"""
Maintenance tasks — cleanup and housekeeping.

Scheduled via Celery Beat to run daily at 03:00 UTC.
"""

import logging
from datetime import timedelta

from django.utils import timezone

from config.celery import app

logger = logging.getLogger(__name__)


@app.task(name="tasks.maintenance.prune_old_heartbeat_logs", bind=True)
def prune_old_heartbeat_logs(self, days: int = 30) -> dict:  # type: ignore[type-arg]
    """
    Delete HeartbeatLog records older than `days` days.

    Returns the count of deleted rows for monitoring/alerting.
    Runs as a single bulk DELETE to avoid row-by-row overhead.
    """
    from apps.core.models import HeartbeatLog

    cutoff = timezone.now() - timedelta(days=days)
    deleted_count, _ = HeartbeatLog.objects.filter(timestamp__lt=cutoff).delete()

    logger.info(
        "maintenance.prune_old_heartbeat_logs: deleted %d records older than %d days",
        deleted_count,
        days,
    )
    return {"status": "ok", "deleted": deleted_count, "cutoff_days": days}