import 'package:flutter/material.dart';

/// App-wide theme mode. `main.dart` listens to this and rebuilds MaterialApp;
/// any screen can set it. Persisting the choice is the ViewModel's job — this
/// only carries the live value.
class ThemeController {
  ThemeController._();

  static final ValueNotifier<ThemeMode> mode = ValueNotifier<ThemeMode>(
    ThemeMode.dark,
  );

  /// The stored string ('dark' | 'light' | 'system') for the current mode.
  static String get name => mode.value.name;

  static void apply(String stored) {
    mode.value = switch (stored) {
      'light' => ThemeMode.light,
      'system' => ThemeMode.system,
      _ => ThemeMode.dark,
    };
  }
}