iOS FCM Push Notifications

import UIKit
import FirebaseCore
import FirebaseMessaging
import CometChatUIKitSwift
import CometChatSDK

@main
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate, MessagingDelegate {

    func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {

        FirebaseApp.configure()

        Messaging.messaging().delegate = self

        UNUserNotificationCenter.current().delegate = self
        UNUserNotificationCenter.current().requestAuthorization(
            options: [.alert, .badge, .sound]
        ) { granted, error in
            print("Notification permission granted:", granted)
            if let error = error {
                print("Permission error:", error.localizedDescription)
            }
            
            // Only register for remote notifications if permission granted
            if granted {
                DispatchQueue.main.async {
                    print("Registering for remote notifications...")
                    application.registerForRemoteNotifications()
                }
            } else {
                print("Push notification permission denied by user")
            }
        }

        return true
    }

    func application(
        _ application: UIApplication,
        didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data
    ) {
        Messaging.messaging().apnsToken = deviceToken
        
        // Store the token for later registration after login
        let hexString = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
        UserDefaults.standard.set(hexString, forKey: "apnsPushToken")
        print("APNs token received and stored: \(hexString)")
    }
    
    func application(
        _ application: UIApplication,
        didFailToRegisterForRemoteNotificationsWithError error: Error
    ) {
        print("Failed to register for remote notifications: \(error.localizedDescription)")
    }
    
    func application(
        _ application: UIApplication,
        didReceiveRemoteNotification userInfo: [AnyHashable : Any],
        fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void
    ) {
        print("Background notification received:", userInfo)
        completionHandler(.newData)
    }

    func messaging(
        _ messaging: Messaging,
        didReceiveRegistrationToken fcmToken: String?
    ) {
        guard let fcmToken = fcmToken else {
            print("FCM token is nil")
            return
        }

        print("FCM Token received:", fcmToken)
        
        // Store FCM token as well
        UserDefaults.standard.set(fcmToken, forKey: "fcmPushToken")
        
        if let apnsToken = UserDefaults.standard.string(forKey: "apnsPushToken") {
            print("Registering APNs token with CometChat: \(apnsToken)")
            CometChatNotifications.registerPushToken(
                pushToken: fcmToken,
                platform: CometChatNotifications.PushPlatforms.FCM_IOS,
                providerId: AppConstants.PROVIDER_ID,
                onSuccess: { success in
                    print("APNs token registered with CometChat: \(success)")
                },
                onError: { error in
                    print("APNs token registration failed: \(error.errorCode) - \(error.errorDescription)")
                }
            )
        } else {
            print("No stored APNs token found - Check if Push Notifications capability is enabled in Xcode")
        }
    }


    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        completionHandler([.banner, .sound, .badge])
    }
    
    // Call this method AFTER CometChat login succeeds
    static func registerStoredPushToken() {
        guard CometChat.getLoggedInUser() != nil else {
            print("Cannot register push token: User not logged in")
            return
        }
        
        // Register APNs token
        if let apnsToken = UserDefaults.standard.string(forKey: "apnsPushToken") {
            print("Registering APNs token with CometChat: \(apnsToken)")
            CometChatNotifications.registerPushToken(
                pushToken: apnsToken,
                platform: CometChatNotifications.PushPlatforms.APNS_IOS_DEVICE,
                providerId: AppConstants.PROVIDER_ID,
                onSuccess: { success in
                    print("APNs token registered with CometChat: \(success)")
                },
                onError: { error in
                    print("APNs token registration failed: \(error.errorCode) - \(error.errorDescription)")
                }
            )
        } else {
            print("No stored APNs token found - Check if Push Notifications capability is enabled in Xcode")
        }
        
        // Register FCM token
        if let fcmToken = UserDefaults.standard.string(forKey: "fcmPushToken") {
            print("Registering FCM token with CometChat...")
            CometChat.registerTokenForPushNotification(
                token: fcmToken,
                onSuccess: { message in
                    print("CometChat FCM token registered successfully")
                },
                onError: { error in
                    print("CometChat FCM token registration failed:", error?.errorDescription ?? "Unknown error")
                }
            )
        } else {
            print("No stored FCM token found")
        }
    }
}