Files
product/services/llm.py
T
2026-03-27 17:10:41 +08:00

92 lines
3.3 KiB
Python

from __future__ import annotations
import logging
import os
from typing import Optional
from collections import deque
from config import settings
logger = logging.getLogger(__name__)
class LLMService:
def __init__(self) -> None:
self._ready = False
self._error: Optional[str] = None
self._client = None
self._model = (settings.llm_model or "").strip()
self._base_url = (settings.llm_base_url or "").strip()
self._history: deque[dict] = deque(maxlen=12) # 6 turns (user+assistant)
self._system_prompt = "请用中文口语化简短回复,1-2句。"
if not settings.llm_api_key:
self._error = "missing LLM api key: set LLM_API_KEY or DEEPSEEK_API_KEY"
return
# If DeepSeek key is provided but no explicit base URL override,
# route to DeepSeek-compatible OpenAI endpoint by default.
if (
os.getenv("DEEPSEEK_API_KEY")
and not os.getenv("LLM_BASE_URL")
and not os.getenv("DEEPSEEK_BASE_URL")
and (self._base_url.lower() == "https://api.openai.com/v1" or not self._base_url)
):
self._base_url = "https://api.deepseek.com/v1"
if not self._model:
base = self._base_url.lower()
self._model = "deepseek-chat" if "deepseek" in base else "gpt-4o-mini"
try:
from openai import AsyncOpenAI
self._client = AsyncOpenAI(
api_key=settings.llm_api_key,
base_url=self._base_url,
timeout=settings.llm_timeout,
)
self._ready = True
self._error = None
except Exception as exc: # pragma: no cover
self._error = str(exc)
logger.warning("LLM online mode unavailable: %s", exc)
async def reply_with_meta(self, text: str) -> tuple[str, str]:
if not self._ready or self._client is None:
return f"收到:{text}。这是本地兜底回复。", "fallback"
try:
resp = await self._client.chat.completions.create(
model=self._model,
messages=[{"role": "system", "content": self._system_prompt}, *list(self._history), {"role": "user", "content": text}],
max_tokens=settings.llm_max_tokens,
temperature=0.7,
)
content = (resp.choices[0].message.content or "").strip()
if content:
self._history.append({"role": "user", "content": text})
self._history.append({"role": "assistant", "content": content})
return content, "online"
except Exception as exc: # pragma: no cover
self._error = str(exc)
logger.warning("LLM request failed, fallback used: %s", exc)
return f"收到:{text}。这是本地兜底回复。", "fallback"
async def reply(self, text: str) -> str:
content, _ = await self.reply_with_meta(text)
return content
@property
def health(self) -> dict:
return {
"ready": self._ready,
"model": self._model,
"base_url": self._base_url,
"history_items": len(self._history),
"error": self._error,
}
def clear_history(self) -> None:
self._history.clear()