Performed first authentication

moneymgr_mobile/lib/services/api/api_client.dart

@@ -1,7 +1,72 @@
+import 'package:dart_jsonwebtoken/dart_jsonwebtoken.dart';
+import 'package:dio/dio.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:moneymgr_mobile/services/api/api_token.dart';
+import 'package:moneymgr_mobile/utils/string_utils.dart';
 import 'package:riverpod_annotation/riverpod_annotation.dart';
 
-/// Client API
-@riverpod
-class ClientAPI {
+part 'api_client.g.dart';
 
-}
+/// API token header
+const apiTokenHeader = "X-Auth-Token";
+
+/// Client API
+class ApiClient {
+  final ApiToken token;
+  final Dio client;
+
+  ApiClient({required this.token})
+    : client = Dio(BaseOptions(baseUrl: token.apiUrl));
+
+  /// Get Dio instance
+  Future<Response<T>> execute<T>(String uri, {String method = "GET"}) async {
+    return client.request(
+      uri,
+      options: Options(
+        method: method,
+        headers: {apiTokenHeader: _genJWT(method, uri)},
+      ),
+    );
+  }
+
+  /// Generate authentication JWT
+  String _genJWT(String method, String uri) {
+    final jwt = JWT(
+      {"nonce": getRandomString(15), "met": method, "uri": uri},
+      header: {"kid": token.tokenId.toString()},
+    );
+
+    return jwt.sign(
+      SecretKey(token.tokenValue),
+      algorithm: JWTAlgorithm.HS256,
+      expiresIn: Duration(minutes: 15),
+    );
+  }
+}
+
+/// An API service that handles authentication and exposes an [ApiClient].
+///
+/// Every API call coming from UI should watch/read this provider instead of
+/// instantiating the [ApiClient] itself. When being watched, it will force any
+/// data provider (provider that fetches data) to refetch when the
+/// authentication state changes.
+///
+/// The API client is kept alive to follow dio's recommendation to use the same
+/// client instance for the entire app.
+@riverpod
+ApiClient apiService(Ref ref) {
+  /*final token = ref.watch(currentAuthStateProvider);
+
+  final ApiClient client;
+
+  const mock = bool.fromEnvironment('MOCK_API', defaultValue: false);
+  client = switch (mock) {
+    true =>
+    token != null ? MockedApiClient.withToken(token) : MockedApiClient(),
+    false => token != null ? ApiClient.withToken(token) : ApiClient(),
+  };
+  ref.keepAlive();
+
+  return client;*/
+  throw Exception("TODO"); // TODO
+}