"""OpenAI 兼容 LLM 客户端（httpx）。支持云端与本地 vLLM/Ollama（密钥可空）。"""

import httpx

from config import config

_client = httpx.Client(timeout=300.0)


def chat(messages: list[dict], temperature: float = 0.4, max_tokens: int = 4096) -> str:
    base_url, api_key, model = config.effective_llm()
    headers = {"Content-Type": "application/json"}
    if api_key:  # 本地无鉴权端点不发送 Authorization
        headers["Authorization"] = f"Bearer {api_key}"

    resp = _client.post(
        f"{base_url.rstrip('/')}/chat/completions",
        headers=headers,
        json={
            "model": model,
            "messages": messages,
            "temperature": temperature,
            "max_tokens": max_tokens,
            "stream": False,
        },
    )
    resp.raise_for_status()
    data = resp.json()
    return data["choices"][0]["message"]["content"]