import crypto from 'node:crypto';

const ANALYTICS_MARKER = 'data-memind-analytics="1"';

export function resolveMindSpaceAnalyticsConfig(env = process.env) {
  const enabled = String(env.MEMIND_ANALYTICS_ENABLED ?? '').toLowerCase() === 'true';
  const websiteId = String(env.MEMIND_ANALYTICS_WEBSITE_ID ?? '').trim();
  const secret = String(env.MEMIND_ANALYTICS_ID_SECRET ?? '').trim();
  return {
    enabled: enabled && Boolean(websiteId) && Boolean(secret),
    websiteId,
    idSecret: secret,
    identityMode: String(env.MEMIND_ANALYTICS_IDENTITY_MODE ?? 'pseudonymous').trim().toLowerCase() === 'raw'
      ? 'raw'
      : 'pseudonymous',
    analyticsUrl: String(env.MEMIND_ANALYTICS_URL ?? 'http://127.0.0.1:3100').trim() || 'http://127.0.0.1:3100',
    scriptPath: String(env.MEMIND_ANALYTICS_SCRIPT_PATH ?? '/analytics/script.js').trim() || '/analytics/script.js',
    hostPath: String(env.MEMIND_ANALYTICS_HOST_PATH ?? '/analytics').trim() || '/analytics',
    domains: String(env.MEMIND_ANALYTICS_DOMAINS ?? '').trim(),
  };
}

export function resolveProductAnalyticsConfig(
  env = process.env,
  baseConfig = resolveMindSpaceAnalyticsConfig(env),
) {
  const websiteId = String(env.MEMIND_PRODUCT_ANALYTICS_WEBSITE_ID ?? '').trim();
  const enabled = String(env.MEMIND_PRODUCT_ANALYTICS_ENABLED ?? '').toLowerCase() === 'true';
  return {
    enabled: enabled && Boolean(websiteId) && Boolean(baseConfig?.idSecret),
    websiteId,
    idSecret: String(baseConfig?.idSecret ?? '').trim(),
    identityMode: baseConfig?.identityMode === 'raw' ? 'raw' : 'pseudonymous',
    scriptPath: String(baseConfig?.scriptPath ?? '/analytics/script.js').trim() || '/analytics/script.js',
    hostPath: String(baseConfig?.hostPath ?? '/analytics').trim() || '/analytics',
    domains: String(baseConfig?.domains ?? '').trim(),
  };
}

export function pseudonymizeAnalyticsId(value, secret) {
  const normalized = String(value ?? '').trim();
  const key = String(secret ?? '').trim();
  if (!normalized || !key) return '';
  return crypto.createHmac('sha256', key).update(normalized).digest('hex').slice(0, 32);
}

export function resolveAnalyticsIdentity(value, config = {}) {
  const normalized = String(value ?? '').trim().replace(/[\r\n\t]+/g, '').slice(0, 128);
  if (!normalized) return '';
  return config?.identityMode === 'raw'
    ? normalized
    : pseudonymizeAnalyticsId(normalized, config?.idSecret);
}

export function resolveAnalyticsOwnerSegment(user = {}) {
  if (user?.role === 'admin') return 'admin';
  const plan = String(user?.planType ?? user?.plan_type ?? 'free').trim().toLowerCase();
  return `plan:${plan || 'free'}`;
}

export function resolveAnalyticsPlan(user = {}) {
  if (user?.role === 'admin') return 'admin';
  return String(user?.planType ?? user?.plan_type ?? 'free').trim().toLowerCase() || 'free';
}

export function resolveAnalyticsOwnerLabel(user = {}) {
  const label = String(user?.displayName ?? user?.display_name ?? user?.username ?? '').trim();
  return label.replace(/[\r\n\t]+/g, ' ').slice(0, 80) || '未命名用户';
}

export function buildProductAnalyticsContext({ config, user = null } = {}) {
  if (!config?.enabled || !config.websiteId) return { enabled: false };
  const distinctId = user?.id ? resolveAnalyticsIdentity(user.id, config) : '';
  return {
    enabled: true,
    websiteId: config.websiteId,
    scriptPath: config.scriptPath || '/analytics/script.js',
    hostPath: config.hostPath || '/analytics',
    domains: config.domains || '',
    identity: distinctId
      ? {
          distinctId,
          username: resolveAnalyticsOwnerLabel(user),
          ownerSegment: resolveAnalyticsOwnerSegment(user),
          planType: resolveAnalyticsPlan(user),
          channel: 'h5',
          surface: 'product',
          identityMode: config.identityMode === 'raw' ? 'raw' : 'pseudonymous',
        }
      : null,
  };
}

export function sendMindSpaceAnalyticsEvent({
  config,
  eventName,
  ownerId,
  pageId = '',
  publicationId = '',
  agentRunId = '',
  channel = 'h5',
  ownerSegment = 'unknown',
  ownerLabel = '未命名用户',
  planType = 'unknown',
  generatedAt = '',
  url = '',
} = {}) {
  if (!config?.enabled || !config.websiteId || !config.idSecret || !eventName) return Promise.resolve(false);
  const owner = resolveAnalyticsIdentity(ownerId, config);
  if (!owner) return Promise.resolve(false);
  const endpoint = `${String(config.analyticsUrl || 'http://127.0.0.1:3100').replace(/\/$/, '')}/api/send`;
  const payload = {
    website: config.websiteId,
    id: owner,
    hostname: '127.0.0.1',
    url: url || '/',
    name: String(eventName),
    data: {
      owner_id: owner,
      page_id: String(pageId || ''),
      publication_id: String(publicationId || ''),
      agent_run_id: String(agentRunId || ''),
      channel,
      owner_segment: String(ownerSegment || 'unknown'),
      plan_type: String(planType || 'unknown'),
      owner_label: resolveAnalyticsOwnerLabel({ displayName: ownerLabel }),
      generated_at: String(generatedAt || ''),
      identity_mode: config.identityMode === 'raw' ? 'raw' : 'pseudonymous',
    },
  };
  return fetch(endpoint, {
    method: 'POST',
    headers: { 'content-type': 'application/json', 'user-agent': 'Memind/local-analytics' },
    body: JSON.stringify({ type: 'event', payload }),
    signal: AbortSignal.timeout(1500),
  }).then((response) => response.ok).catch(() => false);
}

function jsonForInlineScript(value) {
  return JSON.stringify(value)
    .replaceAll('<', '\\u003c')
    .replaceAll('>', '\\u003e')
    .replaceAll('&', '\\u0026');
}

export function injectMindSpaceAnalytics(html, {
  ownerId,
  pageId = '',
  publicationId = '',
  ownerSegment = 'unknown',
  ownerLabel = '未命名用户',
  planType = 'unknown',
  generatedAt = '',
  channel = 'h5',
  config = resolveMindSpaceAnalyticsConfig(),
} = {}) {
  const source = String(html ?? '');
  if (!config?.enabled || !config.websiteId || !/^\s*(<!doctype html|<html\b)/i.test(source)) return source;
  if (source.includes(ANALYTICS_MARKER)) return source;
  const owner = resolveAnalyticsIdentity(ownerId, config);
  if (!owner) return source;
  const metadata = { owner_id: owner, username: resolveAnalyticsOwnerLabel({ displayName: ownerLabel }), owner_segment: String(ownerSegment || 'unknown'), plan_type: String(planType || 'unknown'), page_id: String(pageId || ''), publication_id: String(publicationId || ''), generated_at: String(generatedAt || ''), identity_mode: config.identityMode === 'raw' ? 'raw' : 'pseudonymous', channel, surface: 'generated_page' };
  const attrs = [
    ANALYTICS_MARKER,
    `data-website-id="${config.websiteId.replaceAll('"', '&quot;')}"`,
    'data-auto-track="false"',
    `data-host-url="${config.hostPath}"`,
  ];
  if (config.domains) attrs.push(`data-domains="${config.domains.replaceAll('"', '&quot;')}"`);
  const block = `<script ${attrs.join(' ')} defer src="${config.scriptPath}"></script><script ${ANALYTICS_MARKER}>(function(){var d=${jsonForInlineScript(metadata)},seen={};function safeTarget(h){if(!h)return'';try{var u=new URL(h,location.href);return u.origin===location.origin?u.pathname:'external:'+u.hostname;}catch{return'';}}function t(n,x){if(!window.umami||typeof window.umami.track!=='function')return;var p=Object.assign({},d,{page_url:location.href,page_route:location.pathname,page_title:document.title},x||{});window.umami.track(n,p);}function identify(){if(!window.umami||typeof window.umami.identify!=='function')return;window.umami.identify(d.owner_id,{username:d.username,memind_page_url:location.href,owner_segment:d.owner_segment,plan_type:d.plan_type,channel:d.channel,surface:d.surface,identity_mode:d.identity_mode});}function pageview(){if(!window.umami||typeof window.umami.track!=='function')return;window.umami.track();}function once(n,x){if(seen[n])return;seen[n]=1;t(n,x);}function ready(){identify();pageview();document.addEventListener('click',function(e){var el=e.target&&e.target.closest?e.target.closest('a,button,[role="button"],[data-umami-event]'):null;if(!el)return;var custom=el.getAttribute('data-umami-event');var href=el.tagName==='A'?el.getAttribute('href')||'':'';t(custom||'page_click',{element:el.tagName.toLowerCase(),element_id:el.id||'',event_label:(custom||el.getAttribute('aria-label')||'').slice(0,100),target_path:safeTarget(href)});},{passive:true});document.addEventListener('submit',function(e){var form=e.target;t('page_form_submit',{form_id:form&&form.id||'',form_action:safeTarget(form&&form.getAttribute('action')||'')});},{passive:true});var marks=[25,50,75,90];function scroll(){var h=document.documentElement.scrollHeight-window.innerHeight;if(h<=0){once('page_scroll_100');return;}var pct=Math.round(window.scrollY/h*100);marks.forEach(function(m){if(pct>=m)once('page_scroll_'+m);});}window.addEventListener('scroll',scroll,{passive:true});setTimeout(function(){once('page_engaged_10s');},10000);setTimeout(function(){once('page_engaged_30s');},30000);scroll();}if(document.readyState==='loading'){document.addEventListener('DOMContentLoaded',ready,{once:true});}else{ready();}})();</script>`;
  if (/<\/head>/i.test(source)) return source.replace(/<\/head>/i, `${block}</head>`);
  return source.replace(/<body\b/i, `${block}<body`);
}