/*
 * Copyright 2017 Google
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import UIKit
import FirebaseCore
import FirebaseMessaging
import UserNotifications

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

  var window: UIWindow?

  static let isWithinUnitTest: Bool = {
    if let testClass = NSClassFromString("XCTestCase") {
      return true
    } else {
      return false
    }
  }()

  static var hasPresentedInvalidServiceInfoPlistAlert = false

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    guard !AppDelegate.isWithinUnitTest else {
      // During unit tests, we don't want to initialize Firebase, since by default we want to able
      // to run unit tests without requiring a non-dummy GoogleService-Info.plist file
      return true
    }

    guard SampleAppUtilities.appContainsRealServiceInfoPlist() else {
      // We can't run because the GoogleService-Info.plist file is likely the dummy file which needs
      // to be replaced with a real one, or somehow the file has been removed from the app bundle.
      // See: https://github.com/firebase/firebase-ios-sdk/
      // We'll present a friendly alert when the app becomes active.
      return true
    }

    FirebaseApp.configure()
    Messaging.messaging().delegate = self
    Messaging.messaging().shouldEstablishDirectChannel = true
    // Just for logging to the console when we establish/tear down our socket connection.
    listenForDirectChannelStateChanges();

    NotificationsController.configure()

    if #available(iOS 8.0, *) {
      // Always register for remote notifications. This will not show a prompt to the user, as by
      // default it will provision silent notifications. We can use UNUserNotificationCenter to
      // request authorization for user-facing notifications.
      application.registerForRemoteNotifications()
    } else {
      // iOS 7 didn't differentiate between user-facing and other notifications, so we should just
      // register for remote notifications
      NotificationsController.shared.registerForUserFacingNotificationsFor(application)
    }
    return true
  }

  func application(_ application: UIApplication,
                   didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    print("APNS Token: \(deviceToken.hexByteString)")
    NotificationCenter.default.post(name: APNSTokenReceivedNotification, object: nil)
    if #available(iOS 8.0, *) {
    } else {
      // On iOS 7, receiving a device token also means our user notifications were granted, so fire
      // the notification to update our user notifications UI
      NotificationCenter.default.post(name: UserNotificationsChangedNotification, object: nil)
    }
  }

  func application(_ application: UIApplication,
                   didRegister notificationSettings: UIUserNotificationSettings) {
    NotificationCenter.default.post(name: UserNotificationsChangedNotification, object: nil)
  }

  func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
    print("application:didReceiveRemoteNotification:fetchCompletionHandler: called, with notification:")
    print("\(userInfo.jsonString ?? "{}")")
    completionHandler(.newData)
  }

  func applicationDidBecomeActive(_ application: UIApplication) {
    // If the app didn't start property due to an invalid GoogleService-Info.plist file, show an
    // alert to the developer.
    if !SampleAppUtilities.appContainsRealServiceInfoPlist() &&
       !AppDelegate.hasPresentedInvalidServiceInfoPlistAlert {
      if let vc = window?.rootViewController {
        SampleAppUtilities.presentAlertForInvalidServiceInfoPlistFrom(vc)
        AppDelegate.hasPresentedInvalidServiceInfoPlistAlert = true
      }
    }
  }
}

extension AppDelegate: MessagingDelegate {
  // FCM tokens are always provided here. It is called generally during app start, but may be called
  // more than once, if the token is invalidated or updated. This is the right spot to upload this
  // token to your application server, or to subscribe to any topics.
  func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String) {
    if let token = Messaging.messaging().fcmToken {
      print("FCM Token: \(token)")
    } else {
      print("FCM Token: nil")
    }
  }

  // Direct channel data messages are delivered here, on iOS 10.0+.
  // The `shouldEstablishDirectChannel` property should be be set to |true| before data messages can
  // arrive.
  func messaging(_ messaging: Messaging, didReceive remoteMessage: MessagingRemoteMessage) {
    // Convert to pretty-print JSON
    guard let prettyPrinted = remoteMessage.appData.jsonString else {
      print("Received direct channel message, but could not parse as JSON: \(remoteMessage.appData)")
      return
    }
    print("Received direct channel message:\n\(prettyPrinted)")
  }
}

extension AppDelegate {
    func listenForDirectChannelStateChanges() {
        NotificationCenter.default.addObserver(self, selector: #selector(onMessagingDirectChannelStateChanged(_:)), name: .MessagingConnectionStateChanged, object: nil)
    }

    func onMessagingDirectChannelStateChanged(_ notification: Notification) {
        print("FCM Direct Channel Established: \(Messaging.messaging().isDirectChannelEstablished)")
    }
}

extension Dictionary {
  /// Utility method for printing Dictionaries as pretty-printed JSON.
  var jsonString: String? {
    if let jsonData = try? JSONSerialization.data(withJSONObject: self, options: [.prettyPrinted]),
       let jsonString = String(data: jsonData, encoding: .utf8) {
      return jsonString
    }
    return nil
  }
}