doc(arch): update readme

packages/wyatt_architecture/README.md

@@ -16,31 +16,159 @@
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
 -->
 
-
 # Flutter - Wyatt Architecture
 
 <p align="left">
   <a href="https://git.wyatt-studio.fr/Wyatt-FOSS/wyatt-packages/src/branch/master/packages/wyatt_analysis">
+
     <img src="https://img.shields.io/badge/Style-Wyatt%20Analysis-blue.svg?style=flat-square" alt="Style: Wyatt Analysis" />
+
   </a>
   <img src="https://img.shields.io/badge/SDK-Flutter-blue?style=flat-square" alt="SDK: Flutter" />
 </p>
 
-Architecture for Flutter.
+The Wyatt Architecture for Flutter.
-
-Following: <https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html>
 
 ## Features
 
-- Usecase
+* Usecase
-- Repository
+* Repository
-- DataSource
+* DataSource
-- Entity
+* Entity
-
-## Getting started
-
-<!-- TODO -->
 
 ## Usage
 
-<!-- TODO -->
+### Domain
+
+Create your entities by extending `Entity` :
+
+```dart
+class Photo extends Entity {
+  final int id;
+  final String url;
+
+  const Photo({
+    required this.id,
+    required this.url,
+  });
+}
+```
+
+Then create the data sources by extending `BaseLocalDataSource` or `BaseRemoteDataSource` depending the type of data source.
+
+```dart
+abstract class PhotoRemoteDataSource extends BaseRemoteDataSource {
+  Future<Photo> getPhoto(int id);
+  Future<List<Photo>> getAllPhotos({int? start, int? limit});
+}
+
+```
+
+Then you can create your repositories by extenting `BaseRepository` :
+
+```dart
+abstract class PhotoRepository extends BaseRepository {
+  FutureResult<Photo> getPhoto(int id);
+  FutureResult<List<Photo>> getAllPhotos({int? start, int? limit});
+}
+```
+
+> Here the repository is just a proxy of the data sources with result type (to have beautiful  error handling).
+
+And finaly create your different usecases by using `UseCase<Parameters, ReturnType>` :
+
+```dart
+class RetrieveAllPhoto extends UseCase<QueryParameters, List<Photo>> {
+  final PhotoRepository _photoRepository;
+
+  RetrieveAllPhotos(this._photoRepository);
+
+  @override
+  FutureResult<List<Photo>> call(QueryParameters params) {
+    final photos = _photoRepository.getAllPhotos(
+      start: params.start,
+      limit: params.limit,
+    );
+    return photos;
+  }
+}
+```
+
+> In fact, here we need a new parameter object, so let's create it:
+
+```dart
+class QueryParameters {
+  final int? start;
+  final int? limit;
+
+  QueryParameters(this.start, this.limit);
+}
+```
+
+### Data
+
+We start by creating models for photos and list of photos. You can use `freezed`. The `PhotoModel` extends `Photo` with some de/serializer capabilities. And those are used only in data layer.
+
+Then implements your data sources:
+
+```dart
+class PhotoApiDataSourceImpl extends PhotoRemoteDataSource {
+  final MiddlewareClient _client;
+
+  PhotoApiDataSourceImpl(this._client);
+
+  @override
+  Future<Photo> getPhoto(int id) async {
+    final response = await _client.get(Uri.parse('/photos/$id'));
+    final photo =
+        PhotoModel.fromJson(jsonDecode(response.body) as Map<String, Object?>);
+    return photo;
+  }
+
+  @override
+  Future<List<Photo>> getAllPhotos({int? start, int? limit}) async {
+    final startQuery = start.isNotNull ? '_start=$start' : '';
+    final limitQuery = limit.isNotNull ? '_limit=$limit' : '';
+    final delimiter1 =
+        (startQuery.isNotEmpty || limitQuery.isNotEmpty) ? '?' : '';
+    final delimiter2 =
+        (startQuery.isNotEmpty && limitQuery.isNotEmpty) ? '&' : '';
+    final url = '/photos$delimiter1$startQuery$delimiter2$limitQuery';
+    final response = await _client.get(Uri.parse(url));
+    final photos =
+        ListPhotoModel.fromJson({'photos': jsonDecode(response.body)});
+    return photos.photos;
+  }
+}
+```
+
+> 1: Note that here we use `MiddlewareClient` from our http package.
+
+> 2: You can create multiple implementations (one real and one mock for example).
+
+And implement the repositories:
+
+```dart
+class PhotoRepositoryImpl extends PhotoRepository {
+  final PhotoRemoteDataSource _photoRemoteDataSource;
+
+  PhotoRepositoryImpl(
+    this._photoRemoteDataSource,
+  );
+
+  @override
+  FutureResult<Photo> getPhoto(int id) => Result.tryCatchAsync(
+        () => _photoRemoteDataSource.getPhoto(id),
+        (error) => ServerException('Cannot retrieve photo $id.'),
+      );
+
+  @override
+  FutureResult<List<Photo>> getAllPhotos({int? start, int? limit}) async =>
+      Result.tryCatchAsync(
+        () => _photoRemoteDataSource.getAllPhotos(start: start, limit: limit),
+        (error) => ServerException('Cannot retrieve all photos.'),
+      );
+}
+```
+
+That's all.

packages/wyatt_architecture/test/wyatt_architecture_test.dart

@@ -14,4 +14,4 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-// TODO(wyatt): Add some tests
+// Nothing to test as there is no logic in this package.