/**
 * Default backend base URL — the operator-set fallback used when no specific
 * instance is active. Resolution order:
 *
 *   1. window.__APP_CONFIG__.apiBaseUrl  — runtime, injected by the container
 *      at start from $PUBLIC_API_BASE_URL (see public/config.js). Lets one
 *      prebuilt image point at any backend origin without rebuilding.
 *   2. import.meta.env.PUBLIC_API_BASE_URL — build-time default (rsbuild inlines
 *      PUBLIC_* vars). Used in local dev and as a baked fallback.
 *   3. '/api/v1' — same-origin relative path (works behind a reverse proxy).
 *
 * The user's chosen instance still wins over all of these — see
 * runtime-config.ts / instances.ts.
 */
function runtimeApiBaseUrl(): string | undefined {
  if (typeof window === 'undefined') return undefined;
  const value = window.__APP_CONFIG__?.apiBaseUrl;
  return value ? value : undefined;
}

export const DEFAULT_API_BASE_URL =
  runtimeApiBaseUrl() ?? import.meta.env.PUBLIC_API_BASE_URL ?? '/api/v1';

/**
 * Whether the public sign-up UI is shown. Same precedence as the base URL:
 * runtime operator config (injected into `window.__APP_CONFIG__` at container
 * start) wins over the build-time `PUBLIC_ENABLE_REGISTRATION` env, which
 * defaults to enabled. This only gates the *UI*; the backend independently
 * enforces `ALLOW_REGISTRATION` and is the real authority.
 */
function parseFlag(value: string | undefined): boolean | undefined {
  if (value == null || value === '') return undefined;
  return value !== 'false' && value !== '0';
}

export const REGISTRATION_ENABLED: boolean =
  (typeof window !== 'undefined'
    ? window.__APP_CONFIG__?.enableRegistration
    : undefined) ??
  parseFlag(import.meta.env.PUBLIC_ENABLE_REGISTRATION) ??
  true;