"""
APScheduler-based batch scheduler for the Overlay pipeline.

Integrated into FastAPI's lifespan via start_scheduler() / stop_scheduler().
"""

import logging
from datetime import datetime, timezone

logger = logging.getLogger(__name__)

_scheduler = None


def _get_scheduler():
    """Lazily create the APScheduler instance."""
    global _scheduler
    if _scheduler is None:
        try:
            from apscheduler.schedulers.asyncio import AsyncIOScheduler
            from apscheduler.triggers.cron import CronTrigger
            _scheduler = AsyncIOScheduler(timezone="UTC")
        except ImportError:
            logger.warning("apscheduler not installed; overlay batch scheduling disabled")
            return None
    return _scheduler


async def _run_collect_job() -> None:
    """Scheduled job: collect RSS + wiki + youtube + trends."""
    from app.core.database import AsyncSessionLocal
    from app.services.overlay.overlay_pipeline import OverlayPipeline

    pipeline = OverlayPipeline()
    async with AsyncSessionLocal() as db:
        try:
            counts = await pipeline.collect_all(db)
            logger.info(f"[Scheduler] collect_all completed: {counts}")
        except Exception as e:
            logger.error(f"[Scheduler] collect_all failed: {e}")


async def _run_build_job() -> None:
    """Scheduled job: build features for all TOP_50 symbols."""
    from app.core.database import AsyncSessionLocal
    from app.services.overlay.overlay_pipeline import OverlayPipeline

    pipeline = OverlayPipeline()
    async with AsyncSessionLocal() as db:
        try:
            built = await pipeline.build_features_batch(db)
            logger.info(f"[Scheduler] feature_build completed: {built} symbols")
        except Exception as e:
            logger.error(f"[Scheduler] feature_build failed: {e}")


def start_scheduler() -> None:
    """Start the APScheduler with overlay jobs. Call from FastAPI lifespan startup."""
    from app.core.config import settings

    if not getattr(settings, "OVERLAY_ENABLED", True):
        logger.info("Overlay disabled; scheduler not started")
        return

    sched = _get_scheduler()
    if sched is None:
        return

    try:
        from apscheduler.triggers.cron import CronTrigger

        # Collect: 23:30 UTC daily on weekdays (≈ 18:30 ET)
        sched.add_job(
            _run_collect_job,
            trigger=CronTrigger(day_of_week="mon-fri", hour=23, minute=30, timezone="UTC"),
            id="overlay_collect",
            replace_existing=True,
            misfire_grace_time=600,
        )
        # Feature build: 01:30 UTC (≈ 20:30 ET)
        sched.add_job(
            _run_build_job,
            trigger=CronTrigger(day_of_week="mon-fri", hour=1, minute=30, timezone="UTC"),
            id="overlay_feature_build",
            replace_existing=True,
            misfire_grace_time=600,
        )

        sched.start()
        logger.info("Overlay scheduler started (collect @ 23:30 UTC, build @ 01:30 UTC, weekdays)")
    except Exception as e:
        logger.error(f"Overlay scheduler start failed: {e}")


def stop_scheduler() -> None:
    """Stop the scheduler. Call from FastAPI lifespan shutdown."""
    sched = _get_scheduler()
    if sched and sched.running:
        sched.shutdown(wait=False)
        logger.info("Overlay scheduler stopped")