ChickenFarm/UI/CF.APP/chicken_farm/lib/components/watermarked_camera.dart

import 'dart:io';
import 'dart:typed_data';
import 'dart:ui' as ui;

import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:intl/intl.dart';
import 'package:path_provider/path_provider.dart';
import 'package:chicken_farm/core/utils/logger.dart';

class WatermarkedCamera extends StatefulWidget {
  final Function(File)? onImageCaptured;
  final String? watermarkText;

  const WatermarkedCamera({
    super.key,
    this.onImageCaptured,
    this.watermarkText,
  });

  @override
  State<WatermarkedCamera> createState() => _WatermarkedCameraState();
}

class _WatermarkedCameraState extends State<WatermarkedCamera> {
  XFile? _capturedImage;
  File? _watermarkedImage;
  bool _isProcessing = false;

  Future<void> _takePicture() async {
    try {
      final ImagePicker picker = ImagePicker();
      final XFile? photo = await picker.pickImage(
        source: ImageSource.camera,
        imageQuality: 80,
      );

      if (photo != null) {
        setState(() {
          _capturedImage = photo;
          _isProcessing = true;
        });

        // 添加水印并处理图像
        await _addWatermark(photo);
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(
          context,
        ).showSnackBar(SnackBar(content: Text('拍照失败: $e')));
      }
      logger.e('拍照失败: $e');
    }
  }

  Future<void> _addWatermark(XFile imageFile) async {
    try {
      // 获取水印文本
      String watermark =
          widget.watermarkText ??
          DateFormat('yyyy-MM-dd HH:mm:ss').format(DateTime.now());

      // 将图片转换为字节以便处理
      final Uint8List imageBytes = await imageFile.readAsBytes();

      // 创建图片对象
      final ui.Codec codec = await ui.instantiateImageCodec(imageBytes);
      final ui.FrameInfo frameInfo = await codec.getNextFrame();
      final ui.Image image = frameInfo.image;

      // 创建画布
      final ui.PictureRecorder recorder = ui.PictureRecorder();
      final ui.Canvas canvas = ui.Canvas(recorder);

      // 绘制原始图片
      canvas.drawImage(image, Offset.zero, ui.Paint());

      // 添加水印文字
      final ui.ParagraphBuilder paragraphBuilder = ui.ParagraphBuilder(
        ui.ParagraphStyle(
          textAlign: TextAlign.left,
          fontSize: 24.0,
          textDirection: ui.TextDirection.ltr,
        ),
      );

      paragraphBuilder.pushStyle(
        ui.TextStyle(
          color: const ui.Color(0x80FFFFFF), // 半透明白色
          fontSize: 24.0,
        ),
      );

      paragraphBuilder.addText(watermark);

      final ui.Paragraph paragraph = paragraphBuilder.build()
        ..layout(ui.ParagraphConstraints(width: image.width.toDouble()));

      // 在右下角绘制水印
      canvas.drawParagraph(
        paragraph,
        Offset(
          image.width.toDouble() - paragraph.width - 20,
          image.height.toDouble() - 40,
        ),
      );

      // 完成绘制
      final ui.Picture picture = recorder.endRecording();
      final ui.Image watermarkedImage = await picture.toImage(
        image.width,
        image.height,
      );

      // 转换为字节数据
      final ByteData? byteData = await watermarkedImage.toByteData(
        format: ui.ImageByteFormat.png,
      );

      if (byteData != null) {
        // 保存到临时文件
        final tempDir = await getTemporaryDirectory();
        final file = File(
          '${tempDir.path}/watermarked_${DateTime.now().millisecondsSinceEpoch}.png',
        );
        await file.writeAsBytes(byteData.buffer.asUint8List());

        setState(() {
          _watermarkedImage = file;
          _isProcessing = false;
        });
      } else {
        setState(() {
          _isProcessing = false;
        });

        if (mounted) {
          ScaffoldMessenger.of(
            context,
          ).showSnackBar(const SnackBar(content: Text('处理图片失败')));
        }
        logger.e('处理图片失败');
      }
    } catch (e) {
      setState(() {
        _isProcessing = false;
      });

      if (mounted) {
        ScaffoldMessenger.of(
          context,
        ).showSnackBar(SnackBar(content: Text('添加水印失败: $e')));
      }
      logger.e('添加水印失败: $e');
    }
  }

  void _confirmImage() {
    if (_watermarkedImage != null && widget.onImageCaptured != null) {
      widget.onImageCaptured!(_watermarkedImage!);
    }

    Navigator.of(context).pop();
  }

  void _retakePicture() {
    setState(() {
      _capturedImage = null;
      _watermarkedImage = null;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('拍照签到'),
        leading: IconButton(
          icon: const Icon(Icons.close),
          onPressed: () => Navigator.of(context).pop(),
        ),
      ),
      body: Column(
        children: [
          Expanded(
            child: _capturedImage == null
                ? Center(
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        const Icon(
                          Icons.camera_alt,
                          size: 100,
                          color: Colors.grey,
                        ),
                        const SizedBox(height: 20),
                        const Text('点击按钮拍照', style: TextStyle(fontSize: 18)),
                      ],
                    ),
                  )
                : _isProcessing
                ? const Center(child: CircularProgressIndicator())
                : Center(
                    child: _watermarkedImage != null
                        ? Image.file(_watermarkedImage!)
                        : Image.file(File(_capturedImage!.path)),
                  ),
          ),
          Padding(
            padding: const EdgeInsets.all(16.0),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                if (_capturedImage == null)
                  FloatingActionButton(
                    onPressed: _takePicture,
                    child: const Icon(Icons.camera),
                  )
                else if (!_isProcessing)
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                    children: [
                      ElevatedButton(
                        onPressed: _retakePicture,
                        style: ElevatedButton.styleFrom(
                          backgroundColor: Colors.grey,
                          foregroundColor: Colors.white,
                        ),
                        child: const Text('重新拍照'),
                      ),
                      ElevatedButton(
                        onPressed: _confirmImage,
                        style: ElevatedButton.styleFrom(
                          backgroundColor: Colors.green,
                          foregroundColor: Colors.white,
                        ),
                        child: const Text('确认提交'),
                      ),
                    ],
                  ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}