const MVLOG_CACHE_PREFIX = 'mvlog-pwa-';
const MVLOG_CACHE_VERSION = 'mvlog-pwa-v6';
const APP_SHELL_CACHE = `${MVLOG_CACHE_VERSION}-app-shell`;
const RUNTIME_CACHE = `${MVLOG_CACHE_VERSION}-runtime`;

const APP_SHELL_URLS = [
  '/',
  '/offline.html',
  '/style.css',
  '/js/map_lightbox.js',
  '/assets/fonts/BebasNeue-Regular.ttf',
  '/assets/fonts/IBMPlexSans-SemiBold.ttf',
  '/assets/fonts/NotoSans-Bold.ttf',
  '/assets/img/background.jpg',
  '/assets/img/moto_travel.png',
  '/assets/img/pwa-icon-192.png',
  '/assets/img/pwa-icon-512.png',
  '/assets/img/pwa-maskable-512.png',
  '/assets/img/apple-touch-icon.png',
  '/manifest.json'
];

self.addEventListener('install', event => {
  event.waitUntil((async () => {
    const cache = await caches.open(APP_SHELL_CACHE);
    await Promise.all(APP_SHELL_URLS.map(url =>
      cache.add(new Request(url, { cache: 'reload' })).catch(() => undefined)
    ));
    await self.skipWaiting();
  })());
});

self.addEventListener('activate', event => {
  event.waitUntil((async () => {
    const names = await caches.keys();
    await Promise.all(names.map(name => {
      if (name.startsWith(MVLOG_CACHE_PREFIX) && ![APP_SHELL_CACHE, RUNTIME_CACHE].includes(name)) {
        return caches.delete(name);
      }
      return undefined;
    }));
    await clients.claim();
  })());
});

function shouldBypassFetch(request, url) {
  if (request.method !== 'GET') return true;
  if (!['http:', 'https:'].includes(url.protocol)) return true;
  if (url.origin !== self.location.origin) return false;

  const path = url.pathname;
  if (path === '/admin.php' || path === '/login.php' || path === '/logout.php') return true;
  if (path === '/push_config.php' || path === '/push_subscribe.php' || path === '/job_status.php') return true;
  if (path.startsWith('/api/') || path.startsWith('/lib/') || path.startsWith('/cache/') || path.startsWith('/in-dir/')) return true;
  if (path.startsWith('/out-dir/') && /\.(mp4|m4v|mov|webm)$/i.test(path)) return true;
  if (/\.(mp4|m4v|mov|webm)$/i.test(path)) return true;

  return false;
}

function isStaticAsset(url) {
  if (url.origin !== self.location.origin) return false;
  const path = url.pathname;
  return path === '/style.css'
    || path === '/manifest.json'
    || path === '/offline.html'
    || path.startsWith('/assets/')
    || path.startsWith('/js/');
}

async function networkFirstNavigation(request) {
  try {
    const response = await fetch(request);
    if (response && response.ok) {
      const cache = await caches.open(RUNTIME_CACHE);
      cache.put(request, response.clone()).catch(() => undefined);
    }
    return response;
  } catch (error) {
    const exact = await caches.match(request);
    if (exact) return exact;
    const offline = await caches.match('/offline.html');
    if (offline) return offline;
    const home = await caches.match('/');
    if (home) return home;
    return new Response('Offline', { status: 503, headers: { 'Content-Type': 'text/plain; charset=utf-8' } });
  }
}

async function staleWhileRevalidate(request) {
  const cached = await caches.match(request);
  const cache = await caches.open(RUNTIME_CACHE);
  const network = fetch(request).then(response => {
    if (response && response.ok) {
      cache.put(request, response.clone()).catch(() => undefined);
    }
    return response;
  }).catch(() => cached);
  return cached || network;
}

self.addEventListener('fetch', event => {
  const request = event.request;
  const url = new URL(request.url);
  if (shouldBypassFetch(request, url)) return;

  if (request.mode === 'navigate') {
    event.respondWith(networkFirstNavigation(request));
    return;
  }

  if (isStaticAsset(url)) {
    event.respondWith(staleWhileRevalidate(request));
  }
});

self.addEventListener('push', event => {
  let data = {};
  try { data = event.data ? event.data.json() : {}; } catch (e) { data = { title: 'MVLog', body: event.data ? event.data.text() : 'New article @ MVLog!' }; }
  const title = data.title || 'MVLog';
  const options = {
    body: data.body || 'New article @ MVLog!',
    icon: 'assets/img/moto_travel.png',
    badge: 'assets/img/moto_travel.png',
    data: { url: data.url || './' },
    tag: data.tag || 'mvlog-new-video',
    renotify: true
  };
  event.waitUntil(self.registration.showNotification(title, options));
});

self.addEventListener('notificationclick', event => {
  event.notification.close();
  const url = event.notification.data && event.notification.data.url ? event.notification.data.url : './';
  event.waitUntil(clients.matchAll({ type: 'window', includeUncontrolled: true }).then(clientList => {
    for (const client of clientList) {
      if (client.url === url && 'focus' in client) return client.focus();
    }
    return clients.openWindow(url);
  }));
});