import 'dart:io';

/// 拍照/相册服务
/// 提供拍照和从相册选择图片的功能
class CameraService {
  static CameraService? _instance;

  CameraService._internal();

  factory CameraService() {
    _instance ??= CameraService._internal();
    return _instance!;
  }

  /// 拍照
  Future<CapturedImage?> takePicture() async {
    try {
      // TODO: 使用 image_picker 拍照
      // final picker = ImagePicker();
      // final XFile? image = await picker.pickImage(
      //   source: ImageSource.camera,
      //   maxWidth: 1920,
      //   maxHeight: 1080,
      //   imageQuality: 85,
      // );
      // if (image != null) {
      //   return CapturedImage(
      //     path: image.path,
      //     name: image.name,
      //     size: await image.length(),
      //   );
      // }

      // 模拟拍照结果
      print('[CameraService] 拍照（模拟）');
      return CapturedImage(
        path: '/mock/camera/photo_${DateTime.now().millisecondsSinceEpoch}.jpg',
        name: 'photo_${DateTime.now().millisecondsSinceEpoch}.jpg',
        size: 1024 * 1024, // 1MB
        source: ImageSource.camera,
      );
    } catch (e) {
      print('[CameraService] 拍照失败: $e');
      return null;
    }
  }

  /// 从相册选择图片
  Future<CapturedImage?> pickFromGallery() async {
    try {
      // TODO: 使用 image_picker 从相册选择
      // final picker = ImagePicker();
      // final XFile? image = await picker.pickImage(
      //   source: ImageSource.gallery,
      //   maxWidth: 1920,
      //   maxHeight: 1080,
      //   imageQuality: 85,
      // );
      // if (image != null) {
      //   return CapturedImage(
      //     path: image.path,
      //     name: image.name,
      //     size: await image.length(),
      //   );
      // }

      // 模拟选择结果
      print('[CameraService] 从相册选择（模拟）');
      return CapturedImage(
        path: '/mock/gallery/image_${DateTime.now().millisecondsSinceEpoch}.jpg',
        name: 'image_${DateTime.now().millisecondsSinceEpoch}.jpg',
        size: 2 * 1024 * 1024, // 2MB
        source: ImageSource.gallery,
      );
    } catch (e) {
      print('[CameraService] 选择图片失败: $e');
      return null;
    }
  }

  /// 选择多张图片
  Future<List<CapturedImage>> pickMultipleImages() async {
    try {
      // TODO: 使用 image_picker 多选
      // final picker = ImagePicker();
      // final List<XFile> images = await picker.pickMultiImage();
      // return images.map((img) => CapturedImage(...)).toList();

      print('[CameraService] 多选图片（模拟）');
      return [];
    } catch (e) {
      print('[CameraService] 多选图片失败: $e');
      return [];
    }
  }

  /// 上传图片文件
  Future<String?> uploadImage(File file, {String? uploadPath}) async {
    try {
      // TODO: 使用 Dio 上传文件
      // final formData = FormData.fromMap({
      //   'file': await MultipartFile.fromFile(file.path),
      // });
      // final response = await DioClient().post('/upload', data: formData);
      // return response.data['data']['url'];

      print('[CameraService] 上传图片（模拟）: ${file.path}');
      return 'https://api.example.com/uploads/mock_image.jpg';
    } catch (e) {
      print('[CameraService] 上传图片失败: $e');
      return null;
    }
  }
}

/// 拍摄/选择的图片模型
class CapturedImage {
  final String path;
  final String name;
  final int size;
  final ImageSource source;

  CapturedImage({
    required this.path,
    required this.name,
    required this.size,
    required this.source,
  });

  String get sizeFormatted {
    if (size < 1024) return '$size B';
    if (size < 1024 * 1024) return '${(size / 1024).toStringAsFixed(1)} KB';
    return '${(size / 1024 / 1024).toStringAsFixed(1)} MB';
  }
}

/// 图片来源
enum ImageSource {
  camera,
  gallery,
}