/**
 * Service Worker for Push Notifications
 * LocalGreenChain PWA Support
 */

// Cache name versioning
const CACHE_NAME = 'lgc-cache-v1';

// Files to cache for offline support
const STATIC_CACHE = [
  '/',
  '/offline',
  '/icons/icon-192x192.png'
];

// Install event - cache static assets
self.addEventListener('install', (event) => {
  console.log('[SW] Installing service worker...');
  event.waitUntil(
    caches.open(CACHE_NAME)
      .then((cache) => {
        console.log('[SW] Caching static assets');
        return cache.addAll(STATIC_CACHE);
      })
      .catch((error) => {
        console.log('[SW] Failed to cache:', error);
      })
  );
  self.skipWaiting();
});

// Activate event - clean up old caches
self.addEventListener('activate', (event) => {
  console.log('[SW] Activating service worker...');
  event.waitUntil(
    caches.keys().then((cacheNames) => {
      return Promise.all(
        cacheNames
          .filter((name) => name !== CACHE_NAME)
          .map((name) => {
            console.log('[SW] Deleting old cache:', name);
            return caches.delete(name);
          })
      );
    })
  );
  self.clients.claim();
});

// Push event - handle incoming push notifications
self.addEventListener('push', (event) => {
  console.log('[SW] Push notification received');

  let data = {
    title: 'LocalGreenChain',
    body: 'You have a new notification',
    icon: '/icons/icon-192x192.png',
    badge: '/icons/badge-72x72.png',
    data: {}
  };

  if (event.data) {
    try {
      data = { ...data, ...event.data.json() };
    } catch (e) {
      data.body = event.data.text();
    }
  }

  const options = {
    body: data.body,
    icon: data.icon,
    badge: data.badge,
    vibrate: [100, 50, 100],
    data: data.data,
    actions: data.actions || [
      { action: 'view', title: 'View', icon: '/icons/check.png' },
      { action: 'dismiss', title: 'Dismiss', icon: '/icons/close.png' }
    ],
    tag: data.tag || 'lgc-notification',
    renotify: true,
    requireInteraction: data.requireInteraction || false
  };

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

// Notification click event - handle user interaction
self.addEventListener('notificationclick', (event) => {
  console.log('[SW] Notification clicked:', event.action);

  event.notification.close();

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

  // Default action or 'view' action
  const urlToOpen = event.notification.data?.url || '/notifications';

  event.waitUntil(
    clients.matchAll({ type: 'window', includeUncontrolled: true })
      .then((windowClients) => {
        // Check if there's already a window open
        for (const client of windowClients) {
          if (client.url.includes(self.location.origin) && 'focus' in client) {
            client.navigate(urlToOpen);
            return client.focus();
          }
        }
        // Open new window if none found
        if (clients.openWindow) {
          return clients.openWindow(urlToOpen);
        }
      })
  );
});

// Notification close event
self.addEventListener('notificationclose', (event) => {
  console.log('[SW] Notification closed');

  // Track notification dismissal if needed
  const notificationData = event.notification.data;
  if (notificationData?.trackDismissal) {
    // Could send analytics here
  }
});

// Fetch event - network-first with cache fallback
self.addEventListener('fetch', (event) => {
  // Skip non-GET requests
  if (event.request.method !== 'GET') return;

  // Skip API requests
  if (event.request.url.includes('/api/')) return;

  event.respondWith(
    fetch(event.request)
      .then((response) => {
        // Clone the response for caching
        const responseClone = response.clone();

        caches.open(CACHE_NAME).then((cache) => {
          cache.put(event.request, responseClone);
        });

        return response;
      })
      .catch(() => {
        // Return cached response if available
        return caches.match(event.request)
          .then((cachedResponse) => {
            if (cachedResponse) {
              return cachedResponse;
            }
            // Return offline page for navigation requests
            if (event.request.mode === 'navigate') {
              return caches.match('/offline');
            }
            return new Response('Offline', { status: 503 });
          });
      })
  );
});

// Message event - handle messages from client
self.addEventListener('message', (event) => {
  console.log('[SW] Message received:', event.data);

  if (event.data && event.data.type === 'SKIP_WAITING') {
    self.skipWaiting();
  }

  if (event.data && event.data.type === 'GET_VERSION') {
    event.ports[0].postMessage({ version: CACHE_NAME });
  }
});

// Periodic sync for background updates (if supported)
self.addEventListener('periodicsync', (event) => {
  if (event.tag === 'check-notifications') {
    event.waitUntil(checkForNewNotifications());
  }
});

async function checkForNewNotifications() {
  try {
    const response = await fetch('/api/notifications?unreadOnly=true&limit=1');
    const data = await response.json();

    if (data.success && data.data.unreadCount > 0) {
      self.registration.showNotification('LocalGreenChain', {
        body: `You have ${data.data.unreadCount} unread notification(s)`,
        icon: '/icons/icon-192x192.png',
        badge: '/icons/badge-72x72.png'
      });
    }
  } catch (error) {
    console.log('[SW] Failed to check notifications:', error);
  }
}

console.log('[SW] Service worker loaded');