src/api/models.py

   1 # -*- coding: utf-8 -*-
   2 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   3 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   4 #
   5 from django.contrib.auth.models import User
   6 from django.contrib.contenttypes.models import ContentType
   7 from django.db import models
   8 from django.db.models.signals import pre_delete
   9 from django.utils.translation import ugettext_lazy as _
  10
  11 from catalogue.models import Book, Tag
  12
  13
  14 class Deleted(models.Model):
  15     object_id = models.IntegerField()
  16     slug = models.SlugField(_('slug'), max_length=120, blank=True, db_index=True)
  17     content_type = models.ForeignKey(ContentType)
  18     category = models.CharField(max_length=64, null=True, blank=True, db_index=True)
  19     created_at = models.DateTimeField(editable=False, db_index=True)
  20     deleted_at = models.DateTimeField(auto_now_add=True, db_index=True)
  21
  22     class Meta:
  23         unique_together = (('content_type', 'object_id'),)
  24
  25
  26 def _pre_delete_handler(sender, instance, **kwargs):
  27     """ save deleted objects for change history purposes """
  28
  29     if sender in (Book, Tag):
  30         if sender == Tag:
  31             if instance.category in ('book', 'set'):
  32                 return
  33             else:
  34                 category = instance.category
  35         else:
  36             category = None
  37         content_type = ContentType.objects.get_for_model(sender)
  38         Deleted.objects.create(
  39             content_type=content_type, object_id=instance.id, created_at=instance.created_at, category=category,
  40             slug=instance.slug)
  41 pre_delete.connect(_pre_delete_handler)
  42
  43
  44 class BookUserData(models.Model):
  45     book = models.ForeignKey(Book)
  46     user = models.ForeignKey(User)
  47     complete = models.BooleanField(default=False)
  48     last_changed = models.DateTimeField(auto_now=True)
  49
  50     @property
  51     def state(self):
  52         return 'complete' if self.complete else 'reading'
  53
  54     @classmethod
  55     def update(cls, book, user, state):
  56         instance, created = cls.objects.get_or_create(book=book, user=user)
  57         instance.complete = state == 'complete'
  58         instance.save()
  59         return instance