import 'dart:async';
import 'package:flutter/material.dart';
import 'package:photo_classifier/photo_classifier.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:photo_classifier/models.dart';

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

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

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

class _MyAppState extends State<MyApp> {
  final _photoclassifier = PhotoClassifier();
  bool _hasPermission = false;
  StreamSubscription<ClassificationEvent?>? _subscription;
  ClassificationProgress? _progress;
  List<ClassifiedImageGroup> _similarResult = [];
  List<ClassifiedImage> _peopleResult = [];
  List<ClassifiedImage> _screenshotResult = [];
  List<ClassifiedImage> _blurryResult = [];
  bool _isClassifying = false;
  String _errorMessage = '';

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

  Future<void> _checkPermissions() async {
    final status = await Permission.photos.status;
    setState(() {
      _hasPermission = status.isGranted;
      if (!status.isGranted) {
        _errorMessage = '需要相册权限才能进行照片分类，请点击上方按钮申请权限';
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('照片分类插件示例'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              if (!_hasPermission)
                ElevatedButton(
                  onPressed: _requestPermission,
                  child: const Text('请求照片库权限'),
                ),
              if (!_hasPermission)
                Padding(
                  padding: const EdgeInsets.only(top: 16.0),
                  child: ElevatedButton(
                    onPressed: () => openAppSettings(),
                    style: ElevatedButton.styleFrom(
                      backgroundColor: Colors.orange,
                    ),
                    child: const Text('打开系统设置'),
                  ),
                ),
              if (_hasPermission && !_isClassifying)
                ElevatedButton(
                  onPressed: _startClassificationWithStream,
                  child: const Text('开始分类'),
                ),
              if (_isClassifying)
                ElevatedButton(
                  onPressed: _cancelClassification,
                  child: const Text('取消分类'),
                ),
              if (_progress != null) ...[
                const SizedBox(height: 20),
                Text('进度: ${(_progress!.rate * 100).toStringAsFixed(1)}%',
                    style: const TextStyle(fontSize: 18)),
                const SizedBox(height: 10),
                LinearProgressIndicator(value: _progress!.rate),
                Text('已处理: ${_progress!.currentBatch}/${_progress!.totalBatches}'),
              ],
              if (_errorMessage.isNotEmpty) ...[
                const SizedBox(height: 20),
                Container(
                  padding: const EdgeInsets.all(12),
                  decoration: BoxDecoration(
                    color: Colors.red.withOpacity(0.1),
                    borderRadius: BorderRadius.circular(8),
                    border: Border.all(color: Colors.red.withOpacity(0.5)),
                  ),
                  child: Column(
                    children: [
                      const Icon(Icons.error_outline, color: Colors.red, size: 28),
                      const SizedBox(height: 8),
                      Text(
                        _errorMessage,
                        style: const TextStyle(color: Colors.red),
                        textAlign: TextAlign.center,
                      ),
                    ],
                  ),
                ),
              ],
              if (_progress != null) ...[
                const SizedBox(height: 20),
                const Text('分类结果:', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
                _buildResultSummary(),
              ],
              if (_progress?.isCompleted == true)
                ElevatedButton(
                  onPressed: _resetAll,
                  style: ElevatedButton.styleFrom(
                    backgroundColor: Colors.blueGrey,
                  ),
                  child: const Text('重置'),
                ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildResultSummary() {
    if (_similarResult.isEmpty && _peopleResult.isEmpty && _screenshotResult.isEmpty && _blurryResult.isEmpty) return const Text('无结果');
    
    return Expanded(
      child: ListView(
        children: [
          _buildResultItem('相似图片组', _similarResult.length, isGroup: true),
          _buildResultItem('人物照片', _peopleResult.length),
          _buildResultItem('屏幕截图', _screenshotResult.length),
          _buildResultItem('模糊图片', _blurryResult.length),
        ],
      ),
    );
  }

  Widget _buildResultItem(String title, dynamic items, {bool isGroup = false}) {
    if (items == null) return const SizedBox.shrink();
    
    final count = isGroup ? (items as List).length : (items as List).length;
    final itemsText = isGroup ? '$count 组' : '$count 张';
    
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 8.0),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text('$title: $itemsText', 
               style: const TextStyle(fontWeight: FontWeight.bold)),
          // 这里可以添加图片预览
        ],
      ),
    );
  }

  Future<void> _requestPermission() async {
    try {
      // 使用permission_handler请求权限
      final status = await Permission.photos.request();
      final granted = status.isGranted;
      
      setState(() {
        _hasPermission = granted;
        if (!granted) {
          _errorMessage = '需要相册权限才能进行照片分类';
        } else {
          _errorMessage = '';
        }
      });
      
      // 如果被拒绝且不能再次请求，提示用户前往设置
      if (status.isPermanentlyDenied || status.isDenied) {
        setState(() {
          _errorMessage = '权限被拒绝，请点击下方按钮前往设置手动开启相册权限';
        });
      }
    } catch (e) {
      setState(() {
        _errorMessage = '请求权限失败: $e';
      });
    }
  }

  Future<void> _startClassificationWithStream() async {
    setState(() {
      _isClassifying = true;
      _errorMessage = '';
      _progress = null;
      _similarResult = [];
      _peopleResult = [];
      _screenshotResult = [];
      _blurryResult = [];
    });

    try {
      // 先配置分类器
      await _photoclassifier.configureClassifier(
        batchSize: 200,
        maxConcurrentProcessing: 4,
        similarityThreshold: 0.75,
      );
      
      // 设置流监听
      _subscription = _photoclassifier
          .startClassificationStream()
          .listen( 
          (event) {
          if (event == null) return;
          setState(() {
            _progress = event.progress;
            print("批次: ${event.progress?.currentBatch}/${event.progress?.totalBatches}, 用时: ${event.progress?.batchDuration}");
            print("${event.result?.screenshotImages?.length}");
            var result = event.result;
            if (result != null) {
              _similarResult.addAll(result.similarGroups?.map((group) => group).toList() ?? []);
              _peopleResult.addAll(result.peopleImages?.map((image) => image).toList() ?? []);
              _screenshotResult.addAll(result.screenshotImages?.map((image) => image).toList() ?? []);
              _blurryResult.addAll(result.blurryImages?.map((image) => image).toList() ?? []);
            }
            if (event.progress?.isCompleted == true) {
              _isClassifying = false;
              _subscription?.cancel();
              // 取消订阅
              _subscription = null;
            }
          });
        },
        onError: (error) {
          setState(() {
            _errorMessage = '分类过程中出错: $error';
            _isClassifying = false;
          });
        },
        onDone: () {
          if (_progress?.isCompleted != true) {
            setState(() {
              _errorMessage = '分类过程意外结束';
              _isClassifying = false;
            });
          }
        },
      );
    } catch (e) {
      setState(() {
        _errorMessage = '启动分类失败: $e';
        _isClassifying = false;
      });
    }
  }

  void _cancelClassification() {
    _subscription?.cancel();
    _subscription = null;
    
    setState(() {
      _isClassifying = false;
    });
    
    _photoclassifier.resetClassifier();
  }

  void _resetAll() {
    setState(() {
      _progress = null;
      _similarResult = [];
      _peopleResult = [];
      _screenshotResult = [];
      _blurryResult = [];
      _errorMessage = '';
      _isClassifying = false;
    });
    // _photoclassifier.resetClassifier();
  }

  @override
  void dispose() {
    _subscription?.cancel();
    super.dispose();
  }
}