import json

class UserList:
    def __init__(self, db_file='db/data/user/user_id_list.json'):
        """初始化用户管理，自动打开并加载 JSON 数据文件。"""
        self.db_file = db_file
        with open(self.db_file, 'r', encoding='utf-8') as f:
            self.db = json.load(f)

    def add_user(self, user_id, password):
        """添加新的用户登录信息"""
        # 检查是否已经有该用户
        if user_id not in self.db:
            self.db[user_id] = password
            with open(self.db_file, 'w', encoding='utf-8') as f:
                json.dump(self.db, f, indent=4)
        else:
            print(f"User with ID {user_id} already exists.")

    def has_user(self, user_id):
        """检查用户是否存在"""
        return user_id in self.db
    
    def get_user_pswd(self, user_id):
        """获取指定 user_id 的用户信息"""
        if user_id in self.db:
            result = self.db[user_id]
            return result
        return None
    
    def update_password(self, user_id, new_password):
        """更新用户的密码"""
        assert self.db.get(user_id) is not None, f"User with ID {user_id} does not exist."
        self.db[user_id] = new_password
        with open(self.db_file, 'w', encoding='utf-8') as f:
            json.dump(self.db, f, indent=4)

    def delete_user(self, user_id):
        """删除用户"""
        assert self.db.get(user_id) is not None, f"User with ID {user_id} does not exist."
        self.db.remove(user_id)
        
    def get_all_users(self):
        """获取所有用户的信息"""
        return list(self.db.keys())

# 创建 UserList 实例
# user_list = UserList()

# # 添加用户
# user_list.add_user("user123", "password123")
# user_list.add_user("user456", "password456")

# # 获取用户
# user = user_list.get_user("user123")
# print(user)

# # 更新密码
# user_list.update_password("user123", "newpassword")

# # 获取所有用户
# all_users = user_list.get_all_users()
# print(all_users)

# # 删除用户
# user_list.delete_user("user123")