DataRush/services/backend/apps/competition/signals.py

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

from apps.achievement.models import Achievement, UserAchievement
from apps.competition.models import State


@receiver(post_save, sender=State)
def assign_start_competition_achievement(sender, instance, created, **kwargs):
    if created:
        if (
            State.objects.filter(
                user=instance.user, state=State.StateChoices.STARTED.value
            ).count()
            == 1
            and not State.objects.filter(
                user=instance.user, state=State.StateChoices.FINISHED.value
            ).exists()
        ):
            start_competition_achievement = Achievement.objects.get(
                slug="start_competition"
            )
            UserAchievement.objects.create(
                user=instance.user, achievement=start_competition_achievement
            )