from datetime import date
from celery import shared_task
from django.db import transaction
from django.db.models import Q
from django.utils import timezone

from core.models import EventPage, EventHistoryPage


@shared_task
def move_past_events_to_history():
    """
    Daily task to:
    1. Move past events that are not partner events to the history
    2. Unpublish partner events that are past
    """
    today = date.today()

    # Find all live EventPage objects with a start_date in the past
    past_events = EventPage.objects.live().filter(
        Q(end_date__lt=timezone.now()) | Q(end_date__isnull=True, start_date__lt=timezone.now()))

    # Find the first EventHistoryPage to use as the target for moving events
    try:
        history_page = EventHistoryPage.objects.live().first()
        if not history_page:
            # If no history page exists, we can't move events
            return "No EventHistoryPage found. Cannot move past events."
    except EventHistoryPage.DoesNotExist:
        return "No EventHistoryPage found. Cannot move past events."

    moved_count = 0
    unpublished_count = 0

    with transaction.atomic():
        # Process each past event
        for event in past_events:
            if event.is_partner_event:
                # Unpublish partner events
                event.unpublish()
                unpublished_count += 1
            else:
                # Move non-partner events to history
                # Get the current parent page
                current_parent = event.get_parent()

                # Only move if not already under the history page
                if current_parent.id != history_page.id:
                    # Move the event to be a child of the history page
                    event.move(history_page, pos='last-child')
                    moved_count += 1

    return f"Processed past events: {moved_count} moved to history, {unpublished_count} partner events unpublished."