import 'dart:js_interop';

@JS('navigator.userAgent')
external String get _navigatorUserAgent;

@JS('window.matchMedia')
external _MediaQueryList _matchMedia(String query);

extension type _MediaQueryList._(JSObject _) implements JSObject {
  external bool get matches;
}

/// Returns true when the user is on iOS Safari and the app has NOT been added
/// to the Home Screen (i.e., not running in standalone mode).
///
/// When this returns true, we show the "Add to Home Screen" install banner so
/// that users can unlock iOS 16.4+ web push notifications.
bool detectIosSafariNotInstalled() {
  final ua = _navigatorUserAgent.toLowerCase();
  final isIos =
      ua.contains('iphone') || ua.contains('ipad') || ua.contains('ipod');
  if (!isIos) return false;

  // The PWA is "installed" if the display-mode: standalone media query matches.
  final isStandalone = _matchMedia('(display-mode: standalone)').matches;
  return !isStandalone;
}