changing the ui when the use logs in/out

NavigationAuthController.swift

import Foundation
import Combine

class NavigationAuthController: ObservableObject {
    
    @Published var selection: Int = 1
    @Published var detailIsShown: Bool = false
    @Published var alertIsShown: Bool = false
    
    var subscriptions = Set<AnyCancellable>()
    
    init() {
        AuthSubscriptionManager.shared.$firebaseUser
            .removeDuplicates()
            .sink { (user) in
                print("--- new user -- close open docs")
                self.resetAll()
        }.store(in: &subscriptions)
    }
    
    func resetAll() {
        self.selection = 0
        self.detailIsShown = false
        self.alertIsShown = false
    }
}


 //using singelton to have one Authentication instance for all open windows
import FirebaseAuth

class AuthSubscriptionManager: NSObject, ObservableObject {
    static let shared = AuthSubscriptionManager()
    @Published var firebaseUser: User?
    init() {
        //do Firebase init and login
    }
}