import 'package:flutter_riverpod/flutter_riverpod.dart';

import 'providers.dart';

enum TutorialStep { dragPiece, clearLine, explainHud }

/// First-play guided tutorial. State null = inactive. Events arriving in the
/// wrong step are ignored, so engine wiring can fire them unconditionally.
class TutorialNotifier extends Notifier<TutorialStep?> {
  @override
  TutorialStep? build() => null;

  void start() {
    if (ref.read(saveRepositoryProvider).tutorialDone) return;
    state = TutorialStep.dragPiece;
  }

  void onPlaced() {
    if (state == TutorialStep.dragPiece) state = TutorialStep.clearLine;
  }

  void onLineCleared() {
    if (state == TutorialStep.clearLine) state = TutorialStep.explainHud;
  }

  Future<void> dismissHud() async {
    if (state != TutorialStep.explainHud) return;
    await _finish();
  }

  Future<void> skip() async {
    if (state == null) return;
    await _finish();
  }

  Future<void> _finish() async {
    state = null;
    await ref.read(saveRepositoryProvider).markTutorialDone();
  }
}