import 'dart:async';

import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

import '../state/app/modules/chat/bloc/chat_bloc.dart';
import '../widget/debug/debug_tile.dart';
import '../widget/debug/json_viewer.dart';
import '../widget/info_dialog.dart';
import 'notification_tasks.dart';

// `vm:entry-point` keeps this alive through AOT tree-shaking — the FCM
// background isolate looks the class up by name from native code.
@pragma('vm:entry-point')
class NotificationController {
  @pragma('vm:entry-point')
  static Future<void> onBackgroundMessageHandler(RemoteMessage message) async {
    NotificationTasks.updateBadgeCount(message);
  }

  static Future<void> onForegroundMessageHandler(
    RemoteMessage message,
    BuildContext context,
  ) async {
    final pushToken = _extractChatToken(message);
    final chatBloc = context.read<ChatBloc>();
    // hasOpenChat, not currentToken: currentToken sticks around after
    // leaveChat so didPopNext can re-claim a stacked chat.
    final activeToken = chatBloc.state.data?.currentToken ?? '';
    final chatIsOpen =
        chatBloc.hasOpenChat &&
        pushToken != null &&
        pushToken.isNotEmpty &&
        pushToken == activeToken;

    NotificationTasks.updateBadgeCount(message);

    if (chatIsOpen) {
      // Long-poll handles the message; just dismiss any stray tray entry.
      unawaited(NotificationTasks.clearNotificationsForChat(pushToken));
      return;
    }

    NotificationTasks.updateProviders(context);
  }

  static Future<void> onAppOpenedByNotification(
    RemoteMessage message,
    BuildContext context,
  ) async {
    NotificationTasks.navigateToTalk(
      context,
      chatToken: _extractChatToken(message),
    );
    NotificationTasks.updateProviders(context);

    DebugTile(context).run(() {
      InfoDialog.show(
        context,
        'Dieser Bericht wird angezeigt, da du den Entwicklermodus aktiviert hast und die App über eine Benachrichtigung geöffnet wurde.\n\n'
        '${JsonViewer.format(message.data)}',
        copyable: true,
        title: 'Notification report',
      );
    });
  }

  static String? _extractChatToken(RemoteMessage message) {
    for (final key in const ['chatToken', 'token', 'roomToken']) {
      final value = message.data[key];
      if (value is String && value.isNotEmpty) return value;
    }
    return null;
  }
}