// 图片选择 + 压缩 + 缩略图生成工具类
//
// 职责：
// - 从相机/相册选择图片
// - 压缩到合理尺寸（≤1024px, 质量 85）
// - 生成缩略图（≤200px, 质量 70）

import 'package:flutter_image_compress/flutter_image_compress.dart';
import 'package:image_picker/image_picker.dart';
import 'package:path_provider/path_provider.dart';
import 'package:uuid/uuid.dart';

/// 图片选择 + 压缩 + 缩略图生成
class ImagePickerHandler {
  static const _uuid = Uuid();

  /// 从相机或相册选择图片
  /// 返回压缩后的本地文件路径，取消返回 null
  static Future<String?> pickImage({required bool fromCamera}) async {
    final picker = ImagePicker();
    final xFile = await picker.pickImage(
      source: fromCamera ? ImageSource.camera : ImageSource.gallery,
      maxWidth: 1024,
      maxHeight: 1024,
      imageQuality: 85,
    );
    if (xFile == null) return null;

    // 压缩图片
    final compressedPath = await _compressImage(xFile.path);
    return compressedPath;
  }

  /// 生成缩略图路径
  static Future<String> generateThumbnail(String imagePath) async {
    final dir = await getApplicationDocumentsDirectory();
    final thumbName = 'thumb_${_uuid.v4()}.jpg';
    final thumbPath = '${dir.path}/$thumbName';

    final result = await FlutterImageCompress.compressAndGetFile(
      imagePath,
      thumbPath,
      minHeight: 200,
      minWidth: 200,
      quality: 70,
    );

    return result?.path ?? imagePath;
  }

  /// 压缩原图
  static Future<String> _compressImage(String path) async {
    final dir = await getApplicationDocumentsDirectory();
    final fileName = 'img_${_uuid.v4()}.jpg';
    final targetPath = '${dir.path}/$fileName';

    final result = await FlutterImageCompress.compressAndGetFile(
      path,
      targetPath,
      quality: 85,
      minWidth: 1024,
      minHeight: 1024,
    );

    return result?.path ?? path;
  }
}