# models.py

class Post(models.Model):
    title = models.CharField(_('title'), max_length=125)
    description = models.TextField(_('description'))
    is_read = models.BooleanField(default=False)
    publication = models.DateTimeField(_('date published'), auto_now_add=True)
    created_at = models.DateTimeField(_('created at'), auto_now_add=True)
    blog = models.ForeignKey(Blog, related_name='post',
                             verbose_name=_('blog'),
                             on_delete=models.CASCADE)

    class Meta:
        verbose_name = _('post')
        verbose_name_plural = _('posts')

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse('blog:post_detail', kwargs={'id': self.id})


@receiver(post_save, sender=Post)
def post_created(sender, instance, created, **kwargs):
    if created:
        blog_title = instance.title
        post_url = instance.get_absolute_url()
        user_emails = instance.blog.subscriptions.all().values_list(
            'email', flat=True)
        for email in user_emails:
            django_rq.enqueue(email_notification_subscriber, email,
                              blog_title, post_url)


# tasks.py

from django.conf import settings
from django.core.mail import send_mail, BadHeaderError
from django_rq import job


@job
def email_notification_subscriber(email, blog_title, post_url):
    try:
        subject = 'Новый пост от %s' % blog_title
        message = f'''
            Блог <{blog_title}> опубликовал новый пост.
            Пост доступен по прямой ссылке - {post_url}.
        '''
        email_from = settings.EMAIL_HOST_USER
        email_to = [email]
        send_mail(subject, message, email_from, email_to)
        return True
    except BadHeaderError:
        return False