import 'package:flutter/material.dart';
import 'dart:async';

import 'package:flutter/services.dart';
import 'package:idcard/idcard.dart';
import 'package:idcard/idcard_platform_interface.dart';

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

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

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

class _MyAppState extends State<MyApp> {
  String _platformVersion = 'Unknown';
  String _status = '未连接';
  IdCardInfo? _cardInfo;
  bool _isReading = false;
  bool _isLoading = false;
  bool _isConnected = false;
  String _statusMessage = '未连接';
  final _idcardPlugin = Idcard();

  final String _portType = "USB";
  final String _portPara = "0400C35A";
  final String _portExtend = "MI";

  @override
  void initState() {
    super.initState();
    initPlatformState();
  }

  /// 初始化平台状态
  Future<void> initPlatformState() async {
    String platformVersion;
    try {
      platformVersion = await _idcardPlugin.getPlatformVersion() ?? 'Unknown platform version';
    } on PlatformException {
      platformVersion = 'Failed to get platform version.';
    }

    if (!mounted) return;

    setState(() {
      _platformVersion = platformVersion;
    });
  }

  /// 连接设备
  Future<void> _connectDevice() async {
    setState(() {
      _isLoading = true;
      _statusMessage = '正在连接设备...';
      _status = '正在连接设备...';
    });

    try {
      // 首先获取USB权限
      setState(() {
        _statusMessage = '正在请求USB权限...';
        _status = '正在请求USB权限...';
      });

      //      int vid = int.parse(portPara.substring(0, 4), radix: 16);
      //       int pid = int.parse(portPara.substring(4, 8), radix: 16);

      final permissionResult = await _idcardPlugin.getUsbPermission(vid: int.parse(_portPara.substring(0, 4), radix: 16), pid: int.parse(_portPara.substring(4, 8), radix: 16));
      if (permissionResult != 0) {
        throw Exception('获取USB权限失败: $permissionResult');
      }

      // 打开设备
      setState(() {
        _statusMessage = '正在打开设备...';
        _status = '正在打开设备...';
      });

      // "USB", "0400C35A", "MI";
      final openResult = await _idcardPlugin.openDevice(portType: _portType, portPara: _portPara, extendPara: _portExtend);
      print("设备句柄：$openResult");
      if (openResult <= 0) {
        throw Exception('打开设备失败: $openResult');
      }

      setState(() {
        _isConnected = true;
        _statusMessage = '设备连接成功';
        _status = '设备连接成功';
      });
    } on PlatformException catch (e) {
      String errorMessage = '连接失败: ${e.message}';
      
      // 针对不同错误提供用户友好的提示
      if (e.code == 'PERMISSION_DENIED') {
        errorMessage = 'USB权限被拒绝。\n\n解决方法：\n1. 请在弹出的权限对话框中点击"允许"\n2. 或者在系统设置中手动授权USB权限\n3. 确保设备已正确连接';
      } else if (e.code == 'DEVICE_NOT_FOUND') {
        errorMessage = '未找到身份证读卡器设备。\n\n请检查：\n1. 设备是否已连接\n2. 设备驱动是否正常\n3. VID/PID是否正确';
      }
      
      setState(() {
        _statusMessage = errorMessage;
        _status = errorMessage;
        _isConnected = false;
      });
    } catch (e) {
      setState(() {
        _statusMessage = '连接失败: $e';
        _status = '连接失败: $e';
        _isConnected = false;
      });
    } finally {
      setState(() {
        _isLoading = false;
      });
    }
  }

  /// 断开设备连接
  Future<void> _disconnectDevice() async {
    try {
      await _idcardPlugin.closeDevice();
      setState(() {
        _status = '设备已断开';
        _statusMessage = '设备已断开';
        _isConnected = false;
        _cardInfo = null;
      });
    } catch (e) {
      setState(() {
        _status = '断开连接失败：$e';
        _statusMessage = '断开连接失败：$e';
      });
    }
  }

  /// 读取身份证
  Future<void> _readCard() async {
    if (_isReading) return;

    setState(() {
      _isReading = true;
      _status = '请将身份证放在读卡器上...';
      _cardInfo = null;
    });

    try {
      // 使用完整的读卡流程
      IdCardInfo cardInfo = await _idcardPlugin.readCardComplete();
      print(cardInfo);
      
      setState(() {
        _cardInfo = cardInfo;
        _status = '读卡成功';
        _isReading = false;
      });
    } catch (e) {
      setState(() {
        _status = '读卡失败：$e';
        _isReading = false;
      });
    }
  }

  /// 构建身份证信息显示卡片
  Widget _buildCardInfoWidget() {
    if (_cardInfo == null) {
      return const SizedBox.shrink();
    }

    return Card(
      margin: const EdgeInsets.all(16),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text(
              '身份证信息',
              style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
            ),
            const SizedBox(height: 16),
            _buildInfoRow('姓名', _cardInfo!.name),
            _buildInfoRow('性别', _cardInfo!.gender),
            _buildInfoRow('民族', _cardInfo!.nation),
            _buildInfoRow('出生日期', _cardInfo!.birthDate),
            _buildInfoRow('身份证号', _cardInfo!.idNumber),
            _buildInfoRow('地址', _cardInfo!.address),
            _buildInfoRow('签发机关', _cardInfo!.signOrgan),
            _buildInfoRow('有效期', _cardInfo!.validTerm),
            if (_cardInfo!.photo != null) ...[
              const SizedBox(height: 16),
              const Text('照片：'),
              const SizedBox(height: 8),
              Container(
                width: 120,
                height: 160,
                decoration: BoxDecoration(
                  border: Border.all(color: Colors.grey),
                  borderRadius: BorderRadius.circular(8),
                ),
                child: Image.memory(
                  Uint8List.fromList(_cardInfo!.photo!),
                  fit: BoxFit.cover,
                  errorBuilder: (context, error, stackTrace) {
                    return const Center(
                      child: Text('照片加载失败'),
                    );
                  },
                ),
              ),
            ],
          ],
        ),
      ),
    );
  }

  /// 构建信息行
  Widget _buildInfoRow(String label, String value) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          SizedBox(
            width: 80,
            child: Text(
              '$label：',
              style: const TextStyle(fontWeight: FontWeight.w500),
            ),
          ),
          Expanded(
            child: Text(value),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: '身份证读卡器示例',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        useMaterial3: true,
      ),
      home: Scaffold(
        appBar: AppBar(
          title: const Text('身份证读卡器示例'),
          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        ),
        body: SingleChildScrollView(
          child: Column(
            children: [
              // 平台信息
              Card(
                margin: const EdgeInsets.all(16),
                child: Padding(
                  padding: const EdgeInsets.all(16),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      const Text(
                        '平台信息',
                        style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
                      ),
                      const SizedBox(height: 8),
                      Text('运行平台：$_platformVersion'),
                      const SizedBox(height: 8),
                      Text('设备状态：$_status'),
                    ],
                  ),
                ),
              ),
              
              // 操作按钮
              Padding(
                padding: const EdgeInsets.symmetric(horizontal: 16),
                child: Row(
                  children: [
                    Expanded(
                      child: ElevatedButton(
                        onPressed: (_isLoading || _isConnected) ? null : _connectDevice,
                        child: _isLoading
                            ? const Row(
                                mainAxisAlignment: MainAxisAlignment.center,
                                children: [
                                  SizedBox(
                                    width: 16,
                                    height: 16,
                                    child: CircularProgressIndicator(
                                      strokeWidth: 2,
                                    ),
                                  ),
                                  SizedBox(width: 8),
                                  Text('连接中...'),
                                ],
                              )
                            : const Text('连接设备'),
                      ),
                    ),
                    const SizedBox(width: 16),
                    Expanded(
                      child: ElevatedButton(
                        onPressed: (_isLoading || !_isConnected) ? null : _disconnectDevice,
                        child: const Text('断开连接'),
                      ),
                    ),
                  ],
                ),
              ),
              
              const SizedBox(height: 16),
              
              // 读卡按钮
              Padding(
                padding: const EdgeInsets.symmetric(horizontal: 16),
                child: SizedBox(
                  width: double.infinity,
                  child: ElevatedButton(
                    onPressed: (_isReading || !_isConnected || _isLoading) ? null : _readCard,
                    style: ElevatedButton.styleFrom(
                      backgroundColor: Colors.green,
                      foregroundColor: Colors.white,
                      padding: const EdgeInsets.symmetric(vertical: 16),
                    ),
                    child: _isReading
                        ? const Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: [
                              SizedBox(
                                width: 20,
                                height: 20,
                                child: CircularProgressIndicator(
                                  strokeWidth: 2,
                                  valueColor: AlwaysStoppedAnimation<Color>(Colors.white),
                                ),
                              ),
                              SizedBox(width: 8),
                              Text('正在读卡...'),
                            ],
                          )
                        : const Text(
                            '读取身份证',
                            style: TextStyle(fontSize: 16),
                          ),
                  ),
                ),
              ),
              
              // 身份证信息显示
              _buildCardInfoWidget(),
            ],
          ),
        ),
      ),
    );
  }
}