from django.db import models


class TimeStampedModel(models.Model):
    """带创建/更新时间的基类。"""

    created_at = models.DateTimeField(auto_now_add=True, verbose_name="创建时间")
    updated_at = models.DateTimeField(auto_now=True, verbose_name="更新时间")

    class Meta:
        abstract = True


class SoftDeleteQuerySet(models.QuerySet):
    def alive(self):
        return self.filter(is_deleted=False)

    def delete(self):
        return super().update(is_deleted=True)

    def hard_delete(self):
        return super().delete()


class SoftDeleteManager(models.Manager):
    def get_queryset(self):
        return SoftDeleteQuerySet(self.model, using=self._db).filter(is_deleted=False)


class SoftDeleteModel(TimeStampedModel):
    """软删除基类。"""

    is_deleted = models.BooleanField(default=False, db_index=True, verbose_name="已删除")

    objects = SoftDeleteManager()
    all_objects = models.Manager()

    class Meta:
        abstract = True

    def delete(self, using=None, keep_parents=False):
        self.is_deleted = True
        self.save(update_fields=["is_deleted", "updated_at"])