/* ObsiGate — Service Worker (PWA offline + push)
 * Version: 4 (2026-09-12)
 *
 * Caching policy (fixes stale-asset loads behind Cloudflare / mobile):
 *   - navigations & code (HTML / JS / CSS / manifest) : NETWORK-FIRST
 *   - API                                              : network-first (+ offline)
 *   - other static (images, fonts…)                    : stale-while-revalidate
 *
 * Assets are served without content hashes. The previous "cache-first with a
 * fixed cache name" kept an old build forever on mobile: flushing the browser
 * cache or Cloudflare does NOT clear the Service Worker Cache Storage, which is
 * a separate store. Bumping SW_VERSION invalidates it on every release.
 */
const SW_VERSION = 'v24';
const CODE_CACHE = `obsigate-code-${SW_VERSION}`;
const RUNTIME_CACHE = `obsigate-runtime-${SW_VERSION}`;
const API_CACHE = `obsigate-api-${SW_VERSION}`;
const OFFLINE_URL = '/index.html';

// Core shell precached for offline use. Paths MUST be the real served URLs
// (the app is mounted under /static, not /frontend).
const PRECACHE_URLS = [
  '/',
  OFFLINE_URL,
  '/manifest.json',
  '/static/style.css',
  '/static/js/app.js',
  '/static/js/state.js',
  '/static/js/auth.js',
  '/static/js/ui.js',
  '/static/js/sidebar.js',
  '/static/js/viewer.js',
  '/static/js/search.js',
  '/static/js/config.js',
  '/static/js/utils.js',
  '/static/js/i18n.js',
  '/static/js/offline.js',
  '/static/js/offline-db.js',
  '/static/js/sync.js',
  '/static/js/legacy.js',
  '/static/js/collab.js',
];

// ── Install: precache the shell, then activate immediately ──────────────────
self.addEventListener('install', (event) => {
  event.waitUntil((async () => {
    const cache = await caches.open(CODE_CACHE);
    // Precache individually so a single 404 never aborts the whole install.
    await Promise.all(PRECACHE_URLS.map((url) =>
      cache.add(new Request(url, { cache: 'reload' })).catch(() => {})
    ));
    await self.skipWaiting();
  })());
});

// ── Activate: drop every previous cache (old fixed-name caches included) ────
self.addEventListener('activate', (event) => {
  event.waitUntil((async () => {
    const keep = new Set([CODE_CACHE, RUNTIME_CACHE, API_CACHE]);
    const names = await caches.keys();
    await Promise.all(names.map((name) => (keep.has(name) ? null : caches.delete(name))));
    await self.clients.claim();
  })());
});

function isCodeRequest(url, request) {
  if (request.mode === 'navigate') return true;
  if (url.pathname === '/sw.js' || url.pathname === '/manifest.json') return true;
  if (url.pathname.startsWith('/static/js/')) return true;
  return /\.(?:js|mjs|css|html|json)$/i.test(url.pathname);
}

async function networkFirst(request, cacheName, makeFallback) {
  try {
    const response = await fetch(request);
    if (response && response.ok && response.type === 'basic') {
      const cache = await caches.open(cacheName);
      cache.put(request, response.clone());
    }
    return response;
  } catch (error) {
    const cached = await caches.match(request);
    if (cached) return cached;
    if (makeFallback) return makeFallback();
    return new Response('Offline', { status: 503 });
  }
}

async function staleWhileRevalidate(request, cacheName) {
  const cache = await caches.open(cacheName);
  const cached = await cache.match(request);
  const fresh = fetch(request).then((response) => {
    if (response && response.ok && response.type === 'basic') {
      cache.put(request, response.clone());
    }
    return response;
  }).catch(() => null);
  if (cached) return cached;
  return (await fresh) || new Response('Offline', { status: 503 });
}

// ── Fetch routing ───────────────────────────────────────────────────────────
self.addEventListener('fetch', (event) => {
  const { request } = event;
  if (request.method !== 'GET') return;

  const url = new URL(request.url);
  if (url.origin !== self.location.origin) return;
  // Let the browser handle range requests (PDF/streamed media) directly.
  if (request.headers.has('range')) return;

  // Streamed audio/video is large and range-driven — never cache it
  // (roadmap #109-E2). Image thumbnails (/api/media/{vault}/thumb) stay cached.
  if (url.pathname.startsWith('/api/media/') && !url.pathname.endsWith('/thumb')) {
    event.respondWith(fetch(request));
    return;
  }

  if (url.pathname.startsWith('/api/')) {
    event.respondWith(networkFirst(request, API_CACHE, () =>
      new Response(JSON.stringify({ error: 'Offline' }), {
        status: 503,
        headers: { 'Content-Type': 'application/json' },
      })
    ));
    return;
  }

  if (isCodeRequest(url, request)) {
    event.respondWith(networkFirst(request, CODE_CACHE, async () => {
      const cached = await caches.match(OFFLINE_URL);
      return cached || new Response('<h1>Hors ligne</h1>', {
        status: 503,
        headers: { 'Content-Type': 'text/html; charset=utf-8' },
      });
    }));
    return;
  }

  event.respondWith(staleWhileRevalidate(request, RUNTIME_CACHE));
});

// ── Message from the page ───────────────────────────────────────────────────
self.addEventListener('message', (event) => {
  if (event.data?.type === 'SKIP_WAITING') self.skipWaiting();
});

// ── Push Event: Display notification ───────────────────────────────────────
self.addEventListener('push', (event) => {
  if (!event.data) return;

  const data = event.data.json();
  const options = {
    body: data.body || data.message || 'Nouvelle notification',
    icon: '/static/icon-192.png',
    badge: '/static/badge-72.png',
    vibrate: [200, 100, 200],
    tag: data.tag || 'obsigate-notification',
    renotify: true,
    data: data.data || {},
    actions: [
      { action: 'open', title: 'Ouvrir' },
      { action: 'dismiss', title: 'Ignorer' }
    ],
    requireInteraction: false
  };

  event.waitUntil(
    self.registration.showNotification(data.title || 'ObsiGate', options)
  );
});

// ── Notification Click: Open the app ───────────────────────────────────────
self.addEventListener('notificationclick', (event) => {
  event.notification.close();

  if (event.action === 'dismiss') return;

  const urlToOpen = event.notification.data?.url || '/';

  event.waitUntil(
    clients.matchAll({ type: 'window', includeUncontrolled: true }).then((clientList) => {
      for (const client of clientList) {
        if (client.url.includes(urlToOpen) && 'focus' in client) {
          return client.focus();
        }
      }
      if (clients.openWindow) {
        return clients.openWindow(urlToOpen);
      }
    })
  );
});

self.addEventListener('notificationclose', (event) => {
  console.log('[SW] Notification closed:', event.notification.tag);
});

// ── Background Sync: Periodic index sync ──────────────────────────────────
self.addEventListener('sync', (event) => {
  if (event.tag === 'sync-file-index') {
    event.waitUntil(syncFileIndex());
  }
});

async function syncFileIndex() {
  try {
    const resp = await fetch('/api/search/advanced?q=**&vault=all&limit=200');
    if (resp.ok) {
      const data = await resp.json();
      const files = (data.results || []).map((r) => ({
        vault: r.vault,
        path: r.path,
        title: r.title,
        tags: r.tags || [],
        snippet: r.snippet || '',
        modified: r.modified || ''
      }));

      const clients = await self.clients.matchAll();
      clients.forEach((client) => client.postMessage({
        type: 'OFFLINE_INDEX_SYNC',
        files
      }));
    }
  } catch (e) {
    console.warn('[SW] Background sync failed:', e);
  }
}

self.addEventListener('periodicsync', (event) => {
  if (event.tag === 'periodic-index-sync') {
    event.waitUntil(syncFileIndex());
  }
});