         "SP1": (1, "szkoła podstawowa"),
797         "SP2": (1, "szkoła podstawowa"),
798         "SP3": (1, "szkoła podstawowa"),
799         "P": (1, "szkoła podstawowa"),
800         "G": (2, "gimnazjum"),
801         "L": (3, "liceum"),
802         "LP": (3, "liceum"),
803     }
804
805     def audiences_pl(self):
806         audiences = self.get_extra_info_json().get('audiences', [])
807         audiences = sorted(set([self._audiences_pl.get(a, (99, a)) for a in audiences]))
808         return [a[1] for a in audiences]
809
810     def stage_note(self):
811         stage = self.get_extra_info_json().get('stage')
812         if stage and stage < '0.4':
813             return (_('This work needs modernisation'),
814                     reverse('infopage', args=['wymagajace-uwspolczesnienia']))
815         else:
816             return None, None
817
818     def choose_fragment(self):
819         fragments = self.fragments.order_by()
820         fragments_count = fragments.count()
821         if not fragments_count and self.children.exists():
822             fragments = Fragment.objects.filter(book__ancestor=self).order_by()
823             fragments_count = fragments.count()
824         if fragments_count:
825             return fragments[randint(0, fragments_count - 1)]
826         elif self.parent:
827             return self.parent.choose_fragment()
828         else:
829             return None
830
831     def fragment_data(self):
832         fragment = self.choose_fragment()
833         if fragment:
834             return {
835                 'title': fragment.book.pretty_title(),
836                 'html': re.sub('</?blockquote[^>]*>', '', fragment.get_short_text()),
837             }
838         else:
839             return None
840
841     def update_popularity(self):
842         count = self.tags.filter(category='set').values('user').order_by('user').distinct().count()
843         try:
844             pop = self.popularity
845             pop.count = count
846             pop.save()
847         except BookPopularity.DoesNotExist:
848             BookPopularity.objects.create(book=self, count=count)
849
850     def ridero_link(self):
851         return 'https://ridero.eu/%s/books/wl_%s/' % (get_language(), self.slug.replace('-', '_'))
852
853     def like(self, user):
854         from social.utils import likes, get_set, set_sets
855         if not likes(user, self):
856             tag = get_set(user, '')
857             set_sets(user, self, [tag])
858
859     def unlike(self, user):
860         from social.utils import likes, set_sets
861         if likes(user, self):
862             set_sets(user, self, [])
863
864     def full_sort_key(self):
865         return self.SORT_KEY_SEP.join((self.sort_key_author, self.sort_key, str(self.id)))
866
867     def cover_color(self):
868         return WLCover.epoch_colors.get(self.get_extra_info_json().get('epoch'), '#000000')
869
870     @cached_render('catalogue/book_mini_box.html')
871     def mini_box(self):
872         return {
873             'book': self
874         }
875
876     @cached_render('catalogue/book_mini_box.html')
877     def mini_box_nolink(self):
878         return {
879             'book': self,
880             'no_link': True,
881         }
882
883 def add_file_fields():
884     for format_ in Book.formats:
885         field_name = "%s_file" % format_
886         # This weird globals() assignment makes Django migrations comfortable.
887         _upload_to = _ebook_upload_to('book/%s/%%s.%s' % (format_, format_))
888         _upload_to.__name__ = '_%s_upload_to' % format_
889         globals()[_upload_to.__name__] = _upload_to
890
891         EbookField(
892             format_, _("%s file" % format_.upper()),
893             upload_to=_upload_to,
894             storage=bofh_storage,
895             max_length=255,
896             blank=True,
897             default=''
898         ).contribute_to_class(Book, field_name)
899         if format_ != 'xml':
900             models.CharField(max_length=255, editable=False, default='', db_index=True).contribute_to_class(Book, f'{field_name}_etag')
901
902
903 add_file_fields()
904
905
906 class BookPopularity(models.Model):
907     book = models.OneToOneField(Book, models.CASCADE, related_name='popularity')
908     count = models.IntegerField(default=0, db_index=True)