webtest-agent v1.0.0: AI网页测试智能体（LLM决策+agent-browser执行+断言+报告）

llm.py

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+#!/usr/bin/env python3
+"""LLM 客户端（OpenAI 兼容接口）"""
+import json
+import re
+import urllib.request
+import urllib.error
+
+from config import LLM_BASE_URL, LLM_API_KEY, LLM_MODEL, LLM_TEMPERATURE, LLM_TIMEOUT
+
+
+class LLMError(Exception):
+    pass
+
+
+def _extract_json(text):
+    """从 LLM 输出中提取 JSON（容忍 markdown 代码块等包裹）"""
+    if not text:
+        return None
+    text = text.strip()
+    # 去掉 markdown 代码块
+    fence = re.search(r'```(?:json)?\s*(.*?)```', text, re.S)
+    if fence:
+        text = fence.group(1).strip()
+    try:
+        return json.loads(text)
+    except json.JSONDecodeError:
+        pass
+    # 尝试截取第一个 { 到最后一个 }
+    s, e = text.find('{'), text.rfind('}')
+    if s != -1 and e > s:
+        try:
+            return json.loads(text[s:e + 1])
+        except json.JSONDecodeError:
+            return None
+    return None
+
+
+def chat(messages, temperature=None, max_tokens=None, timeout=None):
+    """调用 OpenAI 兼容 chat/completions，返回 content 字符串"""
+    url = f'{LLM_BASE_URL}/chat/completions'
+    body = {
+        'model': LLM_MODEL,
+        'messages': messages,
+        'temperature': temperature if temperature is not None else LLM_TEMPERATURE,
+    }
+    if max_tokens:
+        body['max_tokens'] = max_tokens
+    req = urllib.request.Request(
+        url,
+        data=json.dumps(body).encode('utf-8'),
+        headers={
+            'Content-Type': 'application/json',
+            'Authorization': f'Bearer {LLM_API_KEY}',
+        },
+        method='POST',
+    )
+    try:
+        with urllib.request.urlopen(req, timeout=timeout or LLM_TIMEOUT) as resp:
+            data = json.loads(resp.read().decode('utf-8'))
+    except urllib.error.HTTPError as e:
+        detail = e.read().decode('utf-8', 'ignore')[:300]
+        raise LLMError(f'LLM HTTP {e.code}: {detail}')
+    except Exception as e:
+        raise LLMError(f'LLM 调用失败: {e}')
+
+    try:
+        return data['choices'][0]['message']['content']
+    except (KeyError, IndexError, TypeError):
+        raise LLMError(f'LLM 响应异常: {str(data)[:300]}')
+
+
+def chat_json(messages, temperature=None, max_tokens=None, retries=2):
+    """调用 LLM 并强制解析 JSON，失败重试"""
+    last_err = None
+    for i in range(retries + 1):
+        try:
+            content = chat(messages, temperature=temperature, max_tokens=max_tokens)
+            obj = _extract_json(content)
+            if obj is not None:
+                return obj
+            last_err = f'无法从输出解析 JSON: {content[:200]}'
+        except LLMError as e:
+            last_err = str(e)
+        if i < retries:
+            messages = messages + [
+                {'role': 'assistant', 'content': content if 'content' in dir() else ''},
+                {'role': 'user', 'content': f'刚才的输出不是合法 JSON，请只输出严格的 JSON 对象。错误: {last_err}'},
+            ]
+    raise LLMError(f'LLM JSON 解析失败: {last_err}')