import UIKit

@main
final class AppDelegate: UIResponder, UIApplicationDelegate {
    func application(_ application: UIApplication,
                     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil) -> Bool {
        Badge.registerBackgroundRefresh()
        Offline.shared.resume()
        Outbox.watch()
        return true
    }

    /// A download kept going while the app was closed has finished (#425): the system launched us
    /// to hand it over, and waits on this handler.
    func application(_ application: UIApplication, handleEventsForBackgroundURLSession identifier: String,
                     completionHandler: @escaping () -> Void) {
        Offline.shared.backgroundCompletion = completionHandler
        Offline.shared.resume()
    }

    /// Apple's address for this phone's copy of the app (#433), handed to the page to register.
    func application(_ application: UIApplication,
                     didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        Push.token = deviceToken.map { String(format: "%02x", $0) }.joined()
    }

    /// ipx's count, arriving with the app closed (#433): `content-available` wakes the app for a
    /// moment, which the badge alone does not, so the widget's count follows the icon's (#428).
    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any],
                     fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
        guard let n = (userInfo["aps"] as? [String: Any])?["badge"] as? Int else {
            completionHandler(.noData)
            return
        }
        WidgetFeed.update { $0.unread = n }
        completionHandler(.newData)
    }

    func application(_ application: UIApplication,
                     didFailToRegisterForRemoteNotificationsWithError error: Error) {
        NSLog("ipx: push registration: %@", error.localizedDescription)
    }
}

/// The one window. iOS will not run an app that has not adopted scenes, and a CarPlay app would
/// be a second scene beside this one.
final class SceneDelegate: UIResponder, UIWindowSceneDelegate {
    var window: UIWindow?

    func scene(_ scene: UIScene, willConnectTo session: UISceneSession,
               options: UIScene.ConnectionOptions) {
        guard let scene = scene as? UIWindowScene else { return }
        let window = UIWindow(windowScene: scene)
        window.rootViewController = WebViewController()
        window.makeKeyAndVisible()
        self.window = window
    }

    /// iOS wants the request made as the app leaves, with the user's last look at the list; the
    /// one made on coming forward stays for a run that was cut short.
    func sceneDidEnterBackground(_ scene: UIScene) {
        Badge.scheduleBackgroundRefresh()
    }

    func sceneDidBecomeActive(_ scene: UIScene) {
        Badge.requestPermission()
        Badge.scheduleBackgroundRefresh()
        Task {
            await Outbox.flush()
            await Badge.refresh()
        }
    }
}