"""Retention jobs for audit data (``INFRASYNTH_AUDIT.RETENTION_DAYS``)."""

from __future__ import annotations

import logging
from datetime import timedelta

from celery import shared_task
from django.utils import timezone

from infrasynth.shared.settings_utils import get_setting

logger = logging.getLogger(__name__)


@shared_task(name="infrasynth.audit.purge_expired_logs")
def purge_expired_logs(tenant_id=None):
    """Deletes audit rows older than the configured retention window.

    ``RETENTION_DAYS <= 0`` disables retention (rows are kept forever).
    Returns a ``{model_label: deleted_count}`` mapping.
    """
    retention_days = int(get_setting("INFRASYNTH_AUDIT", "RETENTION_DAYS", 365))
    if retention_days <= 0:
        return {}

    from .models import APIInteractionLog, ModelChangeLog, SecurityEvent

    cutoff = timezone.now() - timedelta(days=retention_days)
    deleted: dict[str, int] = {}
    for model in (ModelChangeLog, APIInteractionLog, SecurityEvent):
        qs = model.objects.filter(timestamp__lt=cutoff)
        if tenant_id:
            qs = qs.filter(tenant_id=tenant_id)
        count, _ = qs.delete()
        deleted[model._meta.label] = count
    logger.info("Audit retention purge removed %s", deleted)
    return deleted