feat: Add a REST API Client package (#521)

* feat: Add a REST API Client package

* test: add rest_api_client_test

* chore: update slang file

* refactor: rest_api_client to pub_dev_api_client

* chore: rename provider

* chore: update dependencies and improve pub.dev package providers

* refactor: rename package details provider and implement new provider for pub.dev package details

packages/flutter_app/lib/features/pub_dev_packages/query/pub_dev_package_details_provider.dart

@@ -0,0 +1,18 @@
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:pub_dev_api_client/pub_dev_api_client.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+import '../../../package_adaptor/pub_dev_api_client_provider.dart';
+
+part 'pub_dev_package_details_provider.g.dart';
+
+/// Provider for pub.dev package details by package name.
+@riverpod
+Future<GetPackageDetailsResponseBody> pubDevPackageDetails(
+  Ref ref, {
+  required String packageName,
+}) async {
+  final client = ref.watch(pubDevApiClientProvider);
+  final response = await client.getPackageDetails(packageName: packageName);
+  return response;
+}

packages/flutter_app/lib/features/pub_dev_packages/query/pub_dev_packages_page_state_provider.dart

@@ -0,0 +1,56 @@
+import 'package:pub_dev_api_client/pub_dev_api_client.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+import '../../../package_adaptor/pub_dev_api_client_provider.dart';
+
+part 'pub_dev_packages_page_state_provider.g.dart';
+
+/// Provider for the search word of pub.dev packages.
+@Riverpod(keepAlive: true)
+class PubDevPackageSearchWordState extends _$PubDevPackageSearchWordState {
+  @override
+  String build() => '';
+
+  /// Update the search word.
+  // ignore: use_setters_to_change_properties
+  void update(String word) {
+    state = word;
+  }
+
+  /// Clear the search word.
+  void clear() {
+    state = '';
+  }
+}
+
+@Riverpod(keepAlive: true)
+class PubDevPackagesPageState extends _$PubDevPackagesPageState {
+  @override
+  Future<GetSearchedPackagesResponseBody> build() async {
+    final searchWord = ref.watch(pubDevPackageSearchWordStateProvider);
+    final client = ref.watch(pubDevApiClientProvider);
+    final response = await client.getSearchedPackages(searchWord: searchWord);
+    return response;
+  }
+
+  Future<void> loadNext(int nextPage) async {
+    state = const AsyncLoading<GetSearchedPackagesResponseBody>()
+        .copyWithPrevious(state);
+
+    final searchWord = ref.read(pubDevPackageSearchWordStateProvider);
+    final client = ref.read(pubDevApiClientProvider);
+    final response = await client.getSearchedPackages(
+      searchWord: searchWord,
+      page: nextPage,
+    );
+    final currentPackages = state.requireValue.packages;
+    final newPackages = [...currentPackages, ...response.packages];
+
+    state = AsyncData(
+      GetSearchedPackagesResponseBody(
+        packages: newPackages,
+        nextPageUrl: response.nextPageUrl,
+      ),
+    );
+  }
+}

packages/flutter_app/lib/features/pub_dev_packages/query/query.dart

@@ -0,0 +1,2 @@
+export 'pub_dev_package_details_provider.dart';
+export 'pub_dev_packages_page_state_provider.dart';