"""Scheduled background jobs.

Registers periodic tasks on an APScheduler ``BackgroundScheduler``:

* **MITRE sync** — every 24 hours (see :func:`sync_mitre`)
* **Intel scan** — every 7 days (see :func:`scan_intel`)

Each job manages its own database session (created on entry, closed in
``finally``) so it is fully independent from FastAPI's request-scoped
sessions.
"""

import logging

from apscheduler.schedulers.background import BackgroundScheduler

from app.database import SessionLocal
from app.services.mitre_sync_service import sync_mitre
from app.services.intel_service import scan_intel
from app.services.notification_service import cleanup_old_notifications
from app.services.snapshot_service import create_snapshot, cleanup_old_snapshots
from app.services.campaign_scheduler_service import check_and_run_recurring_campaigns

logger = logging.getLogger(__name__)

# ---------------------------------------------------------------------------
# Module-level scheduler instance
# ---------------------------------------------------------------------------

scheduler = BackgroundScheduler()


# ---------------------------------------------------------------------------
# Job functions
# ---------------------------------------------------------------------------


def _run_mitre_sync() -> None:
    """Execute a MITRE sync inside its own DB session."""
    logger.info("Scheduled MITRE sync job starting...")
    db = SessionLocal()
    try:
        summary = sync_mitre(db)
        logger.info("Scheduled MITRE sync job finished — %s", summary)
    except Exception:
        logger.exception("Scheduled MITRE sync job failed")
    finally:
        db.close()


def _run_notification_cleanup() -> None:
    """Clean up old read notifications."""
    logger.info("Scheduled notification cleanup job starting...")
    db = SessionLocal()
    try:
        deleted = cleanup_old_notifications(db, days=90)
        logger.info("Notification cleanup finished — deleted %d old notifications", deleted)
    except Exception:
        logger.exception("Notification cleanup job failed")
    finally:
        db.close()


def _run_weekly_snapshot() -> None:
    """Create a weekly coverage snapshot and clean up old ones."""
    logger.info("Scheduled weekly snapshot job starting...")
    db = SessionLocal()
    try:
        snapshot = create_snapshot(db, name="Auto-weekly")
        logger.info(
            "Weekly snapshot created — score %.1f, %d techniques",
            snapshot.organization_score,
            snapshot.total_techniques,
        )
        deleted = cleanup_old_snapshots(db, keep_last=52)
        if deleted:
            logger.info("Cleaned up %d old snapshots", deleted)
    except Exception:
        logger.exception("Weekly snapshot job failed")
    finally:
        db.close()


def _run_recurring_campaigns() -> None:
    """Check and run any due recurring campaigns."""
    logger.info("Scheduled recurring campaigns check starting...")
    db = SessionLocal()
    try:
        spawned = check_and_run_recurring_campaigns(db)
        logger.info("Recurring campaigns check finished — spawned %d campaigns", spawned)
    except Exception:
        logger.exception("Recurring campaigns check failed")
    finally:
        db.close()


def _run_intel_scan() -> None:
    """Execute an intel scan inside its own DB session."""
    logger.info("Scheduled intel scan job starting...")
    db = SessionLocal()
    try:
        summary = scan_intel(db)
        logger.info("Scheduled intel scan job finished — %s", summary)
    except Exception:
        logger.exception("Scheduled intel scan job failed")
    finally:
        db.close()


# ---------------------------------------------------------------------------
# Scheduler bootstrap
# ---------------------------------------------------------------------------


def start_scheduler() -> None:
    """Register all periodic jobs and start the background scheduler.

    Jobs registered:

    * ``mitre_sync`` — every **24 hours**
    * ``intel_scan`` — every **7 days**

    Neither job fires immediately on startup.
    """
    scheduler.add_job(
        _run_mitre_sync,
        trigger="interval",
        hours=24,
        id="mitre_sync",
        name="MITRE ATT&CK sync (every 24h)",
        replace_existing=True,
    )
    scheduler.add_job(
        _run_intel_scan,
        trigger="interval",
        weeks=1,
        id="intel_scan",
        name="Intel scan (every 7d)",
        replace_existing=True,
    )
    scheduler.add_job(
        _run_notification_cleanup,
        trigger="interval",
        hours=24,
        id="notification_cleanup",
        name="Notification cleanup (daily)",
        replace_existing=True,
    )
    scheduler.add_job(
        _run_weekly_snapshot,
        trigger="cron",
        day_of_week="sun",
        hour=0,
        minute=0,
        id="weekly_snapshot",
        name="Weekly coverage snapshot (Sundays 00:00)",
        replace_existing=True,
    )
    scheduler.add_job(
        _run_recurring_campaigns,
        trigger="interval",
        hours=24,
        id="recurring_campaigns",
        name="Recurring campaigns check (daily)",
        replace_existing=True,
    )
    scheduler.start()
    logger.info(
        "Background scheduler started — mitre_sync (24h), intel_scan (7d), "
        "notification_cleanup (24h), weekly_snapshot (Sundays 00:00), "
        "recurring_campaigns (daily)"
    )