Ios Notifications

Here’s a quick-start example for iOS notifications using `UserNotifications` and APNs.

```swift
import UIKit
import UserNotifications

@main
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {
    var window: UIWindow?

    func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
    ) -> Bool {
        let center = UNUserNotificationCenter.current()
        center.delegate = self

        // Ideally show an in-app primer before this system prompt.
        center.requestAuthorization(options: [.alert, .badge, .sound]) { granted, error in
            if let error = error {
                print("Notification permission error: \(error)")
                return
            }

            guard granted else { return }
            DispatchQueue.main.async {
                application.registerForRemoteNotifications()
            }
        }

        return true
    }

    func application(
        _ application: UIApplication,
        didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data
    ) {
        let token = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
        print("APNs token: \(token)")
        // Send token to your backend here.
    }

    func application(
        _ application: UIApplication,
        didFailToRegisterForRemoteNotificationsWithError error: Error
    ) {
        print("APNs registration failed: \(error)")
    }

    // Foreground notification handling
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        completionHandler([.banner, .sound, .badge])
    }

    // User tapped notification
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        didReceive response: UNNotificationResponse,
        withCompletionHandler completionHandler: @escaping () -> Void
    ) {
        let userInfo = response.notification.request.content.userInfo
        print("Notification payload: \(userInfo)")
        completionHandler()
    }
}
```

Optional local notification example:

```swift
func scheduleLocalNotification() {
    let content = UNMutableNotificationContent()
    content.title = "Reminder"
    content.body = "Don't forget to check the app."
    content.sound = .default
    content.badge = 1

    let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)
    let request = UNNotificationRequest(
        identifier: UUID().uuidString,
        content: content,
        trigger: trigger
    )

    UNUserNotificationCenter.current().add(request)
}
```

Notes:

- Use `UNUserNotificationCenterDelegate` so notifications can be handled in foreground and on tap.
- Register for remote notifications only after permission is granted.
- Clear badges when appropriate, for example:

```swift
UIApplication.shared.applicationIconBadgeNumber = 0
```