初始化

app/services/ai_tool.py

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+"""AI 调用工具封装"""
+
+import json
+import re
+from typing import Any
+
+from langchain_openai import ChatOpenAI
+from langchain_core.messages import SystemMessage, HumanMessage
+
+from app.core.logger import log
+
+# markdown 代码块正则
+_CODE_BLOCK_RE = re.compile(r"```\w*\s*\n?(.*?)\n?\s*```", re.DOTALL)
+# 控制字符正则（保留 \t \n \r）
+_CONTROL_CHAR_RE = re.compile(r"[\x00-\x08\x0b\x0c\x0e-\x1f]")
+
+
+def clean_ai_response(response: str) -> str:
+    """从 AI 返回的文本中提取干净的 JSON 字符串"""
+    if not response or not response.strip():
+        return ""
+
+    result = response.strip()
+
+    # 尝试从 markdown 代码块提取
+    match = _CODE_BLOCK_RE.search(result)
+    if match:
+        result = match.group(1).strip()
+    else:
+        # 定位首个 JSON 起始符
+        obj_start = result.find("{")
+        arr_start = result.find("[")
+        if obj_start < 0:
+            start = arr_start
+        elif arr_start < 0:
+            start = obj_start
+        else:
+            start = min(obj_start, arr_start)
+        if start > 0:
+            result = result[start:]
+
+    # 清除控制字符
+    result = _CONTROL_CHAR_RE.sub("", result)
+    return result
+
+
+async def ai_chat(llm: ChatOpenAI, system_prompt: str, user_message: str) -> str:
+    """异步调用 LLM，返回原始文本"""
+    messages = [
+        SystemMessage(content=system_prompt),
+        HumanMessage(content=user_message),
+    ]
+    response = await llm.ainvoke(messages)
+    return response.content
+
+
+async def ai_chat_json(llm: ChatOpenAI, system_prompt: str, user_message: str) -> Any:
+    """异步调用 LLM，返回解析后的 JSON 对象"""
+    raw = await ai_chat(llm, system_prompt, user_message)
+    cleaned = clean_ai_response(raw)
+    try:
+        return json.loads(cleaned)
+    except json.JSONDecodeError as e:
+        log.warning("AI JSON 解析失败: {}, raw={}", e, raw[:200])
+        return None