/**
 * Environment access, in one place so nothing else has to guess.
 */

/**
 * The origin the device and the browser reach us on.
 *
 * Prefers what the request actually arrived as, because the panel has to be
 * handed a URL it can fetch — a mismatch here shows up as a blank screen in a
 * shop window, which is the most expensive place to debug. Falls back to the
 * configured domain for calls that have no request, such as background jobs.
 */
export function publicBaseUrl(request?: Request): string {
  if (request) {
    const host = request.headers.get('x-forwarded-host') ?? request.headers.get('host');
    if (host) {
      const proto = request.headers.get('x-forwarded-proto') ?? new URL(request.url).protocol.replace(':', '');
      return `${proto}://${host}`;
    }
  }

  const configured = process.env.NEXTAUTH_URL;
  if (configured) {
    return configured.replace(/\/$/, '');
  }

  const domain = process.env.APP_DOMAIN;
  if (domain) {
    return domain.startsWith('http') ? domain.replace(/\/$/, '') : `https://${domain}`;
  }

  return 'http://localhost:3000';
}

/**
 * Whether the panel may talk to us over plain HTTP.
 *
 * Off by default. It exists because these ESP32 firmwares sometimes fail on a
 * certificate chain, and a shop with a blank window needs a way out that does
 * not involve reflashing. The device token is separate and revocable precisely
 * so this switch stays survivable.
 */
export function deviceAllowsHttp(): boolean {
  return process.env.DEVICE_ALLOW_HTTP === 'true';
}