"""
数据订阅服务
"""
import logging
from datetime import datetime
from typing import List, Optional

from sqlalchemy.orm import Session

from app.models import Subscription
from app.db.init_db import SQLiteSessionLocal

logger = logging.getLogger(__name__)


class SubscriptionService:
    """数据订阅服务"""
    
    @staticmethod
    def create_subscription(
        user_id: int,
        symbol: str,
        period: Optional[str] = None,
        subscription_type: str = "kline"
    ) -> tuple[Subscription, bool]:
        """
        创建订阅
        
        Args:
            user_id: 用户 ID
            symbol: 品种代码
            period: 周期
            subscription_type: 订阅类型
            
        Returns:
            tuple[Subscription, bool]: (订阅对象，是否为新创建)
            
        Raises:
            ValueError: 当重复订阅时抛出异常
        """
        with SQLiteSessionLocal() as db:
            # 检查是否已存在活跃订阅
            existing = db.query(Subscription).filter(
                Subscription.user_id == user_id,
                Subscription.symbol == symbol,
                Subscription.period == period,
                Subscription.subscription_type == subscription_type,
                Subscription.is_active == True
            ).first()
            
            if existing:
                # 重复订阅检查：如果已存在活跃订阅，抛出异常
                raise ValueError(f"您已订阅 {symbol} ({period})，请勿重复订阅")
            
            # 检查是否存在非活跃订阅，可以重新激活
            inactive = db.query(Subscription).filter(
                Subscription.user_id == user_id,
                Subscription.symbol == symbol,
                Subscription.period == period,
                Subscription.subscription_type == subscription_type,
                Subscription.is_active == False
            ).first()
            
            if inactive:
                inactive.is_active = True
                inactive.created_at = datetime.utcnow()
                db.commit()
                db.refresh(inactive)
                return inactive, False
            
            subscription = Subscription(
                user_id=user_id,
                symbol=symbol,
                period=period,
                subscription_type=subscription_type
            )
            db.add(subscription)
            db.commit()
            db.refresh(subscription)
            return subscription, True
    
    @staticmethod
    def get_user_subscriptions(
        user_id: int,
        subscription_type: Optional[str] = None
    ) -> List[Subscription]:
        """获取用户订阅列表"""
        with SQLiteSessionLocal() as db:
            query = db.query(Subscription).filter(
                Subscription.user_id == user_id,
                Subscription.is_active == True
            )
            if subscription_type:
                query = query.filter(Subscription.subscription_type == subscription_type)
            return query.order_by(Subscription.created_at.desc()).all()
    
    @staticmethod
    def get_subscription_by_id(subscription_id: int, user_id: int) -> Optional[Subscription]:
        """根据 ID 获取订阅"""
        with SQLiteSessionLocal() as db:
            return db.query(Subscription).filter(
                Subscription.id == subscription_id,
                Subscription.user_id == user_id
            ).first()
    
    @staticmethod
    def cancel_subscription(subscription_id: int, user_id: int) -> bool:
        """取消订阅"""
        with SQLiteSessionLocal() as db:
            subscription = db.query(Subscription).filter(
                Subscription.id == subscription_id,
                Subscription.user_id == user_id
            ).first()
            
            if not subscription:
                return False
            
            subscription.is_active = False
            db.commit()
            return True
    
    @staticmethod
    def get_subscribers_for_symbol(symbol: str, subscription_type: str = "kline") -> List[int]:
        """获取订阅某品种的用户 ID 列表"""
        with SQLiteSessionLocal() as db:
            subscriptions = db.query(Subscription).filter(
                Subscription.symbol == symbol,
                Subscription.subscription_type == subscription_type,
                Subscription.is_active == True
            ).all()
            return [s.user_id for s in subscriptions]