AI 助手 2.0：多轮对话、卡片化与文章页感知

function buildSystemPrompt(articlesContext) {
  const hasArticles = Boolean(articlesContext && articlesContext.trim());

  const articleRules = hasArticles
    ? `- 相关文章会由页面底部的「相关文章推荐」卡片自动展示，所以正文里不要罗列文章标题清单，也不要输出链接、Markdown 链接或 <a> 标签
- 只有读者明确问起某篇具体文章时，才可以自然提一次标题，但不要附带链接
- 读者问某篇文章讲了什么时，直接用上面给出的「内容摘要」概括 1-2 句`
    : `- 当前没有可引用的博客文章，就用自己的知识回答，但不要编造或罗列博客里并不存在的文章标题`;

  return `你是${config.BOT_NAME}… ${articlesContext} …${articleRules}`;
}

function tidyReply(text) {
  // 去掉 emoji / 符号表情
  var out = String(text).replace(/[\u{1F000}-\u{1FAFF}\u{2600}-\u{27BF}\u{2B00}-\u{2BFF}\u{FE0F}\u{200D}]/gu, '');
  // 每行行首的标点（列表的 "-" 要保留）
  out = out.split('\n').map(function (line) {
    return line.replace(/^[\s，。、；：,.!?！？;:~～…—]+/, '');
  }).join('\n');
  return out.replace(/[ \t]{2,}/g, ' ').trim();
}

function buildArticleCards(articles, title) {
  var html = '<div class="ai-chatbot-articles"><div class="ai-chatbot-articles-title">' + (title || '相关文章推荐：') + '</div>';
  articles.forEach(function (a) {
    html += '<a class="ai-chatbot-article-card" href="' + a.url + '" target="_blank">'
      + '<div class="ai-chatbot-article-body">'
      + '<div class="ai-chatbot-article-title">' + a.title + '</div>'
      + (a.tags && a.tags.length ? '<div class="ai-chatbot-article-tags">' + tags(a.tags) + '</div>' : '')
      + '</div></a>';
  });
  return html + '</div>';
}

// 前端
body: JSON.stringify({
  message: message,
  history: chatHistory.slice(-HISTORY_TURNS * 2),
  context_articles: lastArticles.map(function (a) { return { url: a.url }; }),
  page: location.pathname || '',
  client: 2
})

// 后端：历史上限 8 条、每条 600 字
function normalizeHistory(history) {
  return (Array.isArray(history) ? history : [])
    .filter(h => h && (h.role === 'user' || h.role === 'assistant') && typeof h.content === 'string')
    .map(h => ({ role: h.role, content: h.content.slice(0, 600) }))
    .slice(-8);
}

// 当前句子没匹配到文章时，回落到上一轮卡片里的文章
const matched = findRelevantArticles(message);
const relevantArticles = matched.length ? matched : resolveContextArticles(contextArticles);

// ai_bot/tools/gen_flinks.js
for (const group of groups) {
  if (!group || group.lost_contact) continue;
  for (const item of group.link_list || []) {
    if (item.link.replace(/\/+$/, '') === selfUrl) continue;   // 不推荐自己
    links.push({ name: item.name, url: item.link, descr: item.descr, recommend: item.recommend === true });
  }
}

function siteDays() {
  const launch = faqData.site.launch;                     // 2022-07-01
  return Math.max(0, Math.floor((Date.now() - new Date(launch + 'T00:00:00+08:00')) / 86400000));
}

function renderAnswer(text) {
  const days = siteDays();
  return text
    .replace(/\{days\}/g, () => String(days))
    .replace(/\{years\}/g, () => String(Math.max(1, Math.floor(days / 365))));
}

async function fetchAiSummary(abbr) {
  const hit = summaryCache.get(abbr);
  if (hit && Date.now() - hit.at < SUMMARY_CACHE_TTL) return hit.text;   // 10 分钟内存缓存
  for (const base of SUMMARY_ENDPOINTS) {
    try {
      const resp = await axios.get(base, { params: { key: 'p:' + abbr }, timeout: 1500 });
      if (resp.data && resp.data.summary) return resp.data.summary.trim();
    } catch (e) { /* 换下一个源 */ }
  }
  return '';
}

function syncIntroToPage() { if (chatbotOpen) loadIntro(); }

function loadIntro() {
  var pagePath = currentPath();
  if (introLoaded && introPage === pagePath) return;      // 同页反复开合，不重复请求
  if (introPage && introPage !== pagePath) resetConversation();  // 换页：清空上一篇的对话
  introPage = pagePath;
  // …fetch intro、渲染 hint + chips
}

let rawBuf = Buffer.alloc(0);

response.data.on('data', (chunk) => {
  rawBuf = Buffer.concat([rawBuf, chunk]);
  let idx;
  while ((idx = rawBuf.indexOf(10)) !== -1) {           // 0x0A
    const line = rawBuf.subarray(0, idx).toString('utf8');
    rawBuf = rawBuf.subarray(idx + 1);
    handleSseLine(line);                                 // 只处理完整行
  }
});

let clientEnded = false;
const endClient = (payload) => {
  if (clientEnded) return;
  clientEnded = true;
  try { if (payload) res.write(`data: ${JSON.stringify(payload)}\n\n`); res.end(); }
  catch (e) { console.error('SSE close error:', e.message); }
};

// 前端
client: 2
// 后端
const wantsCards = Number(req.body.client) >= 2;