"""LLM 客户端 — 用于 PPT Master 管线中的策略师和执行器阶段"""

import httpx
import json
from typing import Generator
from config import config


class LLMClient:
    """OpenAI 兼容的 LLM 客户端"""

    def __init__(self):
        self.api_key = config.OPENAI_API_KEY
        self.base_url = config.OPENAI_BASE_URL.rstrip("/")
        self.model = config.OPENAI_MODEL
        self.client = httpx.Client(timeout=300.0)

    def chat(
        self,
        messages: list[dict],
        temperature: float = 0.7,
        max_tokens: int = 16384,
        stream: bool = False,
    ) -> str:
        """同步聊天完成"""
        headers = {
            "Authorization": f"Bearer {self.api_key}",
            "Content-Type": "application/json",
        }
        payload = {
            "model": self.model,
            "messages": messages,
            "temperature": temperature,
            "max_tokens": max_tokens,
            "stream": stream,
        }

        if stream:
            return self._stream_chat(headers, payload)

        resp = self.client.post(
            f"{self.base_url}/chat/completions",
            headers=headers,
            json=payload,
        )
        resp.raise_for_status()
        data = resp.json()
        return data["choices"][0]["message"]["content"]

    def _stream_chat(self, headers: dict, payload: dict) -> str:
        """流式聊天，收集完整响应"""
        full_content = ""
        with self.client.stream(
            "POST",
            f"{self.base_url}/chat/completions",
            headers=headers,
            json=payload,
        ) as resp:
            resp.raise_for_status()
            for line in resp.iter_lines():
                if not line.startswith("data: "):
                    continue
                data_str = line[6:]
                if data_str == "[DONE]":
                    break
                try:
                    chunk = json.loads(data_str)
                    delta = chunk["choices"][0].get("delta", {})
                    content = delta.get("content", "")
                    if content:
                        full_content += content
                except (json.JSONDecodeError, KeyError, IndexError):
                    continue
        return full_content

    def close(self):
        self.client.close()


llm_client = LLMClient()