# app/services/session_service.py

from datetime import datetime, timedelta
import uuid

from sqlalchemy.orm import Session as DBSession
from sqlalchemy import delete

from app.models.session import VasSession
from app.models.user import VasUser


class SessionService:

    # ============================
    # token → user（鉴权用）
    # ============================
    @staticmethod
    def get_user_by_token(db: DBSession, session_id: str) -> VasUser:
        session_obj = db.query(VasSession).filter(VasSession.id == session_id).first()
        if not session_obj:
            return None

        # session 是否过期
        if session_obj.expire_at < datetime.utcnow():
            # 自动删除过期 session
            SessionService.delete_session(db, session_id)
            return None

        user = db.query(VasUser).filter(VasUser.id == session_obj.user_id).first()
        return user

    # ============================
    # 删除 session（登出）
    # ============================
    @staticmethod
    def delete_session(db: DBSession, session_id: str):
        db.query(VasSession).filter(VasSession.id == session_id).delete()
        db.commit()