import UIKit
import UserNotifications
 
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
 
    var window: UIWindow?
 
    func application(_ application: UIApplication, didFinishLaunchingWithOptions
        launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        //请求通知权限
        UNUserNotificationCenter.current()
            .requestAuthorization(options: [.alert, .sound, .badge]) {
                (accepted, error) in
                if !accepted {
                    print("用户不允许消息通知。")
                }
        }
         
        return true
    }
 
    func applicationWillResignActive(_ application: UIApplication) {
    }
 
    func applicationDidEnterBackground(_ application: UIApplication) {
    }
 
    func applicationWillEnterForeground(_ application: UIApplication) {
    }
 
    func applicationDidBecomeActive(_ application: UIApplication) {
    }
 
    func applicationWillTerminate(_ application: UIApplication) {
    }
}

UNUserNotificationCenter.current().getNotificationSettings {
    settings in
    switch settings.authorizationStatus {
    case .authorized:
        return
    case .notDetermined:
        //请求授权
        UNUserNotificationCenter.current()
            .requestAuthorization(options: [.alert, .sound, .badge]) {
                (accepted, error) in
                if !accepted {
                    print("用户不允许消息通知。")
                }
        }
    case .denied:
        DispatchQueue.main.async(execute: { () -> Void in
            let alertController = UIAlertController(title: "消息推送已关闭",
                                        message: "想要及时获取消息。点击“设置”，开启通知。",
                                        preferredStyle: .alert)
             
            let cancelAction = UIAlertAction(title:"取消", style: .cancel, handler:nil)
             
            let settingsAction = UIAlertAction(title:"设置", style: .default, handler: {
                (action) -> Void in
                let url = URL(string: UIApplicationOpenSettingsURLString)
                if let url = url, UIApplication.shared.canOpenURL(url) {
                    if #available(iOS 10, *) {
                        UIApplication.shared.open(url, options: [:],
                                                  completionHandler: {
                                                    (success) in
                        })
                    } else {
                        UIApplication.shared.openURL(url)
                    }
                }
            })
             
            alertController.addAction(cancelAction)
            alertController.addAction(settingsAction)
             
            self.present(alertController, animated: true, completion: nil)
        })
    }
}

UNUserNotificationCenter.current().getNotificationSettings {
    settings in
    var message = "是否允许通知："
    switch settings.authorizationStatus {
    case .authorized:
        message.append("允许")
    case .notDetermined:
        message.append("未确定")
    case .denied:
        message.append("不允许")
    }
     
    message.append("\n声音：")
    switch settings.soundSetting{
    case .enabled:
        message.append("开启")
    case .disabled:
        message.append("关闭")
    case .notSupported:
        message.append("不支持")
    }
     
    message.append("\n应用图标标记：")
    switch settings.badgeSetting{
    case .enabled:
        message.append("开启")
    case .disabled:
        message.append("关闭")
    case .notSupported:
        message.append("不支持")
    }
     
    message.append("\n在锁定屏幕上显示：")
    switch settings.lockScreenSetting{
    case .enabled:
        message.append("开启")
    case .disabled:
        message.append("关闭")
    case .notSupported:
        message.append("不支持")
    }
     
    message.append("\n在历史记录中显示：")
    switch settings.notificationCenterSetting{
    case .enabled:
        message.append("开启")
    case .disabled:
        message.append("关闭")
    case .notSupported:
        message.append("不支持")
    }
     
    message.append("\n横幅显示：")
    switch settings.alertSetting{
    case .enabled:
        message.append("开启")
    case .disabled:
        message.append("关闭")
    case .notSupported:
        message.append("不支持")
    }
     
    message.append("\n显示预览：")
    switch settings.showPreviewsSetting{
    case .always:
        message.append("始终（默认）")
    case .whenAuthenticated:
        message.append("解锁时")
    case .never:
        message.append("从不")
    }
     
     
    print(message)
}