Flutter: Рефакторинг

main.dart

// ЗАДАНИЕ:
// Проведите ревью кода приложения. Попробуйте его запустить.
// Что можно сделать, чтобы привести его в production-ready вид?
import 'package:flutter/material.dart';
import 'dart:convert';

import 'package:http/http.dart' as http;

void main() {
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  var userAgent = "";

  Future<void> loadUserAgent() async {
    if (userAgent != "") {
      return;
    }
    var url = Uri.https('httpbin.org', 'get');
    var response = await http.get(url);
    print('Response status: ${response.statusCode}');
    print('Response body: ${response.body}');
    var decodedResponse = jsonDecode(utf8.decode(response.bodyBytes)) as Map;
    var userAgent2 = decodedResponse["headers"]["User-Agent"];
    setState(() {
      userAgent = userAgent2;
    });
  }

  @override
  Widget build(BuildContext context) {
    loadUserAgent();
    
    return MaterialApp(
      title: 'Мой User-Agent',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        colorSchemeSeed: Colors.blue,
      ),
      home: Scaffold(
        appBar: AppBar(title: Text("Мой User-Agent")),
        body: Column(
          children: [
            Container(
              padding: EdgeInsets.all(16),
              child: Container(
                color: Colors.black12,
                child: Container(
                  padding: EdgeInsets.all(16),
                  child: Row(
                    children: [
                      Text(userAgent),
                      SizedBox(width: 16),
                      FilledButton(
                        onPressed: () {
                          setState(() {
                            userAgent = "";
                          });
                        },
                        child: Text("Обновить"),
                      ),
                    ],
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}