import { api } from '../stores/api';

function urlBase64ToUint8Array(base64String) {
  const padding = '='.repeat((4 - (base64String.length % 4)) % 4);
  const base64 = (base64String + padding).replace(/-/g, '+').replace(/_/g, '/');
  const rawData = window.atob(base64);
  const outputArray = new Uint8Array(rawData.length);
  for (let i = 0; i < rawData.length; i += 1) {
    outputArray[i] = rawData.charCodeAt(i);
  }
  return outputArray;
}

export function pushSupported() {
  return 'serviceWorker' in navigator && 'PushManager' in window && 'Notification' in window;
}

export async function getPushSubscription() {
  if (!pushSupported()) return null;
  const registration = await navigator.serviceWorker.getRegistration('/push/');
  if (!registration) return null;
  return registration.pushManager.getSubscription();
}

export async function enablePushNotifications() {
  if (!pushSupported()) {
    throw new Error("Ce navigateur ne supporte pas les notifications push");
  }
  const config = await api.get('/notifications/configuration');
  if (!config.enabled || !config.public_key) {
    throw new Error("Les notifications ne sont pas configurées sur ce serveur");
  }
  const permission = await Notification.requestPermission();
  if (permission !== 'granted') {
    throw new Error("La permission de notification a été refusée");
  }
  const registration = await navigator.serviceWorker.register('/push-sw.js', { scope: '/push/' });
  const existing = await registration.pushManager.getSubscription();
  const subscription = existing || await registration.pushManager.subscribe({
    userVisibleOnly: true,
    applicationServerKey: urlBase64ToUint8Array(config.public_key),
  });
  await api.post('/notifications/abonnement', subscription.toJSON());
  return subscription;
}

export async function disablePushNotifications() {
  const subscription = await getPushSubscription();
  if (!subscription) return;
  await api.request('DELETE', `/notifications/abonnement?endpoint=${encodeURIComponent(subscription.endpoint)}`);
  await subscription.unsubscribe();
}

export async function sendTestNotification() {
  return api.post('/notifications/test', {});
}