// Service Worker for LittleShop Admin PWA
const CACHE_NAME = 'littleshop-admin-v2';
const urlsToCache = [
  '/Admin/Dashboard',
  '/manifest.json',
  '/lib/bootstrap/css/bootstrap.min.css',
  '/lib/fontawesome/css/all.min.css',
  '/css/modern-admin.css',
  '/css/mobile-admin.css',
  '/lib/jquery/jquery.min.js',
  '/lib/bootstrap/js/bootstrap.bundle.min.js',
  '/js/pwa.js',
  '/js/notifications.js',
  '/icons/icon-192x192.png',
  '/icons/icon-512x512.png'
];

// Install event - cache essential files
self.addEventListener('install', event => {
  event.waitUntil(
    caches.open(CACHE_NAME)
      .then(cache => {
        console.log('Service Worker: Caching essential files');
        return cache.addAll(urlsToCache);
      })
      .then(() => self.skipWaiting())
  );
});

// Activate event - clean up old caches
self.addEventListener('activate', event => {
  event.waitUntil(
    caches.keys().then(cacheNames => {
      return Promise.all(
        cacheNames
          .filter(cacheName => cacheName !== CACHE_NAME)
          .map(cacheName => caches.delete(cacheName))
      );
    }).then(() => self.clients.claim())
  );
});

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

  // Skip API requests from cache
  if (event.request.url.includes('/api/')) {
    event.respondWith(
      fetch(event.request)
        .catch(() => {
          // If offline and it's an API request, return offline message
          return new Response(
            JSON.stringify({ error: 'Offline - Please check your connection' }),
            { headers: { 'Content-Type': 'application/json' } }
          );
        })
    );
    return;
  }

  // For everything else, try network first, then cache
  event.respondWith(
    fetch(event.request)
      .then(response => {
        // Don't cache if not a successful response
        if (!response || response.status !== 200 || response.type === 'error') {
          return response;
        }

        // Clone the response as it can only be consumed once
        const responseToCache = response.clone();

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

        return response;
      })
      .catch(() => {
        // If network fails, try cache
        return caches.match(event.request)
          .then(response => {
            if (response) {
              return response;
            }
            // If not in cache, return offline page for navigation requests
            if (event.request.mode === 'navigate') {
              return caches.match('/offline.html');
            }
          });
      })
  );
});

// Push notification event
self.addEventListener('push', event => {
  console.log('Push notification received:', event);

  let notificationData = {
    title: 'LittleShop Admin',
    body: 'You have a new notification',
    icon: '/icons/icon-192x192.png',
    badge: '/icons/icon-96x96.png',
    vibrate: [200, 100, 200],
    data: {
      dateOfArrival: Date.now(),
      primaryKey: 1
    }
  };

  if (event.data) {
    try {
      const data = event.data.json();
      notificationData = {
        title: data.title || notificationData.title,
        body: data.body || notificationData.body,
        icon: data.icon || notificationData.icon,
        badge: data.badge || notificationData.badge,
        vibrate: data.vibrate || notificationData.vibrate,
        data: data.data || notificationData.data,
        tag: data.tag,
        requireInteraction: data.requireInteraction || false,
        actions: data.actions || []
      };
    } catch (e) {
      console.error('Error parsing push data:', e);
    }
  }

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

// Notification click event
self.addEventListener('notificationclick', event => {
  console.log('Notification clicked:', event);
  event.notification.close();

  // Handle action clicks
  if (event.action) {
    switch (event.action) {
      case 'view':
        clients.openWindow(event.notification.data.url || '/Admin/Dashboard');
        break;
      case 'dismiss':
        // Just close the notification
        break;
      default:
        clients.openWindow('/Admin/Dashboard');
    }
    return;
  }

  // Default click - open the app or focus if already open
  event.waitUntil(
    clients.matchAll({ type: 'window', includeUncontrolled: true })
      .then(clientList => {
        // Check if there's already a window open
        for (let client of clientList) {
          if (client.url.includes('/Admin/') && 'focus' in client) {
            return client.focus();
          }
        }
        // If no window is open, open a new one
        if (clients.openWindow) {
          return clients.openWindow(event.notification.data?.url || '/Admin/Dashboard');
        }
      })
  );
});

// Background sync for offline actions
self.addEventListener('sync', event => {
  console.log('Background sync triggered:', event.tag);

  if (event.tag === 'sync-orders') {
    event.waitUntil(syncOrders());
  } else if (event.tag === 'sync-products') {
    event.waitUntil(syncProducts());
  }
});

// Sync orders when back online
async function syncOrders() {
  try {
    // Get any pending orders from IndexedDB
    const db = await openDB();
    const tx = db.transaction('pending-orders', 'readonly');
    const store = tx.objectStore('pending-orders');
    const pendingOrders = await store.getAll();

    for (const order of pendingOrders) {
      await fetch('/api/orders', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(order)
      });

      // Remove from pending after successful sync
      const deleteTx = db.transaction('pending-orders', 'readwrite');
      await deleteTx.objectStore('pending-orders').delete(order.id);
    }

    // Show notification of successful sync
    self.registration.showNotification('Orders Synced', {
      body: `${pendingOrders.length} orders synchronized successfully`,
      icon: '/icons/icon-192x192.png'
    });
  } catch (error) {
    console.error('Error syncing orders:', error);
  }
}

// Sync products when back online
async function syncProducts() {
  try {
    const response = await fetch('/api/catalog/products');
    if (response.ok) {
      const products = await response.json();

      // Update cached products
      const cache = await caches.open(CACHE_NAME);
      await cache.put('/api/catalog/products', new Response(JSON.stringify(products)));

      console.log('Products synced successfully');
    }
  } catch (error) {
    console.error('Error syncing products:', error);
  }
}

// Helper function to open IndexedDB
function openDB() {
  return new Promise((resolve, reject) => {
    const request = indexedDB.open('LittleShopDB', 1);

    request.onerror = () => reject(request.error);
    request.onsuccess = () => resolve(request.result);

    request.onupgradeneeded = event => {
      const db = event.target.result;

      if (!db.objectStoreNames.contains('pending-orders')) {
        db.createObjectStore('pending-orders', { keyPath: 'id', autoIncrement: true });
      }

      if (!db.objectStoreNames.contains('pending-products')) {
        db.createObjectStore('pending-products', { keyPath: 'id', autoIncrement: true });
      }
    };
  });
}

// Message event for communication with the app
self.addEventListener('message', event => {
  console.log('Service Worker received message:', event.data);

  if (event.data.action === 'skipWaiting') {
    self.skipWaiting();
  }

  if (event.data.action === 'clearCache') {
    event.waitUntil(
      caches.keys().then(cacheNames => {
        return Promise.all(
          cacheNames.map(cacheName => caches.delete(cacheName))
        );
      }).then(() => {
        event.ports[0].postMessage({ success: true });
      })
    );
  }
});

console.log('Service Worker loaded successfully');