import 'dart:developer';

import 'package:easy_debounce/easy_debounce.dart';
import 'package:hydrated_bloc/hydrated_bloc.dart';

import '../../../../../storage/settings.dart';
import '../../../../../view/pages/settings/data/default_settings.dart';
import '../../app_modules.dart';

class SettingsCubit extends HydratedCubit<Settings> {
  static const _debounceTag = 'settings_persist';

  SettingsCubit() : super(DefaultSettings.get());

  Settings val({bool write = false}) {
    if (write) {
      // Notify listeners immediately so the UI reflects the mutation right away;
      // debounce the actual persistence to disk to avoid hammering on rapid edits.
      _emitFreshInstance();
      EasyDebounce.debounce(_debounceTag, const Duration(milliseconds: 500), _emitFreshInstance);
    }
    return state;
  }

  void _emitFreshInstance() {
    try {
      emit(Settings.fromJson(state.toJson()));
    } catch (e) {
      log('Failed to refresh settings state: $e');
    }
  }

  Future<void> reset() async {
    emit(DefaultSettings.get());
  }

  @override
  Settings fromJson(Map<String, dynamic> json) {
    try {
      return _appendNewModules(Settings.fromJson(json));
    } catch (_) {
      try {
        return _appendNewModules(Settings.fromJson(_mergeSettings(json, DefaultSettings.get().toJson())));
      } catch (_) {
        return DefaultSettings.get();
      }
    }
  }

  // Modules added in newer app versions won't appear in a previously persisted
  // moduleOrder. Append any enum value that is neither ordered nor hidden so it
  // becomes visible in the "Mehr" menu without forcing a full settings reset.
  Settings _appendNewModules(Settings s) {
    final order = s.modulesSettings.moduleOrder;
    final hidden = s.modulesSettings.hiddenModules;
    final missing = Modules.values.where((m) => !order.contains(m) && !hidden.contains(m));
    if (missing.isEmpty) return s;
    s.modulesSettings.moduleOrder = [...order, ...missing];
    return s;
  }

  @override
  Map<String, dynamic>? toJson(Settings state) => state.toJson();

  Map<String, dynamic> _mergeSettings(Map<String, dynamic> oldMap, Map<String, dynamic> newMap) {
    final merged = Map<String, dynamic>.from(newMap);
    oldMap.forEach((key, value) {
      if (merged.containsKey(key)) {
        if (value is Map<String, dynamic> && merged[key] is Map<String, dynamic>) {
          merged[key] = _mergeSettings(value, merged[key]);
        } else {
          merged[key] = value;
        }
      }
    });
    return merged;
  }
}