private let locationManager = CLLocationManager()

private let allowButton = UIButton(type: .system)

private let skipButton = UIButton(type: .system)

private let illustrationView = UIImageView(image: UIImage(named: "onboarding_illustration"))

private let titleImageView = UIImageView(image: UIImage(named: "onboarding_title"))

private let descriptionImageView1 = UIImageView(image: UIImage(named: "onboarding_desc_1"))

private let descriptionImageView2 = UIImageView(image: UIImage(named: "onboarding_desc_2"))

override func viewDidLoad() {

super.viewDidLoad()

view.backgroundColor = UIColor(red: 0.13, green: 0.31, blue: 0.78, alpha: 1)

locationManager.delegate = self

setupUI()

}

private func setupUI() {

[illustrationView, titleImageView, descriptionImageView1, descriptionImageView2].forEach {

$0.translatesAutoresizingMaskIntoConstraints = false

$0.contentMode = .scaleAspectFit

view.addSubview($0)

}

allowButton.configuration = .plain()

allowButton.setImage(UIImage(named: "onboarding_allow_button"), for: .normal)

allowButton.tintColor = .clear

allowButton.adjustsImageWhenHighlighted = true

allowButton.translatesAutoresizingMaskIntoConstraints = false

allowButton.addTarget(self, action: #selector(requestLocation), for: .touchUpInside)

skipButton.configuration = .plain()

skipButton.setImage(UIImage(named: "onboarding_skip"), for: .normal)

skipButton.tintColor = .clear

skipButton.adjustsImageWhenHighlighted = true

skipButton.translatesAutoresizingMaskIntoConstraints = false

skipButton.addTarget(self, action: #selector(skipTapped), for: .touchUpInside)

view.addSubview(allowButton)

view.addSubview(skipButton)

NSLayoutConstraint.activate([

illustrationView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 42),

illustrationView.centerXAnchor.constraint(equalTo: view.centerXAnchor),

illustrationView.widthAnchor.constraint(equalToConstant: 180),

illustrationView.heightAnchor.constraint(equalToConstant: 196),

titleImageView.topAnchor.constraint(equalTo: illustrationView.bottomAnchor, constant: 22),

titleImageView.centerXAnchor.constraint(equalTo: view.centerXAnchor),

titleImageView.widthAnchor.constraint(equalToConstant: 317),

titleImageView.heightAnchor.constraint(equalToConstant: 57),

descriptionImageView1.topAnchor.constraint(equalTo: titleImageView.bottomAnchor, constant: 15),

descriptionImageView1.centerXAnchor.constraint(equalTo: view.centerXAnchor),

descriptionImageView1.widthAnchor.constraint(equalToConstant: 309),

descriptionImageView1.heightAnchor.constraint(equalToConstant: 32),

descriptionImageView2.topAnchor.constraint(equalTo: descriptionImageView1.bottomAnchor, constant: 7),

descriptionImageView2.centerXAnchor.constraint(equalTo: view.centerXAnchor),

descriptionImageView2.widthAnchor.constraint(equalToConstant: 290),

descriptionImageView2.heightAnchor.constraint(equalToConstant: 32),

allowButton.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 18),

allowButton.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -17),

allowButton.heightAnchor.constraint(equalToConstant: 40),

allowButton.bottomAnchor.constraint(equalTo: skipButton.topAnchor, constant: -18),

skipButton.centerXAnchor.constraint(equalTo: view.centerXAnchor),

skipButton.widthAnchor.constraint(equalToConstant: 276),

skipButton.heightAnchor.constraint(equalToConstant: 14),

skipButton.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: -20)

])

}

@objc private func requestLocation() {

switch locationManager.authorizationStatus {

case .authorizedWhenInUse, .authorizedAlways:

goToMain()

case .denied, .restricted:

goToMain()

case .notDetermined:

locationManager.requestWhenInUseAuthorization()

@unknown default:

goToMain()

}

}

@objc private func skipTapped() {

goToMain()

}

_ manager: CLLocationManager,

didChangeAuthorization status: CLAuthorizationStatus

) {

handleAuthorization(status)

switch status {

case .authorizedWhenInUse, .authorizedAlways:

goToMain()

case .denied, .restricted:

goToMain()

default:

break

}

UserDefaults.standard.set(true, forKey: "didShowOnboarding")

let main = MainViewController()

let navigation = UINavigationController(rootViewController: main)

navigation.modalPresentationStyle = .fullScreen

present(navigation, animated: true)