import crypto from 'node:crypto';

const TOKEN_TTL_MS = 55 * 60 * 1000;

let cachedToken = '';
let cachedTokenAt = 0;
let cachedBaseUrl = '';

function normalizeBaseUrl(value = '') {
  return String(value ?? '').trim().replace(/\/$/, '');
}

function resolveUmamiCredentials(env = process.env, analyticsConfig = {}) {
  const baseUrl = normalizeBaseUrl(
    analyticsConfig?.analyticsUrl || env.UMAMI_URL || 'http://127.0.0.1:3100',
  );
  const username = String(env.UMAMI_SSO_USERNAME || env.UMAMI_ADMIN_USERNAME || 'admin').trim();
  const password = String(env.UMAMI_ADMIN_PASSWORD || '').trim();
  const sharedSecret = String(env.MEMIND_UMAMI_SSO_SECRET || '').trim();
  const websiteId = String(analyticsConfig?.websiteId || env.UMAMI_WEBSITE_ID || '').trim();
  return { baseUrl, username, password, sharedSecret, websiteId };
}

async function loginUmamiViaSso({ baseUrl, username, sharedSecret }) {
  const encoded = Buffer.from(
    JSON.stringify({
      username,
      exp: Math.floor(Date.now() / 1000) + 60,
      nonce: crypto.randomUUID(),
    }),
  ).toString('base64url');
  const signature = crypto.createHmac('sha256', sharedSecret).update(encoded).digest('base64url');
  const ticket = `${encoded}.${signature}`;
  const response = await fetch(
    `${baseUrl}/api/auth/memind?ticket=${encodeURIComponent(ticket)}`,
    { signal: AbortSignal.timeout(10_000) },
  );
  const body = await response.json().catch(() => ({}));
  if (!response.ok) {
    throw new Error(body?.error?.message || body?.message || `Umami SSO 登录失败 (${response.status})`);
  }
  const token = String(body?.token ?? '').trim();
  if (!token) throw new Error('Umami SSO 登录响应缺少 token');
  return token;
}

async function loginUmami({ baseUrl, username, password, sharedSecret }) {
  if (sharedSecret) {
    return loginUmamiViaSso({ baseUrl, username, sharedSecret });
  }
  if (!password) {
    throw new Error('未配置 UMAMI_ADMIN_PASSWORD 或 MEMIND_UMAMI_SSO_SECRET，无法拉取 SEO/GEO 页面统计');
  }
  const response = await fetch(`${baseUrl}/api/auth/login`, {
    method: 'POST',
    headers: { 'content-type': 'application/json' },
    body: JSON.stringify({ username, password }),
    signal: AbortSignal.timeout(10_000),
  });
  const body = await response.json().catch(() => ({}));
  if (!response.ok) {
    throw new Error(body?.message || `Umami 登录失败 (${response.status})`);
  }
  const token = String(body?.token ?? '').trim();
  if (!token) throw new Error('Umami 登录响应缺少 token');
  return token;
}

async function getUmamiAuthToken(credentials) {
  const now = Date.now();
  if (
    cachedToken &&
    cachedBaseUrl === credentials.baseUrl &&
    now - cachedTokenAt < TOKEN_TTL_MS
  ) {
    return cachedToken;
  }
  cachedToken = await loginUmami(credentials);
  cachedTokenAt = now;
  cachedBaseUrl = credentials.baseUrl;
  return cachedToken;
}

export async function fetchMemindDiscoveryPages(
  query = {},
  { env = process.env, analyticsConfig = {} } = {},
) {
  const credentials = resolveUmamiCredentials(env, analyticsConfig);
  if (!credentials.websiteId) {
    throw new Error('未配置 Umami Website ID');
  }
  const channel = String(query.discoveryChannel ?? query.channel ?? '').trim().toLowerCase();
  if (channel !== 'seo' && channel !== 'geo') {
    throw new Error('discoveryChannel 必须是 seo 或 geo');
  }

  const params = new URLSearchParams();
  params.set('discoveryChannel', channel);
  params.set('page', String(Math.max(Number(query.page) || 1, 1)));
  params.set('pageSize', String(Math.min(Math.max(Number(query.pageSize) || 10, 1), 100)));
  params.set('sortBy', String(query.sortBy || 'views'));
  params.set('sortOrder', String(query.sortOrder || 'desc'));
  if (query.startAt) params.set('startAt', String(query.startAt));
  if (query.endAt) params.set('endAt', String(query.endAt));
  if (query.timezone) params.set('timezone', String(query.timezone));
  if (query.generatedStartAt) params.set('generatedStartAt', String(query.generatedStartAt));
  if (query.generatedEndAt) params.set('generatedEndAt', String(query.generatedEndAt));

  const token = await getUmamiAuthToken(credentials);
  const response = await fetch(
    `${credentials.baseUrl}/api/websites/${encodeURIComponent(credentials.websiteId)}/memind-pages?${params.toString()}`,
    {
      headers: {
        authorization: `Bearer ${token}`,
        'content-type': 'application/json',
      },
      signal: AbortSignal.timeout(15_000),
    },
  );
  const body = await response.json().catch(() => ({}));
  if (!response.ok) {
    throw new Error(body?.message || `Umami memind-pages 请求失败 (${response.status})`);
  }
  return {
    discoveryChannel: channel,
    ...body,
  };
}

export function resolvePublicPageUrl(row = {}, fallbackHost = 'm.tkmind.cn') {
  const exact = String(row.pageUrl ?? '').trim();
  if (/^https?:\/\//i.test(exact)) return exact.split('#')[0];
  const hostname = String(row.hostname ?? '').trim();
  if (hostname === '127.0.0.1' || hostname === 'localhost') {
    return `http://${hostname}:8081${row.urlPath}`;
  }
  const host = hostname || fallbackHost;
  return `https://${host}${row.urlPath}`;
}