camera_scanner.dart

import 'dart:async';
import 'dart:io';
import 'dart:typed_data';
import 'package:camera/camera.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:google_mlkit_face_detection/google_mlkit_face_detection.dart';


class SelfieCamera extends StatefulWidget {
  const SelfieCamera({
    Key? key,
    required this.camera,
  }) : super(key: key);

  final CameraDescription camera;
  @override
  State<SelfieCamera> createState() => _SelfieCameraState();
}

class _SelfieCameraState extends State<SelfieCamera> with UIToolMixin {
  late CameraController _controller;
  FlashMode? _currentFlashMode;
  late Future<void> _initializeControllerFuture;
  bool faceDetected = false;
  final ValueNotifier<File?> _file = ValueNotifier(null);
  late final FaceDetector faceDetector;
  late double? deviceRatio;

  @override
  void initState() {
    super.initState();
    faceDetector = FaceDetector(
      options: FaceDetectorOptions(
        enableTracking: true,
        enableLandmarks: true,
        enableClassification: true,
        enableContours: true,
        performanceMode: FaceDetectorMode.accurate,
      ),
    );
    _controller = CameraController(
      widget.camera,
      ResolutionPreset.ultraHigh,
    );

    _initializeControllerFuture = _controller.initialize();
  }

  @override
  void dispose() {
    _controller.dispose();
    _controller.stopImageStream();
    faceDetector.close();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    deviceRatio = width(context) / height(context);
    return ClipRRect(
      borderRadius: const BorderRadius.vertical(top: Radius.circular(20)),
      child: Stack(
        children: [
          ValueListenableBuilder<File?>(
            valueListenable: _file,
            builder: (context, value, child) {
              if (value == null) {
                return Stack(
                  fit: StackFit.expand,
                  children: [
                    Column(
                      children: [
                        SizedBox(
                          width: width(context),
                          height: height(context) * 0.85,
                          child: FutureBuilder(
                            future: _initializeControllerFuture,
                            builder: (context, snapshot) {
                              if (snapshot.connectionState ==
                                  ConnectionState.done) {
                                if (Platform.isIOS) {
                                  _controller
                                      .startImageStream(_processCameraImage);
                                }
                                return AspectRatio(
                                  aspectRatio: deviceRatio ?? 0,
                                  child: CameraPreview(
                                    _controller,
                                    child: CustomPaint(
                                      painter: CameraShape(),
                                    ),
                                  ),
                                );
                              } else {
                                return const Center(
                                  child: CircularProgressIndicator.adaptive(),
                                );
                              }
                            },
                          ),
                        ),
                        Expanded(
                          child: Container(
                            color: Colors.white,
                          ),
                        ),
                      ],
                    ),
                  ],
                );
              }

              return Container(
                color: Colors.white,
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    SizedBox(
                      height: 100.h,
                    ),
                    Padding(
                      padding: EdgeInsets.symmetric(horizontal: 50.w),
                      child: Container(
                        width: 320.w,
                        height: 320.h,
                        decoration: BoxDecoration(
                          color: Colors.blue,
                          borderRadius:
                              BorderRadius.all(Radius.circular(700.r)),
                          image: DecorationImage(
                            image: FileImage(value),
                            fit: BoxFit.cover,
                          ),
                        ),
                      ),
                    ),
                    Expanded(
                      flex: 1,
                      child: Padding(
                        padding: const EdgeInsets.symmetric(
                            horizontal: 22.0, vertical: 40),
                        child: Column(
                          children: [
                            Padding(
                              padding:
                                  const EdgeInsets.symmetric(horizontal: 42.0),
                              child: Text(
                                'Take a selfie of yourself, We\'ll match this photo with the one on your BVN and ID card',
                                style: TextStyle(
                                  fontSize: 14.sp,
                                ),
                                textAlign: TextAlign.center,
                              ),
                            ),
                            const Spacer(),
                            AppOutlineButton(
                              title: 'Take Another Image',
                              useMerchantTheme: false,
                              onTap: () async {
                                _file.value!.delete();
                                _file.value = null;
                                _controller.resumePreview();
                              },
                            ),
                            const SizedBox(height: 10),
                            AkuFlatButton(
                              title: 'Submit',
                              useMerchantTheme: false,
                              onTap: () async {
                                if (faceDetected) {
                                  Navigator.of(context).pop(value);
                                  return;
                                }
                                showMessage(
                                  context: context,
                                  useMerchantTheme: false,
                                  title: 'Image Error',
                                  subtitle:
                                      'Please capture an image with a face',
                                  isDismissible: true,
                                  isRestriction: false,
                                );
                              },
                            ),
                          ],
                        ),
                      ),
                    ),
                  ],
                ),
              );
            },
          ),
          Container(
            color: Colors.white,
            child: Padding(
              padding: const EdgeInsets.only(
                  left: 18.0, right: 18.0, top: 19, bottom: 35),
              child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  Text(
                    'Take Picture',
                    style: TextStyle(
                      fontSize: 15.sp,
                      fontWeight: FontWeight.w600,
                      color: Colors.black,
                    ),
                  ),
                  InkWell(
                    onTap: () {
                      Navigator.pop(context);
                    },
                    child: Image.asset(
                      'assets/cancel.png',
                      height: 27.h,
                    ),
                  ),
                ],
              ),
            ),
          ),
          ValueListenableBuilder<File?>(
              valueListenable: _file,
              builder: (context, value, child) {
                if (value == null) {
                  return Positioned(
                    top: 620.h,
                    left: 0,
                    right: 0,
                    bottom: 46.h,
                    child: Container(
                      color: Colors.white,
                      child: Padding(
                        padding: const EdgeInsets.symmetric(horizontal: 22.0),
                        child: Column(
                          children: [
                            SizedBox(height: 40.h),
                            Padding(
                              padding:
                                  const EdgeInsets.symmetric(horizontal: 42.0),
                              child: Text(
                                'Take a selfie of yourself, We\'ll match this photo with the one on your BVN and ID card',
                                style: TextStyle(
                                  fontSize: 14.sp,
                                  color: Colors.black,
                                ),
                                textAlign: TextAlign.center,
                              ),
                            ),
                            const Spacer(),
                            AkuFlatButton(
                              title: 'Capture Picture',
                              useMerchantTheme: false,
                              onTap: () async {
                                if (Platform.isIOS) {
                                  if (faceDetected) {
                                    await _controller.setFlashMode(
                                      FlashMode.off,
                                    );
                                    _controller.pausePreview();
                                    XFile image =
                                        await _controller.takePicture();
                                    _file.value = File(image.path);
                                    _controller.stopImageStream();
                                    return;
                                  }
                                  showMessage(
                                    context: context,
                                    useMerchantTheme: false,
                                    title: 'Selfie Error',
                                    subtitle: 'Picture Target is not a face',
                                    isDismissible: true,
                                    isRestriction: false,
                                  );
                                } else {
                                  await _controller.setFlashMode(
                                    FlashMode.off,
                                  );
                                  _controller.pausePreview();
                                  XFile image = await _controller.takePicture();
                                  _file.value = File(image.path);
                                  _recognizeImage(File(image.path));
                                }
                              },
                            ),
                          ],
                        ),
                      ),
                    ),
                  );
                } else {
                  return Container();
                }
              }),
        ],
      ),
    );
  }

  Future<bool> _detect(InputImage inputImage) async {
    final List<Face> faces = await faceDetector.processImage(inputImage);

    for (Face face in faces) {
      final FaceLandmark? leftEar = face.landmarks[FaceLandmarkType.leftEar];
      final FaceLandmark? rightEar = face.landmarks[FaceLandmarkType.rightEye];
      final FaceLandmark? rightEye = face.landmarks[FaceLandmarkType.rightEye];
      final FaceLandmark? leftEye = face.landmarks[FaceLandmarkType.leftEye];

      if (leftEar == null && rightEar == null) {
        return false;
      }

      if (leftEye == null && rightEye == null) {
        return false;
      }

      if (face.smilingProbability == null) {
        return false;
      }

      return true;
    }

    return false;
  }

  // this function is for detecting faces in an already taken image
  // this is for android because doing it from the image stream consumes a lot of resources
  void _recognizeImage(File image) async {
    final inputImage = InputImage.fromFilePath(image.path);
    final faceDetected = await _detect(inputImage);

    if (!mounted) {
      return;
    }
    setState(() {
      this.faceDetected = faceDetected;
    });
  }

  // this function is for detecting on ios because checking the file type returned on ios 
  // is not in a format the plugin can work with, so you have detect the face while working with the image
  // stream
  Future _processCameraImage(CameraImage image) async {
    final WriteBuffer allBytes = WriteBuffer();
    for (final Plane plane in image.planes) {
      allBytes.putUint8List(plane.bytes);
    }
    final bytes = allBytes.done().buffer.asUint8List();

    final Size imageSize =
        Size(image.width.toDouble(), image.height.toDouble());

    const imageRotation = InputImageRotation.rotation90deg;

    final inputImageFormat =
        InputImageFormatValue.fromRawValue(image.format.raw) ??
            InputImageFormat.nv21;

    final planeData = image.planes.map(
      (Plane plane) {
        return InputImagePlaneMetadata(
          bytesPerRow: plane.bytesPerRow,
          height: plane.height,
          width: plane.width,
        );
      },
    ).toList();

    final inputImageData = InputImageData(
      size: imageSize,
      imageRotation: imageRotation,
      inputImageFormat: inputImageFormat,
      planeData: planeData,
    );

    final inputImage =
        InputImage.fromBytes(bytes: bytes, inputImageData: inputImageData);

    final faceDetected = await _detect(inputImage);
    if (!mounted) {
      return;
    }
    setState(() {
      this.faceDetected = faceDetected;
    });
  }
}

class CameraShape extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    canvas.drawPath(
        Path()
          ..moveTo(0, 0)
          ..lineTo(0, size.height)
          ..lineTo(size.width, size.height)
          ..lineTo(size.width, 0)
          ..close()
          ..moveTo(size.width / 2, size.height / 2)
          ..addOval(Rect.fromCircle(
              center: Offset(size.width / 2, size.height / 2), radius: 170))
          ..close(),
        Paint()..color = Colors.black54);
    canvas.drawPath(
      Path()
        ..moveTo(size.width / 2, size.height / 2)
        ..addOval(Rect.fromCircle(
            center: Offset(size.width / 2, size.height / 2), radius: 170))
        ..close(),
      Paint()
        ..color = Colors.cyan
        ..style = PaintingStyle.stroke,
    );
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) {
    return false;
  }
}

class CameraClip extends CustomClipper<Rect> {
  @override
  bool shouldReclip(covariant CustomClipper oldClipper) {
    return false;
  }

  @override
  Rect getClip(Size size) {
    return Rect.fromCircle(
        center: Offset(size.width / 2, size.width / 3), radius: 150);
  }
}