/**
 * Canonical FC endpoint derivation, shared by the background client and the
 * options page so a URL entered either way behaves identically.
 *
 * FC serves two things on one origin: the JSON API under `/api`, and the Vue
 * SPA from the root. `api.js` builds requests as `${baseUrl}/credentials`, so
 * the stored base URL has to carry the `/api` suffix.
 */

/**
 * Accept what an operator would naturally type — the instance root
 * (`http://curator.example.com`) or the API root (`.../api`) — and return the
 * API root either way.
 *
 * Worth normalizing rather than validating: a root-form URL doesn't fail
 * loudly, it lands on the SPA catch-all, which answers `GET /credentials` with
 * 200 HTML and rejects `POST /credentials` with 405. The operator sees a
 * working Test Connection and a broken export.
 */
function normalizeApiUrl(raw) {
  const trimmed = (raw || '').trim().replace(/\/+$/, '');
  if (!trimmed) return '';
  return /\/api$/i.test(trimmed) ? trimmed : `${trimmed}/api`;
}

/**
 * The SPA root — where the Vue router (artist pages) and the served XPI live,
 * NOT the JSON API. Accepts either input form, same as normalizeApiUrl.
 */
function webRootFromApiUrl(raw) {
  return normalizeApiUrl(raw).replace(/\/api$/i, '');
}