loris/lib/business_logic/auth/oauth.dart

import 'dart:convert';

import 'package:http/http.dart' as http;
import 'package:url_launcher/url_launcher.dart';
import '../../global.dart' as global;
import '../../business_logic/settings.dart' as settings;

class App {
  late String clientSecret;
  late String clientId;
  late String id;
  late String name;
  late String website;
  late String redirectUri;
  App(
      {required this.clientSecret,
      required this.clientId,
      required this.id,
      required this.name,
      required this.website,
      required this.redirectUri});
  factory App.fromJson(Map<String, dynamic> json) {
    return App(
        id: json["id"].toString(),
        name: json["name"].toString(),
        website: json["website"].toString(),
        redirectUri: json["redirect_uri"].toString(),
        clientId: json["client_id"].toString(),
        clientSecret: json["client_secret"].toString());
  }
}

Future<http.Response> askKnownServerForAppRegistration() async {
  String url = await settings.loadInstanceUrl();
  try {
    return await registerApp(url);
  } catch (e) {
    return http.Response(jsonEncode({}), 404);
  }
}

Future<http.Response> registerApp(String baseurl) async {
  //String url = baseurl Uri."api/v1/apps";
  Uri url = Uri.https(baseurl, "/api/v1/apps");
  final response = await http.post(url,
      headers: global.defaultHeaders,
      body: jsonEncode({
        'client_name': global.name,
        'redirect_uris': "urn:ietf:wg:oauth:2.0:oob",
        'scopes': "read write",
        'website': global.website
      }));
  return response;
}

void openBrowserForAuthCode(String baseurl, App app) {
  Uri url = Uri.https(
      baseurl,
      // ignore: prefer_interpolation_to_compose_strings
      "/oauth/authorize"
              "?client_id=" +
          app.clientId +
          "&scope=read+write" +
          "&redirect_uri=urn:ietf:wg:oauth:2.0:oob" +
          "&response_type=code");
  launchUrl(url);
}