import asyncio
import logging
from datetime import datetime

from apscheduler.schedulers.background import BackgroundScheduler

from app.database import SessionLocal
from app.models.reminder import ReminderSchedule
from app.models.user import User
from app.models.quiz import Quiz

logger = logging.getLogger(__name__)

scheduler = BackgroundScheduler()


def check_and_send_reminders():
    """Check for due reminders and send emails."""
    db = SessionLocal()
    try:
        due_reminders = db.query(ReminderSchedule).filter(
            ReminderSchedule.is_active == True,
            ReminderSchedule.next_reminder_at <= datetime.utcnow(),
        ).all()

        if not due_reminders:
            return

        logger.info(f"Found {len(due_reminders)} due reminders")

        for reminder in due_reminders:
            user = db.query(User).filter(User.id == reminder.user_id).first()
            quiz = db.query(Quiz).filter(Quiz.id == reminder.quiz_id).first()

            if not user or not quiz:
                reminder.is_active = False
                continue

            # Send email asynchronously
            try:
                from app.services.email_service import send_reminder_email
                loop = asyncio.new_event_loop()
                loop.run_until_complete(
                    send_reminder_email(
                        email=user.email,
                        user_name=user.name,
                        quiz_title=quiz.title,
                        score=reminder.performance_score,
                        next_date=reminder.next_reminder_at.strftime("%Y-%m-%d"),
                    )
                )
                loop.close()
            except Exception as e:
                logger.error(f"Failed to send reminder {reminder.id}: {e}")

            # Schedule next reminder
            from datetime import timedelta
            reminder.next_reminder_at = datetime.utcnow() + timedelta(days=reminder.interval_days)

        db.commit()
    except Exception as e:
        logger.exception(f"Scheduler error: {e}")
    finally:
        db.close()


def start_scheduler():
    """Start the APScheduler with daily reminder check."""
    scheduler.add_job(
        check_and_send_reminders,
        "interval",
        hours=24,
        id="reminder_check",
        replace_existing=True,
    )
    scheduler.start()
    logger.info("Scheduler started — reminder check runs every 24 hours")


def stop_scheduler():
    if scheduler.running:
        scheduler.shutdown()