/**
 * Notification permission helper — request and check notification permissions (Task 5.24).
 */

export type NotificationPermissionState = 'default' | 'granted' | 'denied' | 'unsupported';

export function getNotificationPermission(): NotificationPermissionState {
  if (!('Notification' in window)) return 'unsupported';
  return Notification.permission as NotificationPermissionState;
}

export async function requestNotificationPermission(): Promise<NotificationPermissionState> {
  if (!('Notification' in window)) return 'unsupported';
  if (Notification.permission === 'granted') return 'granted';
  if (Notification.permission === 'denied') return 'denied';

  try {
    const result = await Notification.requestPermission();
    return result as NotificationPermissionState;
  } catch {
    return 'denied';
  }
}

export function showNotification(title: string, options?: NotificationOptions): void {
  if (!('Notification' in window) || Notification.permission !== 'granted') return;
  try {
    new Notification(title, options);
  } catch {
    // Notification creation can fail in some browsers
  }
}

export function isPWAInstalled(): boolean {
  try {
    return window.matchMedia('(display-mode: standalone)').matches ||
      (window.navigator as unknown as { standalone?: boolean }).standalone === true;
  } catch {
    return false;
  }
}