import UIKit
import Firebase
import FirebaseMessaging
import UserNotifications

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate, FIRMessagingDelegate {

var window: UIWindow?


func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    FIRApp.configure()

    if #available(iOS 10.0, *) {
        let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
        UNUserNotificationCenter.current().requestAuthorization(
            options: authOptions,
            completionHandler: {_, _ in })

        // For iOS 10 display notification (sent via APNS)
        UNUserNotificationCenter.current().delegate = self
        // For iOS 10 data message (sent via FCM)
        FIRMessaging.messaging().remoteMessageDelegate = self

    } else {
        let settings: UIUserNotificationSettings =
            UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
        application.registerUserNotificationSettings(settings)
    }

    application.registerForRemoteNotifications()

    return true
}



func applicationReceivedRemoteMessage(_ remoteMessage: FIRMessagingRemoteMessage) {
    print("applicationReceivedRemoteMessage")
}



func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    if let refreshedToken = FIRInstanceID.instanceID().token() {
        print("InstanceID token: (refreshedToken)")
        FIRMessaging.messaging().subscribe(toTopic: "/topics/global")
    }
}



@available(iOS 10.0, *)
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
    completionHandler(UNNotificationPresentationOptions.alert)
}



func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
    // If you are receiving a notification message while your app is in the background,
    // this callback will not be fired till the user taps on the notification launching the application.
}



func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
    // If you are receiving a notification message while your app is in the background,
    // this callback will not be fired till the user taps on the notification launching the application.
}

if Messaging.messaging().fcmToken != nil {
    Messaging.messaging().subscribe(toTopic: “foo”)
}

func messaging(_ messaging: Messaging, didRefreshRegistrationToken fcmToken: String) {
    Messaging.messaging().subscribe(toTopic: “foo”)
}