如何使用flutter针对OAUth 2.0API (fatsecret)进行授权

dependencies:
  flutter:
    sdk: flutter
  http: ^0.13.3
  dio: ^4.0.0

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

Future<String> getAuthorizationCode() async {
  const clientId = 'YOUR_CLIENT_ID';
  const redirectUri = 'YOUR_REDIRECT_URI';
  const scope = 'basic';

  const url = Uri.https('platform.fatsecret.com', '/oauth/authorize', {
    'client_id': clientId,
    'response_type': 'code',
    'redirect_uri': redirectUri,
    'scope': scope,
  });

  if (await canLaunch(url.toString())) {
    await launch(url.toString());
  } else {
    throw 'Could not launch $url';
  }

  // 假设用户授权后，重定向到YOUR_REDIRECT_URI，并附带授权码
  // 这里需要处理重定向逻辑，获取授权码
  String authorizationCode = 'YOUR_AUTHORIZATION_CODE';

  return authorizationCode;
}

import 'package:dio/dio.dart';

Future<String> getAccessToken(String authorizationCode) async {
  const clientId = 'YOUR_CLIENT_ID';
  const clientSecret = 'YOUR_CLIENT_SECRET';
  const redirectUri = 'YOUR_REDIRECT_URI';

  final dio = Dio();
  final response = await dio.post('https://platform.fatsecret.com/oauth/token', data: {
    'grant_type': 'authorization_code',
    'client_id': clientId,
    'client_secret': clientSecret,
    'code': authorizationCode,
    'redirect_uri': redirectUri,
  });

  if (response.statusCode == 200) {
    final Map<String, dynamic> data = jsonDecode(response.data);
    return data['access_token'];
  } else {
    throw 'Failed to get access token';
  }
}

Future<void> fetchUserRecipes(String accessToken) async {
  final dio = Dio();
  final response = await dio.get('https://platform.fatsecret.com/rest/server.json', options: Options(headers: {
    'Authorization': 'Bearer $accessToken',
  }));

  if (response.statusCode == 200) {
    final Map<String, dynamic> data = jsonDecode(response.data);
    print(data);
  } else {
    throw 'Failed to fetch user recipes';
  }
}