/**
 * Tractatus Service Worker - Minimal Version
 * ONLY for version checking and update notifications
 * NO aggressive caching (rely on HTTP caching instead)
 */

const CACHE_VERSION = '0.1.3';

// Install immediately, don't cache anything
self.addEventListener('install', (event) => {
  console.log('[Service Worker] Installing version:', CACHE_VERSION);
  self.skipWaiting(); // Activate immediately
});

// Activate and clean up old caches
self.addEventListener('activate', (event) => {
  console.log('[Service Worker] Activating version:', CACHE_VERSION);
  event.waitUntil(
    caches.keys().then((cacheNames) => {
      // Delete ALL caches - we're not using SW caching anymore
      return Promise.all(
        cacheNames.map((cacheName) => {
          console.log('[Service Worker] Deleting cache:', cacheName);
          return caches.delete(cacheName);
        })
      );
    }).then(() => {
      return self.clients.claim(); // Take control immediately
    })
  );
});

// Fetch event - DON'T intercept, let browser handle normally
self.addEventListener('fetch', (event) => {
  // Do nothing - let requests go directly to network
  // This allows nginx caching and ?v= parameters to work properly
  return;
});

// Version check function
async function checkVersion() {
  try {
    const response = await fetch('/version.json', { cache: 'no-store' });
    const serverVersion = await response.json();
    
    return {
      currentVersion: CACHE_VERSION,
      serverVersion: serverVersion.version,
      updateAvailable: CACHE_VERSION !== serverVersion.version,
      forceUpdate: serverVersion.forceUpdate,
      changelog: serverVersion.changelog
    };
  } catch (error) {
    console.error('[Service Worker] Version check failed:', error);
    return {
      currentVersion: CACHE_VERSION,
      serverVersion: null,
      updateAvailable: false,
      error: true
    };
  }
}

// Message handler
self.addEventListener('message', (event) => {
  if (event.data.type === 'CHECK_VERSION') {
    checkVersion().then((versionInfo) => {
      event.ports[0].postMessage({
        type: 'VERSION_INFO',
        ...versionInfo
      });
    });
  }
  
  if (event.data.type === 'SKIP_WAITING') {
    self.skipWaiting();
  }
});