// JGA Prag 2026 — Service Worker
// Cache-Strategie: cache-first für HTML/Assets, network-first für externe APIs (OSRM)
const CACHE_VERSION = 'jga-2026-v1';
const CORE_ASSETS = [
  './',
  './index.html',
  './tourenplan.html',
  './tourenplan-mit-tram.html',
  './wetter.html',
  './packliste.html',
  './manifest.json'
];

// Install: alle Core-Files cachen
self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open(CACHE_VERSION)
      .then(cache => cache.addAll(CORE_ASSETS))
      .then(() => self.skipWaiting())
  );
});

// Activate: alte Caches aufräumen
self.addEventListener('activate', (event) => {
  event.waitUntil(
    caches.keys()
      .then(keys => Promise.all(
        keys.filter(k => k !== CACHE_VERSION).map(k => caches.delete(k))
      ))
      .then(() => self.clients.claim())
  );
});

// Fetch: cache-first für eigene Files, network-first für externe APIs
self.addEventListener('fetch', (event) => {
  const url = new URL(event.request.url);

  // Externe APIs (OSRM, OpenStreetMap, Wetter) → network-first
  if (url.origin !== self.location.origin) {
    event.respondWith(
      fetch(event.request)
        .then(response => {
          // Erfolgreich: clone & cache für offline
          if (response.ok && (url.hostname.includes('openstreetmap') ||
                              url.hostname.includes('cartocdn') ||
                              url.hostname.includes('unpkg'))) {
            const clone = response.clone();
            caches.open(CACHE_VERSION).then(c => c.put(event.request, clone));
          }
          return response;
        })
        .catch(() => caches.match(event.request))
    );
    return;
  }

  // Eigene Files → cache-first
  event.respondWith(
    caches.match(event.request)
      .then(cached => cached || fetch(event.request)
        .then(response => {
          if (response.ok) {
            const clone = response.clone();
            caches.open(CACHE_VERSION).then(c => c.put(event.request, clone));
          }
          return response;
        })
      )
  );
});