feat(presentation): add game state Notifier

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/presentation/providers/game_provider.dart

@@ -0,0 +1,77 @@
+import 'dart:math';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import '../../core/config/app_constants.dart';
+import '../../domain/game/game_engine.dart';
+import '../../domain/game/game_state.dart';
+import 'pokedex_provider.dart';
+import 'repository_provider.dart';
+
+/// Orchestration de la partie : relie GameEngine (règles), le repository (données)
+/// et SharedPreferences (best score).
+class GameNotifier extends Notifier<GameState> {
+  static const _engine = GameEngine();
+  final _random = Random();
+
+  @override
+  GameState build() => const GameState();
+
+  Future<void> startNewGame() async {
+    state = _engine.newGame(state);
+    await _loadBestScore();
+    await loadNextPokemon();
+  }
+
+  Future<void> _loadBestScore() async {
+    final prefs = await SharedPreferences.getInstance();
+    state = state.copyWith(bestScore: prefs.getInt(AppConstants.prefsBestScore) ?? 0);
+  }
+
+  Future<void> loadNextPokemon() async {
+    state = state.copyWith(status: GameStatus.loading);
+    final repo = ref.read(pokemonRepositoryProvider);
+    final isShiny = _random.nextInt(AppConstants.shinyOdds) == 0;
+
+    final id = _random.nextInt(AppConstants.totalPokemon) + 1;
+    final pokemon = await repo.getById(id);
+
+    if (pokemon == null) {
+      state = state.copyWith(status: GameStatus.error);
+      return;
+    }
+    state = _engine.startRound(state, pokemon, isShiny: isShiny);
+  }
+
+  Future<GuessResult> submitGuess(String guess) async {
+    final outcome = _engine.submitGuess(state, guess);
+    state = outcome.state;
+
+    if (outcome.result == GuessResult.correct) {
+      final repo = ref.read(pokemonRepositoryProvider);
+      final caught = state.currentPokemon;
+      if (caught != null) await repo.update(caught);
+      await _persistBestScore();
+      ref.invalidate(pokedexProvider); // rafraîchit la liste
+    }
+    return outcome.result;
+  }
+
+  Future<void> _persistBestScore() async {
+    final prefs = await SharedPreferences.getInstance();
+    final stored = prefs.getInt(AppConstants.prefsBestScore) ?? 0;
+    if (state.currentScore > stored) {
+      await prefs.setInt(AppConstants.prefsBestScore, state.currentScore);
+    }
+  }
+
+  void useHint() => state = _engine.useHint(state);
+
+  Future<void> useSkip() async {
+    final updated = _engine.useSkip(state);
+    if (updated.skips == state.skips) return; // pas de skip dispo
+    state = updated;
+    await loadNextPokemon();
+  }
+}
+
+final gameProvider = NotifierProvider<GameNotifier, GameState>(GameNotifier.new);