List<CameraDescription>? cameras;

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  cameras = await availableCameras();
}

// ----------- ai page .

class TestPage extends StatefulWidget {
  const TestPage({Key? key}) : super(key: key);

  @override
  State<TestPage> createState() => _TestPageState();
}

class _TestPageState extends State<TestPage> {
  bool isLoading = false;
  CameraImage? cameraImage;
  CameraController? cameraController;
  String result = '';

  loadCamera() {
    // 0 -- back camera
    // 1 -- front camera

    cameraController = CameraController(cameras![0], ResolutionPreset.medium);
    cameraController!.initialize().then((value) {
      if (!mounted) {
        return;
      } else {
        setState(() {
          cameraController!.startImageStream((imageFromStream) {
            if (!isLoading) {
              isLoading = true;
              cameraImage = imageFromStream;
              runModelOnStreamFrames();
            }
          });
        });
      }
    });
  }

  runModelOnStreamFrames() async {
    if (cameraImage != null) {
      var recognitions = await Tflite.runModelOnFrame(
          bytesList: cameraImage!.planes.map((plane) {
            return plane.bytes;
          }).toList(),
          imageHeight: cameraImage!.height,
          imageWidth: cameraImage!.width,
          imageMean: 127.5,
          imageStd: 127.5,
          rotation: 90,
          numResults: 2,
          threshold: 0.1,
          asynch: true);

      setState(() {
      result = '';
      for (var response in recognitions!) {
        result += response["label"] +
            " " +
            (response["confidence"] as double).toStringAsFixed(2) +
            "nn";
                 isLoading = false;
      }
      });
    }
  }

  loadModel() async {
    await Tflite.loadModel(
      model: "assets/machine/object.tflite",
      labels: "assets/machine/object.txt",
    );
  }

  @override
  void dispose() {
    super.dispose();
    Tflite.close();
    cameraController!.dispose();
  }

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

    loadModel().then((value) {
      setState(() {
        isLoading = false;
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('TestPage'),
      ),
      body: Container(
        decoration: const BoxDecoration(
          image: DecorationImage(
            image: AssetImage('assets/images/onboarding3.png'),
            fit: BoxFit.cover,
          ),
        ),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            if (cameraImage != null)
              Center(
                child: AspectRatio(
                  aspectRatio: cameraController!.value.aspectRatio,
                  child: CameraPreview(cameraController!),
                ),
              ),
            if (cameraImage == null)
            Center(
              child: ElevatedButton(
                  onPressed: () {
                    loadCamera();
                  },
                  child: Icon(Icons.camera_alt_outlined)),
            ),
            Center(
              child: Container(
                margin: const EdgeInsets.only(top: 20),
                child: Text(
                  result,
                  style: const TextStyle(
                    color: Colors.black,
                    fontSize: 20,
                  ),
                  textAlign: TextAlign.center,
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}