Push notifications with UserNotifications framework

import UserNotifications
import UIKit

class NotificationManager: NSObject {
    static let shared = NotificationManager()

    private override init() {
        super.init()
    }

    func requestAuthorization() {
        UNUserNotificationCenter.current().requestAuthorization(
            options: [.alert, .badge, .sound]
        ) { granted, error in
            if granted {
                print("Notification permission granted")
                self.registerForRemoteNotifications()
            } else if let error = error {
                print("Error requesting notification permission: \(error)")
            }
        }
    }

    private func registerForRemoteNotifications() {
        DispatchQueue.main.async {
            UIApplication.shared.registerForRemoteNotifications()
        }
    }

    func handleDeviceToken(_ deviceToken: Data) {
        let token = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
        print("Device token: \(token)")

        // Send to backend
        Task {
            await APIService.shared.registerDeviceToken(token)
        }
    }

    func scheduleLocalNotification(
        title: String,
        body: String,
        timeInterval: TimeInterval,
        identifier: String
    ) {
        let content = UNMutableNotificationContent()
        content.title = title
        content.body = body
        content.sound = .default
        content.badge = 1

        let trigger = UNTimeIntervalNotificationTrigger(
            timeInterval: timeInterval,
            repeats: false
        )

        let request = UNNotificationRequest(
            identifier: identifier,
            content: content,
            trigger: trigger
        )

        UNUserNotificationCenter.current().add(request) { error in
            if let error = error {
                print("Error scheduling notification: \(error)")
            }
        }
    }

    func cancelNotification(identifier: String) {
        UNUserNotificationCenter.current()
            .removePendingNotificationRequests(withIdentifiers: [identifier])
    }

    func cancelAllNotifications() {
        UNUserNotificationCenter.current().removeAllPendingNotificationRequests()
    }

    func getBadgeCount() -> Int {
        return UIApplication.shared.applicationIconBadgeNumber
    }

    func setBadgeCount(_ count: Int) {
        DispatchQueue.main.async {
            UIApplication.shared.applicationIconBadgeNumber = count
        }
    }
}

extension NotificationManager: UNUserNotificationCenterDelegate {
    // Called when notification arrives while app is in foreground
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        // Show notification even in foreground
        completionHandler([.banner, .sound, .badge])
    }

    // Called when user taps notification
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        didReceive response: UNNotificationResponse,
        withCompletionHandler completionHandler: @escaping () -> Void
    ) {
        let userInfo = response.notification.request.content.userInfo

        // Handle notification tap
        if let postId = userInfo["post_id"] as? Int {
            // Navigate to post detail
            NotificationCenter.default.post(
                name: .navigateToPost,
                object: nil,
                userInfo: ["postId": postId]
            )
        }

        completionHandler()
    }
}

extension Notification.Name {
    static let navigateToPost = Notification.Name("navigateToPost")
}