import logging

from celery import shared_task
from django.utils import timezone

from labs.models import ExamAttempt as DBExamAttempt
from labs.exams.attempt import ExamAttempt

logger = logging.getLogger(__name__)

AUTO_SUBMIT_EXPIRED_EXAM_ATTEMPTS_BATCH_SIZE = 1000


@shared_task()
def auto_submit_expired_exam_attempts():
    now = timezone.now()
    expired_attempt_ids = list(
        DBExamAttempt.objects.filter(
            submitted_at__isnull=True,
            expires_at__lt=now,
        )
        .order_by("expires_at", "id")
        .values_list("id", flat=True)[:AUTO_SUBMIT_EXPIRED_EXAM_ATTEMPTS_BATCH_SIZE]
    )

    for attempt_id in expired_attempt_ids:
        try:
            db_attempt = DBExamAttempt.objects.filter(
                id=attempt_id,
                submitted_at__isnull=True,
                expires_at__lt=now,
            ).first()
            if db_attempt is None:
                continue

            attempt = ExamAttempt(db_attempt)
            attempt.submit_exam()
            logger.info(f"Auto-submitted expired exam attempt {attempt_id}")
        except Exception as e:
            logger.error(f"Failed to auto-submit exam attempt {attempt_id}: {e}")