import 'dart:async';
import 'dart:io';
import 'dart:typed_data';

import 'package:pointycastle/asn1/asn1_parser.dart';
import 'package:pointycastle/asn1/primitives/asn1_integer.dart';
import 'package:pointycastle/asn1/primitives/asn1_sequence.dart';
import 'package:pointycastle/asymmetric/api.dart';
import 'package:pointycastle/digests/sha256.dart';
import 'package:star_lock/app_settings/app_settings.dart';
import 'package:star_lock/flavors.dart';
import 'package:star_lock/network/start_chart_api.dart';
import 'package:star_lock/talk/startChart/command/message_command.dart';
import 'package:star_lock/talk/startChart/constant/ip_constant.dart';
import 'package:star_lock/talk/startChart/constant/listen_addr_type_constant.dart';
import 'package:star_lock/talk/startChart/entity/relay_info_entity.dart';
import 'package:star_lock/talk/startChart/entity/report_information_data.dart';
import 'package:star_lock/talk/startChart/entity/scp_message.dart';
import 'package:star_lock/talk/startChart/entity/star_chart_register_node_entity.dart';
import 'package:star_lock/tools/deviceInfo_utils.dart';
import 'package:star_lock/tools/storage.dart';
import 'package:uuid/uuid.dart';

import 'dart:convert';
import 'dart:typed_data';
import 'package:crypto/crypto.dart';
import 'package:pointycastle/export.dart' as pc; // 为 Pointy Castle 添加命名空间
import 'package:asn1lib/asn1lib.dart' as asn1lib; // Prefix for asn1lib

class StartChartManage {
  // 私有构造函数，防止外部直接new对象
  StartChartManage._internal();

  // 单例对象
  static final StartChartManage _instance = StartChartManage._internal();

  // 工厂构造函数，返回单例对象
  factory StartChartManage() {
    return _instance;
  }

  // 产品昵称
  final String _productName = F.navTitle;

  RawDatagramSocket? _udpSocket;
  late String remoteHost = ''; // 远程主机地址(服务器返回)
  late int remotePort = 0; // 远程主机端口(服务器返回)
  final int localPort = 62289; // 本地端口
  String localPublicHost = ''; // 本地公网ip地址

  int heartbeatIntervalTime = 1; // 心跳包间隔时间（s）
  Timer? _heartBeatTimer; // 心跳包定时器
  bool _heartBeatTimerRunning = false; // 心跳包定时任务发送状态

  String ToPeerId = ''; // 对端ID
  String FromPeerId = ''; // 我的ID

  bool _isLoginSuccessfulToStartChart = false; // 是否在星图登录成功

  // 星图服务初始化
  Future<void> init() async {
    // 客户端注册
    await _clientRegister();

    // 中继查询
    await _relayQuery();

    // 上报
    await reportInformation();

    // 初始化udp服务
    await _onlineRelayService();

    // 发送心跳消息
    _sendHeartbeatMessage();

    // 发送送上线消息
    await _sendOnlineMessage();
  }

  /// 客户端注册
  Future<void> _clientRegister() async {
    _log(text: '开始注册客户端');
    final StarChartRegisterNodeEntity requestStarChartRegisterNode =
        await _requestStarChartRegisterNode();
    await _saveStarChartRegisterNodeToStorage(requestStarChartRegisterNode);
    _log(text: '获取到星图注册节点信息:$requestStarChartRegisterNode');
  }

  // 中继查询
  Future<void> _relayQuery() async {
    final RelayInfoEntity relayInfoEntity =
        await StartChartApi.to.relayQueryInfo();
    _saveRelayInfoEntityToStorage(relayInfoEntity);
    if (relayInfoEntity.client_addr != null) {
      localPublicHost = relayInfoEntity.client_addr!;
    }

    if (relayInfoEntity.relay_list?.length != 0) {
      final data = relayInfoEntity.relay_list?[0];
      FromPeerId = data?.peerID ?? '';
      final parseUdpUrl = _parseUdpUrl(data?.listenAddr ?? '');
      remoteHost = parseUdpUrl['host'] ?? '';
      remotePort = parseUdpUrl['port'] ?? '';
      _log(text: '中继信息----》${data}');
    }
  }

  void closeUdpSocket() {
    if (_udpSocket != null) {
      _udpSocket?.close();
    }
  }

  // 初始化udp
  Future<void> _onlineRelayService() async {
    var addressIListenFrom = InternetAddress.anyIPv4;
    RawDatagramSocket.bind(addressIListenFrom, localPort)
        .then((RawDatagramSocket socket) {
      _udpSocket = socket;

      /// 广播功能
      _udpSocket!.broadcastEnabled = true;

      /// 设置数据接收回调
      _onReceiveData(_udpSocket!);
    }).catchError((error) {
      _log(text: 'Failed to bind UDP socket: $error');
    });
  }

  // 接收返回的数据
  void _onReceiveData(RawDatagramSocket socket) {
    socket.listen((RawSocketEvent event) {
      if (event == RawSocketEvent.read) {
        Datagram? dg = socket.receive();
        try {
          _log(text: '收到消息---> 长度：${dg?.data?.length}, 数据：${dg?.data}');
          if (dg?.data != null) {
            final deserialize = ScpMessage.deserialize(dg!.data);
            _log(text: 'Udp收到结构体数据---》$deserialize');
          }
        } catch (e) {
          _log(text: '❌ Udp ----> $e');
        }
      }
    });
  }

  // 上报信息至发现服务
  Future<void> reportInformation() async {
    _log(text: '上报信息至发现服务');
    // 构建参数
    ReportInformationData data = await _makeReportInformationData();
    final response = await StartChartApi.to.reportInformation(
      reportInformationData: data,
    );
    if (response.statusCode == 200) {
      // TODO 登录成功之后的逻辑
      _log(text: '星图登录成功');
    }
  }

  // 发送上线消息
  Future<void> _sendOnlineMessage() async {
    // 组装上线消息
    final message = MessageCommand.goOnlineRelay();
    await _sendMessage(message: message);
  }

  // 发送回声测试消息
  void sendEchoMessage({required String ToPeerId}) async {
    final message = MessageCommand.echoMessage(
      ToPeerId: ToPeerId,
      FromPeerId: FromPeerId,
    );
    await _sendMessage(message: message);
  }

  // 发送心跳包消息
  void _sendHeartbeatMessage() {
    if (_heartBeatTimerRunning) {
      _log(text: '心跳已经开始了. 请勿重复发送心跳包消息');
      return;
    }
    _heartBeatTimer ??= Timer.periodic(
      Duration(
        seconds: heartbeatIntervalTime,
      ),
      (Timer timer) async {
        final List<int> message = MessageCommand.heartbeatMessage();
        await _sendMessage(message: message);
      },
    );
    _heartBeatTimerRunning = true;
  }

  // 停止定时发送心跳包
  void stopHeartbeat() {
    _heartBeatTimer?.cancel();
    _heartBeatTimer = null; // 清除定时器引用
    _heartBeatTimerRunning = false;
    _log(text: '发送心跳包结束');
  }

  // 发送消息
  Future<void> _sendMessage({required List<int> message}) async {
    _log(text: '发送给中继的消息体：${message}，序列化之后的数据：【${bytesToHex(message)}】');
    var result = await _udpSocket?.send(
        message, InternetAddress(remoteHost), remotePort);
    if (result != message.length) {
      AppLog.log('❌Udp ---->   send data error $result ${message.length}');
      _udpSocket = null;
    }
  }

  // 请求注册节点
  Future<StarChartRegisterNodeEntity> _requestStarChartRegisterNode() async {
    // 获取设备信息
    final Map<String, String> deviceInfo = await _getDeviceInfo();
    // 发送注册节点请求
    final StarChartRegisterNodeEntity response =
        await StartChartApi.to.starChartRegisterNode(
      product: _productName,
      model: '${deviceInfo['brand']}_${deviceInfo['model']}',
      name: '${deviceInfo['id']}',
      unique: deviceInfo['id'] ?? Uuid().v1(),
    );
    return response;
  }

  // 保存星图注册节点信息至缓存
  Future<void> _saveStarChartRegisterNodeToStorage(
      StarChartRegisterNodeEntity starChartRegisterNodeEntity) async {
    if (starChartRegisterNodeEntity != null) {
      await Storage.saveStarChartRegisterNodeInfo(starChartRegisterNodeEntity);
      _log(text: '注册成功');
    }
  }

  // 保存星图中继服务器信息至缓存
  Future<void> _saveRelayInfoEntityToStorage(
      RelayInfoEntity relayInfoEntity) async {
    if (relayInfoEntity != null) {
      await Storage.saveRelayInfo(relayInfoEntity);
    }
  }

  // 构造上报信息数据参数
  Future<ReportInformationData> _makeReportInformationData() async {
    // 获取当前时间戳
    int currentTimestamp = DateTime.now().millisecondsSinceEpoch ~/ 1000;
    // 获取公钥
    final publicKey = await getPublicKey();
    // 获取私钥
    final privateKey = await getPrivateKey();
    // 生成签名
    final sign = await _generateSign(
      currentTimestamp: currentTimestamp,
      privateKeyHex: privateKey,
    );

    // 获取本机所有ip地址和中继返回的外网地址
    final List<ListenAddrData> listenAddrDataList =
        await _makeListenAddrDataList();

    // 从缓存中获取中继信息
    final RelayInfoEntity? relayInfoEntity = await Storage.getRelayInfo();
    final RelayServiceData relayServiceData = RelayServiceData(
      name: relayInfoEntity?.relay_list?[0].name ?? '',
      listen_addr: relayInfoEntity?.relay_list?[0].listenAddr ?? '',
      peers_max: relayInfoEntity?.relay_list?[0].peerMax ?? 0,
      peers_current: relayInfoEntity?.relay_list?[0].peerCurrent ?? 0,
    );

    ReportInformationData data = ReportInformationData(
      id: FromPeerId,
      public_key: publicKey,
      listen_addr: listenAddrDataList,
      relay_service: relayServiceData,
      time: currentTimestamp,
      sign: sign,
    );

    return data;
  }

  // 获取本机所有ip地址和中继返回的外网地址
  Future<List<ListenAddrData>> _makeListenAddrDataList() async {
    final List<ListenAddrData> listenAddrDataList = [];
    final List<String> localIp = await _getAllIpAddresses();
    // 从缓存中获取中继信息
    final RelayInfoEntity? relayInfoEntity = await Storage.getRelayInfo();
    if (relayInfoEntity != null && relayInfoEntity.client_addr != null) {
      listenAddrDataList.add(
        ListenAddrData(
          type: ListenAddrTypeConstant.relay,
          address: IpConstant.udpUrl +
              relayInfoEntity.client_addr! +
              ':' +
              localPort.toString(),
        ),
      );
    }
    localIp.forEach((element) {
      listenAddrDataList.add(
        ListenAddrData(
          type: ListenAddrTypeConstant.local,
          address: IpConstant.udpUrl + element + ':' + localPort.toString(),
        ),
      );
    });
    return listenAddrDataList ?? [];
  }

  /// 获取本机所有ip
  Future<List<String>> _getAllIpAddresses() async {
    final List<String> ipAddresses = [];
    try {
      final List<NetworkInterface> interfaces = await NetworkInterface.list(
        includeLoopback: true,
        type: InternetAddressType.any,
      );

      for (final interface in interfaces) {
        for (final address in interface.addresses) {
          if (address.address.isNotEmpty &&
              !IpConstant.reportExcludeIp.contains(address.address)) {
            ipAddresses.add(address.address);
          }
        }
      }
    } catch (e) {
      _log(text: '❌--->获取本机IP时出现错误: $e');
    }
    return ipAddresses ?? [];
  }

  void _log({required String text}) {
    AppLog.log('$_productName=====${text}');
  }

  /// 获取设备信息
  Future<Map<String, String>> _getDeviceInfo() async {
    final Map<String, String> deviceInfo =
        await DeviceInfoUtils.getDeviceInfo();
    return deviceInfo;
  }

  /// 解析 UDP URL 并提取 IP 地址和端口号
  Map<String, dynamic> _parseUdpUrl(String url) {
    // 使用正则表达式匹配 IP 地址和端口号
    final regex = RegExp(r'udp://(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}):(\d+)')
        .firstMatch(url);

    if (regex != null) {
      final ip = regex.group(1);
      final portStr = regex.group(2);
      final port = int.tryParse(portStr ?? '');

      if (ip != null && port != null) {
        return {'host': ip, 'port': port};
      }
    }
    throw FormatException('无法解析 URL 格式: $url');
  }

  String bytesToHex(List<int> bytes) {
    return bytes.map((byte) => byte.toRadixString(16).padLeft(2, '0')).join('');
  }

  // 生成签名sing
  Future<String> _generateSign({
    required int currentTimestamp,
    required String privateKeyHex,
  }) async {
    String resultSign = '';
    try {
      // 1. 获取当前时间戳并编码为小端字节序
      Uint8List signData = Uint8List(4);
      ByteData.view(signData.buffer)
          .setUint32(0, currentTimestamp, Endian.little);

      // 2. 对时间戳数据计算 SHA-256 哈希值
      Digest hash = sha256.convert(signData);

      // 3. 使用 RSA 私钥进行签名 (需要提供 RsaPrivateKey)
      pc.RSAPrivateKey privateKey =
          loadPrivateKey(privateKeyHex); // 需要加载你的 RSA 私钥
      Uint8List signature = rsaSign(privateKey, hash.bytes);

      // 4. 将签名结果转换为十六进制字符串
      String hexSignature = signature
          .map((byte) => byte.toRadixString(16).padLeft(2, '0'))
          .join();
      resultSign = hexSignature;
    } catch (e) {
      _log(text: '❌--->上报信息生成签名时出现错误: $e');
    }
    return resultSign ?? '';
  }

  /// 自定义 PEM 格式的 RSA 私钥解析器
  pc.RSAPrivateKey loadPrivateKey(String privateKeyHex) {
    // 将十六进制字符串转换为字节数组
    final uint8list = Uint8List.fromList(hexToBytes(privateKeyHex));
    try {
      // 使用 asn1lib 的 ASN1Parser 解析
      final asn1Parser = asn1lib.ASN1Parser(uint8list);
      final topLevelSeq = asn1Parser.nextObject() as asn1lib.ASN1Sequence;

      final modulus = bytesToBigInt(
          (topLevelSeq.elements[1] as asn1lib.ASN1Integer).valueBytes());
      final privateExponent = bytesToBigInt(
          (topLevelSeq.elements[3] as asn1lib.ASN1Integer).valueBytes());
      final p = bytesToBigInt(
          (topLevelSeq.elements[4] as asn1lib.ASN1Integer).valueBytes());
      final q = bytesToBigInt(
          (topLevelSeq.elements[5] as asn1lib.ASN1Integer).valueBytes());

      return pc.RSAPrivateKey(modulus, privateExponent, p, q);
    } catch (e) {
      // 如果发生解码错误，打印错误信息
      print("Error decoding private key: $e");
      rethrow;
    }
  }

  // 解析对端数据
  Future<void> analyzeInformationOtherEnd() async {
    await StartChartApi.to.analyzeInformationOtherEnd(peerId: ToPeerId);
  }

  // 将十六进制字符串转换为字节数组
  List<int> hexToBytes(String hex) {
    return List<int>.generate(hex.length ~/ 2,
        (i) => int.parse(hex.substring(i * 2, i * 2 + 2), radix: 16));
  }

  BigInt bytesToBigInt(Uint8List bytes) {
    return BigInt.parse(
      bytes.map((byte) => byte.toRadixString(16).padLeft(2, '0')).join(),
      radix: 16,
    );
  }

  /// 使用 RSA 私钥进行 PKCS#1 v1.5 签名
  Uint8List rsaSign(pc.RSAPrivateKey privateKey, List<int> data) {
    final signer = pc.RSASigner(pc.SHA256Digest(), '06052b24030203')
      ..init(true, pc.PrivateKeyParameter<pc.RSAPrivateKey>(privateKey));
    return signer.generateSignature(Uint8List.fromList(data)).bytes;
  }

  Future<String> getPublicKey() async {
    // 从缓存中获取星图注册节点信息
    final StarChartRegisterNodeEntity? starChartRegisterNodeInfo =
        await Storage.getStarChartRegisterNodeInfo();
    return starChartRegisterNodeInfo?.peer?.publicKey ?? '';
  }

  Future<String> getPrivateKey() async {
    // 从缓存中获取星图注册节点信息
    final StarChartRegisterNodeEntity? starChartRegisterNodeInfo =
        await Storage.getStarChartRegisterNodeInfo();
    return starChartRegisterNodeInfo?.peer?.privateKey ?? '';
  }
}