"""Daily APScheduler cron that purges expired trash.

A single job at 03:30 UTC (services/scheduler.py). Iterates every user and
applies that user's own `trash_retention_days` setting; 0 disables auto-purge
for that user.
"""
from __future__ import annotations

import asyncio
import logging

from apscheduler.triggers.cron import CronTrigger
from sqlalchemy import select

from scribe.models import async_session
from scribe.models.user import User
from scribe.services import trash as trash_svc
from scribe.services.scheduler import ScheduledJob
from scribe.services.settings import get_setting

logger = logging.getLogger(__name__)


async def _run_purge() -> None:
    async with async_session() as session:
        user_ids = (await session.execute(select(User.id))).scalars().all()

    purged = 0
    for uid in user_ids:
        raw = await get_setting(uid, "trash_retention_days", "90")
        try:
            days = int(raw)
        except (TypeError, ValueError):
            days = 90
        purged += await trash_svc.purge_expired(uid, days)
    if purged:
        logger.info("trash purge: removed %d expired row(s)", purged)
    else:
        logger.debug("trash purge: nothing expired")


_JOB = ScheduledJob("trash_retention_purge", _run_purge, label="Trash retention")


def start_trash_scheduler(loop: asyncio.AbstractEventLoop) -> None:
    _JOB.start(loop, CronTrigger(hour=3, minute=30, timezone="UTC"), describe="daily 03:30 UTC")


def stop_trash_scheduler() -> None:
    _JOB.stop()