"""LLM API 客户端，兼容 OpenAI API 格式"""
import json
import logging
from typing import Optional

from openai import OpenAI, APIError

from config import settings

logger = logging.getLogger(__name__)


class AIClient:
    """封装 LLM 调用，支持重试和 JSON 输出"""

    def __init__(
        self,
        api_key: Optional[str] = None,
        base_url: Optional[str] = None,
        model: Optional[str] = None,
        timeout: Optional[int] = None,
        max_retries: Optional[int] = None,
    ):
        self.api_key = api_key or settings.OPENAI_API_KEY
        self.base_url = base_url or settings.OPENAI_BASE_URL
        self.model = model or settings.OPENAI_MODEL
        self.timeout = timeout or settings.OPENAI_TIMEOUT
        self.max_retries = max_retries or settings.OPENAI_MAX_RETRIES

        self._client: Optional[OpenAI] = None

    @property
    def client(self) -> OpenAI:
        if self._client is None:
            self._client = OpenAI(
                api_key=self.api_key,
                base_url=self.base_url,
                timeout=self.timeout,
                max_retries=self.max_retries,
            )
        return self._client

    def chat_completion(
        self,
        system_prompt: str,
        user_prompt: str,
        temperature: float = 0.3,
        json_mode: bool = False,
    ) -> str:
        """调用 LLM 返回文本"""
        messages = [
            {"role": "system", "content": system_prompt},
            {"role": "user", "content": user_prompt},
        ]

        kwargs = {
            "model": self.model,
            "messages": messages,
            "temperature": temperature,
        }
        if json_mode:
            kwargs["response_format"] = {"type": "json_object"}

        try:
            resp = self.client.chat.completions.create(**kwargs)
            content = resp.choices[0].message.content or ""
            return content.strip()
        except APIError as exc:
            logger.error("LLM API 调用失败: %s", exc)
            raise

    def chat_completion_json(
        self,
        system_prompt: str,
        user_prompt: str,
        temperature: float = 0.3,
    ) -> dict:
        """调用 LLM 并解析返回的 JSON"""
        content = self.chat_completion(
            system_prompt=system_prompt,
            user_prompt=user_prompt,
            temperature=temperature,
            json_mode=True,
        )
        try:
            return json.loads(content)
        except json.JSONDecodeError as exc:
            logger.error("LLM 返回不是合法 JSON: %s - content=%s", exc, content[:500])
            raise


ai_client = AIClient()