10082020-iOS-PasswordManager-solution.swift

import UIKit

protocol SettingViewControllerProtocol {
    var isPasswordProtected: Bool { get set }
    
    func validate(password: String?, confirmPassword: String?, from: SettingViewController) -> Bool
}

class SettingViewController: UIViewController {

    var delegate: SettingViewControllerProtocol!
    
    @IBOutlet weak var passwordTextField: UITextField!
    @IBOutlet weak var confirmPasswordTextField: UITextField!
    
    @IBOutlet weak var isPasswordProtected: UISwitch! {
        didSet {
            isPasswordProtected.isOn = delegate.isPasswordProtected
        }
    }
}

extension SettingViewController {
    
    @IBAction func passwordProtect(_ sender: UIButton) {
        
        let validPassword = delegate.validate(password: passwordTextField.text,
                                              confirmPassword: confirmPasswordTextField.text,
                                              from: self)
        guard validPassword else { return }
        
        delegate.isPasswordProtected = true
    }
    
    @IBAction func togglePasswordProtection(_ sender: UISwitch) {
        delegate.isPasswordProtected = !isPasswordProtected.isOn
    }
}