kers/events/models.py

from django.db import models

from users.models import CustomUser


class Event(models.Model):
    date = models.DateTimeField()
    capacity = models.IntegerField()


class EventRegistration(models.Model):
    REGISTRATION_STATE = (
        ('I', 'Interested'),
        ('A', 'Admitted'),
        ('D', 'Denied'),
    )
    event = models.ForeignKey(Event, on_delete=models.CASCADE)
    user = models.ForeignKey(CustomUser, on_delete=models.CASCADE)
    state = models.CharField(max_length=1, choices=REGISTRATION_STATE)

    def __str__(self):
        return f'Reservation[{self.user.username}:{self.event.date}:{self.state}]'