"""Scheduled automatic in-app reminders."""

import logging
from datetime import timedelta

from celery import shared_task
from django.utils import timezone

from apps.events.models import Event, Registration
from apps.notifications.services import notify_user

logger = logging.getLogger(__name__)


@shared_task
def send_event_reminders():
    reminder_target = timezone.now() + timedelta(hours=24)
    window = timedelta(minutes=30)
    events = Event.objects.filter(
        start_time__range=(reminder_target - window, reminder_target + window),
        is_published=True,
        is_cancelled=False,
        is_deleted=False,
    )
    total_sent = 0
    for event in events:
        registrations = Registration.objects.filter(
            event=event,
            status=Registration.StatusChoices.CONFIRMED,
            is_deleted=False,
        ).select_related("user")
        for registration in registrations:
            notify_user(registration.user_id, {
                "type": "event_reminder",
                "title": f"یادآوری برگزاری «{event.title}»",
                "message": "رویداد شما در ۲۴ ساعت آینده برگزار می‌شود.",
                "level": "info",
                "action_url": f"/events/{event.slug}",
                "entity_type": "event",
                "entity_id": event.id,
            })
            total_sent += 1
    logger.info("Event reminders sent to %s users", total_sent)
    return f"Event reminders sent to {total_sent} users"