feat: add methods for saving unfinished puzzle

lib/main_development.dart

@@ -1,20 +1,36 @@
+import 'dart:async';
+
+import 'package:flutter/widgets.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 import 'package:sudoku/api/api.dart';
 import 'package:sudoku/app/app.dart';
 import 'package:sudoku/bootstrap.dart';
 import 'package:sudoku/cache/cache.dart';
 import 'package:sudoku/env/env.dart';
 import 'package:sudoku/repository/repository.dart';
+import 'package:sudoku/storage/storage.dart';
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  unawaited(
+    bootstrap(() async {
+      final apiClient = SudokuDioClient(baseUrl: Env.apiBaseUrl);
+      final cacheClient = CacheClient();
 
-void main() {
-  bootstrap(() {
-    final apiClient = SudokuDioClient(baseUrl: Env.apiBaseUrl);
+      final storageClient = LocalStorageClient(
+        plugin: await SharedPreferences.getInstance(),
+      );
 
-    final cacheClient = CacheClient();
-    final puzzleRepository = PuzzleRepository(cacheClient: cacheClient);
+      final puzzleRepository = PuzzleRepository(
+        cacheClient: cacheClient,
+        storageClient: storageClient,
+      );
 
-    return App(
-      apiClient: apiClient,
-      puzzleRepository: puzzleRepository,
-    );
-  });
+      return App(
+        apiClient: apiClient,
+        puzzleRepository: puzzleRepository,
+      );
+    }),
+  );
 }

lib/main_production.dart

@@ -1,20 +1,36 @@
+import 'dart:async';
+
+import 'package:flutter/widgets.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 import 'package:sudoku/api/api.dart';
 import 'package:sudoku/app/app.dart';
 import 'package:sudoku/bootstrap.dart';
 import 'package:sudoku/cache/cache.dart';
 import 'package:sudoku/env/env.dart';
 import 'package:sudoku/repository/repository.dart';
+import 'package:sudoku/storage/storage.dart';
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  unawaited(
+    bootstrap(() async {
+      final apiClient = SudokuDioClient(baseUrl: Env.apiBaseUrl);
+      final cacheClient = CacheClient();
 
-void main() {
-  bootstrap(() {
-    final apiClient = SudokuDioClient(baseUrl: Env.apiBaseUrl);
+       final storageClient = LocalStorageClient(
+        plugin: await SharedPreferences.getInstance(),
+      );
 
-    final cacheClient = CacheClient();
-    final puzzleRepository = PuzzleRepository(cacheClient: cacheClient);
+      final puzzleRepository = PuzzleRepository(
+        cacheClient: cacheClient,
+        storageClient: storageClient,
+      );
 
-    return App(
-      apiClient: apiClient,
-      puzzleRepository: puzzleRepository,
-    );
-  });
+      return App(
+        apiClient: apiClient,
+        puzzleRepository: puzzleRepository,
+      );
+    }),
+  );
 }

lib/main_staging.dart

@@ -1,20 +1,36 @@
+import 'dart:async';
+
+import 'package:flutter/widgets.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 import 'package:sudoku/api/api.dart';
 import 'package:sudoku/app/app.dart';
 import 'package:sudoku/bootstrap.dart';
 import 'package:sudoku/cache/cache.dart';
 import 'package:sudoku/env/env.dart';
 import 'package:sudoku/repository/repository.dart';
+import 'package:sudoku/storage/storage.dart';
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  unawaited(
+    bootstrap(() async {
+      final apiClient = SudokuDioClient(baseUrl: Env.apiBaseUrl);
+      final cacheClient = CacheClient();
 
-void main() {
-  bootstrap(() {
-    final apiClient = SudokuDioClient(baseUrl: Env.apiBaseUrl);
+      final storageClient = LocalStorageClient(
+        plugin: await SharedPreferences.getInstance(),
+      );
 
-    final cacheClient = CacheClient();
-    final puzzleRepository = PuzzleRepository(cacheClient: cacheClient);
+      final puzzleRepository = PuzzleRepository(
+        cacheClient: cacheClient,
+        storageClient: storageClient,
+      );
 
-    return App(
-      apiClient: apiClient,
-      puzzleRepository: puzzleRepository,
-    );
-  });
+      return App(
+        apiClient: apiClient,
+        puzzleRepository: puzzleRepository,
+      );
+    }),
+  );
 }

lib/repository/puzzle_repository.dart

@@ -1,35 +1,55 @@
 import 'package:flutter/widgets.dart';
 import 'package:sudoku/cache/cache.dart';
 import 'package:sudoku/puzzle/puzzle.dart';
+import 'package:sudoku/storage/storage.dart';
 
 /// {@template puzzle_repository}
 /// A repository that handles `puzzle` related data.
 ///
-/// Used to pass data from home page to puzzle page.
+/// Used to pass data from home page to puzzle page, and to save and
+/// retrieve unfinished puzzle from local memory.
 /// {@endtemplate}
 class PuzzleRepository {
   /// {@macro puzzle_repository}
   const PuzzleRepository({
     required CacheClient cacheClient,
-  }) : _cacheClient = cacheClient;
+    required StorageAPI storageClient,
+  })  : _cacheClient = cacheClient,
+        _storageClient = storageClient;
 
   final CacheClient _cacheClient;
 
-  /// The key used for storing the puzzle in-memory.
+  final StorageAPI _storageClient;
+
+  /// The key used for storing the puzzle in cache.
   ///
   /// This is only exposed for testing and shouldn't be used by consumers of
   /// this library.
   @visibleForTesting
   static const kPuzzleKey = '__puzzle_key__';
 
-  /// Provides the puzzle stored in-memory.
+  /// Provides the puzzle stored in cache.
   ///
   /// Returns null, if there is no puzzle.
-  Puzzle? getPuzzle() => _cacheClient.read<Puzzle>(key: kPuzzleKey);
+  Puzzle? fetchPuzzleFromCache() => _cacheClient.read<Puzzle>(key: kPuzzleKey);
 
-  /// Saves a puzzle in-memory.
+  /// Saves a puzzle in cache.
   ///
   /// If there's already a puzzle there, it will be replaced.
-  void storePuzzle({required Puzzle puzzle}) =>
+  void savePuzzleToCache({required Puzzle puzzle}) =>
       _cacheClient.write<Puzzle>(key: kPuzzleKey, value: puzzle);
+
+  /// Emits the puzzle stored in local storage. If there's not puzzle,
+  /// it simply emits null.
+  Stream<Puzzle?> getPuzzleFromLocalMemory() => _storageClient.getPuzzle();
+
+  /// Stores the puzzle in local storage. The aim is to save unfinished puzzle.
+  Future<void> storePuzzleInLocalMemory({required Puzzle puzzle}) =>
+      _storageClient.storePuzzle(puzzle: puzzle);
+
+  /// Clears out the local storage, after an unfinished puzzle is completed.
+  Future<void> clearPuzzleInLocalMemory() => _storageClient.clearPuzzleStore();
+
+  /// Closed any resources used during the above operations.
+  Future<void> close() => _storageClient.close();
 }

lib/storage/local_storage_client.dart

@@ -1,6 +1,7 @@
 import 'dart:convert';
 
 import 'package:flutter/widgets.dart';
+import 'package:rxdart/rxdart.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:sudoku/puzzle/models/puzzle.dart';
 import 'package:sudoku/storage/storage.dart';
@@ -10,12 +11,27 @@ import 'package:sudoku/storage/storage.dart';
 /// {@endtemplate}
 class LocalStorageClient extends StorageAPI {
   /// {@macro local_storage_client}
-  const LocalStorageClient({
+  LocalStorageClient({
     required SharedPreferences plugin,
-  }) : _plugin = plugin;
+  }) : _plugin = plugin {
+    _initializeStreamController();
+  }
 
   final SharedPreferences _plugin;
 
+  final _puzzleStreamController = BehaviorSubject<Puzzle?>.seeded(null);
+
+  void _initializeStreamController() {
+    final source = _getValue(kPuzzleStorageKey);
+    if (source != null) {
+      final jsonMap = json.decode(source) as Map<String, dynamic>;
+      final puzzle = Puzzle.fromJson(jsonMap);
+      _puzzleStreamController.add(puzzle);
+    } else {
+      _puzzleStreamController.add(null);
+    }
+  }
+
   /// The key used for storing the puzzle locally.
   ///
   /// This is only exposed for testing and shouldn't be used by consumers.
@@ -28,22 +44,23 @@ class LocalStorageClient extends StorageAPI {
       _plugin.setString(key, value);
 
   @override
-  Future<Puzzle?> getPuzzle() async {
-    final source = _getValue(kPuzzleStorageKey);
-    if (source == null) return null;
-
-    final jsonMap = json.decode(source) as Map<String, dynamic>;
-    return Puzzle.fromJson(jsonMap);
-  }
+  Stream<Puzzle?> getPuzzle() => _puzzleStreamController.asBroadcastStream();
 
   @override
   Future<void> storePuzzle({required Puzzle puzzle}) async {
+    _puzzleStreamController.add(puzzle);
     return _setValue(kPuzzleStorageKey, json.encode(puzzle));
   }
 
   @override
   Future<void> clearPuzzleStore() async {
+    _puzzleStreamController.add(null);
     await _plugin.remove(kPuzzleStorageKey);
     return;
   }
+
+  @override
+  Future<void> close() {
+    return _puzzleStreamController.close();
+  }
 }

lib/storage/storage_api.dart

@@ -12,11 +12,14 @@ abstract class StorageAPI {
   /// If a [puzzle] exists, it will be replaced.
   Future<void> storePuzzle({required Puzzle puzzle});
 
-  /// Provides the stored puzzle.
+  /// Provides a [Stream] of the stored puzzle.
   ///
-  /// Returns null, if there is no puzzle stored.
-  Future<Puzzle?> getPuzzle();
+  /// Emits null, if there is no puzzle stored.
+  Stream<Puzzle?> getPuzzle();
 
   /// Clears the stored puzzle.
   Future<void> clearPuzzleStore();
+
+  /// Closes the client and frees up any resources.
+  Future<void> close();
 }

pubspec.lock

@@ -629,6 +629,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "4.1.0"
+  rxdart:
+    dependency: "direct main"
+    description:
+      name: rxdart
+      sha256: "5c3004a4a8dbb94bd4bf5412a4def4acdaa12e12f269737a5751369e12d1a962"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.28.0"
   shared_preferences:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -22,6 +22,7 @@ dependencies:
   intl: ^0.19.0
   json_annotation: ^4.9.0
   loading_indicator: ^3.1.1
+  rxdart: ^0.28.0
   shared_preferences: ^2.2.3
 
 dev_dependencies: