/// Thin wrapper around [SharedPreferences] for local key-value persistence.
library;

import 'package:shared_preferences/shared_preferences.dart';

import '../utils/constants.dart';

/// Loads and stores user preferences. Call [init] once at startup.
class StorageService {
  StorageService({this._preferences});

  SharedPreferences? _preferences;

  Future<void> init() async {
    _preferences ??= await SharedPreferences.getInstance();
  }

  SharedPreferences get _prefs {
    final prefs = _preferences;
    if (prefs == null) {
      throw StateError('StorageService.init() must be called before use.');
    }
    return prefs;
  }

  String get themeModeName =>
      _prefs.getString(StorageKeys.themeMode) ?? 'light';

  Future<void> setThemeModeName(String value) {
    return _prefs.setString(StorageKeys.themeMode, value);
  }

  /// Serialized Values Sort session JSON, or null when none saved.
  String? get sortSessionJson => _prefs.getString(StorageKeys.sortSession);

  Future<void> setSortSessionJson(String json) {
    return _prefs.setString(StorageKeys.sortSession, json);
  }

  Future<void> clearSortSession() {
    return _prefs.remove(StorageKeys.sortSession);
  }
}