/**
 * KGV PWA – Service Worker
 *
 * Strategie:
 *  - HTML-Seiten: Network-first (frische Inhalte, Fallback auf Cache)
 *  - Statische Assets (CSS/JS/Bilder/Fonts): Cache-first
 */

'use strict';

const CACHE_NAME    = 'kgv-pwa-v1-0-1';
const OFFLINE_PAGE  = '/';

const PRECACHE_URLS = [
	'/',
];

// -----------------------------------------------------------------------
// Install: Precache-Ressourcen laden
// -----------------------------------------------------------------------
self.addEventListener( 'install', function ( event ) {
	event.waitUntil(
		caches.open( CACHE_NAME ).then( function ( cache ) {
			return cache.addAll( PRECACHE_URLS );
		} )
	);
	self.skipWaiting();
} );

// -----------------------------------------------------------------------
// Activate: Alte Caches löschen
// -----------------------------------------------------------------------
self.addEventListener( 'activate', function ( event ) {
	event.waitUntil(
		caches.keys().then( function ( keys ) {
			return Promise.all(
				keys
					.filter( function ( key ) { return key !== CACHE_NAME; } )
					.map( function ( key ) { return caches.delete( key ); } )
			);
		} )
	);
	self.clients.claim();
} );

// -----------------------------------------------------------------------
// Fetch: Anfragen abfangen
// -----------------------------------------------------------------------
self.addEventListener( 'fetch', function ( event ) {
	var request = event.request;

	// Nur GET-Anfragen behandeln
	if ( request.method !== 'GET' ) {
		return;
	}

	// Nur Anfragen gleichen Ursprungs behandeln
	if ( ! request.url.startsWith( self.location.origin ) ) {
		return;
	}

	var url = new URL( request.url );

	// Admin-Bereich und WP-Cron ausschließen
	if (
		url.pathname.startsWith( '/wp-admin' ) ||
		url.pathname.startsWith( '/wp-cron' ) ||
		url.pathname.includes( 'wp-login' )
	) {
		return;
	}

	// HTML-Navigation: Network-first
	if ( request.mode === 'navigate' ) {
		event.respondWith(
			fetch( request )
				.then( function ( response ) {
					// Erfolgreiche Antwort im Cache speichern
					if ( response && response.status === 200 ) {
						var clone = response.clone();
						caches.open( CACHE_NAME ).then( function ( cache ) {
							cache.put( request, clone );
						} );
					}
					return response;
				} )
				.catch( function () {
					// Offline-Fallback: gecachte Startseite
					return caches.match( request ).then( function ( cached ) {
						return cached || caches.match( OFFLINE_PAGE );
					} );
				} )
		);
		return;
	}

	// Statische Assets: Cache-first
	if ( /\.(css|js|png|jpg|jpeg|gif|svg|webp|woff2?|ttf|eot|ico)(\?.*)?$/.test( url.pathname ) ) {
		event.respondWith(
			caches.match( request ).then( function ( cached ) {
				if ( cached ) {
					return cached;
				}
				return fetch( request ).then( function ( response ) {
					if ( response && response.status === 200 ) {
						var clone = response.clone();
						caches.open( CACHE_NAME ).then( function ( cache ) {
							cache.put( request, clone );
						} );
					}
					return response;
				} );
			} )
		);
		return;
	}
} );