Initial commit: 网页联机狼人杀（FastAPI+WebSocket 后端 / React+TS+Sass 前端）

backend/app/game/ai/llm_client.py

@@ -0,0 +1,75 @@
+"""OpenAI 兼容异步客户端：JSON 决策与自由文本发言，自动降级重试。"""
+from __future__ import annotations
+
+import asyncio
+import json
+import re
+
+from ...config import CONFIG, LLMConfig
+
+
+def parse_json_obj(text: str) -> dict | None:
+    if not text:
+        return None
+    text = text.strip()
+    text = re.sub(r"^```(?:json)?\s*|\s*```$", "", text, flags=re.S)
+    start, end = text.find("{"), text.rfind("}")
+    if start == -1 or end <= start:
+        return None
+    try:
+        data = json.loads(text[start:end + 1])
+        return data if isinstance(data, dict) else None
+    except json.JSONDecodeError:
+        return None
+
+
+class LLMClient:
+    def __init__(self, cfg: LLMConfig) -> None:
+        from openai import AsyncOpenAI
+        self.model = cfg.model
+        self.temperature = cfg.temperature
+        self._client = AsyncOpenAI(
+            base_url=cfg.base_url, api_key=cfg.api_key, timeout=30, max_retries=0)
+
+    async def _create(self, system: str, user: str, *, json_mode: bool, timeout: float) -> str:
+        kwargs: dict = {
+            "model": self.model,
+            "temperature": self.temperature,
+            "messages": [
+                {"role": "system", "content": system},
+                {"role": "user", "content": user},
+            ],
+            "timeout": timeout,
+        }
+        if json_mode:
+            kwargs["response_format"] = {"type": "json_object"}
+            try:
+                resp = await self._client.chat.completions.create(**kwargs)
+                return resp.choices[0].message.content or ""
+            except Exception:
+                kwargs.pop("response_format", None)  # 部分兼容端点不支持 response_format
+        resp = await self._client.chat.completions.create(**kwargs)
+        return resp.choices[0].message.content or ""
+
+    async def chat_json(self, system: str, user: str, *, timeout: float = 22.0) -> dict:
+        last = ""
+        for _ in range(2):
+            text = await self._create(system, user, json_mode=True, timeout=timeout)
+            data = parse_json_obj(text)
+            if data is not None:
+                return data
+            last = text
+        raise ValueError(f"LLM 未返回有效 JSON: {last[:120]}")
+
+    async def chat_text(self, system: str, user: str, *, timeout: float = 40.0) -> str:
+        return (await self._create(system, user, json_mode=False, timeout=timeout)).strip()
+
+
+_client: LLMClient | None = None
+
+
+def get_llm_client() -> LLMClient:
+    global _client
+    if _client is None:
+        _client = LLMClient(CONFIG.llm)
+    return _client