Bar text update.
[wolnelektury.git] / src / catalogue / models / book.py
index 0ed9716..c0d47f9 100644 (file)
@@ -3,6 +3,7 @@
 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
 #
 from collections import OrderedDict
 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
 #
 from collections import OrderedDict
+from datetime import date, timedelta
 from random import randint
 import os.path
 import re
 from random import randint
 import os.path
 import re
@@ -13,15 +14,20 @@ from django.db.models import permalink
 import django.dispatch
 from django.contrib.contenttypes.fields import GenericRelation
 from django.core.urlresolvers import reverse
 import django.dispatch
 from django.contrib.contenttypes.fields import GenericRelation
 from django.core.urlresolvers import reverse
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import ugettext_lazy as _, get_language
+from django.utils.deconstruct import deconstructible
 import jsonfield
 from fnpdjango.storage import BofhFileSystemStorage
 from ssify import flush_ssi_includes
 import jsonfield
 from fnpdjango.storage import BofhFileSystemStorage
 from ssify import flush_ssi_includes
+
+from librarian.cover import WLCover
+from librarian.html import transform_abstrakt
 from newtagging import managers
 from catalogue import constants
 from catalogue.fields import EbookField
 from catalogue.models import Tag, Fragment, BookMedia
 from newtagging import managers
 from catalogue import constants
 from catalogue.fields import EbookField
 from catalogue.models import Tag, Fragment, BookMedia
-from catalogue.utils import create_zip, gallery_url, gallery_path
+from catalogue.utils import create_zip, gallery_url, gallery_path, split_tags
+from catalogue.models.tag import prefetched_relations
 from catalogue import app_settings
 from catalogue import tasks
 from wolnelektury.utils import makedirs
 from catalogue import app_settings
 from catalogue import tasks
 from wolnelektury.utils import makedirs
@@ -29,18 +35,23 @@ from wolnelektury.utils import makedirs
 bofh_storage = BofhFileSystemStorage()
 
 
 bofh_storage = BofhFileSystemStorage()
 
 
-def _make_upload_to(path):
-    def _upload_to(i, n):
-        return path % i.slug
-    return _upload_to
+@deconstructible
+class UploadToPath(object):
+    def __init__(self, path):
+        self.path = path
+
+    def __call__(self, instance, filename):
+        return self.path % instance.slug
 
 
 
 
-_cover_upload_to = _make_upload_to('book/cover/%s.jpg')
-_cover_thumb_upload_to = _make_upload_to('book/cover_thumb/%s.jpg')
+_cover_upload_to = UploadToPath('book/cover/%s.jpg')
+_cover_thumb_upload_to = UploadToPath('book/cover_thumb/%s.jpg')
+_cover_api_thumb_upload_to = UploadToPath('book/cover_api_thumb/%s.jpg')
+_simple_cover_upload_to = UploadToPath('book/cover_simple/%s.jpg')
 
 
 def _ebook_upload_to(upload_path):
 
 
 def _ebook_upload_to(upload_path):
-    return _make_upload_to(upload_path)
+    return UploadToPath(upload_path)
 
 
 class Book(models.Model):
 
 
 class Book(models.Model):
@@ -53,12 +64,18 @@ class Book(models.Model):
     common_slug = models.SlugField(_('slug'), max_length=120, db_index=True)
     language = models.CharField(_('language code'), max_length=3, db_index=True, default=app_settings.DEFAULT_LANGUAGE)
     description = models.TextField(_('description'), blank=True)
     common_slug = models.SlugField(_('slug'), max_length=120, db_index=True)
     language = models.CharField(_('language code'), max_length=3, db_index=True, default=app_settings.DEFAULT_LANGUAGE)
     description = models.TextField(_('description'), blank=True)
+    abstract = models.TextField(_('abstract'), blank=True)
     created_at = models.DateTimeField(_('creation date'), auto_now_add=True, db_index=True)
     created_at = models.DateTimeField(_('creation date'), auto_now_add=True, db_index=True)
-    changed_at = models.DateTimeField(_('creation date'), auto_now=True, db_index=True)
+    changed_at = models.DateTimeField(_('change date'), auto_now=True, db_index=True)
     parent_number = models.IntegerField(_('parent number'), default=0)
     extra_info = jsonfield.JSONField(_('extra information'), default={})
     gazeta_link = models.CharField(blank=True, max_length=240)
     wiki_link = models.CharField(blank=True, max_length=240)
     parent_number = models.IntegerField(_('parent number'), default=0)
     extra_info = jsonfield.JSONField(_('extra information'), default={})
     gazeta_link = models.CharField(blank=True, max_length=240)
     wiki_link = models.CharField(blank=True, max_length=240)
+    print_on_demand = models.BooleanField(_('print on demand'), default=False)
+    recommended = models.BooleanField(_('recommended'), default=False)
+    audio_length = models.CharField(_('audio length'), blank=True, max_length=8)
+    preview = models.BooleanField(_('preview'), default=False)
+    preview_until = models.DateField(_('preview until'), blank=True, null=True)
 
     # files generated during publication
     cover = EbookField(
 
     # files generated during publication
     cover = EbookField(
@@ -72,12 +89,25 @@ class Book(models.Model):
         null=True, blank=True,
         upload_to=_cover_thumb_upload_to,
         max_length=255)
         null=True, blank=True,
         upload_to=_cover_thumb_upload_to,
         max_length=255)
+    cover_api_thumb = EbookField(
+        'cover_api_thumb', _('cover thumbnail for mobile app'),
+        null=True, blank=True,
+        upload_to=_cover_api_thumb_upload_to,
+        max_length=255)
+    simple_cover = EbookField(
+        'simple_cover', _('cover for mobile app'),
+        null=True, blank=True,
+        upload_to=_simple_cover_upload_to,
+        max_length=255)
     ebook_formats = constants.EBOOK_FORMATS
     formats = ebook_formats + ['html', 'xml']
 
     parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
     ancestor = models.ManyToManyField('self', blank=True, editable=False, related_name='descendant', symmetrical=False)
 
     ebook_formats = constants.EBOOK_FORMATS
     formats = ebook_formats + ['html', 'xml']
 
     parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
     ancestor = models.ManyToManyField('self', blank=True, editable=False, related_name='descendant', symmetrical=False)
 
+    cached_author = models.CharField(blank=True, max_length=240, db_index=True)
+    has_audience = models.BooleanField(default=False)
+
     objects = models.Manager()
     tagged = managers.ModelTaggedItemManager(Tag)
     tags = managers.TagDescriptor(Tag)
     objects = models.Manager()
     tagged = managers.ModelTaggedItemManager(Tag)
     tags = managers.TagDescriptor(Tag)
@@ -86,7 +116,7 @@ class Book(models.Model):
     html_built = django.dispatch.Signal()
     published = django.dispatch.Signal()
 
     html_built = django.dispatch.Signal()
     published = django.dispatch.Signal()
 
-    short_html_url_name = 'catalogue_book_short'
+    SORT_KEY_SEP = '$'
 
     class AlreadyExists(Exception):
         pass
 
     class AlreadyExists(Exception):
         pass
@@ -97,7 +127,7 @@ class Book(models.Model):
         verbose_name_plural = _('books')
         app_label = 'catalogue'
 
         verbose_name_plural = _('books')
         app_label = 'catalogue'
 
-    def __unicode__(self):
+    def __str__(self):
         return self.title
 
     def get_initial(self):
         return self.title
 
     def get_initial(self):
@@ -109,14 +139,56 @@ class Book(models.Model):
     def authors(self):
         return self.tags.filter(category='author')
 
     def authors(self):
         return self.tags.filter(category='author')
 
+    def epochs(self):
+        return self.tags.filter(category='epoch')
+
+    def genres(self):
+        return self.tags.filter(category='genre')
+
+    def kinds(self):
+        return self.tags.filter(category='kind')
+
+    def tag_unicode(self, category):
+        relations = prefetched_relations(self, category)
+        if relations:
+            return ', '.join(rel.tag.name for rel in relations)
+        else:
+            return ', '.join(self.tags.filter(category=category).values_list('name', flat=True))
+
+    def tags_by_category(self):
+        return split_tags(self.tags.exclude(category__in=('set', 'theme')))
+
     def author_unicode(self):
     def author_unicode(self):
-        return ", ".join(self.authors().values_list('name', flat=True))
+        return self.cached_author
+
+    def kind_unicode(self):
+        return self.tag_unicode('kind')
+
+    def epoch_unicode(self):
+        return self.tag_unicode('epoch')
+
+    def genre_unicode(self):
+        return self.tag_unicode('genre')
+
+    def translator(self):
+        translators = self.extra_info.get('translators')
+        if not translators:
+            return None
+        if len(translators) > 3:
+            translators = translators[:2]
+            others = ' i inni'
+        else:
+            others = ''
+        return ', '.join(u'\xa0'.join(reversed(translator.split(', ', 1))) for translator in translators) + others
+
+    def cover_source(self):
+        return self.extra_info.get('cover_source', self.parent.cover_source() if self.parent else '')
 
     def save(self, force_insert=False, force_update=False, **kwargs):
         from sortify import sortify
 
         self.sort_key = sortify(self.title)[:120]
 
     def save(self, force_insert=False, force_update=False, **kwargs):
         from sortify import sortify
 
         self.sort_key = sortify(self.title)[:120]
-        self.title = unicode(self.title)  # ???
+        self.title = str(self.title)  # ???
 
         try:
             author = self.authors().first().sort_key
 
         try:
             author = self.authors().first().sort_key
@@ -124,18 +196,16 @@ class Book(models.Model):
             author = u''
         self.sort_key_author = author
 
             author = u''
         self.sort_key_author = author
 
+        self.cached_author = self.tag_unicode('author')
+        self.has_audience = 'audience' in self.extra_info
+
         ret = super(Book, self).save(force_insert, force_update, **kwargs)
 
         return ret
 
     @permalink
     def get_absolute_url(self):
         ret = super(Book, self).save(force_insert, force_update, **kwargs)
 
         return ret
 
     @permalink
     def get_absolute_url(self):
-        return 'catalogue.views.book_detail', [self.slug]
-
-    @staticmethod
-    @permalink
-    def create_url(slug):
-        return 'catalogue.views.book_detail', [slug]
+        return 'book_detail', [self.slug]
 
     def gallery_path(self):
         return gallery_path(self.slug)
 
     def gallery_path(self):
         return gallery_path(self.slug)
@@ -156,12 +226,39 @@ class Book(models.Model):
     def is_foreign(self):
         return self.language_code() != settings.LANGUAGE_CODE
 
     def is_foreign(self):
         return self.language_code() != settings.LANGUAGE_CODE
 
+    def set_audio_length(self):
+        length = self.get_audio_length()
+        if length > 0:
+            self.audio_length = self.format_audio_length(length)
+            self.save()
+
+    @staticmethod
+    def format_audio_length(seconds):
+        if seconds < 60*60:
+            minutes = seconds // 60
+            seconds = seconds % 60
+            return '%d:%02d' % (minutes, seconds)
+        else:
+            hours = seconds // 3600
+            minutes = seconds % 3600 // 60
+            seconds = seconds % 60
+            return '%d:%02d:%02d' % (hours, minutes, seconds)
+
+    def get_audio_length(self):
+        total = 0
+        for media in self.get_mp3() or ():
+            total += app_settings.GET_MP3_LENGTH(media.file.path)
+        return int(total)
+
     def has_media(self, type_):
         if type_ in Book.formats:
             return bool(getattr(self, "%s_file" % type_))
         else:
             return self.media.filter(type=type_).exists()
 
     def has_media(self, type_):
         if type_ in Book.formats:
             return bool(getattr(self, "%s_file" % type_))
         else:
             return self.media.filter(type=type_).exists()
 
+    def has_audio(self):
+        return self.has_media('mp3')
+
     def get_media(self, type_):
         if self.has_media(type_):
             if type_ in Book.formats:
     def get_media(self, type_):
         if self.has_media(type_):
             if type_ in Book.formats:
@@ -183,27 +280,84 @@ class Book(models.Model):
     def get_daisy(self):
         return self.get_media("daisy")
 
     def get_daisy(self):
         return self.get_media("daisy")
 
+    def media_url(self, format_):
+        media = self.get_media(format_)
+        if media:
+            if self.preview:
+                return reverse('embargo_link', kwargs={'slug': self.slug, 'format_': format_})
+            else:
+                return media.url
+        else:
+            return None
+
+    def html_url(self):
+        return self.media_url('html')
+
+    def pdf_url(self):
+        return self.media_url('pdf')
+
+    def epub_url(self):
+        return self.media_url('epub')
+
+    def mobi_url(self):
+        return self.media_url('mobi')
+
+    def txt_url(self):
+        return self.media_url('txt')
+
+    def fb2_url(self):
+        return self.media_url('fb2')
+
+    def xml_url(self):
+        return self.media_url('xml')
+
     def has_description(self):
         return len(self.description) > 0
     has_description.short_description = _('description')
     has_description.boolean = True
 
     def has_description(self):
         return len(self.description) > 0
     has_description.short_description = _('description')
     has_description.boolean = True
 
-    # ugly ugly ugly
     def has_mp3_file(self):
     def has_mp3_file(self):
-        return bool(self.has_media("mp3"))
+        return self.has_media("mp3")
     has_mp3_file.short_description = 'MP3'
     has_mp3_file.boolean = True
 
     def has_ogg_file(self):
     has_mp3_file.short_description = 'MP3'
     has_mp3_file.boolean = True
 
     def has_ogg_file(self):
-        return bool(self.has_media("ogg"))
+        return self.has_media("ogg")
     has_ogg_file.short_description = 'OGG'
     has_ogg_file.boolean = True
 
     def has_daisy_file(self):
     has_ogg_file.short_description = 'OGG'
     has_ogg_file.boolean = True
 
     def has_daisy_file(self):
-        return bool(self.has_media("daisy"))
+        return self.has_media("daisy")
     has_daisy_file.short_description = 'DAISY'
     has_daisy_file.boolean = True
 
     has_daisy_file.short_description = 'DAISY'
     has_daisy_file.boolean = True
 
+    def get_audiobooks(self):
+        ogg_files = {}
+        for m in self.media.filter(type='ogg').order_by().iterator():
+            ogg_files[m.name] = m
+
+        audiobooks = []
+        projects = set()
+        for mp3 in self.media.filter(type='mp3').iterator():
+            # ogg files are always from the same project
+            meta = mp3.extra_info
+            project = meta.get('project')
+            if not project:
+                # temporary fallback
+                project = u'CzytamySłuchając'
+
+            projects.add((project, meta.get('funded_by', '')))
+
+            media = {'mp3': mp3}
+
+            ogg = ogg_files.get(mp3.name)
+            if ogg:
+                media['ogg'] = ogg
+            audiobooks.append(media)
+
+        projects = sorted(projects)
+        return audiobooks, projects
+
     def wldocument(self, parse_dublincore=True, inherit=True):
         from catalogue.import_utils import ORMDocProvider
         from librarian.parser import WLDocument
     def wldocument(self, parse_dublincore=True, inherit=True):
         from catalogue.import_utils import ORMDocProvider
         from librarian.parser import WLDocument
@@ -228,7 +382,7 @@ class Book(models.Model):
                 format_)
 
         field_name = "%s_file" % format_
                 format_)
 
         field_name = "%s_file" % format_
-        books = Book.objects.filter(parent=None).exclude(**{field_name: ""})
+        books = Book.objects.filter(parent=None).exclude(**{field_name: ""}).exclude(preview=True)
         paths = [(pretty_file_name(b), getattr(b, field_name).path) for b in books.iterator()]
         return create_zip(paths, app_settings.FORMAT_ZIPS[format_])
 
         paths = [(pretty_file_name(b), getattr(b, field_name).path) for b in books.iterator()]
         return create_zip(paths, app_settings.FORMAT_ZIPS[format_])
 
@@ -247,10 +401,11 @@ class Book(models.Model):
                 index.index_tags()
             if commit:
                 index.index.commit()
                 index.index_tags()
             if commit:
                 index.index.commit()
-        except Exception, e:
+        except Exception as e:
             index.index.rollback()
             raise e
 
             index.index.rollback()
             raise e
 
+    # will make problems in conjunction with paid previews
     def download_pictures(self, remote_gallery_url):
         gallery_path = self.gallery_path()
         # delete previous files, so we don't include old files in ebooks
     def download_pictures(self, remote_gallery_url):
         gallery_path = self.gallery_path()
         # delete previous files, so we don't include old files in ebooks
@@ -266,6 +421,13 @@ class Book(models.Model):
                 ilustr_path = os.path.join(gallery_path, ilustr_src)
                 urllib.urlretrieve('%s/%s' % (remote_gallery_url, ilustr_src), ilustr_path)
 
                 ilustr_path = os.path.join(gallery_path, ilustr_src)
                 urllib.urlretrieve('%s/%s' % (remote_gallery_url, ilustr_src), ilustr_path)
 
+    def load_abstract(self):
+        abstract = self.wldocument(parse_dublincore=False).edoc.getroot().find('.//abstrakt')
+        if abstract is not None:
+            self.abstract = transform_abstrakt(abstract)
+        else:
+            self.abstract = ''
+
     @classmethod
     def from_xml_file(cls, xml_file, **kwargs):
         from django.core.files import File
     @classmethod
     def from_xml_file(cls, xml_file, **kwargs):
         from django.core.files import File
@@ -284,7 +446,7 @@ class Book(models.Model):
 
     @classmethod
     def from_text_and_meta(cls, raw_file, book_info, overwrite=False, dont_build=None, search_index=True,
 
     @classmethod
     def from_text_and_meta(cls, raw_file, book_info, overwrite=False, dont_build=None, search_index=True,
-                           search_index_tags=True, remote_gallery_url=None):
+                           search_index_tags=True, remote_gallery_url=None, days=0):
         if dont_build is None:
             dont_build = set()
         dont_build = set.union(set(dont_build), set(app_settings.DONT_BUILD))
         if dont_build is None:
             dont_build = set()
         dont_build = set.union(set(dont_build), set(app_settings.DONT_BUILD))
@@ -307,6 +469,9 @@ class Book(models.Model):
         if created:
             book_shelves = []
             old_cover = None
         if created:
             book_shelves = []
             old_cover = None
+            book.preview = bool(days)
+            if book.preview:
+                book.preview_until = date.today() + timedelta(days)
         else:
             if not overwrite:
                 raise Book.AlreadyExists(_('Book %s already exists') % book_slug)
         else:
             if not overwrite:
                 raise Book.AlreadyExists(_('Book %s already exists') % book_slug)
@@ -316,6 +481,8 @@ class Book(models.Model):
 
         # Save XML file
         book.xml_file.save('%s.xml' % book.slug, raw_file, save=False)
 
         # Save XML file
         book.xml_file.save('%s.xml' % book.slug, raw_file, save=False)
+        if book.preview:
+            book.xml_file.set_readable(False)
 
         book.language = book_info.language
         book.title = book_info.title
 
         book.language = book_info.language
         book.title = book_info.title
@@ -324,10 +491,16 @@ class Book(models.Model):
         else:
             book.common_slug = book.slug
         book.extra_info = book_info.to_dict()
         else:
             book.common_slug = book.slug
         book.extra_info = book_info.to_dict()
+        book.load_abstract()
         book.save()
 
         meta_tags = Tag.tags_from_info(book_info)
 
         book.save()
 
         meta_tags = Tag.tags_from_info(book_info)
 
+        for tag in meta_tags:
+            if not tag.for_books:
+                tag.for_books = True
+                tag.save()
+
         book.tags = set(meta_tags + book_shelves)
 
         cover_changed = old_cover != book.cover_info()
         book.tags = set(meta_tags + book_shelves)
 
         cover_changed = old_cover != book.cover_info()
@@ -361,6 +534,8 @@ class Book(models.Model):
         if 'cover' not in dont_build:
             book.cover.build_delay()
             book.cover_thumb.build_delay()
         if 'cover' not in dont_build:
             book.cover.build_delay()
             book.cover_thumb.build_delay()
+            book.cover_api_thumb.build_delay()
+            book.simple_cover.build_delay()
 
         # Build HTML and ebooks.
         book.html_file.build_delay()
 
         # Build HTML and ebooks.
         book.html_file.build_delay()
@@ -378,6 +553,8 @@ class Book(models.Model):
         for child in notify_cover_changed:
             child.parent_cover_changed()
 
         for child in notify_cover_changed:
             child.parent_cover_changed()
 
+        book.save()  # update sort_key_author
+        book.update_popularity()
         cls.published.send(sender=cls, instance=book)
         return book
 
         cls.published.send(sender=cls, instance=book)
         return book
 
@@ -462,6 +639,8 @@ class Book(models.Model):
             if 'cover' not in app_settings.DONT_BUILD:
                 self.cover.build_delay()
                 self.cover_thumb.build_delay()
             if 'cover' not in app_settings.DONT_BUILD:
                 self.cover.build_delay()
                 self.cover_thumb.build_delay()
+                self.cover_api_thumb.build_delay()
+                self.simple_cover.build_delay()
             for format_ in constants.EBOOK_FORMATS_WITH_COVERS:
                 if format_ not in app_settings.DONT_BUILD:
                     getattr(self, '%s_file' % format_).build_delay()
             for format_ in constants.EBOOK_FORMATS_WITH_COVERS:
                 if format_ not in app_settings.DONT_BUILD:
                     getattr(self, '%s_file' % format_).build_delay()
@@ -491,6 +670,13 @@ class Book(models.Model):
             names = [tag[0] for tag in names]
         return ', '.join(names)
 
             names = [tag[0] for tag in names]
         return ', '.join(names)
 
+    def publisher(self):
+        publisher = self.extra_info['publisher']
+        if isinstance(publisher, str):
+            return publisher
+        elif isinstance(publisher, list):
+            return ', '.join(publisher)
+
     @classmethod
     def tagged_top_level(cls, tags):
         """ Returns top-level books tagged with `tags`.
     @classmethod
     def tagged_top_level(cls, tags):
         """ Returns top-level books tagged with `tags`.
@@ -511,7 +697,7 @@ class Book(models.Model):
         """
 
         books_by_parent = {}
         """
 
         books_by_parent = {}
-        books = cls.objects.order_by('parent_number', 'sort_key').only('title', 'parent', 'slug')
+        books = cls.objects.order_by('parent_number', 'sort_key').only('title', 'parent', 'slug', 'extra_info')
         if book_filter:
             books = books.filter(book_filter).distinct()
 
         if book_filter:
             books = books.filter(book_filter).distinct()
 
@@ -544,6 +730,7 @@ class Book(models.Model):
         "SP": (1, u"szkoła podstawowa"),
         "SP1": (1, u"szkoła podstawowa"),
         "SP2": (1, u"szkoła podstawowa"),
         "SP": (1, u"szkoła podstawowa"),
         "SP1": (1, u"szkoła podstawowa"),
         "SP2": (1, u"szkoła podstawowa"),
+        "SP3": (1, u"szkoła podstawowa"),
         "P": (1, u"szkoła podstawowa"),
         "G": (2, u"gimnazjum"),
         "L": (3, u"liceum"),
         "P": (1, u"szkoła podstawowa"),
         "G": (2, u"gimnazjum"),
         "L": (3, u"liceum"),
@@ -576,6 +763,16 @@ class Book(models.Model):
         else:
             return None
 
         else:
             return None
 
+    def fragment_data(self):
+        fragment = self.choose_fragment()
+        if fragment:
+            return {
+                'title': fragment.book.pretty_title(),
+                'html': re.sub('</?blockquote[^>]*>', '', fragment.get_short_text()),
+            }
+        else:
+            return None
+
     def update_popularity(self):
         count = self.tags.filter(category='set').values('user').order_by('user').distinct().count()
         try:
     def update_popularity(self):
         count = self.tags.filter(category='set').values('user').order_by('user').distinct().count()
         try:
@@ -585,6 +782,26 @@ class Book(models.Model):
         except BookPopularity.DoesNotExist:
             BookPopularity.objects.create(book=self, count=count)
 
         except BookPopularity.DoesNotExist:
             BookPopularity.objects.create(book=self, count=count)
 
+    def ridero_link(self):
+        return 'https://ridero.eu/%s/books/wl_%s/' % (get_language(), self.slug.replace('-', '_'))
+
+    def like(self, user):
+        from social.utils import likes, get_set, set_sets
+        if not likes(user, self):
+            tag = get_set(user, '')
+            set_sets(user, self, [tag])
+
+    def unlike(self, user):
+        from social.utils import likes, set_sets
+        if likes(user, self):
+            set_sets(user, self, [])
+
+    def full_sort_key(self):
+        return self.SORT_KEY_SEP.join((self.sort_key_author, self.sort_key, str(self.id)))
+
+    def cover_color(self):
+        return WLCover.epoch_colors.get(self.extra_info.get('epoch'), '#000000')
+
 
 def add_file_fields():
     for format_ in Book.formats:
 
 def add_file_fields():
     for format_ in Book.formats:
@@ -603,9 +820,10 @@ def add_file_fields():
             default=''
         ).contribute_to_class(Book, field_name)
 
             default=''
         ).contribute_to_class(Book, field_name)
 
+
 add_file_fields()
 
 
 class BookPopularity(models.Model):
     book = models.OneToOneField(Book, related_name='popularity')
 add_file_fields()
 
 
 class BookPopularity(models.Model):
     book = models.OneToOneField(Book, related_name='popularity')
-    count = models.IntegerField(default=0)
+    count = models.IntegerField(default=0, db_index=True)