"""APScheduler periodic tasks for routermon."""
import logging

logger = logging.getLogger(__name__)


def cleanup_old_queries():
    """Delete DnsQuery rows older than retention_days. Run periodically."""
    try:
        from datetime import timedelta
        from django.utils import timezone
        from .models import RouterMonSettings, DnsQuery

        settings = RouterMonSettings.get()
        if settings.retention_days <= 0:
            return

        cutoff = timezone.now() - timedelta(days=settings.retention_days)
        deleted, _ = DnsQuery.objects.filter(timestamp__lt=cutoff).delete()
        if deleted:
            logger.info('routermon: pruned %d old DNS query records (>%d days)', deleted, settings.retention_days)
    except Exception as exc:
        logger.error('routermon: cleanup_old_queries error: %s', exc, exc_info=True)