fix: code refactoring (#5)

lib/services/manager_api.dart

@@ -1,52 +1,19 @@
 import 'dart:io';
-import 'package:dio/dio.dart';
-import 'package:injectable/injectable.dart';
-import 'package:path_provider/path_provider.dart' as p;
 import 'package:revanced_manager/constants.dart';
 import 'package:revanced_manager/services/github_api.dart';
 
-@lazySingleton
 class ManagerAPI {
-  final Dio dio = Dio();
-  final GithubAPI githubAPI = GithubAPI();
+  final GithubAPI _githubAPI = GithubAPI();
 
-  Future<String?> getPath() async {
-    final path = await p.getApplicationSupportDirectory();
-    Directory('${path.path}/revanced').createSync();
-    final workDirPath = '${path.path}/revanced';
-    return workDirPath;
+  Future<File?> downloadPatches() async {
+    return await _githubAPI.latestRelease(ghOrg, patchesRepo);
   }
 
-  Future<File?> downloadAssets(String repo) async {
-    try {
-      final workDir = await getPath();
-      final dlUrl = await githubAPI.latestRelease(ghOrg, repo);
-      final name = dlUrl
-          ?.split('/')
-          .lastWhere((element) => element.contains('revanced'));
-      final assetFile = File('$workDir/$name');
-      final response = await dio.get(
-        dlUrl!,
-        options: Options(
-          responseType: ResponseType.bytes,
-          followRedirects: true,
-          receiveTimeout: 0,
-        ),
-      );
-      final raf = assetFile.openSync(mode: FileMode.write);
-      raf.writeFromSync(response.data);
-      raf.closeSync();
-      return assetFile;
-    } catch (e) {
-      return null;
-    }
+  Future<File?> downloadIntegrations() async {
+    return await _githubAPI.latestRelease(ghOrg, integrationsRepo);
   }
 
-  Future<void> downloadPatches() async {
-    await downloadAssets(patchesRepo);
-  }
-
-  Future<void> downloadIntegrations() async {
-    await downloadAssets(integrationsRepo);
+  Future<File?> downloadManager() async {
+    return await _githubAPI.latestRelease(ghOrg, managerRepo);
   }
 }