"""Stale job janitor: marks claimed/running jobs as failed when their
satellite stops reporting (e.g. satellite offline, job crashed).
"""

import asyncio
from datetime import UTC, datetime, timedelta

from sqlalchemy import select

from app.core.config import get_settings
from app.core.database import async_session_factory
from app.core.logging import get_logger
from app.models.update_job import JobStatus, UpdateJob

settings = get_settings()
logger = get_logger(__name__)

CHECK_INTERVAL = 60  # seconds


async def run_janitor() -> None:
    """Background task; runs until cancelled."""
    while True:
        try:
            await _sweep()
        except Exception as exc:  # noqa: BLE001 - janitor must never die
            logger.error("janitor.error", error=str(exc))
        await asyncio.sleep(CHECK_INTERVAL)


async def _sweep() -> None:
    cutoff = datetime.now(UTC) - timedelta(seconds=settings.job_stale_timeout)
    async with async_session_factory() as db:
        result = await db.execute(
            select(UpdateJob).where(
                UpdateJob.status.in_([JobStatus.CLAIMED, JobStatus.RUNNING]),
                UpdateJob.last_report_at < cutoff,
            )
        )
        stale = list(result.scalars().all())
        for job in stale:
            job.status = JobStatus.FAILED
            job.error = "Satellite meldet sich nicht mehr (Timeout)"
            job.finished_at = datetime.now(UTC)
            logger.warning("janitor.job_stale", job_id=job.id, satellite_id=job.satellite_id)
        if stale:
            await db.commit()