blockchain-flutter/lib/core/network/api_client.dart

import 'package:dio/dio.dart';
import 'package:flutter/foundation.dart';

class ApiClient {
  static const String _defaultBaseUrl = 'http://localhost:3000';
  // Use 10.0.2.2 for Android emulator to reach host localhost
  static const String _androidEmulatorUrl = 'http://10.0.2.2:3000';

  late final Dio dio;

  ApiClient({String? baseUrl}) {
    final url = baseUrl ?? _resolveBaseUrl();

    dio = Dio(BaseOptions(
      baseUrl: url,
      connectTimeout: const Duration(seconds: 5),
      receiveTimeout: const Duration(seconds: 10),
      headers: {'Content-Type': 'application/json'},
    ));

    dio.interceptors.add(LogInterceptor(
      requestBody: true,
      responseBody: true,
      logPrint: (log) => debugPrint(log.toString()),
    ));
  }

  static String _resolveBaseUrl() {
    // Android emulator uses 10.0.2.2 to reach host machine
    if (defaultTargetPlatform == TargetPlatform.android) {
      return _androidEmulatorUrl;
    }
    return _defaultBaseUrl;
  }

  // Chain
  Future<Map<String, dynamic>> getChainInfo() async {
    final response = await dio.get('/api/chain/info');
    return response.data;
  }

  Future<Map<String, dynamic>> validateChain() async {
    final response = await dio.post('/api/chain/validate');
    return response.data;
  }

  // Blocks
  Future<Map<String, dynamic>> getBlocks({int offset = 0, int limit = 10}) async {
    final response = await dio.get('/api/blocks', queryParameters: {
      'offset': offset,
      'limit': limit,
    });
    return response.data;
  }

  Future<Map<String, dynamic>> getBlock(String hash) async {
    final response = await dio.get('/api/blocks/$hash');
    return response.data;
  }

  // Wallets
  Future<Map<String, dynamic>> createWallet() async {
    final response = await dio.post('/api/wallets');
    return response.data;
  }

  Future<Map<String, dynamic>> getBalance(String address) async {
    final response = await dio.get('/api/wallets/$address/balance');
    return response.data;
  }

  // Transactions
  Future<Map<String, dynamic>> submitTransaction(Map<String, dynamic> tx) async {
    final response = await dio.post('/api/transactions', data: tx);
    return response.data;
  }

  Future<List<dynamic>> getPendingTransactions() async {
    final response = await dio.get('/api/transactions/pending');
    return response.data;
  }

  // Mining
  Future<Map<String, dynamic>> mine(String minerAddress) async {
    final response = await dio.post('/api/mine', data: {
      'miner_address': minerAddress,
    });
    return response.data;
  }

  Future<Map<String, dynamic>> getMiningStatus() async {
    final response = await dio.get('/api/mining/status');
    return response.data;
  }

  // Health
  Future<bool> healthCheck() async {
    try {
      await dio.get('/api/health');
      return true;
    } catch (_) {
      return false;
    }
  }
}