AutonetSellCar/backend/app/services/promo_notification_service.py

"""
Promo Notification Service
Sends email notifications to users when their preferred vehicle is added to a promotion
"""
import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from typing import List, Optional
from sqlalchemy.orm import Session
import asyncio

from ..config import get_settings
from ..models.user import User
from ..models.car import Car

settings = get_settings()


def get_users_with_matching_preference(
    db: Session,
    maker_name: Optional[str] = None,
    model_name: Optional[str] = None
) -> List[User]:
    """
    Find users whose promo preference matches the given maker/model
    Only returns users who have promo_email_enabled = True
    """
    query = db.query(User).filter(
        User.promo_email_enabled == True,
        User.email.isnot(None)
    )

    if maker_name:
        # Match maker only (for users who selected maker but any model)
        # or match exact maker+model
        query = query.filter(User.promo_preferred_maker == maker_name)

    if model_name:
        # If model is specified, also filter by model (or users with no model preference)
        query = query.filter(
            (User.promo_preferred_model == model_name) |
            (User.promo_preferred_model.is_(None)) |
            (User.promo_preferred_model == "")
        )

    return query.all()


async def send_promo_notification_email(
    email: str,
    car: Car,
    language: str = "en"
) -> bool:
    """Send promo notification email to a single user"""
    try:
        # Email templates by language
        subjects = {
            "en": f"AutonetSellCar - Your Preferred Vehicle is Now on Promotion!",
            "ko": f"AutonetSellCar - 관심 차량이 프로모션에 등록되었습니다!",
            "mn": f"AutonetSellCar - Таны сонирхсон машин урамшуулалд орлоо!",
            "ru": f"AutonetSellCar - Ваш желаемый автомобиль теперь в акции!"
        }

        car_name = car.car_name or "Unknown Vehicle"
        car_year = car.year or ""
        car_mileage = f"{car.mileage:,}km" if car.mileage else ""
        car_url = f"https://autonetsellcar.com/cars/{car.id}"

        bodies = {
            "en": f"""
Hello,

Great news! A vehicle matching your preference is now available on promotion!

Vehicle: {car_name}
Year: {car_year}
Mileage: {car_mileage}

View this vehicle: {car_url}

As a promoted vehicle, you can view all photos for free!

Best regards,
AutonetSellCar Team

---
You received this email because you signed up for promotion notifications.
To unsubscribe, update your preferences in your account settings.
""",
            "ko": f"""
안녕하세요,

좋은 소식입니다! 관심 차량이 프로모션에 등록되었습니다!

차량: {car_name}
연식: {car_year}
주행거리: {car_mileage}

차량 보기: {car_url}

프로모션 차량은 모든 사진을 무료로 보실 수 있습니다!

감사합니다,
AutonetSellCar 팀

---
프로모션 알림 신청으로 이 이메일을 받으셨습니다.
수신 거부를 원하시면 계정 설정에서 변경해 주세요.
""",
            "mn": f"""
Сайн байна уу,

Сайхан мэдээ! Таны сонирхсон машин урамшуулалд орлоо!

Машин: {car_name}
Он: {car_year}
Гүйлт: {car_mileage}

Машин үзэх: {car_url}

Урамшуулалтай машины бүх зургийг үнэгүй үзэх боломжтой!

Хүндэтгэсэн,
AutonetSellCar баг

---
Та урамшуулалын мэдэгдэл хүлээн авахаар бүртгүүлсэн тул энэ имэйлийг хүлээн авлаа.
Татгалзахыг хүсвэл данс тохиргооноос өөрчилнө үү.
""",
            "ru": f"""
Здравствуйте,

Отличные новости! Автомобиль, соответствующий вашим предпочтениям, теперь в акции!

Автомобиль: {car_name}
Год: {car_year}
Пробег: {car_mileage}

Посмотреть автомобиль: {car_url}

Как акционный автомобиль, вы можете просмотреть все фотографии бесплатно!

С уважением,
Команда AutonetSellCar

---
Вы получили это письмо, потому что подписались на уведомления об акциях.
Чтобы отписаться, измените настройки в вашем аккаунте.
"""
        }

        subject = subjects.get(language, subjects["en"])
        body = bodies.get(language, bodies["en"])

        # Check if SMTP is configured
        if not settings.SMTP_USER or not settings.SMTP_PASSWORD:
            # Development mode - just log
            print(f"[DEV] Promo notification email for {email}: {car_name}")
            return True

        # Send actual email
        msg = MIMEMultipart()
        msg['From'] = f"{settings.SMTP_FROM_NAME} <{settings.SMTP_FROM_EMAIL or settings.SMTP_USER}>"
        msg['To'] = email
        msg['Subject'] = subject
        msg.attach(MIMEText(body, 'plain', 'utf-8'))

        with smtplib.SMTP(settings.SMTP_HOST, settings.SMTP_PORT) as server:
            server.starttls()
            server.login(settings.SMTP_USER, settings.SMTP_PASSWORD)
            server.send_message(msg)

        print(f"[INFO] Promo notification sent to {email} for car {car.id}")
        return True

    except Exception as e:
        print(f"[ERROR] Failed to send promo notification to {email}: {e}")
        return False


async def notify_users_for_promo_vehicle(
    db: Session,
    car: Car
) -> int:
    """
    Notify all users whose preference matches the car being promoted
    Returns the number of notifications sent
    """
    # Get maker and model names from car
    maker_name = car.maker.name if car.maker else None
    model_name = car.model.name if car.model else None

    if not maker_name:
        print(f"[INFO] Car {car.id} has no maker, skipping promo notifications")
        return 0

    # Find matching users
    matching_users = get_users_with_matching_preference(
        db=db,
        maker_name=maker_name,
        model_name=model_name
    )

    if not matching_users:
        print(f"[INFO] No users with matching preference for {maker_name} {model_name}")
        return 0

    print(f"[INFO] Found {len(matching_users)} users with preference for {maker_name} {model_name}")

    # Send notifications
    sent_count = 0
    for user in matching_users:
        if user.email:
            # Determine language based on user's country
            language = "en"  # Default
            if user.country:
                country_lower = user.country.lower()
                if country_lower in ["korea", "south korea", "kr", "한국"]:
                    language = "ko"
                elif country_lower in ["mongolia", "mn", "монгол"]:
                    language = "mn"
                elif country_lower in ["russia", "ru", "россия"]:
                    language = "ru"

            success = await send_promo_notification_email(
                email=user.email,
                car=car,
                language=language
            )
            if success:
                sent_count += 1

    return sent_count


def notify_users_for_promo_vehicle_sync(db: Session, car: Car) -> int:
    """Synchronous wrapper for notify_users_for_promo_vehicle"""
    try:
        loop = asyncio.get_event_loop()
    except RuntimeError:
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)

    if loop.is_running():
        # If already in async context, create a task
        import concurrent.futures
        with concurrent.futures.ThreadPoolExecutor() as executor:
            future = executor.submit(
                asyncio.run,
                notify_users_for_promo_vehicle(db, car)
            )
            return future.result()
    else:
        return loop.run_until_complete(notify_users_for_promo_vehicle(db, car))