import {
  buildChatSkillPrompt,
  buildWebNewsSkillPrompt,
  extractSelectedChatSkillName,
  hasExplicitChatSkillPrompt,
  isPageDataIntent,
  isPageGenerationIntent,
  isProductCampaignIntent,
  PAGE_DATA_COLLECT_SKILL_NAME,
} from './chat-skills.mjs';
import { isDirectChatSessionId } from './direct-chat-service.mjs';
import {
  memoryLimitForIntervention,
  resolveMemoryInterventionMode,
} from './memory-intervention.mjs';
import { filterMemoriesByQuery } from './memory-legacy-fallback.mjs';

export const CHAT_INTENT_ROUTE = {
  DIRECT_CHAT: 'direct_chat',
  AGENT: 'agent_orchestration',
};

export const ROUTER_DECISION_ROUTE = {
  CHAT: 'chat',
  AGENT: 'agent',
};

export const ROUTER_DECISION_MODE = {
  SSE: 'sse',
  WS: 'ws',
};

export const ROUTER_DECISION_SESSION_HINT = {
  REUSE: 'reuse',
  NEW: 'new',
};

const ALLOWED_ROUTER_DECISION_FLAGS = new Set([
  'memory_recall',
  'selected_skill',
  'force_deep_reasoning',
  'code_task',
  'long_running',
]);

const AGENT_ORCHESTRATION_HEADER = '【Memind 任务编排】';

const SKILL_PROMPT_KEYS = {
  web: 'web',
  search: 'search',
  'static-page-publish': 'generate-page',
  'page-data-collect': 'page-data-collect',
  'form-builder': 'form-builder',
  'table-viewer': 'table-viewer',
  'product-campaign-page': 'product-campaign-page',
};

const OBVIOUS_AGENT_PATTERNS = [
  /\bpublic\/[^\s"'<>]+\.html\b/i,
  /MindSpace\/[^/\s]+\/public\/[^\s"'<>]+\.html/i,
  /(?:生成|创建|制作|做|写|设计|发布).{0,24}(?:H5|h5|HTML|html|网页|页面|活动页|宣传页|落地页|分享页)/u,
  /(?:H5|h5|HTML|html|网页|页面).{0,24}(?:生成|创建|制作|做|写|设计|发布)/u,
  /(?:写|做|生成|制作|设计).{0,16}主题(?:页面|文章)/u,
  /主题(?:页面|文章).{0,16}(?:写|做|生成|制作|设计)/u,
];

const OBVIOUS_DIRECT_PATTERNS = [
  /^(?:你好|您好|在吗|在不在|嗨|hi|hello|hey)[!！。.\s]*$/iu,
  /^(?:测试\s*\d*|test\s*\d*)[!！。.\s]*$/iu,
  /^[?？]+$/u,
];

/** Short confirmations in an ongoing agent session must stay on Agent (not direct chat). */
const AGENT_SESSION_CONTINUE_PATTERNS = [
  /^(?:可以|好的|好|行|确认|没问题|是的|对|嗯|OK|ok)[!！。.\s]*$/iu,
  /^(?:开始吧|按默认做|默认方案|继续|就这样|就这样吧)[!！。.\s]*$/iu,
];

/** Pure text chat/creative prompts — fast-path even when LLM router is enabled. */
const OBVIOUS_DIRECT_CHAT_PATTERNS = [
  /(?:讲|说|来|编).{0,10}(?:个|一段|一首|一个)?(?:睡前故事|故事|笑话|段子)/u,
  /(?:写|作|创|生成).{0,10}(?:首|一段|一篇|一个)?(?:诗|散文|笑话|段子|故事)/u,
  /(?:继续|再).{0,8}(?:写|讲|说|编).{0,10}(?:诗|故事|笑话|散文)/u,
];

/** Realtime / web-search prompts — fast-path to agent even when LLM router is enabled. */
const REALTIME_INFO_AGENT_PATTERNS = [
  /(?:世界杯|欧冠|NBA|英超|西甲|意甲|德甲|法甲|欧洲杯|亚洲杯|奥运会).{0,16}(?:赛况|赛程|比分|战况|结果|积分|排名|进展|情况)/u,
  /(?:赛况|赛程|比分|战况|积分榜|最新比赛|比赛结果).{0,16}(?:如何|怎样|怎么样|多少|是什么)/u,
  /(?:看看|查(?:一下|查)?|搜索|打听|了解).{0,16}(?:今天|今日|现在|最新|当前).{0,16}(?:新闻|赛况|比分|天气|行情|股价|汇率|热点)/u,
  /(?:今天|今日|现在|最新|当前).{0,12}(?:的)?(?:新闻|赛况|比分|天气|行情|股价|汇率|热点)/u,
  /(?:实时|最新).{0,8}(?:信息|数据|情况|动态|资讯)/u,
];

const RICH_PUBLISHABLE_CONTENT_HINT_PATTERNS = [
  /(?:服务号|公众号|H5|h5).{0,24}(?:用户|读者|粉丝|阅读|推送|发布|消息|文章|内容)/u,
  /(?:整理|排版|美化|输出).{0,24}(?:给|成|为).{0,12}(?:服务号|公众号|H5|h5)/u,
  /(?:服务号|公众号|H5|h5|页面|文章|推文|图文|长文|专题).{0,24}(?:用户|读者|粉丝|客户|阅读|推送|发布|转发|分享|展示|内容)/u,
  /(?:整理|排版|美化|输出|生成|制作|做成).{0,24}(?:给|成|为|适合).{0,16}(?:用户|读者|粉丝|客户|服务号|公众号|H5|h5|图文|文章|页面|推文|转发|分享|阅读)/u,
  /(?:适合|方便).{0,12}(?:用户|读者|粉丝|客户).{0,12}(?:阅读|转发|分享)/u,
];

const MEMORY_RECALL_PATTERNS = [
  /你(?:还)?记得(?:我)?/u,
  /(?:有没有|是否).{0,6}记住/u,
  /你对(?:我)?(?:的)?记忆/u,
  /(?:我|之前).{0,16}(?:说过|提到|聊过|告诉)/u,
  /(?:我的|之前的)(?:记忆|偏好|计划|目标|想法)/u,
  /之前(?:说|提|聊)(?:过|的)/u,
  /之前.{0,24}记住/u,
  /记住.{0,16}(?:是什么|叫什么|多少|哪个)/u,
];

export function isMemoryRecallQuestion(text) {
  const normalized = String(text ?? '').trim();
  if (!normalized) return false;
  return MEMORY_RECALL_PATTERNS.some((pattern) => pattern.test(normalized));
}

export function isAgentSessionContinueText(text) {
  const normalized = String(text ?? '').trim();
  if (!normalized) return false;
  return AGENT_SESSION_CONTINUE_PATTERNS.some((pattern) => pattern.test(normalized));
}

export function isRealtimeInfoQuestion(text) {
  const normalized = String(text ?? '').trim();
  if (!normalized) return false;
  return REALTIME_INFO_AGENT_PATTERNS.some((pattern) => pattern.test(normalized));
}

export function isRichPublishableContentIntent(text) {
  const normalized = String(text ?? '').trim();
  if (!normalized || normalized.length < 260) return false;
  if (!RICH_PUBLISHABLE_CONTENT_HINT_PATTERNS.some((pattern) => pattern.test(normalized))) return false;
  const bulletCount = (normalized.match(/(?:^|\n)\s*(?:[-*•]|[0-9]+[.、]|[🌍🇺🇸⚽🎤📉🌡️📰])\s*/gu) ?? []).length;
  const headingCount = (normalized.match(/(?:^|\n)\s*(?:#{1,3}\s+|[🌍🇺🇸⚽🎤📉🌡️📰].{0,24}$)/gmu) ?? []).length;
  const sectionLikeCount = (normalized.match(/(?:^|\n)\s*(?:[^\n]{1,24})\n(?:\s*[-*•]\s+)/gu) ?? []).length;
  return bulletCount + headingCount + sectionLikeCount >= 5;
}

export function isRichChannelPageIntent(text) {
  return isRichPublishableContentIntent(text);
}

function buildRealtimeInfoClassification() {
  return normalizeClassification({
    route: CHAT_INTENT_ROUTE.AGENT,
    confidence: 0.98,
    reason: '需要搜索实时资料',
    suggested_skill: 'web',
    agent_brief: REALTIME_WEB_AGENT_BRIEF,
  }, { source: 'rule' });
}

export function coercePageDataSkill(classification, text, { grantedSkills = [] } = {}) {
  if (!classification || classification.route !== CHAT_INTENT_ROUTE.AGENT) return classification;
  if (!isPageDataIntent(text)) return classification;
  if (grantedSkills.length > 0 && !grantedSkills.includes(PAGE_DATA_COLLECT_SKILL_NAME)) {
    return classification;
  }

  return {
    ...classification,
    suggestedSkill: PAGE_DATA_COLLECT_SKILL_NAME,
    agentBrief:
      '在 MindSpace 页面实现数据收集与持久化：建表、注册 dataset、配置 page policy、HTML 使用 page-data-client.js；禁止自建后端服务。',
    reason: `${classification.reason}（页面数据交互意图）`,
  };
}

export function coercePageGenerationSkill(classification, text, { grantedSkills = [] } = {}) {
  if (!classification || classification.route !== CHAT_INTENT_ROUTE.AGENT) return classification;
  if (isPageDataIntent(text)) return classification;
  if (!isPageGenerationIntent(text) || isProductCampaignIntent(text)) return classification;
  if (grantedSkills.length > 0 && !grantedSkills.includes('static-page-publish')) return classification;

  const shouldUsePublishSkill =
    !classification.suggestedSkill || classification.suggestedSkill === 'product-campaign-page';
  if (!shouldUsePublishSkill) return classification;

  const reasonSuffix = classification.suggestedSkill === 'product-campaign-page'
    ? '（内容页意图，改用 static-page-publish）'
    : '（内容页生成意图）';
  return {
    ...classification,
    suggestedSkill: 'static-page-publish',
    agentBrief: '生成或更新 MindSpace 公开内容页面，并返回可访问链接；信息不足时使用合理默认，不要停在追问。',
    reason: `${classification.reason}${reasonSuffix}`,
  };
}

export function coerceRealtimeWebSkill(classification, text, { grantedSkills = [] } = {}) {
  if (!classification || classification.route !== CHAT_INTENT_ROUTE.AGENT) return classification;
  if (!isRealtimeInfoQuestion(text)) return classification;
  if (grantedSkills.length > 0 && !grantedSkills.includes('web')) return classification;
  const reason = String(classification.reason ?? '').trim();
  return {
    ...classification,
    suggestedSkill: 'web',
    agentBrief: REALTIME_WEB_AGENT_BRIEF,
    reason: reason.includes('web') ? reason : `${reason || '需要搜索实时资料'}（实时查询强制 web）`,
  };
}

function resolveRouterFallbackRoute(env, overrides = {}) {
  const raw = overrides.fallbackRoute
    ?? normalizeRoute(env?.MEMIND_CHAT_ROUTER_FALLBACK_ROUTE)
    ?? CHAT_INTENT_ROUTE.AGENT;
  // Timeout/parse failures must fail open to agent so realtime/tool tasks are not dropped.
  return raw === CHAT_INTENT_ROUTE.DIRECT_CHAT ? CHAT_INTENT_ROUTE.AGENT : raw;
}

const DEFAULT_ROUTER_TIMEOUT_MS = 2500;
const DEFAULT_ROUTER_MEMORY_LIMIT = 8;
const DEFAULT_ROUTER_MIN_CONFIDENCE = 0.55;
const REALTIME_WEB_AGENT_BRIEF =
  '先 load_skill → web；优先 web_search/fetch_url 获取实时信息。若 web_search 不可用，立即改用 fetch_url 抓取 Bing/新华网/央视等可达来源；禁止使用 search 技能查工作区，不要反复 scrape 同一站点。';

function envFlag(value, fallback = false) {
  const raw = String(value ?? '').trim().toLowerCase();
  if (!raw) return fallback;
  return ['1', 'true', 'yes', 'on'].includes(raw);
}

function boundedNumber(value, fallback, { min = 0, max = Number.POSITIVE_INFINITY } = {}) {
  if (value == null || value === '') return fallback;
  const parsed = Number(value);
  if (!Number.isFinite(parsed)) return fallback;
  return Math.min(max, Math.max(min, parsed));
}

function pickDefined(source, keys) {
  return Object.fromEntries(
    keys
      .filter((key) => source[key] !== undefined)
      .map((key) => [key, source[key]]),
  );
}

function truncateText(value, maxLength) {
  const text = String(value ?? '').replace(/\s+/g, ' ').trim();
  if (!text) return '';
  return text.length > maxLength ? `${text.slice(0, maxLength)}...` : text;
}

function firstSentence(value, maxLength) {
  const text = truncateText(value, maxLength);
  if (!text) return '';
  const match = text.match(/^(.{12,}?[。.!！?？])/u);
  return truncateText(match?.[1] ?? text, maxLength);
}

function normalizeMemoryText(item) {
  if (typeof item === 'string') return { label: null, text: item };
  const text = item?.text ?? item?.memory_text ?? item?.memoryText ?? item?.content ?? item?.summary ?? '';
  const label = String(item?.label ?? item?.type ?? '').trim() || null;
  return { label, text };
}

function withTimeout(promise, timeoutMs, label) {
  const timeout = Number(timeoutMs);
  if (!Number.isFinite(timeout) || timeout <= 0) return promise;
  let timer = null;
  const timeoutPromise = new Promise((_, reject) => {
    timer = setTimeout(() => {
      const err = new Error(`${label} timed out after ${timeout}ms`);
      err.code = 'CHAT_INTENT_ROUTER_TIMEOUT';
      reject(err);
    }, timeout);
  });
  return Promise.race([promise, timeoutPromise]).finally(() => {
    if (timer) clearTimeout(timer);
  });
}

function messageDisplayText(message) {
  const displayText = message?.metadata?.displayText;
  if (typeof displayText === 'string' && displayText.trim()) return displayText.trim();
  return extractMessageText(message);
}

function extractMessageText(message) {
  const content = message?.content;
  if (typeof content === 'string') return content.trim();
  if (!Array.isArray(content)) return String(message?.text ?? message?.value ?? '').trim();
  return content
    .map((item) => {
      if (typeof item === 'string') return item;
      if (item?.type === 'text') return item.text ?? '';
      return '';
    })
    .join('\n')
    .trim();
}

function isTextOnlyUserMessage(message) {
  const content = message?.content;
  if (!Array.isArray(content)) return Boolean(extractMessageText(message));
  if (content.length === 0) return false;
  return content.every((item) => {
    if (typeof item === 'string') return true;
    return item?.type === 'text';
  });
}

function readSelectedChatSkillId(message) {
  const selected =
    message?.metadata?.memindRun?.selectedChatSkill ??
    message?.metadata?.selectedChatSkill;
  return typeof selected === 'string' && selected.trim() ? selected.trim() : null;
}

function messageHasExplicitChatSkillSelection(message) {
  if (!message) return false;
  if (readSelectedChatSkillId(message)) return true;
  return [extractMessageText(message), messageDisplayText(message)].some((text) =>
    hasExplicitChatSkillPrompt(text),
  );
}

function buildSkillSelectionClassification(userMessage) {
  const selectedSkillId = readSelectedChatSkillId(userMessage);
  const suggestedSkill =
    selectedSkillId ??
    extractSelectedChatSkillName(extractMessageText(userMessage)) ??
    extractSelectedChatSkillName(messageDisplayText(userMessage));
  return normalizeClassification({
    route: CHAT_INTENT_ROUTE.AGENT,
    confidence: 1,
    reason: '用户已选择 skill',
    suggested_skill: suggestedSkill,
    agent_brief: suggestedSkill ? `使用 ${suggestedSkill} 执行用户任务` : '执行用户选择的 skill 任务',
  }, { source: 'rule' });
}

function buildRouterSystemPrompt(grantedSkills = []) {
  const skills = Array.isArray(grantedSkills) ? grantedSkills.filter(Boolean) : [];
  return [
    '你是 TKMind H5 聊天意图路由器，只负责判断用户消息应该走哪条处理通道。',
    '',
    '系统有两条通道：',
    '1. direct_chat — 纯文字交流：问答、解释、闲聊、总结已有文字、给建议，不需要写文件、生成页面、调工具。',
    '2. agent_orchestration — 任务编排 Agent：需要实际执行并产出结果的任务，例如生成/修改 HTML 页面、发布到 MindSpace、搜索实时资料、写代码改仓库、表单收集、数据表格、商品页、docx/长图导出等。',
    '',
    '判断原则：',
    '- 用户只要文字回答，不要求“做出来/发布/生成链接/改文件” → direct_chat',
    '- 用户要产出可访问页面、文件、链接，或需要工具/skills → agent_orchestration',
    '- 用户询问实时赛况、新闻、天气、行情等需要联网查询的问题 → agent_orchestration，suggested_skill 填 web（不要填 search）',
    '- 不确定时优先 agent_orchestration，避免漏执行',
    '- 记忆线索只用于辅助判断本轮意图，不能替用户扩写新需求',
    '',
    skills.length ? `当前用户已授权 skills：${skills.join(', ')}` : '当前用户未授权额外 skills。',
    skills.length
      ? '若走 agent_orchestration，可在 suggested_skill 中填写最匹配的 skill 名称（须来自上述列表），否则填 null。'
      : 'suggested_skill 通常填 null。',
    '',
    'skill 选择补充：',
    '- page-data-collect：页面需要问卷/表单/报名/提交记录/后台查看/数据交互/SQLite 持久化；必须用 Page Data API，禁止自建 Express 或独立端口。',
    '- static-page-publish：攻略/游记/主题内容页、城市介绍、活动介绍、任何「做页面/生成链接」且无数据持久化需求。',
    '- product-campaign-page：仅当用户明确提供商品链接或要求购买按钮/电商转化时使用，不要用于旅游攻略或纯内容页。',
    '',
    '只输出 JSON，不要 markdown，不要解释：',
    '{"route":"direct_chat|agent_orchestration","confidence":0.0,"reason":"一句话","suggested_skill":null,"agent_brief":"给 Agent 的执行要点，direct_chat 时可为空"}',
  ].join('\n');
}

export function buildRouterContext(resolveResult, {
  memoryLimit = 5,
  semanticLimit = 3,
  goalLimit = 2,
  memoryTextLimit = 80,
  semanticTextLimit = 60,
  goalTextLimit = 60,
  behaviorTextLimit = 100,
} = {}) {
  const result = resolveResult && typeof resolveResult === 'object' ? resolveResult : {};
  const lines = [];
  let itemsUsed = 0;

  const memories = Array.isArray(result.memories) ? result.memories : [];
  const memoryLines = memories
    .map((item) => normalizeMemoryText(item))
    .map(({ label, text }) => {
      const clipped = truncateText(text, memoryTextLimit);
      if (!clipped) return '';
      return `- ${label ? `[${label}] ` : ''}${clipped}`;
    })
    .filter(Boolean)
    .slice(0, memoryLimit);
  if (memoryLines.length) {
    lines.push('相关记忆：', ...memoryLines);
    itemsUsed += memoryLines.length;
  }

  const semanticLines = (Array.isArray(result.semanticMemories) ? result.semanticMemories : [])
    .map((item) => (typeof item === 'string' ? item : normalizeMemoryText(item).text))
    .map((text) => truncateText(text, semanticTextLimit))
    .filter(Boolean)
    .slice(0, semanticLimit)
    .map((text) => `- ${text}`);
  if (semanticLines.length) {
    lines.push('语义线索：', ...semanticLines);
    itemsUsed += semanticLines.length;
  }

  const behaviorSummary = firstSentence(result.behaviorSummary, behaviorTextLimit);
  if (behaviorSummary) {
    lines.push(`行为摘要：${behaviorSummary}`);
    itemsUsed += 1;
  }

  const goals = Array.isArray(result.activeGoals) && result.activeGoals.length
    ? result.activeGoals
    : (Array.isArray(result.contextGoals) ? result.contextGoals : []);
  const goalLines = goals
    .map((text) => truncateText(text, goalTextLimit))
    .filter(Boolean)
    .slice(0, goalLimit)
    .map((text) => `- ${text}`);
  if (goalLines.length) {
    lines.push('进行中目标：', ...goalLines);
    itemsUsed += goalLines.length;
  }

  return {
    content: lines.join('\n').trim(),
    itemsUsed,
    source: result.source ?? null,
    degraded: Boolean(result.degraded),
    skipped: Boolean(result.skipped),
    reason: result.reason ?? null,
  };
}

function buildRouterUserPrompt({ text, routerContext }) {
  const context = String(routerContext ?? '').trim() || '无';
  return [
    '[Router Context]',
    context,
    '',
    '[User]',
    text || '(empty)',
  ].join('\n');
}

function parseRouterJson(reply) {
  const text = String(reply ?? '').trim();
  if (!text) return null;
  const fenced = text.match(/```(?:json)?\s*([\s\S]*?)```/i);
  const candidate = (fenced?.[1] ?? text).trim();
  try {
    return JSON.parse(candidate);
  } catch {
    const start = candidate.indexOf('{');
    const end = candidate.lastIndexOf('}');
    if (start < 0 || end <= start) return null;
    try {
      return JSON.parse(candidate.slice(start, end + 1));
    } catch {
      return null;
    }
  }
}

function normalizeRoute(value) {
  const normalized = String(value ?? '').trim().toLowerCase();
  if (normalized === CHAT_INTENT_ROUTE.DIRECT_CHAT || normalized === ROUTER_DECISION_ROUTE.CHAT) {
    return CHAT_INTENT_ROUTE.DIRECT_CHAT;
  }
  if (
    normalized === CHAT_INTENT_ROUTE.AGENT ||
    normalized === 'agent' ||
    normalized === 'agent_orchestration' ||
    normalized === ROUTER_DECISION_ROUTE.AGENT
  ) {
    return CHAT_INTENT_ROUTE.AGENT;
  }
  return null;
}

export function resolveNormalizedRouterDecisionMode(env = process.env) {
  const raw = String(env?.MEMIND_ROUTER_NORMALIZED_DECISION ?? '').trim().toLowerCase();
  if (!raw || raw === '0' || raw === 'false' || raw === 'off' || raw === 'no') return 'off';
  if (raw === 'shadow') return 'shadow';
  if (['1', 'true', 'yes', 'on'].includes(raw)) return 'on';
  return 'off';
}

export function isNormalizedRouterDecisionEnabled(env = process.env) {
  return resolveNormalizedRouterDecisionMode(env) === 'on';
}

export function isNormalizedRouterDecisionShadow(env = process.env) {
  return resolveNormalizedRouterDecisionMode(env) === 'shadow';
}

export function buildRouterNormalizedDecision(
  classification,
  {
    sessionId = null,
    sessionMessageCount = null,
    forceDeepReasoning = false,
    toolMode = 'chat',
    text = '',
  } = {},
) {
  const legacyRoute = classification?.route ?? CHAT_INTENT_ROUTE.AGENT;
  const route =
    legacyRoute === CHAT_INTENT_ROUTE.DIRECT_CHAT
      ? ROUTER_DECISION_ROUTE.CHAT
      : ROUTER_DECISION_ROUTE.AGENT;
  const mode = ROUTER_DECISION_MODE.SSE;
  let sessionHint = ROUTER_DECISION_SESSION_HINT.NEW;
  if (sessionId) {
    sessionHint = ROUTER_DECISION_SESSION_HINT.REUSE;
  }
  if (
    sessionId &&
    !isDirectChatSessionId(sessionId) &&
    sessionMessageCount != null &&
    Number(sessionMessageCount) === 0
  ) {
    sessionHint = ROUTER_DECISION_SESSION_HINT.NEW;
  }

  const flags = [];
  if (isMemoryRecallQuestion(text)) flags.push('memory_recall');
  if (forceDeepReasoning) flags.push('force_deep_reasoning');
  if (toolMode === 'code') flags.push('code_task');
  if (classification?.suggestedSkill) flags.push('selected_skill');
  const normalizedFlags = [...new Set(flags)].filter((flag) => ALLOWED_ROUTER_DECISION_FLAGS.has(flag));

  return {
    route,
    mode,
    session_hint: sessionHint,
    flags: normalizedFlags,
  };
}

export function finalizeRouterClassification(classification, context = {}) {
  if (!classification) return classification;
  return {
    ...classification,
    decision: buildRouterNormalizedDecision(classification, context),
  };
}

export function resolveLegacyRouteFromClassification(classification) {
  if (!classification) return null;
  if (isNormalizedRouterDecisionEnabled() && classification.decision?.route) {
    return classification.decision.route === ROUTER_DECISION_ROUTE.CHAT
      ? CHAT_INTENT_ROUTE.DIRECT_CHAT
      : CHAT_INTENT_ROUTE.AGENT;
  }
  return classification.route ?? null;
}

export function logRouterDecisionShadow(
  classification,
  { logger = console, requestId = null, sessionId = null, env = process.env } = {},
) {
  if (!isNormalizedRouterDecisionShadow(env) || !classification?.decision) return;
  const legacyRoute = classification.route ?? null;
  const normalizedLegacyRoute =
    classification.decision.route === ROUTER_DECISION_ROUTE.CHAT
      ? CHAT_INTENT_ROUTE.DIRECT_CHAT
      : CHAT_INTENT_ROUTE.AGENT;
  const payload = {
    requestId,
    sessionId,
    legacyRoute,
    normalizedRoute: normalizedLegacyRoute,
    decision: classification.decision,
    source: classification.source ?? null,
    reason: classification.reason ?? null,
    wouldChangeRoute: legacyRoute != null && legacyRoute !== normalizedLegacyRoute,
  };
  const line = `[router-shadow] ${JSON.stringify(payload)}`;
  if (typeof logger.info === 'function') logger.info(line);
  else logger.log(line);
}

/**
 * Apply router session_hint for goosed agent path without overriding hard rules.
 * Returns null when gateway should start a fresh goosed session.
 */
export function resolveGatewayAgentSessionId({
  agentSessionId = null,
  classification = null,
  forceDeepReasoning = false,
  enabled = isNormalizedRouterDecisionEnabled(),
} = {}) {
  const sessionId = agentSessionId || null;

  if (forceDeepReasoning) {
    return sessionId;
  }

  if (!enabled || !classification?.decision) {
    return sessionId;
  }

  const decision = classification.decision;
  if (Array.isArray(decision.flags) && decision.flags.includes('force_deep_reasoning')) {
    return sessionId;
  }

  if (!sessionId) {
    return null;
  }

  if (isDirectChatSessionId(sessionId)) {
    return sessionId;
  }

  if (decision.session_hint === ROUTER_DECISION_SESSION_HINT.NEW) {
    return null;
  }

  return sessionId;
}

export function resolveChatIntentRouterPolicy({ env = process.env, overrides = {} } = {}) {
  return {
    enabled: envFlag(env?.MEMIND_CHAT_LLM_ROUTER_ENABLED, false),
    modelProviderKeyId: String(env?.MEMIND_CHAT_ROUTER_MODEL_PROVIDER_KEY_ID ?? '').trim() || null,
    model: String(env?.MEMIND_CHAT_ROUTER_MODEL ?? '').trim() || null,
    modelApiType: String(env?.MEMIND_CHAT_ROUTER_MODEL_API ?? '').trim() || 'chat',
    temperature: boundedNumber(env?.MEMIND_CHAT_ROUTER_TEMPERATURE, 0, { min: 0, max: 2 }),
    minConfidence: boundedNumber(
      env?.MEMIND_CHAT_ROUTER_MIN_CONFIDENCE,
      DEFAULT_ROUTER_MIN_CONFIDENCE,
      { min: 0, max: 1 },
    ),
    memoryResolveEnabled: envFlag(env?.MEMIND_CHAT_ROUTER_MEMORY_ENABLED, true),
    memoryResolveLimit: Math.round(boundedNumber(
      env?.MEMIND_CHAT_ROUTER_MEMORY_LIMIT,
      DEFAULT_ROUTER_MEMORY_LIMIT,
      { min: 1, max: 50 },
    )),
    timeoutMs: Math.round(boundedNumber(
      env?.MEMIND_CHAT_ROUTER_TIMEOUT_MS,
      DEFAULT_ROUTER_TIMEOUT_MS,
      { min: 0, max: 30_000 },
    )),
    ...overrides,
    fallbackRoute: resolveRouterFallbackRoute(env, overrides),
  };
}

function normalizeClassification(raw, { source, fallbackRoute = CHAT_INTENT_ROUTE.AGENT } = {}) {
  const route = normalizeRoute(raw?.route) ?? fallbackRoute;
  const confidenceRaw = Number(raw?.confidence);
  const confidence = Number.isFinite(confidenceRaw)
    ? Math.min(1, Math.max(0, confidenceRaw))
    : source === 'llm' ? 0.7 : 1;
  const suggestedSkill = String(raw?.suggested_skill ?? raw?.suggestedSkill ?? '').trim() || null;
  const agentBrief = String(raw?.agent_brief ?? raw?.agentBrief ?? '').trim();
  const reason = String(raw?.reason ?? '').trim() || (source === 'llm' ? '模型路由判定' : '规则路由判定');
  return {
    route,
    confidence,
    reason,
    suggestedSkill,
    agentBrief,
    source,
    providerKeyId: raw?.providerKeyId ?? raw?.provider_key_id ?? null,
    model: raw?.model ?? null,
    memory: raw?.memory ?? null,
  };
}

function resolveSkillPrompt(suggestedSkill, grantedSkills = [], displayText = '') {
  const skillName = String(suggestedSkill ?? '').trim();
  if (!skillName) return '';
  if (grantedSkills.length > 0 && !grantedSkills.includes(skillName)) return '';
  if (skillName === 'web' && isRealtimeInfoQuestion(displayText)) {
    return buildWebNewsSkillPrompt(skillName);
  }
  const promptKey = SKILL_PROMPT_KEYS[skillName];
  if (!promptKey) return '';
  return buildChatSkillPrompt(promptKey, skillName);
}

export function buildAgentOrchestrationAgentText({
  displayText,
  classification,
  skillPrompt = '',
}) {
  const taskBody = String(displayText ?? '').trim();
  const lines = [
    `${AGENT_ORCHESTRATION_HEADER}以下为用户任务，请使用工具与技能实际执行并产出结果，不要只做文字描述。`,
    `路由判定：${classification.reason}`,
    classification.agentBrief ? `执行要点：${classification.agentBrief}` : '',
    classification.suggestedSkill ? `建议 skill：${classification.suggestedSkill}` : '',
    skillPrompt,
    '',
    '用户任务：',
    taskBody,
  ].filter((line, index, all) => line !== '' || index === all.length - 2);
  return lines.join('\n');
}

export function applyAgentOrchestrationToUserMessage(userMessage, classification, { grantedSkills = [] } = {}) {
  const displayText = messageDisplayText(userMessage);
  const skillPrompt = resolveSkillPrompt(classification?.suggestedSkill, grantedSkills, displayText);
  const agentText = buildAgentOrchestrationAgentText({
    displayText,
    classification,
    skillPrompt,
  });
  const content = Array.isArray(userMessage?.content)
    ? userMessage.content.map((item, index) => {
        if (index !== 0) return item;
        if (typeof item === 'string') return agentText;
        if (item?.type === 'text') return { ...item, text: agentText };
        return item;
      })
    : [{ type: 'text', text: agentText }];
  const metadata = {
    ...(userMessage?.metadata ?? {}),
    displayText: displayText || undefined,
    chatIntentRoute: CHAT_INTENT_ROUTE.AGENT,
    chatIntentSource: classification?.source ?? null,
    userVisible: userMessage?.metadata?.userVisible ?? true,
    agentVisible: userMessage?.metadata?.agentVisible ?? true,
  };
  return {
    ...userMessage,
    content,
    metadata,
  };
}

function hasPriorAgentConversation(sessionId, sessionMessageCount) {
  if (!sessionId || isDirectChatSessionId(sessionId)) return false;
  if (sessionMessageCount == null) return true;
  return Number(sessionMessageCount) > 0;
}

export function classifyWithRules({
  text,
  forceDeepReasoning = false,
  toolMode = 'chat',
  sessionId = null,
  sessionMessageCount = null,
  userMessage = null,
  includeIntentPatterns = true,
  llmRouterEnabled = false,
} = {}) {
  const decisionContext = {
    text,
    forceDeepReasoning,
    toolMode,
    sessionId,
    sessionMessageCount,
  };
  const normalized = String(text ?? '').trim();
  if (forceDeepReasoning || toolMode !== 'chat') {
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.AGENT,
      confidence: 1,
      reason: forceDeepReasoning ? '用户开启深度推理' : '代码任务模式',
    }, { source: 'rule' }), decisionContext);
  }
  if (userMessage && messageHasExplicitChatSkillSelection(userMessage)) {
    return finalizeRouterClassification(buildSkillSelectionClassification(userMessage), decisionContext);
  }
  if (userMessage && !isTextOnlyUserMessage(userMessage)) {
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.AGENT,
      confidence: 1,
      reason: '消息包含非文本内容',
    }, { source: 'rule' }), decisionContext);
  }
  if (
    includeIntentPatterns &&
    normalized &&
    isMemoryRecallQuestion(normalized) &&
    !hasPriorAgentConversation(sessionId, sessionMessageCount)
  ) {
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.DIRECT_CHAT,
      confidence: 0.98,
      reason: '用户在询问个人记忆或历史对话',
    }, { source: 'rule' }), decisionContext);
  }
  if (hasPriorAgentConversation(sessionId, sessionMessageCount)) {
    const reason = isAgentSessionContinueText(normalized)
      ? 'Agent 会话确认/续聊'
      : '延续已有 Agent 会话';
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.AGENT,
      confidence: 1,
      reason,
    }, { source: 'rule' }), decisionContext);
  }
  if (
    includeIntentPatterns &&
    normalized &&
    isPageDataIntent(normalized)
  ) {
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.AGENT,
      confidence: 0.96,
      reason: '页面需要数据交互与持久化',
      suggested_skill: PAGE_DATA_COLLECT_SKILL_NAME,
      agent_brief:
        '使用 Page Data API 实现页面表单提交与后台查看；建表、注册 dataset、配置 policy，HTML 引入 page-data-client.js。',
    }, { source: 'rule' }), decisionContext);
  }
  if (
    includeIntentPatterns &&
    normalized &&
    (OBVIOUS_AGENT_PATTERNS.some((pattern) => pattern.test(normalized))
      || isPageGenerationIntent(normalized))
  ) {
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.AGENT,
      confidence: 0.95,
      reason: '明确需要生成或发布页面/文件',
      suggested_skill: 'static-page-publish',
      agent_brief: '生成或更新 MindSpace 公开页面，并返回可访问链接；信息不足时使用合理默认，不要停在追问。',
    }, { source: 'rule' }), decisionContext);
  }
  if (includeIntentPatterns && normalized && isRichPublishableContentIntent(normalized)) {
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.AGENT,
      confidence: 0.93,
      reason: '结构化长内容适合生成页面承载',
      suggested_skill: 'static-page-publish',
      agent_brief: '优先将用户提供的结构化长内容整理为 MindSpace 公开 H5 页面，并返回可访问链接；不要只回复文字摘要。',
    }, { source: 'rule' }), decisionContext);
  }
  if (includeIntentPatterns && normalized && isRealtimeInfoQuestion(normalized)) {
    return finalizeRouterClassification(buildRealtimeInfoClassification(), decisionContext);
  }
  if (
    includeIntentPatterns &&
    normalized &&
    OBVIOUS_DIRECT_PATTERNS.some((pattern) => pattern.test(normalized))
  ) {
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.DIRECT_CHAT,
      confidence: 0.95,
      reason: '简单寒暄或连通性测试',
    }, { source: 'rule' }), decisionContext);
  }
  if (
    includeIntentPatterns &&
    normalized &&
    OBVIOUS_DIRECT_CHAT_PATTERNS.some((pattern) => pattern.test(normalized))
  ) {
    return finalizeRouterClassification(normalizeClassification({
      route: CHAT_INTENT_ROUTE.DIRECT_CHAT,
      confidence: 0.95,
      reason: '纯文字创作或闲聊，无需执行任务',
    }, { source: 'rule' }), decisionContext);
  }
  return null;
}

export function createChatIntentRouter(options = {}) {
  const {
    llmProviderService,
    memoryV2 = null,
    conversationMemoryService = null,
    env = process.env,
    logger = console,
  } = options;
  const policy = options.policy ?? resolveChatIntentRouterPolicy({
    env,
    overrides: pickDefined(options, [
      'enabled',
      'modelProviderKeyId',
      'model',
      'modelApiType',
      'temperature',
      'minConfidence',
      'memoryResolveEnabled',
      'memoryResolveLimit',
      'timeoutMs',
      'fallbackRoute',
    ]),
  });

  function getStatus() {
    return {
      enabled: Boolean(policy.enabled),
      modelProviderKeyId: policy.modelProviderKeyId ?? null,
      model: policy.model ?? null,
      modelApiType: policy.modelApiType ?? 'chat',
      minConfidence: policy.minConfidence,
      memoryResolveEnabled: Boolean(policy.memoryResolveEnabled),
      memoryResolveLimit: policy.memoryResolveLimit,
      timeoutMs: policy.timeoutMs,
      fallbackRoute: policy.fallbackRoute,
      normalizedDecisionEnabled: isNormalizedRouterDecisionEnabled(env),
      normalizedDecisionMode: resolveNormalizedRouterDecisionMode(env),
    };
  }

  function isEnabled() {
    // Skill + rule routing only; LLM intent router is intentionally disabled.
    return false;
  }

  async function resolveRouterContext({ userId, sessionId, text, forceDeepReasoning = false }) {
    const intervention = resolveMemoryInterventionMode({
      forceDeepReasoning,
      recallQuestion: isMemoryRecallQuestion(text),
    });
    const limit = memoryLimitForIntervention(intervention, { context: 'router' });
    if (
      limit <= 0 ||
      !policy.memoryResolveEnabled ||
      !userId ||
      (!memoryV2?.resolve && !conversationMemoryService?.listMemories)
    ) {
      return buildRouterContext(null);
    }
    let primaryFailed = false;
    let memories = [];
    const recallQuestion = isMemoryRecallQuestion(text);
    if (recallQuestion && conversationMemoryService?.listMemories) {
      const legacy = await conversationMemoryService.listMemories(userId, { limit }).catch(() => []);
      memories = filterMemoriesByQuery(legacy, text);
    }
    if (!memories.length && memoryV2?.resolve) {
      try {
        const resolved = await withTimeout(
          memoryV2.resolve({
            userId,
            sessionId,
            query: text,
            limit,
          }),
          policy.timeoutMs,
          'Memory V2 router resolve',
        );
        memories = Array.isArray(resolved?.memories) ? resolved.memories : [];
      } catch (err) {
        primaryFailed = true;
        logger?.warn?.(
          `[chat-intent-router] memory resolve skipped: ${err instanceof Error ? err.message : err}`,
        );
      }
    }
    if (!memories.length && conversationMemoryService?.listMemories) {
      const legacy = await conversationMemoryService.listMemories(userId, { limit }).catch(() => []);
      memories = filterMemoriesByQuery(legacy, text);
      if (memories.length) primaryFailed = false;
    }
    if (primaryFailed && !memories.length) {
      return buildRouterContext({
        degraded: true,
        reason: 'memory_resolve_failed',
      });
    }
    return buildRouterContext({ memories, source: 'router-resolve' });
  }

  async function classify({
    userId = null,
    userMessage,
    sessionId = null,
    sessionMessageCount = null,
    toolMode = 'chat',
    forceDeepReasoning = false,
    grantedSkills = [],
  } = {}) {
    const text = messageDisplayText(userMessage);
    const decisionContext = {
      text,
      forceDeepReasoning,
      toolMode,
      sessionId,
      sessionMessageCount,
    };
    const finalizeWithCoercion = (classification) => {
      if (!classification) return classification;
      const base = { ...classification };
      delete base.decision;
      return finalizeRouterClassification(
        coercePageGenerationSkill(
          coercePageDataSkill(
            coerceRealtimeWebSkill(base, text, { grantedSkills }),
            text,
            { grantedSkills },
          ),
          text,
          { grantedSkills },
        ),
        decisionContext,
      );
    };
    const ruleResult = classifyWithRules({
      text,
      forceDeepReasoning,
      toolMode,
      sessionId,
      sessionMessageCount,
      userMessage,
      includeIntentPatterns: true,
      llmRouterEnabled: false,
    });
    if (ruleResult) return finalizeWithCoercion(ruleResult);
    return finalizeWithCoercion(normalizeClassification({
      route: policy.fallbackRoute,
      confidence: 0.5,
      reason: '规则未命中，走 skill 默认 Agent 通道',
    }, { source: 'fallback' }));
  }

  return {
    getStatus,
    isEnabled,
    classify,
    applyAgentOrchestration: applyAgentOrchestrationToUserMessage,
  };
}

export function createManagedChatIntentRouter({
  llmProviderService,
  memoryV2 = null,
  conversationMemoryService = null,
  configService = null,
  env = process.env,
  logger = console,
} = {}) {
  let activeRouter = null;
  let activeFingerprint = null;
  let activeMeta = { source: 'env', updatedAt: null, updatedBy: null, configError: null };

  async function loadRouterState() {
    if (!configService?.getRuntimeState) {
      return {
        source: 'env',
        updatedAt: null,
        updatedBy: null,
        fingerprint: 'env-only',
        effectiveEnv: { ...env },
        configError: null,
      };
    }
    try {
      const state = await configService.getRuntimeState();
      return {
        source: state?.source ?? 'admin-db',
        updatedAt: state?.updatedAt ?? null,
        updatedBy: state?.updatedBy ?? null,
        fingerprint: state?.fingerprint ?? `admin-db:${Date.now()}`,
        effectiveEnv: { ...env, ...(state?.overrides ?? {}) },
        configError: null,
      };
    } catch (err) {
      logger?.warn?.(
        `[chat-intent-router] admin config unavailable, using process env: ${err instanceof Error ? err.message : err}`,
      );
      return {
        source: 'env-fallback',
        updatedAt: null,
        updatedBy: null,
        fingerprint: 'env-fallback',
        effectiveEnv: { ...env },
        configError: err instanceof Error ? err.message : String(err),
      };
    }
  }

  async function ensureRouter() {
    const state = await loadRouterState();
    if (activeRouter && activeFingerprint === state.fingerprint) {
      activeMeta = state;
      return activeRouter;
    }
    activeRouter = createChatIntentRouter({
      llmProviderService,
      memoryV2,
      conversationMemoryService,
      env: state.effectiveEnv,
      logger,
    });
    activeFingerprint = state.fingerprint;
    activeMeta = state;
    return activeRouter;
  }

  return {
    async getStatus() {
      const router = await ensureRouter();
      return {
        ...router.getStatus(),
        configSource: activeMeta.source,
        configUpdatedAt: activeMeta.updatedAt,
        configUpdatedBy: activeMeta.updatedBy,
        configError: activeMeta.configError,
      };
    },

    async isEnabled() {
      const router = await ensureRouter();
      return router.isEnabled();
    },

    async classify(input = {}) {
      const router = await ensureRouter();
      return router.classify(input);
    },

    applyAgentOrchestration: applyAgentOrchestrationToUserMessage,
  };
}