improve usernames

lib/api/oauth.dart

@@ -1 +1,8 @@
 import 'package:http/http.dart' as http;
+import 'dart:io';
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+
+import 'package:oauth2/oauth2.dart' as oauth2;
+
+// Future<http.Client> authorize({required String userid}) {
+// }

lib/api/user.dart

@@ -19,3 +19,20 @@ Uri urlFromUsername({required String name}) {
   name = cleanUpUsername(name: name);
   return Uri.parse("https://${name.substring(name.indexOf("@") + 1)}");
 }
+
+String userFromUsername({required String name}) {
+  name = cleanUpUsername(name: name);
+  return name.substring(0, name.indexOf("@"));
+}
+
+// A fully qualified and valid username for example (@)hello@world.com
+// The first @ is ignored
+class Username {
+  late final String user;
+  late final Uri url;
+  Username(String username) {
+    assert(isValidUsername(name: username));
+    user = userFromUsername(name: username);
+    url = urlFromUsername(name: username);
+  }
+}