// Service Worker for PWA and Push Notifications
// Handles offline support, caching, and VAPID Web Push

const CACHE_NAME = 'logship-erp-v1'
const OFFLINE_URL = '/'

self.addEventListener('install', (event) => {
  console.log('[SW] Service Worker installed')

  event.waitUntil(
    caches.open(CACHE_NAME).then((cache) => {
      console.log('[SW] Opened cache')
      // Pre-cache essential assets
      return cache.addAll([
        OFFLINE_URL,
        '/favicon.ico',
        '/manifest.json'
      ]).catch((error) => {
        console.warn('[SW] Pre-caching failed:', error)
      })
    }).then(() => self.skipWaiting())
  )
})

self.addEventListener('activate', (event) => {
  console.log('[SW] Service Worker activated')

  event.waitUntil(
    caches.keys().then((cacheNames) => {
      return Promise.all(
        cacheNames.map((cacheName) => {
          if (cacheName !== CACHE_NAME) {
            console.log('[SW] Deleting old cache:', cacheName)
            return caches.delete(cacheName)
          }
        })
      )
    }).then(() => clients.claim())
  )
})

// Keep service worker alive and responsive
// This helps ensure push notifications work in background
self.addEventListener('message', (event) => {
  if (event.data && event.data.type === 'SKIP_WAITING') {
    self.skipWaiting()
  }

  // Respond to keepalive pings
  if (event.data && event.data.type === 'PING') {
    event.ports[0].postMessage({ type: 'PONG' })
  }
})

// Handle incoming push notifications from server
// CRITICAL: This must show a notification synchronously for Android to work in background
self.addEventListener('push', (event) => {
  console.log('[SW] Push event received')

  // Parse notification data
  let data
  try {
    data = event.data ? event.data.json() : {}
  } catch (e) {
    console.error('[SW] Failed to parse push data:', e)
    data = {}
  }

  // Ensure we have required fields
  const title = data.title || '🔔 New Order'
  const body = data.body || 'You have a new update'

  // Minimal notification options for maximum compatibility
  const options = {
    body: body,
    icon: '/favicon.ico',
    badge: '/favicon.ico',
    tag: 'order-' + Date.now(),
    data: {
      url: data.url || '/sales/orders'
    }
  }

  // MUST call showNotification synchronously within push event
  // This is critical for Android background delivery
  event.waitUntil(
    self.registration.showNotification(title, options)
  )
})

// Handle notification click
self.addEventListener('notificationclick', (event) => {
  console.log('[SW] Notification clicked', event.action)
  event.notification.close()

  // Handle different actions
  const action = event.action
  const url = event.notification.data?.url || '/sales/orders'

  if (action === 'dismiss') {
    // Just close notification
    return
  }

  // Focus the window or open a new one
  event.waitUntil(
    clients.matchAll({ type: 'window', includeUncontrolled: true }).then((clientList) => {
      // Check if there's already a window open
      for (let i = 0; i < clientList.length; i++) {
        const client = clientList[i]
        if (client.url.includes(url) && 'focus' in client) {
          return client.focus()
        }
      }
      // If no window is open, open a new one
      if (clients.openWindow) {
        return clients.openWindow(url)
      }
    })
  )
})