import Foundation
import UIKit
import UserNotifications

#if canImport(FirebaseMessaging)
import FirebaseMessaging
#endif

/// Handles remote-notification registration and FCM/APNs token forwarding.
///
/// Add the firebase-ios-sdk SPM package (FirebaseAnalytics + FirebaseMessaging)
/// in Xcode to enable FCM. Without it the app still builds and registers for
/// APNs, but no FCM token is produced and push delivery is disabled.
final class AppDelegate: NSObject, UIApplicationDelegate {
    func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
    ) -> Bool {
        UNUserNotificationCenter.current().delegate = self

        #if canImport(FirebaseMessaging)
        FirebaseApp.configure()
        Messaging.messaging().delegate = self
        #endif

        application.registerForRemoteNotifications()
        return true
    }

    func application(
        _ application: UIApplication,
        didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data
    ) {
        #if canImport(FirebaseMessaging)
        Messaging.messaging().apnsToken = deviceToken
        #else
        _ = deviceToken
        #endif
    }
}

#if canImport(FirebaseMessaging)
extension AppDelegate: MessagingDelegate {
    func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String?) {
        guard let fcmToken else { return }
        Task {
            try? await APIClient.shared.registerPushToken(fcmToken)
        }
    }
}
#endif

extension AppDelegate: UNUserNotificationCenterDelegate {
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        completionHandler([.banner, .sound])
    }
}