import logging
import threading
import time
from datetime import datetime, timezone

from ..database import SessionLocal
from ..models import ParseJob
from .jobs import enqueue_job

logger = logging.getLogger(__name__)

TICK_SECONDS = 30
RECURRING_STATUSES = ("completed", "failed")


def run_scheduler_tick() -> None:
    db = SessionLocal()
    try:
        now = datetime.now(timezone.utc)
        jobs = (
            db.query(ParseJob)
            .filter(
                ParseJob.is_active.is_(True),
                ParseJob.interval_seconds > 0,
                ParseJob.status.in_(RECURRING_STATUSES),
            )
            .all()
        )
        for job in jobs:
            if job.last_run_at is None:
                continue
            elapsed = (now - job.last_run_at).total_seconds()
            if elapsed < job.interval_seconds:
                continue

            job.status = "queued"
            job.last_error = None
            db.commit()
            enqueue_job(job.id, job.source_type, job.source_config)
            logger.info("Re-queued recurring job %s (interval %ss)", job.id, job.interval_seconds)
    except Exception:
        logger.exception("Scheduler tick failed")
        db.rollback()
    finally:
        db.close()


def _scheduler_loop(stop_event: threading.Event) -> None:
    while not stop_event.wait(TICK_SECONDS):
        run_scheduler_tick()


def start_scheduler() -> threading.Event:
    stop_event = threading.Event()
    thread = threading.Thread(target=_scheduler_loop, args=(stop_event,), daemon=True)
    thread.start()
    logger.info("Parse job scheduler started (tick every %ss)", TICK_SECONDS)
    return stop_event