/// Build-time configuration, supplied with `--dart-define-from-file=env.json`.
///
/// Every value has a working default, so the app builds and runs with no
/// `env.json` at all: it starts in demo mode against bundled mock frames, on
/// the free OpenFreeMap base map, with no credentials anywhere. That keeps the
/// repository free of secrets and keeps a fresh clone runnable.
///
/// Values are `const` reads of `String.fromEnvironment` so they are inlined and
/// tree-shaken; they cannot be read from a file at run time.
library;

class Env {
  const Env._();

  /// Which region config to load from `assets/regions/<id>.json`.
  static const String regionId = String.fromEnvironment(
    'REGION_ID',
    defaultValue: 'piemonte',
  );

  /// MapLibre style URL for the base map.
  ///
  /// Empty means the default OpenFreeMap style, which needs no key. Set it to
  /// point at another provider, or to [offlineStyle] to force the bundled
  /// no-network style.
  static const String mapStyleUrl = String.fromEnvironment('MAP_STYLE_URL');

  /// Sentinel for `MAP_STYLE_URL` that selects the bundled offline style.
  static const String offlineStyle = 'offline';

  static bool get wantsOfflineStyle => mapStyleUrl == offlineStyle;

  static bool get hasCustomMapStyle =>
      mapStyleUrl.isNotEmpty && !wantsOfflineStyle;

  /// Base URL of the radar `manifest.json` published by our worker.
  ///
  /// Empty forces the mock radar source regardless of [radarSource].
  static const String radarManifestUrl = String.fromEnvironment(
    'RADAR_MANIFEST_URL',
  );

  /// Radar adapter override: `mock`, `dpc` or `arpa`.
  ///
  /// Empty means "use whatever the region config says".
  static const String radarSource = String.fromEnvironment('RADAR_SOURCE');

  /// True when nothing is configured and the radar is running entirely on
  /// bundled data. Surfaced in the UI so demo frames are never mistaken for a
  /// real observation.
  static bool get isDemoMode => radarManifestUrl.isEmpty;
}