import 'dart:convert';

import 'package:flutter/services.dart' show rootBundle;

class AppConfig {
  static const String _assetPath = 'assets/config/app_config.json';

  final String stompUrl;
  final Duration reconnectDelay;
  final String webviewUrl;
  final String defaultTopic;
  final List<String> topicPresets;
  final String defaultDestination;
  final String defaultPayload;

  const AppConfig({
    required this.stompUrl,
    required this.reconnectDelay,
    required this.webviewUrl,
    required this.defaultTopic,
    required this.topicPresets,
    required this.defaultDestination,
    required this.defaultPayload,
  });

  static Future<AppConfig> load() async {
    final raw = await rootBundle.loadString(_assetPath);
    final json = jsonDecode(raw) as Map<String, dynamic>;
    final server = json['server'] as Map<String, dynamic>;
    final topics = json['topics'] as Map<String, dynamic>;
    final send = json['send'] as Map<String, dynamic>;

    return AppConfig(
      stompUrl: server['stompUrl'] as String,
      reconnectDelay: Duration(
        seconds: (server['reconnectDelaySeconds'] as num).toInt(),
      ),
      webviewUrl: server['webviewUrl'] as String,
      defaultTopic: topics['default'] as String,
      topicPresets: (topics['presets'] as List).cast<String>(),
      defaultDestination: send['defaultDestination'] as String,
      defaultPayload:
          const JsonEncoder.withIndent('  ').convert(send['defaultPayload']),
    );
  }
}