const TURNSTILE_VERIFY_URL = 'https://challenges.cloudflare.com/turnstile/v0/siteverify';

export function isPageDataCaptchaEnabled() {
  return Boolean(String(process.env.PAGE_DATA_TURNSTILE_SECRET ?? '').trim());
}

export async function verifyPageDataCaptcha(token, remoteIp, { fetchImpl = globalThis.fetch } = {}) {
  const secret = String(process.env.PAGE_DATA_TURNSTILE_SECRET ?? '').trim();
  if (!secret) {
    return { ok: true, skipped: true };
  }
  const responseToken = String(token ?? '').trim();
  if (!responseToken) {
    throw Object.assign(new Error('提交表单需要验证码'), { code: 'captcha_required', status: 400 });
  }
  const body = new URLSearchParams({
    secret,
    response: responseToken,
  });
  if (remoteIp) body.set('remoteip', String(remoteIp));
  const response = await fetchImpl(TURNSTILE_VERIFY_URL, {
    method: 'POST',
    headers: { 'content-type': 'application/x-www-form-urlencoded' },
    body: body.toString(),
  });
  const payload = await response.json().catch(() => ({}));
  if (!payload?.success) {
    throw Object.assign(new Error('验证码校验失败'), {
      code: 'captcha_invalid',
      status: 403,
    });
  }
  return { ok: true, skipped: false };
}

export function extractPageDataCaptchaToken(req, payload) {
  return (
    String(req.headers?.['x-page-data-captcha'] ?? '').trim() ||
    String(payload?.turnstile_token ?? payload?.turnstileToken ?? payload?.captcha_token ?? '').trim() ||
    null
  );
}

export const PAGE_DATA_META_FIELDS = new Set([
  'turnstile_token',
  'turnstileToken',
  'captcha_token',
  'updated_by_label',
]);

export function stripPageDataMetaFields(payload) {
  if (!payload || typeof payload !== 'object' || Array.isArray(payload)) return payload;
  const cleaned = { ...payload };
  for (const key of PAGE_DATA_META_FIELDS) {
    delete cleaned[key];
  }
  return cleaned;
}