fix:优化界面

backend/llm_client.py

@@ -0,0 +1,123 @@
+# -*- coding: utf-8 -*-
+"""多模型统一调用：从 store 读取当前模型配置（API Key、base_url、model_name），按 OpenAI 兼容或豆包 Responses API 请求。"""
+import logging
+from typing import List, Optional
+
+logger = logging.getLogger("wechat-backend.llm")
+
+try:
+    from backend import store
+except ImportError:
+    import store
+
+
+def _doubao_input_from_messages(messages: List[dict]) -> list:
+    """将 [{"role":"user","content":"..."}] 转为豆包 Responses API 的 input 格式。"""
+    result = []
+    for m in messages:
+        role = (m.get("role") or "user").lower()
+        if role == "system":
+            role = "user"
+        content = m.get("content")
+        if isinstance(content, str):
+            content = [{"type": "input_text", "text": content}]
+        elif isinstance(content, list):
+            # 已是多模态格式，或需转为 input_text
+            out = []
+            for item in content:
+                if isinstance(item, dict):
+                    if item.get("type") == "input_text":
+                        out.append(item)
+                    elif "text" in item:
+                        out.append({"type": "input_text", "text": item["text"]})
+                else:
+                    out.append({"type": "input_text", "text": str(item)})
+            content = out if out else [{"type": "input_text", "text": ""}]
+        else:
+            content = [{"type": "input_text", "text": str(content or "")}]
+        result.append({"role": role, "content": content})
+    return result
+
+
+async def _chat_doubao(api_key: str, base_url: str, model_name: str, messages: List[dict]) -> Optional[str]:
+    """豆包（Volcengine ARK）Responses API：POST /responses，input 格式见示例。"""
+    import httpx
+    url = base_url.rstrip("/") + "/responses"
+    payload = {"model": model_name, "input": _doubao_input_from_messages(messages)}
+    try:
+        async with httpx.AsyncClient(timeout=60.0) as client:
+            r = await client.post(
+                url,
+                headers={"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"},
+                json=payload,
+            )
+        if r.status_code != 200:
+            logger.warning("doubao API status=%s body=%s", r.status_code, r.text[:500])
+            return None
+        data = r.json()
+        # 常见返回结构：output.output_text / output.text / choices[0].message.content
+        output = data.get("output") or data
+        if isinstance(output, dict):
+            text = output.get("output_text") or output.get("text")
+            if isinstance(text, str):
+                return text
+            choices = output.get("choices")
+            if choices and len(choices) > 0:
+                msg = choices[0].get("message") or choices[0]
+                if isinstance(msg, dict) and msg.get("content"):
+                    return msg["content"]
+        if "choices" in data and data["choices"]:
+            c = data["choices"][0]
+            msg = c.get("message", c)
+            if isinstance(msg, dict) and msg.get("content"):
+                return msg["content"]
+        logger.warning("doubao unknown response shape: %s", list(data.keys()))
+        return None
+    except Exception as e:
+        logger.exception("doubao chat error: %s", e)
+        return None
+
+
+async def chat(messages: List[dict], model_id: Optional[str] = None) -> Optional[str]:
+    """
+    使用已配置的模型进行对话。
+    model_id: 若指定则用该模型，否则用当前选中的模型。
+    返回 assistant 回复文本。
+    """
+    if model_id:
+        model_config = store.get_model(model_id)
+    else:
+        model_config = store.get_current_model()
+    if not model_config or not model_config.get("api_key"):
+        logger.warning("No model configured or no api_key")
+        return None
+    api_key = model_config["api_key"]
+    base_url = (model_config.get("base_url") or "").strip()
+    model_name = (model_config.get("model_name") or "qwen-turbo").strip()
+    provider = (model_config.get("provider") or "openai").lower()
+    if not base_url and provider == "qwen":
+        base_url = "https://dashscope.aliyuncs.com/compatible-mode/v1"
+    if not base_url and provider == "doubao":
+        base_url = "https://ark.cn-beijing.volces.com/api/v3"
+    if not base_url:
+        base_url = "https://api.openai.com/v1"
+    # 豆包：火山方舟支持 chat/completions 兼容接口，优先走统一 OpenAI 客户端；若需 Responses API 可走 _chat_doubao
+    if provider == "doubao":
+        try:
+            from openai import AsyncOpenAI
+            client = AsyncOpenAI(api_key=api_key, base_url=base_url)
+            r = await client.chat.completions.create(model=model_name, messages=messages)
+            if r.choices and r.choices[0].message.content:
+                return r.choices[0].message.content
+        except Exception as e:
+            logger.info("doubao chat/completions failed, try responses API: %s", e)
+        return await _chat_doubao(api_key, base_url, model_name, messages)
+    try:
+        from openai import AsyncOpenAI
+        client = AsyncOpenAI(api_key=api_key, base_url=base_url)
+        r = await client.chat.completions.create(model=model_name, messages=messages)
+        text = r.choices[0].message.content if r.choices else None
+        return text
+    except Exception as e:
+        logger.exception("llm chat error: %s", e)
+        return None