from django.db.models.signals import post_save
from django.dispatch import receiver

from apps.moments.models import Comment, Reaction

from .models import Notification


@receiver(post_save, sender=Reaction)
def notify_on_reaction(sender, instance, created, **kwargs):
    if not created:
        return
    moment = instance.moment
    if instance.user_id == moment.owner_id:
        return
    Notification.objects.create(
        recipient_id=moment.owner_id,
        actor=instance.user,
        verb=Notification.Verb.LIKE,
        moment=moment,
    )


@receiver(post_save, sender=Comment)
def notify_on_comment(sender, instance, created, **kwargs):
    if not created:
        return
    moment = instance.moment

    if instance.parent_id is None:
        if instance.author_id != moment.owner_id:
            Notification.objects.create(
                recipient_id=moment.owner_id,
                actor=instance.author,
                verb=Notification.Verb.COMMENT,
                moment=moment,
                comment=instance,
            )
        return

    parent_author_id = instance.parent.author_id
    if instance.author_id != parent_author_id:
        Notification.objects.create(
            recipient_id=parent_author_id,
            actor=instance.author,
            verb=Notification.Verb.REPLY,
            moment=moment,
            comment=instance,
        )