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

/// Loads and formats the app's Fluent messages. All user-facing strings come
/// from locales/en-US/main.ftl; lookups fall back to the message ID when a
/// message is missing so that missing translations are obvious in the UI.
class Strings {
  final FluentBundle _bundle = FluentBundle('en-US');

  /// Loads the messages from the app's asset bundle.
  Future<void> load() async {
    final source = await rootBundle.loadString('locales/en-US/main.ftl');
    loadSource(source);
  }

  /// Loads messages from an already-read source, so tests can read the file
  /// from disk instead of the asset bundle.
  void loadSource(String source) {
    _bundle.addMessages(source);
  }

  String t(String id, [Map<String, Object?> args = const {}]) {
    return _bundle.format(id, args: args) ?? id;
  }
}

/// Provides [Strings] to the widget tree.
class StringsScope extends InheritedWidget {
  const StringsScope({required this.strings, required super.child, super.key});

  final Strings strings;

  static Strings of(BuildContext context) =>
      context.getInheritedWidgetOfExactType<StringsScope>()!.strings;

  @override
  bool updateShouldNotify(StringsScope oldWidget) => false;
}