Trouble with local notification in AppDelegate - ios

Question

I have an alarm clock app. It has 2 VC. VC1 is a menu VC that linked with VC2. In VC2 there's setting of alarm clock. So I have troubles with getting local notifications.
For example, if I set Alarm Clock on VC2 then I move to VC1 and then go to Home Screen I will receive a notification on the top of the screen. After clicking on notification I will move to VC1 and I will get a message. But I will get an error 'Could not cast value of type 'MyApp.VC1' (0x10ee97730) to 'MyApp.VC2' (0x10ee96bd0)'. If I set Alarm Clock on VC2 then I move to Home Screen I will receive a notification on the top of the screen. After clicking on notification I will move to VC2 and I will get a message and everything will be fine.
Other problem is setting Alarm clock on VC2 and moving to VC1 without moving to Home Screen. When time will I come my app just crashing with same error 'Could not cast value of type 'MyApp.VC1' (0x10ee97730) to 'MyApp.VC2' (0x10ee96bd0)'
func application(_ application: UIApplication, didReceive notification: UILocalNotification) {
let storageController = UIAlertController(title: "Alarm", message: nil, preferredStyle: .alert)
var soundName: String = ""
var index: Int = -1
if let userInfo = notification.userInfo {
soundName = userInfo["soundName"] as! String
index = userInfo["index"] as! Int
}
playSound(soundName)
let stopOption = UIAlertAction(title: "OK", style: .default) {
(action:UIAlertAction)->Void in self.audioPlayer?.stop()
let mainVC = self.window?.visibleViewController as! MainAlarmViewController
storageController.addAction(stopOption)
(self.window?.visibleViewController as! MainAlarmViewController).present(storageController, animated: true, completion: nil)
}
Does anybody know how to resolve it?
When I getting an error I see highlight of this line:
(self.window?.visibleViewController as! MainAlarmViewController).present(storageController, animated: true, completion: nil)
Thank you so much!
P.S. Maybe is it possible to make a notification on the top of a screen with a link to VC2 when app in foreground or app in VC1?
Also sometimes I'm getting a message 'Warning: Attempt to present on whose view is not in the window hierarchy!'

Answer 1

Replace this line
(self.window?.visibleViewController as! MainAlarmViewController).present(storageController, animated: true, completion: nil)
with following code
if let viewController = self.window?.visibleViewController {
if viewController is MainAlarmViewController {
// view controller is MainAlarmViewController
} else {
// view controller is not MainAlarmViewController
}
viewController.present(storageController, animated: true, completion: nil)
} else {
print("Something wrong. Window can't provide visible view controller")
}