lib.itmens/books/models.py

import django.contrib.postgres.fields as postgres
from django.utils.translation import gettext_lazy as _
from django.db import models
from django.shortcuts import reverse
from common.models import Entity, Mark, Review, Tag
from common.utils import GenerateDateUUIDMediaFilePath
from django.conf import settings
from django.db.models import Q


def book_cover_path(instance, filename):
    return GenerateDateUUIDMediaFilePath(instance, filename, settings.BOOK_MEDIA_PATH_ROOT)


class Book(Entity):
    # widely recognized name, usually in Chinese
    title = models.CharField(_("title"), max_length=200)
    subtitle = models.CharField(
        _("subtitle"), blank=True, default='', max_length=200)
    # original name, for books in foreign language
    orig_title = models.CharField(
        _("original title"), blank=True, default='', max_length=200)

    author = postgres.ArrayField(
        models.CharField(_("author"), blank=True, default='', max_length=100),
        null=True,
        blank=True,
        default=list,
    )
    translator = postgres.ArrayField(
        models.CharField(_("translator"), blank=True,
                         default='', max_length=100),
        null=True,
        blank=True,
        default=list,
    )
    language = models.CharField(
        _("language"), blank=True, default='', max_length=10)
    pub_house = models.CharField(
        _("publishing house"), blank=True, default='', max_length=200)
    pub_year = models.IntegerField(_("published year"), null=True, blank=True)
    pub_month = models.IntegerField(
        _("published month"), null=True, blank=True)
    binding = models.CharField(
        _("binding"), blank=True, default='', max_length=50)
    # since data origin is not formatted and might be CNY USD or other currency, use char instead
    price = models.CharField(_("pricing"), blank=True,
                             default='', max_length=50)
    pages = models.PositiveIntegerField(_("pages"), null=True, blank=True)
    isbn = models.CharField(_("ISBN"), blank=True, null=False,
                            max_length=20, db_index=True, default='')
    # to store previously scrapped data
    cover = models.ImageField(_("cover picture"), upload_to=book_cover_path,
                              default=settings.DEFAULT_BOOK_IMAGE, blank=True)
    contents = models.TextField(blank=True, default="")

    class Meta:
        constraints = [
            models.CheckConstraint(check=models.Q(
                pub_year__gte=0), name='pub_year_lowerbound'),
            models.CheckConstraint(check=models.Q(
                pub_month__lte=12), name='pub_month_upperbound'),
            models.CheckConstraint(check=models.Q(
                pub_month__gte=1), name='pub_month_lowerbound'),
        ]

    def __str__(self):
        return self.title

    def get_json(self):
        r = {
            'subtitle': self.subtitle,
            'original_title': self.orig_title,
            'author': self.author,
            'translator': self.translator,
            'publisher': self.pub_house,
            'publish_year': self.pub_year,
            'publish_month': self.pub_month,
            'language': self.language,
            'isbn': self.isbn,
        }
        r.update(super().get_json())
        return r

    def get_absolute_url(self):
        return reverse("books:retrieve", args=[self.id])

    def get_tags_manager(self):
        return self.book_tags

    def get_related_books(self):
        qs = Q(orig_title=self.title)
        if self.isbn:
            qs = qs | Q(isbn=self.isbn)
        if self.orig_title:
            qs = qs | Q(title=self.orig_title)
            qs = qs | Q(orig_title=self.orig_title)
        qs = qs & ~Q(id=self.id)
        return Book.objects.filter(qs)

    def get_identicals(self):
        qs = Q(orig_title=self.title)
        if self.isbn:
            qs = Q(isbn=self.isbn)
            # qs = qs & ~Q(id=self.id)
            return Book.objects.filter(qs)
        else:
            return [self]  # Book.objects.filter(id=self.id)

    @property
    def verbose_category_name(self):
        return _("书籍")


class BookMark(Mark):
    book = models.ForeignKey(
        Book, on_delete=models.CASCADE, related_name='book_marks', null=True)

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=['owner', 'book'], name="unique_book_mark")
        ]


class BookReview(Review):
    book = models.ForeignKey(
        Book, on_delete=models.CASCADE, related_name='book_reviews', null=True)

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=['owner', 'book'], name="unique_book_review")
        ]


class BookTag(Tag):
    book = models.ForeignKey(
        Book, on_delete=models.CASCADE, related_name='book_tags', null=True)
    mark = models.ForeignKey(
        BookMark, on_delete=models.CASCADE, related_name='bookmark_tags', null=True)

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=['content', 'mark'], name="unique_bookmark_tag")
        ]