import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    private var secondWindowPresenter: SecondWindowPresenter?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Move this to willFinishLaunchingWithOptions to reproduce the rotation bug
        secondWindowPresenter = SecondWindowPresenter()
        return true
    }

    func application(_ application: UIApplication, willFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
        window = UIWindow(frame: UIScreen.main.bounds)
        window?.backgroundColor = UIColor.white
        window?.rootViewController = ViewController()

        window?.makeKeyAndVisible()

        // If this is in -didFinishLaunchingWithOptions, the rotation works fine
//        secondWindowPresenter = SecondWindowPresenter()

        return true
    }
}

private class SecondWindowPresenter {
    private let window: UIWindow

    init() {
        let windowFrame: CGRect
        if let mainWindow = UIApplication.shared.keyWindow {
            windowFrame = mainWindow.offsetToAvoidStatusBar()
        } else {
            windowFrame = .zero
        }
        window = UntouchableWindow(frame: windowFrame)
        window.windowLevel = .alert
        window.backgroundColor = UIColor.blue.withAlphaComponent(0.4)

        // Emulate showing the Notice (inside a UIWindow)
        DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(1)) { [weak self] in
            self?.window.isHidden = false
        }
    }
}

private extension UIWindow {
    func offsetToAvoidStatusBar() -> CGRect {
        return self.frame.insetBy(dx: Offsets.minimalEdgeOffset, dy: Offsets.minimalEdgeOffset)
    }

    private enum Offsets {
        static let minimalEdgeOffset: CGFloat = 1.0
    }
}

@objc class UntouchableWindow: UIWindow {
    override init(frame: CGRect) {
        super.init(frame: frame)
        rootViewController = UIViewController()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}