/// [ChangeNotifier] that owns [ThemeMode] and persists it locally.
library;

import 'package:flutter/material.dart';

import '../services/storage_service.dart';
import '../utils/helpers.dart';

/// Provides [themeMode] to [MaterialApp] and writes changes to storage.
class ThemeController extends ChangeNotifier {
  ThemeController(this._storage) {
    _themeMode = themeModeFromName(_storage.themeModeName);
  }

  final StorageService _storage;
  late ThemeMode _themeMode;

  ThemeMode get themeMode => _themeMode;

  bool get isDark => _themeMode == ThemeMode.dark;

  Future<void> setThemeMode(ThemeMode mode) async {
    if (mode == _themeMode) return;
    _themeMode = mode;
    notifyListeners();
    await _storage.setThemeModeName(nameFromThemeMode(mode));
  }

  Future<void> cycleThemeMode() {
    final next = switch (_themeMode) {
      ThemeMode.system => ThemeMode.light,
      ThemeMode.light => ThemeMode.dark,
      ThemeMode.dark => ThemeMode.system,
    };
    return setThemeMode(next);
  }
}