import 'dart:async';
import 'package:dio/dio.dart';
import '../models/models.dart';
import 'network_service.dart';

/// 网速测试服务
class SpeedTestService {
  static final SpeedTestService _instance = SpeedTestService._internal();
  factory SpeedTestService() => _instance;
  SpeedTestService._internal();

  final Dio _dio = Dio();
  
  // 测试文件URL（可配置）
  static const _testUrls = [
    'https://speed.cloudflare.com/__down?bytes=10000000',  // 10MB
    'https://speed.hetzner.de/100MB.bin',
  ];

  /// 测试下载速度
  Future<double> testDownloadSpeed({int testDurationSeconds = 5}) async {
    double totalBytes = 0;
    final stopwatch = Stopwatch()..start();
    
    try {
      final response = await _dio.get<List<int>>(
        _testUrls[0],
        options: Options(
          responseType: ResponseType.bytes,
          receiveTimeout: Duration(seconds: testDurationSeconds + 2),
        ),
        onReceiveProgress: (received, total) {
          totalBytes = received.toDouble();
        },
      );
      
      stopwatch.stop();
      
      // 计算速度 (Mbps)
      final seconds = stopwatch.elapsedMilliseconds / 1000;
      final mbps = (totalBytes * 8) / (seconds * 1000000);
      
      return mbps;
    } catch (e) {
      return 0;
    }
  }

  /// 测试上传速度（简化版，通过POST测试）
  Future<double> testUploadSpeed({int testDurationSeconds = 5}) async {
    // 生成测试数据 (1MB)
    final testData = List.generate(1024 * 1024, (i) => i % 256);
    final stopwatch = Stopwatch()..start();
    
    try {
      await _dio.post(
        'https://speed.cloudflare.com/__up',
        data: testData,
        options: Options(
          sendTimeout: Duration(seconds: testDurationSeconds + 2),
        ),
      );
      
      stopwatch.stop();
      
      final seconds = stopwatch.elapsedMilliseconds / 1000;
      final mbps = (testData.length * 8) / (seconds * 1000000);
      
      return mbps;
    } catch (e) {
      return 0;
    }
  }

  /// 完整网速测试
  Future<NetworkStatus> runFullTest() async {
    final networkService = NetworkService();
    
    // 检测连接
    final isConnected = await networkService.checkInternetConnection();
    if (!isConnected) {
      return NetworkStatus(
        isConnected: false,
        lastCheck: DateTime.now(),
      );
    }

    // 获取本地IP
    final localIp = await networkService.getLocalIp();
    
    // 测量延迟
    final latency = await networkService.measureLatency('8.8.8.8');
    
    // 测试下载速度
    final downloadSpeed = await testDownloadSpeed();
    
    // 测试上传速度
    final uploadSpeed = await testUploadSpeed();

    return NetworkStatus(
      isConnected: true,
      downloadSpeed: downloadSpeed,
      uploadSpeed: uploadSpeed,
      latency: latency,
      localIp: localIp,
      lastCheck: DateTime.now(),
    );
  }

  /// 快速网络检测（仅检测连通性和延迟）
  Future<NetworkStatus> quickCheck() async {
    final networkService = NetworkService();
    
    final isConnected = await networkService.checkInternetConnection();
    final localIp = await networkService.getLocalIp();
    final latency = isConnected 
        ? await networkService.measureLatency('8.8.8.8')
        : -1;

    return NetworkStatus(
      isConnected: isConnected,
      latency: latency,
      localIp: localIp,
      lastCheck: DateTime.now(),
    );
  }
}