src/catalogue/fields.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 import os
   5 from django.conf import settings
   6 from django.core.files import File
   7 from django.db import models
   8 from django.db.models.fields.files import FieldFile
   9 from django.utils.deconstruct import deconstructible
  10 from django.utils.translation import gettext_lazy as _
  11 from catalogue.constants import LANGUAGES_3TO2, EBOOK_FORMATS_WITH_CHILDREN, EBOOK_FORMATS_WITHOUT_CHILDREN
  12 from catalogue.utils import absolute_url, remove_zip, truncate_html_words, gallery_path, gallery_url
  13 from waiter.utils import clear_cache
  14
  15 ETAG_SCHEDULED_SUFFIX = '-scheduled'
  16 EBOOK_BUILD_PRIORITY = 0
  17 EBOOK_REBUILD_PRIORITY = 9
  18
  19
  20 @deconstructible
  21 class UploadToPath(object):
  22     def __init__(self, path):
  23         self.path = path
  24
  25     def __call__(self, instance, filename):
  26         return self.path % instance.slug
  27
  28     def __eq__(self, other):
  29         return isinstance(other, type(self)) and other.path == self.path
  30
  31
  32 class EbookFieldFile(FieldFile):
  33     """Represents contents of an ebook file field."""
  34
  35     def build(self):
  36         """Build the ebook immediately."""
  37         etag = self.field.get_current_etag()
  38         self.field.build(self)
  39         self.update_etag(etag)
  40         self.instance.clear_cache()
  41
  42     def build_delay(self, priority=EBOOK_BUILD_PRIORITY):
  43         """Builds the ebook in a delayed task."""
  44         from .tasks import build_field
  45
  46         self.update_etag(
  47             "".join([self.field.get_current_etag(), ETAG_SCHEDULED_SUFFIX])
  48         )
  49         return build_field.apply_async(
  50             [self.instance.pk, self.field.attname],
  51             priority=priority
  52         )
  53
  54     def set_readable(self, readable):
  55         import os
  56         permissions = 0o644 if readable else 0o600
  57         os.chmod(self.path, permissions)
  58
  59     def update_etag(self, etag):
  60         setattr(self.instance, self.field.etag_field_name, etag)
  61         if self.instance.pk:
  62             self.instance.save(update_fields=[self.field.etag_field_name])
  63
  64
  65 class EbookField(models.FileField):
  66     """Represents an ebook file field, attachable to a model."""
  67     attr_class = EbookFieldFile
  68     ext = None
  69     librarian2_api = False
  70     ZIP = None
  71
  72     def __init__(self, verbose_name=None, with_etag=True, etag_field_name=None, **kwargs):
  73         kwargs.setdefault('verbose_name', verbose_name)
  74         self.with_etag = with_etag
  75         self.etag_field_name = etag_field_name
  76         kwargs.setdefault('max_length', 255)
  77         kwargs.setdefault('blank', True)
  78         kwargs.setdefault('default', '')
  79         kwargs.setdefault('upload_to', self.get_upload_to(self.ext))
  80
  81         super().__init__(**kwargs)
  82
  83     def deconstruct(self):
  84         name, path, args, kwargs = super().deconstruct()
  85         if kwargs.get('max_length') == 255:
  86             del kwargs['max_length']
  87         if kwargs.get('blank') is True:
  88             del kwargs['blank']
  89         if kwargs.get('default') == '':
  90             del kwargs['default']
  91         if self.get_upload_to(self.ext) == kwargs.get('upload_to'):
  92             del kwargs['upload_to']
  93         # with_etag creates a second field, which then deconstructs to manage
  94         # its own migrations. So for migrations, etag_field_name is explicitly
  95         # set to avoid double creation of the etag field.
  96         if self.with_etag:
  97             kwargs['etag_field_name'] = self.etag_field_name
  98         else:
  99             kwargs['with_etag'] = self.with_etag
 100
 101         return name, path, args, kwargs
 102
 103     @classmethod
 104     def get_upload_to(cls, directory):
 105         directory = getattr(cls, 'directory', cls.ext)
 106         upload_template = f'book/{directory}/%s.{cls.ext}'
 107         return UploadToPath(upload_template)
 108
 109     def contribute_to_class(self, cls, name):
 110         super(EbookField, self).contribute_to_class(cls, name)
 111
 112         if self.with_etag and not self.etag_field_name:
 113             self.etag_field_name = f'{name}_etag'
 114             self.etag_field = models.CharField(max_length=255, editable=False, default='', db_index=True)
 115             self.etag_field.contribute_to_class(cls, f'{name}_etag')
 116
 117         def has(model_instance):
 118             return bool(getattr(model_instance, self.attname, None))
 119         has.__doc__ = None
 120         has.__name__ = str("has_%s" % self.attname)
 121         has.short_description = self.name
 122         has.boolean = True
 123
 124         setattr(cls, 'has_%s' % self.attname, has)
 125
 126     def get_current_etag(self):
 127         import pkg_resources
 128         librarian_version = pkg_resources.get_distribution("librarian").version
 129         return librarian_version
 130
 131     def schedule_stale(self, queryset=None):
 132         """Schedule building this format for all the books where etag is stale."""
 133         # If there is not ETag field, bail. That's true for xml file field.
 134         if not self.with_etag:
 135             return
 136
 137         etag = self.get_current_etag()
 138         if queryset is None:
 139             queryset = self.model.objects.all()
 140
 141         if self.format_name in EBOOK_FORMATS_WITHOUT_CHILDREN + ['html']:
 142             queryset = queryset.filter(children=None)
 143
 144         queryset = queryset.exclude(**{
 145             f'{self.etag_field_name}__in': [
 146                 etag, f'{etag}{ETAG_SCHEDULED_SUFFIX}'
 147             ]
 148         })
 149         for obj in queryset:
 150             fieldfile = getattr(obj, self.attname)
 151             priority = EBOOK_REBUILD_PRIORITY if fieldfile else EBOOK_BUILD_PRIORITY
 152             fieldfile.build_delay(priority=priority)
 153
 154     @classmethod
 155     def schedule_all_stale(cls, model):
 156         """Schedules all stale ebooks of all formats to rebuild."""
 157         for field in model._meta.fields:
 158             if isinstance(field, cls):
 159                 field.schedule_stale()
 160
 161     @staticmethod
 162     def transform(wldoc):
 163         """Transforms an librarian.WLDocument into an librarian.OutputFile.
 164         """
 165         raise NotImplemented()
 166
 167     def set_file_permissions(self, fieldfile):
 168         if fieldfile.instance.preview:
 169             fieldfile.set_readable(False)
 170
 171     def build(self, fieldfile):
 172         book = fieldfile.instance
 173         out = self.transform(
 174             book.wldocument2() if self.librarian2_api else book.wldocument(),
 175         )
 176         fieldfile.save(None, File(open(out.get_filename(), 'rb')), save=False)
 177         self.set_file_permissions(fieldfile)
 178         if book.pk is not None:
 179             book.save(update_fields=[self.attname])
 180         if self.ZIP:
 181             remove_zip(self.ZIP)
 182
 183
 184 class XmlField(EbookField):
 185     ext = 'xml'
 186
 187     def build(self, fieldfile):
 188         pass
 189
 190
 191 class TxtField(EbookField):
 192     ext = 'txt'
 193
 194     @staticmethod
 195     def transform(wldoc):
 196         return wldoc.as_text()
 197
 198
 199 class Fb2Field(EbookField):
 200     ext = 'fb2'
 201     ZIP = 'wolnelektury_pl_fb2'
 202
 203     @staticmethod
 204     def transform(wldoc):
 205         return wldoc.as_fb2()
 206
 207
 208 class PdfField(EbookField):
 209     ext = 'pdf'
 210     ZIP = 'wolnelektury_pl_pdf'
 211
 212     @staticmethod
 213     def transform(wldoc):
 214         return wldoc.as_pdf(
 215             morefloats=settings.LIBRARIAN_PDF_MOREFLOATS, cover=True,
 216             base_url=absolute_url(gallery_url(wldoc.book_info.url.slug)), customizations=['notoc'])
 217
 218     def build(self, fieldfile):
 219         super().build(fieldfile)
 220         clear_cache(fieldfile.instance.slug)
 221
 222
 223 class EpubField(EbookField):
 224     ext = 'epub'
 225     librarian2_api = True
 226     ZIP = 'wolnelektury_pl_epub'
 227
 228     @staticmethod
 229     def transform(wldoc):
 230         from librarian.builders import EpubBuilder
 231         return EpubBuilder(
 232                 base_url='file://' + os.path.abspath(gallery_path(wldoc.meta.url.slug)) + '/',
 233                 fundraising=settings.EPUB_FUNDRAISING
 234             ).build(wldoc)
 235
 236
 237 class MobiField(EbookField):
 238     ext = 'mobi'
 239     librarian2_api = True
 240     ZIP = 'wolnelektury_pl_mobi'
 241
 242     @staticmethod
 243     def transform(wldoc):
 244         from librarian.builders import MobiBuilder
 245         return MobiBuilder(
 246                 base_url='file://' + os.path.abspath(gallery_path(wldoc.meta.url.slug)) + '/',
 247                 fundraising=settings.EPUB_FUNDRAISING
 248             ).build(wldoc)
 249
 250
 251 class HtmlField(EbookField):
 252     ext = 'html'
 253
 254     def build(self, fieldfile):
 255         from django.core.files.base import ContentFile
 256         from slugify import slugify
 257         from sortify import sortify
 258         from librarian import html
 259         from catalogue.models import Fragment, Tag
 260
 261         book = fieldfile.instance
 262
 263         html_output = self.transform(book.wldocument(parse_dublincore=False))
 264
 265         # Delete old fragments, create from scratch if necessary.
 266         book.fragments.all().delete()
 267
 268         if html_output:
 269             meta_tags = list(book.tags.filter(
 270                 category__in=('author', 'epoch', 'genre', 'kind')))
 271
 272             lang = book.language
 273             lang = LANGUAGES_3TO2.get(lang, lang)
 274             if lang not in [ln[0] for ln in settings.LANGUAGES]:
 275                 lang = None
 276
 277             fieldfile.save(None, ContentFile(html_output.get_bytes()), save=False)
 278             self.set_file_permissions(fieldfile)
 279             type(book).objects.filter(pk=book.pk).update(**{
 280                 fieldfile.field.attname: fieldfile
 281             })
 282
 283             # Extract fragments
 284             closed_fragments, open_fragments = html.extract_fragments(fieldfile.path)
 285             for fragment in closed_fragments.values():
 286                 try:
 287                     theme_names = [s.strip() for s in fragment.themes.split(',')]
 288                 except AttributeError:
 289                     continue
 290                 themes = []
 291                 for theme_name in theme_names:
 292                     if not theme_name:
 293                         continue
 294                     if lang == settings.LANGUAGE_CODE:
 295                         # Allow creating themes if book in default language.
 296                         tag, created = Tag.objects.get_or_create(
 297                             slug=slugify(theme_name),
 298                             category='theme'
 299                         )
 300                         if created:
 301                             tag.name = theme_name
 302                             setattr(tag, "name_%s" % lang, theme_name)
 303                             tag.sort_key = sortify(theme_name.lower())
 304                             tag.for_books = True
 305                             tag.save()
 306                         themes.append(tag)
 307                     elif lang is not None:
 308                         # Don't create unknown themes in non-default languages.
 309                         try:
 310                             tag = Tag.objects.get(
 311                                 category='theme',
 312                                 **{"name_%s" % lang: theme_name}
 313                             )
 314                         except Tag.DoesNotExist:
 315                             pass
 316                         else:
 317                             themes.append(tag)
 318                 if not themes:
 319                     continue
 320
 321                 text = fragment.to_string()
 322                 short_text = truncate_html_words(text, 15)
 323                 if text == short_text:
 324                     short_text = ''
 325                 new_fragment = Fragment.objects.create(
 326                     anchor=fragment.id,
 327                     book=book,
 328                     text=text,
 329                     short_text=short_text
 330                 )
 331
 332                 new_fragment.save()
 333                 new_fragment.tags = set(meta_tags + themes)
 334                 for theme in themes:
 335                     if not theme.for_books:
 336                         theme.for_books = True
 337                         theme.save()
 338             book.html_built.send(sender=type(self), instance=book)
 339             return True
 340         return False
 341
 342     @staticmethod
 343     def transform(wldoc):
 344         # ugly, but we can't use wldoc.book_info here
 345         from librarian import DCNS
 346         url_elem = wldoc.edoc.getroot().find('.//' + DCNS('identifier.url'))
 347         if url_elem is None:
 348             gal_url = ''
 349             gal_path = ''
 350         else:
 351             slug = url_elem.text.rstrip('/').rsplit('/', 1)[1]
 352             gal_url = gallery_url(slug=slug)
 353             gal_path = gallery_path(slug=slug)
 354         return wldoc.as_html(gallery_path=gal_path, gallery_url=gal_url, base_url=absolute_url(gal_url))
 355
 356
 357 class CoverField(EbookField):
 358     ext = 'jpg'
 359     directory = 'cover'
 360
 361     @staticmethod
 362     def transform(wldoc):
 363         return wldoc.as_cover()
 364
 365     def set_file_permissions(self, fieldfile):
 366         pass
 367
 368
 369 class CoverCleanField(CoverField):
 370     directory = 'cover_clean'
 371
 372     @staticmethod
 373     def transform(wldoc):
 374         if wldoc.book_info.cover_box_position == 'none':
 375             from librarian.cover import WLCover
 376             return WLCover(wldoc.book_info, width=240).output_file()
 377         from librarian.covers.marquise import MarquiseCover
 378         return MarquiseCover(wldoc.book_info, width=240).output_file()
 379
 380
 381 class CoverThumbField(CoverField):
 382     directory = 'cover_thumb'
 383
 384     @staticmethod
 385     def transform(wldoc):
 386         from librarian.cover import WLCover
 387         return WLCover(wldoc.book_info, height=193).output_file()
 388
 389
 390 class CoverApiThumbField(CoverField):
 391     directory = 'cover_api_thumb'
 392
 393     @staticmethod
 394     def transform(wldoc):
 395         from librarian.cover import WLNoBoxCover
 396         return WLNoBoxCover(wldoc.book_info, height=500).output_file()
 397
 398
 399 class SimpleCoverField(CoverField):
 400     directory = 'cover_simple'
 401
 402     @staticmethod
 403     def transform(wldoc):
 404         from librarian.cover import WLNoBoxCover
 405         return WLNoBoxCover(wldoc.book_info, height=1000).output_file()
 406
 407
 408 class CoverEbookpointField(CoverField):
 409     directory = 'cover_ebookpoint'
 410
 411     @staticmethod
 412     def transform(wldoc):
 413         from librarian.cover import EbookpointCover
 414         return EbookpointCover(wldoc.book_info).output_file()