45 lines
1.3 KiB
Python
45 lines
1.3 KiB
Python
''' Models: Subscription. '''
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from django.db.models import CASCADE, ForeignKey, Model
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from apps.users.models import User
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class Subscription(Model):
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''' User subscription to library item. '''
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user: ForeignKey = ForeignKey(
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verbose_name='Пользователь',
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to=User,
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on_delete=CASCADE
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)
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item: ForeignKey = ForeignKey(
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verbose_name='Элемент',
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to='library.LibraryItem',
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on_delete=CASCADE
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)
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class Meta:
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''' Model metadata. '''
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verbose_name = 'Подписка'
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verbose_name_plural = 'Подписки'
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unique_together = [['user', 'item']]
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def __str__(self) -> str:
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return f'{self.user} -> {self.item}'
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@staticmethod
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def subscribe(user: int, item: int) -> bool:
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''' Add subscription. '''
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if Subscription.objects.filter(user_id=user, item_id=item).exists():
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return False
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Subscription.objects.create(user_id=user, item_id=item)
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return True
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@staticmethod
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def unsubscribe(user: int, item: int) -> bool:
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''' Remove subscription. '''
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sub = Subscription.objects.filter(user_id=user, item_id=item).only('pk')
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if not sub.exists():
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return False
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sub.delete()
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return True
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