const CACHE_NAME = 'medi-customers-v1';
const urlsToCache = [
    '/',
    '/static/css/styles.css',
    '/static/js/script.js',
    '/static/images/logo.png',
    '/static/images/icon-192x192.png',
    '/static/images/icon-512x512.png'
];

// Installation des Service Workers
self.addEventListener('install', event => {
    event.waitUntil(
        caches.open(CACHE_NAME)
            .then(cache => {
                console.log('Cache geöffnet');
                return cache.addAll(urlsToCache);
            })
    );
});

// Aktivierung des Service Workers
self.addEventListener('activate', event => {
    event.waitUntil(
        caches.keys().then(cacheNames => {
            return Promise.all(
                cacheNames.map(cacheName => {
                    if (cacheName !== CACHE_NAME) {
                        console.log('Lösche alten Cache:', cacheName);
                        return caches.delete(cacheName);
                    }
                })
            );
        })
    );
});

// Fetch-Event-Handler
self.addEventListener('fetch', event => {
    event.respondWith(
        caches.match(event.request)
            .then(response => {
                // Cache-Treffer - gib die Antwort zurück
                if (response) {
                    return response;
                }

                // Kein Cache-Treffer - führe Netzwerkanfrage durch
                return fetch(event.request)
                    .then(response => {
                        // Prüfe, ob wir eine gültige Antwort erhalten haben
                        if (!response || response.status !== 200 || response.type !== 'basic') {
                            return response;
                        }

                        // Klone die Antwort
                        const responseToCache = response.clone();

                        // Speichere die Antwort im Cache
                        caches.open(CACHE_NAME)
                            .then(cache => {
                                cache.put(event.request, responseToCache);
                            });

                        return response;
                    })
                    .catch(() => {
                        // Fallback für Offline-Zugriff
                        if (event.request.mode === 'navigate') {
                            return caches.match('/offline.html');
                        }
                    });
            })
    );
});