from abc import ABC, abstractmethod
from typing import Dict, Any, Generator, Union, Tuple
import requests

class ModelService(ABC):
    """大模型服务基类"""
    
    @abstractmethod
    def get_api_config(self) -> Tuple[str, str]:
        """获取 API URL 和 Key"""
        pass

    @abstractmethod
    def calculate_cost(self, usage: Dict[str, Any] = None, stream: bool = False) -> float:
        """计算费用"""
        pass

    @abstractmethod
    def check_balance(self, balance: float) -> Tuple[bool, float, str]:
        """检查余额是否充足
        Returns: (is_sufficient, estimated_cost, error_message)
        """
        pass

    @abstractmethod
    def prepare_payload(self, data: Dict[str, Any]) -> Dict[str, Any]:
        """准备请求载荷"""
        pass
    
    @abstractmethod
    def handle_response(self, response: requests.Response, stream: bool) -> Union[Dict[str, Any], Generator]:
        """处理响应"""
        pass