/**
 * Push Notifications Global Plugin
 * Ensures push subscriptions are maintained across all pages
 * This runs on app load to restore push subscriptions for users who already granted permission
 */

export default defineNuxtPlugin(() => {
  // Only run in browser
  if (!process.client) return

  // Run asynchronously without blocking app initialization
  // This ensures the app loads even if push setup fails or takes time
  setTimeout(async () => {
    // Check if push notifications are supported
    if (!('Notification' in window) || !('serviceWorker' in navigator)) {
      console.log('[Push Plugin] Push notifications not supported')
      return
    }

    try {
      // Wait for service worker to be ready
      const registration = await navigator.serviceWorker.ready
      console.log('[Push Plugin] Service Worker ready')

      // Check if we already have notification permission
      if (Notification.permission !== 'granted') {
        console.log('[Push Plugin] No notification permission yet')
        return
      }

      // Check if we have an active push subscription
      const existingSub = await registration.pushManager.getSubscription()

      if (existingSub) {
        console.log('[Push Plugin] ✅ Push subscription active')
        // Subscription exists, we're good
        return
      }

      // Permission granted but no subscription - recreate it
      console.log('[Push Plugin] Permission granted but no subscription, resubscribing...')

      // Get VAPID public key
      const config = useRuntimeConfig()
      const vapidPublicKey = config.public.vapidPublicKey

      if (!vapidPublicKey) {
        console.error('[Push Plugin] VAPID public key not configured')
        return
      }

      // Helper to convert base64 to Uint8Array
      const urlBase64ToUint8Array = (base64String: string) => {
        const padding = '='.repeat((4 - base64String.length % 4) % 4)
        const base64 = (base64String + padding)
          .replace(/-/g, '+')
          .replace(/_/g, '/')

        const rawData = window.atob(base64)
        const outputArray = new Uint8Array(rawData.length)

        for (let i = 0; i < rawData.length; ++i) {
          outputArray[i] = rawData.charCodeAt(i)
        }
        return outputArray
      }

      // Subscribe to push notifications
      const subscription = await registration.pushManager.subscribe({
        userVisibleOnly: true,
        applicationServerKey: urlBase64ToUint8Array(vapidPublicKey)
      })

      console.log('[Push Plugin] ✅ Push subscription created')

      // Save subscription to server
      await $fetch('/api/push/subscribe', {
        method: 'POST',
        body: {
          subscription: subscription.toJSON()
        }
      })

      console.log('[Push Plugin] ✅ Subscription saved to server')
    } catch (error) {
      console.error('[Push Plugin] Error setting up push notifications:', error)
    }
  }, 1000) // Delay 1 second to let app load first
})