from django.contrib.auth.models import User
from django.db import models
from django.utils import timezone
from modelcluster.fields import ParentalKey

from .pages import EventPage


class EventOccurrence(models.Model):
    event = ParentalKey(EventPage, related_name="occurrences", on_delete=models.CASCADE)
    start = models.DateTimeField()
    end = models.DateTimeField()
    signed_up_users = models.ManyToManyField(
        User,
        related_name="event_occurrences_signed_up",
        blank=True,
        help_text="Users who have signed up for this occurrence.",
    )

    class Meta:
        ordering = ["start"]

    def __str__(self):
        return f"{self.event.title} ({self.start} - {self.end})"

    @property
    def attendees_count(self):
        return self.signed_up_users.count()

    @property
    def is_past(self):

        return self.end < timezone.now()

    def user_signed_up(self, user):
        if not user.is_authenticated:
            return False
        return self.signed_up_users.filter(id=user.id).exists()