# myapp/services/user_service.py
import os
from typing import Tuple
from flask import current_app, session


def _username_from_session() -> str:
    """通过 session['user_id'] -> username"""
    user_uuid = session.get("user_uuid")
    if not user_uuid:
        return None
    uuid2username = current_app.extensions["uuid2username"]
    return uuid2username.get(user_uuid)

def get_or_load_current_user():
    """
    返回当前用户对象（如 user_uuid2UserClass 中没有则从 JSON 载入并缓存）
    """
    user_uuid = session.get("user_uuid")
    if not user_uuid:
        return None

    username = _username_from_session()
    if not username:
        return None

    user_map = current_app.extensions["user_uuid2UserClass"]
    if user_uuid not in user_map:
        users_list = current_app.extensions["users_list"]
        user_map[user_uuid] = users_list.get_user_by_name(
            username
        )
    return user_map[user_uuid]

def add_course_for_current_user(course_id: str, course_data):
    user_obj = get_or_load_current_user()
    if user_obj is None:
        return False
    # 你的 UserClass 应该有 select_new_course 接口
    user_obj.select_new_course(course_id, course_data)
    return True