import 'package:blind_master/BlindMasterResources/secure_transmissions.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/foundation.dart';

class FcmService {
  /// Request permission, fetch the FCM token, and register it with the server.
  /// Safe to call on every login/session-restore — the server just upserts the value.
  static Future<void> register() async {
    debugPrint('FCM: register() called');
    try {
      final messaging = FirebaseMessaging.instance;
      final settings = await messaging.requestPermission(alert: true, badge: true, sound: true);
      debugPrint('FCM: authorization status: ${settings.authorizationStatus}');
      if (settings.authorizationStatus == AuthorizationStatus.denied) {
        debugPrint('FCM: notifications denied — enable in Settings > [App] > Notifications');
        return;
      }
      await messaging.setForegroundNotificationPresentationOptions(
        alert: true,
        badge: true,
        sound: true,
      );
      // On iOS, APNs token must be available before FCM token can be fetched.
      // getAPNSToken() can block if iOS hasn't finished APNs registration yet,
      // so cap it with a timeout and retry once after a short delay.
      if (defaultTargetPlatform == TargetPlatform.iOS ||
          defaultTargetPlatform == TargetPlatform.macOS) {
        String? apnsToken = await messaging.getAPNSToken()
            .timeout(const Duration(seconds: 3), onTimeout: () => null);
        if (apnsToken == null) {
          debugPrint('FCM: APNs token not ready, retrying in 5s...');
          await Future.delayed(const Duration(seconds: 5));
          apnsToken = await messaging.getAPNSToken()
              .timeout(const Duration(seconds: 5), onTimeout: () => null);
        }
        if (apnsToken == null) {
          debugPrint('FCM: APNs token unavailable — simulator or APNs not configured');
          return;
        }
        debugPrint('FCM: APNs token acquired');
      }
      final token = await messaging.getToken();
      debugPrint('FCM TOKEN: ${token ?? "null — likely running on simulator"}');
      if (token == null) return;
      await securePost({'token': token}, 'register_fcm_token');
    } catch (e) {
      debugPrint('FCM registration failed: $e');
    }
  }
}