"""LLM Provider 基础抽象层"""
from abc import ABC, abstractmethod
from dataclasses import dataclass


@dataclass
class LLMMessage:
    role: str  # "system", "user", "assistant"
    content: str


@dataclass
class LLMResponse:
    content: str
    model: str
    usage: dict  # {"total_tokens": int, "prompt_tokens": int, "completion_tokens": int}


class BaseLLMProvider(ABC):
    """LLM Provider 抽象基类"""

    @abstractmethod
    async def chat(self, messages: list[LLMMessage]) -> LLMResponse:
        """非流式对话"""
        pass

    @abstractmethod
    async def chat_stream(self, messages: list[LLMMessage]) -> str:
        """流式对话，返回 token 异步生成器"""
        pass

    @abstractmethod
    async def embed(self, texts: list[str]) -> list[list[float]]:
        """生成嵌入向量"""
        pass