import 'dart:io';

import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';
import 'package:thermion_flutter/thermion_flutter.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: '3D模型纹理替换',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: const ModelViewerScreen(),
    );
  }
}

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

  @override
  State<ModelViewerScreen> createState() => _ModelViewerScreenState();
}

class _ModelViewerScreenState extends State<ModelViewerScreen> {
  bool _isLoading = true;
  String? _modelPath;
  String? _texturePath;
  int _keyValue = 0;
  String _statusMessage = "正在加载模型...";

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

  // 加载模型文件到临时目录
  Future<void> _loadModel() async {
    try {
      setState(() {
        _statusMessage = "准备模型目录...";
      });

      final directory = await getApplicationDocumentsDirectory();
      final modelDir = Directory('${directory.path}/model');

      // 确保目录存在
      if (!await modelDir.exists()) {
        await modelDir.create(recursive: true);
      }

      setState(() {
        _statusMessage = "加载GLTF文件...";
      });

      // 加载 .gltf 文件并写入本地
      final gltfData =
          await DefaultAssetBundle.of(context).load('assets/cup/model.gltf');
      final gltfFile = File('${modelDir.path}/model.gltf');
      await gltfFile.writeAsBytes(gltfData.buffer.asUint8List());

      /// ✅ 打印本地路径（关键）
      print('✅ GLTF 本地路径: ${gltfFile.path}');
      print('✅ 是否存在: ${await gltfFile.exists()}');

      setState(() {
        _statusMessage = "加载模型数据...";
      });

      // 加载 .bin 文件并写入本地
      final binData =
          await DefaultAssetBundle.of(context).load('assets/cup/model.bin');
      final binFile = File('${modelDir.path}/model.bin');
      await binFile.writeAsBytes(binData.buffer.asUint8List());

      setState(() {
        _statusMessage = "加载纹理...";
      });

      // 加载纹理文件并写入本地
      final textureData =
          await DefaultAssetBundle.of(context).load('assets/cup/texture.jpg');
      final textureFile = File('${modelDir.path}/texture.jpg');
      await textureFile.writeAsBytes(textureData.buffer.asUint8List());

      /// ✅ 打印纹理路径
      print('✅ 纹理本地路径: ${textureFile.path}');
      print('✅ 是否存在: ${await textureFile.exists()}');

      setState(() {
        _modelPath = gltfFile.path;
        _texturePath = textureFile.path;
        _isLoading = false;
        _statusMessage = "加载完成";
      });
    } catch (e) {
      print('❌ 加载模型失败: $e');
      setState(() {
        _isLoading = false;
        _statusMessage = "加载失败: $e";
      });
    }
  }

  // 使用FilePicker选择新纹理 - 修复配置错误
  Future<void> _pickNewTexture() async {
    try {
      setState(() {
        _statusMessage = "正在选择纹理文件...";
      });

      // 使用FilePicker选择文件 - 修复配置
      // 选项1: 使用FileType.image（不能指定allowedExtensions）
      FilePickerResult? result = await FilePicker.platform.pickFiles(
        type: FileType.image,
        allowMultiple: false,
      );

      // 选项2: 如果需要特定扩展名，使用FileType.custom
      /*
      FilePickerResult? result = await FilePicker.platform.pickFiles(
        type: FileType.custom,
        allowMultiple: false,
        allowedExtensions: ['jpg', 'jpeg', 'png', 'bmp', 'tga'],
      );
      */

      if (result != null &&
          result.files.isNotEmpty &&
          result.files.single.path != null &&
          _texturePath != null) {
        setState(() {
          _statusMessage = "正在应用新纹理...";
        });

        // 获取选中的文件
        PlatformFile file = result.files.first;
        File newTexture = File(file.path!);

        // 检查文件是否存在
        if (await newTexture.exists()) {
          // 复制选中的图片到纹理路径
          await newTexture.copy(_texturePath!);

          // 强制重建ViewerWidget以应用新纹理
          setState(() {
            _keyValue++;
            _statusMessage = "纹理已更新";
          });

          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('纹理已成功更新')),
          );
        } else {
          setState(() {
            _statusMessage = "文件不存在";
          });
        }
      } else {
        setState(() {
          _statusMessage = "取消选择";
        });
      }
    } catch (e) {
      print('更换纹理失败: $e');
      setState(() {
        _statusMessage = "更换纹理失败";
      });
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('更换纹理失败: $e')),
      );
    }

    return;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('3D模型纹理替换'),
        actions: [
          IconButton(
            icon: const Icon(Icons.texture),
            onPressed: _pickNewTexture,
            tooltip: '更换纹理',
          ),
        ],
      ),
      body: _isLoading
          ? Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  const CircularProgressIndicator(),
                  const SizedBox(height: 16),
                  Text(_statusMessage),
                ],
              ),
            )
          : _modelPath == null
              ? Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      const Icon(Icons.error, size: 48, color: Colors.red),
                      const SizedBox(height: 16),
                      const Text('加载模型失败'),
                      const SizedBox(height: 16),
                      ElevatedButton(
                        onPressed: _loadModel,
                        child: const Text('重试'),
                      ),
                    ],
                  ),
                )
              : Column(
                  children: [
                    Expanded(
                      child: ViewerWidget(
                        key: ValueKey(_keyValue),
                        assetPath: _modelPath!,
                        skyboxPath: "assets/default_env_skybox.ktx",
                        iblPath: "assets/default_env_ibl.ktx",
                        transformToUnitCube: true,
                        initialCameraPosition: Vector3(0, 0, 6),
                        background: Colors.grey[200],
                        manipulatorType: ManipulatorType.ORBIT,
                        initial: const Center(
                          child: CircularProgressIndicator(),
                        ),
                      ),
                    ),
                    Container(
                      padding: const EdgeInsets.all(16),
                      color: Colors.grey[100],
                      child: Column(
                        children: [
                          Row(
                            mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                            children: [
                              ElevatedButton.icon(
                                icon: const Icon(Icons.texture),
                                label: const Text('选择纹理图片'),
                                onPressed: _pickNewTexture,
                              ),
                              ElevatedButton.icon(
                                icon: const Icon(Icons.refresh),
                                label: const Text('重置视图'),
                                onPressed: () {
                                  setState(() {
                                    _keyValue++;
                                  });
                                },
                              ),
                            ],
                          ),
                          const SizedBox(height: 8),
                          Text(
                            _statusMessage,
                            style: TextStyle(
                              color: Colors.grey[600],
                              fontStyle: FontStyle.italic,
                            ),
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
    );
  }
}