''' database schema for books and shelves ''' import re from django.db import models from django.utils import timezone from model_utils.managers import InheritanceManager from bookwyrm import activitypub from bookwyrm.settings import DOMAIN from .base_model import BookWyrmModel from .base_model import ActivitypubMixin, OrderedCollectionPageMixin from . import fields class Book(ActivitypubMixin, BookWyrmModel): ''' a generic book, which can mean either an edition or a work ''' origin_id = models.CharField(max_length=255, null=True, blank=True) # these identifiers apply to both works and editions openlibrary_key = fields.CharField( max_length=255, blank=True, null=True, deduplication_field=True) librarything_key = fields.CharField( max_length=255, blank=True, null=True, deduplication_field=True) goodreads_key = fields.CharField( max_length=255, blank=True, null=True, deduplication_field=True) # info about where the data comes from and where/if to sync sync = models.BooleanField(default=True) sync_cover = models.BooleanField(default=True) last_sync_date = models.DateTimeField(default=timezone.now) connector = models.ForeignKey( 'Connector', on_delete=models.PROTECT, null=True) # TODO: edit history # book/work metadata title = fields.CharField(max_length=255) sort_title = fields.CharField(max_length=255, blank=True, null=True) subtitle = fields.CharField(max_length=255, blank=True, null=True) description = fields.HtmlField(blank=True, null=True) languages = fields.ArrayField( models.CharField(max_length=255), blank=True, default=list ) series = fields.CharField(max_length=255, blank=True, null=True) series_number = fields.CharField(max_length=255, blank=True, null=True) subjects = fields.ArrayField( models.CharField(max_length=255), blank=True, null=True, default=list ) subject_places = fields.ArrayField( models.CharField(max_length=255), blank=True, null=True, default=list ) # TODO: include an annotation about the type of authorship (ie, translator) authors = fields.ManyToManyField('Author') # preformatted authorship string for search and easier display author_text = models.CharField(max_length=255, blank=True, null=True) cover = fields.ImageField( upload_to='covers/', blank=True, null=True, alt_field='alt_text') first_published_date = fields.DateTimeField(blank=True, null=True) published_date = fields.DateTimeField(blank=True, null=True) objects = InheritanceManager() @property def edition_info(self): ''' properties of this edition, as a string ''' items = [ self.physical_format if hasattr(self, 'physical_format') else None, self.languages[0] + ' language' if self.languages and \ self.languages[0] != 'English' else None, str(self.published_date.year) if self.published_date else None, ] return ', '.join(i for i in items if i) @property def alt_text(self): ''' image alt test ''' text = '%s cover' % self.title if self.edition_info: text += ' (%s)' % self.edition_info return text def save(self, *args, **kwargs): ''' can't be abstract for query reasons, but you shouldn't USE it ''' if not isinstance(self, Edition) and not isinstance(self, Work): raise ValueError('Books should be added as Editions or Works') if self.id: self.remote_id = self.get_remote_id() else: self.origin_id = self.remote_id self.remote_id = None return super().save(*args, **kwargs) def get_remote_id(self): ''' editions and works both use "book" instead of model_name ''' return 'https://%s/book/%d' % (DOMAIN, self.id) def __repr__(self): return "<{} key={!r} title={!r}>".format( self.__class__, self.openlibrary_key, self.title, ) class Work(OrderedCollectionPageMixin, Book): ''' a work (an abstract concept of a book that manifests in an edition) ''' # library of congress catalog control number lccn = fields.CharField( max_length=255, blank=True, null=True, deduplication_field=True) # this has to be nullable but should never be null default_edition = fields.ForeignKey( 'Edition', on_delete=models.PROTECT, null=True, load_remote=False ) def get_default_edition(self): ''' in case the default edition is not set ''' return self.default_edition or self.editions.first() activity_serializer = activitypub.Work serialize_reverse_fields = [('editions', 'editions')] deserialize_reverse_fields = [('editions', 'editions')] class Edition(Book): ''' an edition of a book ''' # these identifiers only apply to editions, not works isbn_10 = fields.CharField( max_length=255, blank=True, null=True, deduplication_field=True) isbn_13 = fields.CharField( max_length=255, blank=True, null=True, deduplication_field=True) oclc_number = fields.CharField( max_length=255, blank=True, null=True, deduplication_field=True) asin = fields.CharField( max_length=255, blank=True, null=True, deduplication_field=True) pages = fields.IntegerField(blank=True, null=True) physical_format = fields.CharField(max_length=255, blank=True, null=True) publishers = fields.ArrayField( models.CharField(max_length=255), blank=True, default=list ) shelves = models.ManyToManyField( 'Shelf', symmetrical=False, through='ShelfBook', through_fields=('book', 'shelf') ) parent_work = fields.ForeignKey( 'Work', on_delete=models.PROTECT, null=True, related_name='editions', activitypub_field='work') activity_serializer = activitypub.Edition name_field = 'title' def save(self, *args, **kwargs): ''' calculate isbn 10/13 ''' if self.isbn_13 and self.isbn_13[:3] == '978' and not self.isbn_10: self.isbn_10 = isbn_13_to_10(self.isbn_13) if self.isbn_10 and not self.isbn_13: self.isbn_13 = isbn_10_to_13(self.isbn_10) return super().save(*args, **kwargs) def isbn_10_to_13(isbn_10): ''' convert an isbn 10 into an isbn 13 ''' isbn_10 = re.sub(r'[^0-9X]', '', isbn_10) # drop the last character of the isbn 10 number (the original checkdigit) converted = isbn_10[:9] # add "978" to the front converted = '978' + converted # add a check digit to the end # multiply the odd digits by 1 and the even digits by 3 and sum them try: checksum = sum(int(i) for i in converted[::2]) + \ sum(int(i) * 3 for i in converted[1::2]) except ValueError: return None # add the checksum mod 10 to the end checkdigit = checksum % 10 if checkdigit != 0: checkdigit = 10 - checkdigit return converted + str(checkdigit) def isbn_13_to_10(isbn_13): ''' convert isbn 13 to 10, if possible ''' if isbn_13[:3] != '978': return None isbn_13 = re.sub(r'[^0-9X]', '', isbn_13) # remove '978' and old checkdigit converted = isbn_13[3:-1] # calculate checkdigit # multiple each digit by 10,9,8.. successively and sum them try: checksum = sum(int(d) * (10 - idx) for (idx, d) in enumerate(converted)) except ValueError: return None checkdigit = checksum % 11 checkdigit = 11 - checkdigit if checkdigit == 10: checkdigit = 'X' return converted + str(checkdigit)