backend

lib/features/home/abstracts/images_api.dart

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+import 'dart:async';
+
+import '../data/models/image_model.dart';
+
+/// Interface for implementing image-fetching strategies, specific to a resource location on the internet.
+///
+/// Since I used a site that was more obscure than the ones in the examples, this (otherwise pointless
+/// and convoluting) interface is for adding a bit of flexibility to change strategy to some other site.
+abstract class ImagesApi {
+  FutureOr<Iterable<ImageModel>> fetchImageUri({required String token});
+}

lib/features/home/api/unsplash_images_api.dart

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+import 'dart:async';
+import 'dart:math';
+
+import '/features/core/data/constants/const_values.dart';
+import '/l10n/generated/l10n.dart';
+import '../abstracts/images_api.dart';
+import '../data/models/image_model.dart';
+
+class UnsplashImagesApi implements ImagesApi {
+  @override
+  FutureOr<Iterable<ImageModel>> fetchImageUri({required String token}) {
+    final random = Random();
+
+    return Iterable<int>.generate(ConstValues.numberOfImages).map((final imageIndex) {
+      // Drawing from a normal distribution
+      final imageSide = ConstValues.minImageSize +
+          random.nextInt((ConstValues.maxImageSize + 1) - ConstValues.minImageSize);
+
+      final imageUri = _imageUrlGenerator(imageSide: imageSide);
+
+      return ImageModel<int>(
+        comparableIndex: imageIndex,
+        uri: imageUri,
+        imageName: Strings.current.image,
+      );
+    });
+  }
+
+  Uri _imageUrlGenerator({required int imageSide}) => Uri(
+        scheme: ConstValues.httpsScheme,
+        host: ConstValues.backendHost,
+        pathSegments: ConstValues.backendUrlPathSegments..add('${imageSide}x$imageSide'),
+      );
+}

lib/features/home/data/models/image_model.dart

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+class ImageModel<T extends Comparable> {
+  const ImageModel({
+    required this.uri,
+    required this.comparableIndex,
+    required this.imageName,
+  });
+
+  /// An image's target [Uri].
+  ///
+  /// Storing an image's [ByteData] is more expensive, memory-wise.
+  final Uri uri;
+
+  /// A unique identifier that can be used for indexing the image.
+  final T comparableIndex;
+
+  /// Given name of the image.
+  final String imageName;
+}

lib/features/home/services/images_service.dart

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+import 'package:mc_gallery/features/home/data/models/image_model.dart';
+import 'package:mc_gallery/locator.dart';
+
+import '../abstracts/images_api.dart';
+
+/// Handles fetching and storing of Images.
+///
+/// Since this is very simple use-case, this is the only interface. For complex (actual CRUD-based) I/O,
+/// an additional Repository layer interface can be used between [ImagesService] and [ImagesApi].
+class ImagesService {
+  ImagesService({required ImagesApi imagesApi}) : _imagesApi = imagesApi {
+    _init();
+  }
+
+  final ImagesApi _imagesApi;
+
+  late final Iterable<ImageModel> _imageModels;
+
+  Future<void> _init() async {
+    _imageModels = await _imagesApi.fetchImageUri(token: '');
+
+    Locator.instance().signalReady(this);
+  }
+
+  static ImagesService get locate => Locator.locate();
+}