/**
 * H5 Chat Intent Router — FAQ / fast-path rule library.
 *
 * Add patterns here for messages that should bypass LLM routing latency.
 * Consumed by chat-intent-router.mjs → classifyWithRules().
 *
 * Keep rules conservative: task execution, page generation, and realtime lookup
 * must stay on Agent paths (checked via FAQ_EXCLUSION_PATTERNS).
 */

/** Block FAQ match when the message clearly needs Agent / tools. */
export const FAQ_EXCLUSION_PATTERNS = [
  /\bpublic\/[^\s"'<>]+\.html\b/i,
  /MindSpace\/[^/\s]+\/public\/[^\s"'<>]+\.html/i,
  /(?:生成|创建|制作|做|写|设计|发布|搭建).{0,24}(?:H5|h5|HTML|html|网页|页面|活动页|宣传页|落地页|分享页|链接)/u,
  /(?:H5|h5|HTML|html|网页|页面).{0,24}(?:生成|创建|制作|做|写|设计|发布|链接)/u,
  /(?:写|做|生成|制作|设计).{0,16}主题(?:页面|文章)/u,
  /(?:服务号|公众号).{0,16}(?:页面|文章|推文|图文)/u,
  /(?:今天|今日|现在|最新|当前|实时).{0,12}(?:新闻|赛况|比分|天气|行情|股价|汇率|热点)/u,
  /(?:查(?:一下|查)?|搜索|打听).{0,16}(?:今天|今日|现在|最新|当前)/u,
  /(?:世界杯|欧冠|NBA|英超).{0,16}(?:赛况|赛程|比分)/u,
  /(?:load_skill|page-data|sqlite|express|后端服务)/iu,
  /(?:修|改|测试|回归|verify).{0,12}(?:bug|问卷|policy|public)/iu,
];

/**
 * @typedef {{ id: string, reason: string, patterns: RegExp[] }} DirectChatFaqRule
 */

/** @type {DirectChatFaqRule[]} */
export const DIRECT_CHAT_FAQ_RULES = [
  {
    id: 'concept_what_is',
    reason: '概念解释类问答（FAQ）',
    patterns: [
      /^什么是[\s\S]{1,48}[？?]?$/u,
      /^何为[\s\S]{1,48}[？?]?$/u,
      /^什么叫[\s\S]{1,48}[？?]?$/u,
      /^[\s\S]{1,40}是什么[？?]?$/u,
      /^[\s\S]{1,40}是什么意思[？?]?$/u,
      /^[\s\S]{1,40}(?:是什么东西|指什么|啥意思)[？?]?$/u,
    ],
  },
  {
    id: 'concept_explain',
    reason: '解释说明类问答（FAQ）',
    patterns: [
      /^(?:请)?(?:解释|说明|介绍|讲解|阐述)(?:一下|下)?[\s\S]{1,48}[？?]?$/u,
      /^帮我(?:解释|说明|介绍|讲解)(?:一下|下)?[\s\S]{1,48}[？?]?$/u,
      /^能(?:不能|否)(?:解释|说明|介绍)(?:一下|下)?[\s\S]{1,40}[？?]?$/u,
    ],
  },
  {
    id: 'concept_compare',
    reason: '概念对比类问答（FAQ）',
    patterns: [
      /^[\s\S]{1,32}(?:和|与|跟)[\s\S]{1,32}(?:的)?(?:区别|差异|不同|对比|比较)[是什么]?[？?]?$/u,
      /^(?:对比|比较)(?:一下|下)?[\s\S]{1,48}[？?]?$/u,
      /^[\s\S]{1,24}(?:vs|VS|Vs)[\s\S]{1,24}(?:区别|差异|不同)?[？?]?$/u,
    ],
  },
  {
    id: 'concept_how_works',
    reason: '原理/机制类问答（FAQ）',
    patterns: [
      /^[\s\S]{1,40}(?:是怎么|是如何)(?:工作|运行|实现|运作)的[？?]?$/u,
      /^[\s\S]{1,40}(?:原理|机制|流程)(?:是什么|是怎样的)[？?]?$/u,
      /^为什么[\s\S]{1,48}[？?]?$/u,
    ],
  },
  {
    id: 'text_transform',
    reason: '纯文字处理（总结/翻译/改写）',
    patterns: [
      /^(?:请)?(?:帮我|帮忙)?(?:总结|概括|归纳|提炼)(?:一下|下)?[\s\S]{1,80}[？?]?$/u,
      /^(?:请)?(?:帮我|帮忙)?(?:翻译|改写|润色|扩写|缩写|校对)(?:一下|下)?[\s\S]{1,80}[？?]?$/u,
    ],
  },
  {
    id: 'tech_acronym',
    reason: '常见技术名词解释（FAQ）',
    patterns: [
      /^(?:什么是|解释一下|介绍一下)?\s*(?:SSE|WebSocket|REST(?:ful)?|GraphQL|JWT|OAuth|RAG|Embedding|向量数据库|Server-Sent Events)[\s\S]{0,24}[？?]?$/iu,
      /^(?:SSE|WebSocket|REST(?:ful)?|GraphQL|JWT|OAuth|RAG)(?:是什么|什么意思|怎么用)[？?]?$/iu,
    ],
  },
  {
    id: 'learning_advice',
    reason: '学习/选型建议（纯文字）',
    patterns: [
      /^(?:学|学习|入门).{0,24}(?:应该|该|推荐|建议).{0,32}(?:先|从哪|哪个)[？?]?$/u,
      /^(?:初学者|新手|入门).{0,24}(?:应该|该|推荐|建议).{0,32}[？?]?$/u,
      /^.{0,24}(?:先学|从哪学|怎么学).{0,32}[？?]?$/u,
    ],
  },
  {
    id: 'casual_opinion',
    reason: '主观建议/闲聊（无任务执行）',
    patterns: [
      /^你觉得.{1,48}[？?]?$/u,
      /^你认为.{1,48}[？?]?$/u,
      /^(?:随便|随意)(?:聊|说说|谈谈).{0,24}[？?]?$/u,
      /^.{0,16}(?:有什么建议|给点建议|怎么看)[？?]?$/u,
    ],
  },
];

const MAX_FAQ_TEXT_LENGTH = 200;

/**
 * @param {string} text
 * @returns {{ id: string, reason: string } | null}
 */
export function matchDirectChatFaqRule(text) {
  const normalized = String(text ?? '').trim();
  if (!normalized || normalized.length > MAX_FAQ_TEXT_LENGTH) return null;
  if (FAQ_EXCLUSION_PATTERNS.some((pattern) => pattern.test(normalized))) return null;
  for (const rule of DIRECT_CHAT_FAQ_RULES) {
    if (rule.patterns.some((pattern) => pattern.test(normalized))) {
      return { id: rule.id, reason: rule.reason };
    }
  }
  return null;
}