Update clare_core.py

clare_core.py

@@ -176,6 +176,40 @@ def detect_language(message: str, preference: str) -> str:
     if re.search(r"[\u4e00-\u9fff]", message):
         return "中文"
     return "English"
+    
+def get_empty_input_prompt(lang: str) -> str:
+    """
+    空输入时的友好提示，根据语言返回中/英文。
+    """
+    if lang == "中文":
+        return "请先输入一个问题或想法，再按回车发送，我才能帮到你哦。"
+    # 默认英文
+    return "Please type a question or some text before sending, then hit Enter."
+
+def build_error_message(
+    e: Exception,
+    lang: str,
+    op: str = "chat",
+) -> str:
+    """
+    针对不同操作类型（普通对话 / quiz / summary）和语言，生成友好的错误提示。
+    不把原始异常直接暴露给学生，只在后台打印。
+    """
+    if lang == "中文":
+        prefix = {
+            "chat": "抱歉，刚刚在和模型对话时出现了一点问题。",
+            "quiz": "抱歉，刚刚在生成测验题目时出现了一点问题。",
+            "summary": "抱歉，刚刚在生成总结时出现了一点问题。",
+        }.get(op, "抱歉，刚刚出现了一点问题。")
+        return prefix + " 请稍后再试一次，或者换个问法试试。"
+
+    # 默认英文
+    prefix_en = {
+        "chat": "Sorry, I ran into a problem while talking to the model.",
+        "quiz": "Sorry, there was a problem while generating the quiz.",
+        "summary": "Sorry, there was a problem while generating the summary.",
+    }.get(op, "Sorry, something went wrong just now.")
+    return prefix_en + " Please try again in a moment or rephrase your request."
 
 
 # ---------- Session 状态展示 ----------
@@ -317,6 +351,53 @@ def find_similar_past_question(
 
     return None
 
+from config import client, DEFAULT_MODEL, EMBEDDING_MODEL  # 确认已导入 DEFAULT_MODEL
+
+def safe_chat_completion(
+    model_name: str,
+    messages: List[Dict[str, str]],
+    lang: str,
+    op: str = "chat",
+    temperature: float = 0.5,
+) -> str:
+    """
+    统一安全调用 OpenAI Chat Completion：
+    - 最多尝试 2 次
+    - 每次请求 timeout = 20 秒
+    - 第一次用学生选择的模型；出错后，如果不是 DEFAULT_MODEL，则自动回退到 DEFAULT_MODEL 再试一次
+    - 所有异常都会打印到后台 log，但对学生只返回友好的中/英文错误文案
+    """
+    preferred_model = model_name or DEFAULT_MODEL
+    last_error: Optional[Exception] = None
+
+    for attempt in range(2):
+        # 第一次用学生指定模型，第二次（如果需要）切到默认模型
+        if attempt == 0:
+            current_model = preferred_model
+        else:
+            current_model = DEFAULT_MODEL
+
+        try:
+            resp = client.chat.completions.create(
+                model=current_model,
+                messages=messages,
+                temperature=temperature,
+                timeout=20,  # 20 秒超时
+            )
+            return resp.choices[0].message.content
+        except Exception as e:
+            print(
+                f"[safe_chat_completion][{op}] attempt {attempt+1} "
+                f"failed with model={current_model}: {repr(e)}"
+            )
+            last_error = e
+
+            # 如果已经用的是默认模型，或者已经是第二次尝试，就跳出循环
+            if current_model == DEFAULT_MODEL or attempt == 1:
+                break
+
+    # 两次都失败，返回友好的错误文案
+    return build_error_message(last_error or Exception("unknown error"), lang, op)
 
 # ---------- 构建 messages ----------
 def build_messages(