using OpenCvSharp;
using ZXing;
using ZXing.QrCode;
using OpenCvSharp.Extensions;
using ZXing.Windows.Compatibility;
using ZXing.Common;
using System.Runtime.InteropServices;
using System.Drawing;
using System.Net;
using System.Runtime.InteropServices.Marshalling;
using Emgu.CV.Face;

// using Emgu.CV.CvEnum;


namespace BarcodeReaderExample
{
    class Program
    {
        static void Main(string[] args)
        {
            VideoCapture camera = new VideoCapture("/dev/video0", VideoCaptureAPIs.V4L2);

            if (!camera.IsOpened())
                throw new Exception("Nie można otworzyć kamery /dev/video0");

            camera.Set(VideoCaptureProperties.FrameWidth, 1280);
            camera.Set(VideoCaptureProperties.FrameHeight, 720);
            int fps = 60;
            int avalibeImages = 20;
            camera.Set(VideoCaptureProperties.Fps, fps);
            if (Directory.Exists("cache"))
            {
                Directory.Delete("cache", true);
            }

            Directory.CreateDirectory("cache");
            Mat hey = new Mat("photo.png");
            Mat[] Cached = new Mat[avalibeImages];


            int imgX = 0;
            int imgY = 0;

            using var rgb = new Mat();

            // OpenCV stores camera frames as BGR.
            // ZXing's RGBLuminanceSource expects RGB.
            // Cv2.CvtColor(frame, rgb, ColorConversionCodes.BGR2RGB);



            Cv2.NamedWindow("Camera preview", WindowFlags.AutoSize);
            // Mat src = Cv2.ImRead("test.png");
            int whenWasLastTimeQrDetected = 0;
            Mat Lastimage = new Mat();
            IEnumerable<IEnumerable<OpenCvSharp.Point>> contours = null;
                    // PointF[] location;

            string[] files = new string[avalibeImages];
            int files_index = 0;
            while (true)
            {


                camera.Read(frame);

                Result result = ReadQrCode(frame);
// Console.WriteLine(Lastimage.Empty());
                if (!(Lastimage.Empty()))
                {
                    
                    Mat roi2 = frame[new Rect(0, 0, Lastimage.Width, Lastimage.Height)];
                    Lastimage.CopyTo(roi2);
                }

                if (result != null)
                {
                    whenWasLastTimeQrDetected = 5;
                    List<ResultPoint> points = result.ResultPoints.ToList();
                    float[] pos1 = new float[2] { points[0].X, points[0].Y }; /// lewy dolny róg
                    float[] pos2 = new float[2] { points[2].X, points[2].Y };   ///prawy górny róg
                    float[] pos3 = new float[2] { points[1].X, points[1].Y };   ///lewy górny róg
                    int width = (int)(pos2[0] - pos3[0]);
                    int heigh = (int)(pos1[1] - pos3[1]);

                    PointF[] location;
                    try
                    {

                        location = Calculate(pos1, pos2, pos3, new float[2] { points[3].X, points[3].Y });
                    }
                    catch
                    {
                        continue;
                    }
                    var points1 = new List<OpenCvSharp.Point>
{
    GetPoint(location[0]),
    GetPoint(location[1]),
    GetPoint(location[3]),
    GetPoint(location[2])
};
                    int qrWidth = GetPoint(location[1]).X - GetPoint(location[0]).X;
                    int qrHeigh = GetPoint(location[2]).Y - GetPoint(location[0]).Y;


                    imgX = GetPoint(location[0]).X;
                    imgY = GetPoint(location[0]).Y;
                    contours = new[] { points1 };


                    Cv2.FillPoly(frame, contours, Scalar.White);   // fill with white

                    //Write Text
                    // Cv2.PutText(frame, result.Text, new OpenCvSharp.Point((int)(pos2[0]-pos3[0])/2+(int)pos3[0]-160, (int)(pos2[1]-pos3[1])/2+(int)pos3[1]+60), HersheyFonts.HersheySimplex, 0.8, Scalar.Black, 2);

                    if (!files.Contains(result.Text))
                    {
                        files[files_index] = result.Text;
                        Console.WriteLine("downloading: " + result.Text);

                        using (var client = new WebClient())
                        {
                            client.DownloadFile(result.Text, "cache/" + files_index + ".png");
                            // Thread.Sleep(2000);

                        }
                        Cached[files_index] = new Mat("cache/" + files_index + ".png");
                        files_index++;
                    }
                    else
                    {

                        int toload = files.IndexOf(result.Text);
                        Mat toDraw= new Mat();


                        InputArray inputArray = toDraw;
                        // Console.WriteLine($"{qrWidth} , {qrHeigh}");

                        try
                        {
                            
                        Cv2.Resize(Cached[toload],toDraw,new OpenCvSharp.Size(qrWidth,qrHeigh));
                        }
                        catch
                        {continue;}
                        Lastimage = toDraw;

                        // toDraw.Resize(1,3);
                        try
                        {
                            
                        Mat roi2 = frame[new Rect(GetPoint(location[0]).X, GetPoint(location[0]).Y, toDraw.Width, toDraw.Height)];
                        toDraw.CopyTo(roi2);
                        }
                        catch{}

                    }


                }
                else if (whenWasLastTimeQrDetected > 0)
                {
                    Cv2.FillPoly(frame, contours, Scalar.White);   // fill with white

  try
                        {
                    Mat roi2 = frame[new Rect(imgX, imgY, Lastimage.Width, Lastimage.Height)];
                    Lastimage.CopyTo(roi2);
                        }
                        catch{}
                    whenWasLastTimeQrDetected--;

                }


                Cv2.ImShow("Camera preview", frame);
                Thread.Sleep(1000 / fps);

                int key = Cv2.WaitKey(1);
                if (key == 27 || key == 'q')
                    break;
            }

            Cv2.DestroyAllWindows();

        }

        static void rotate()
        {
        }
        static OpenCvSharp.Point GetPoint(PointF pointf)
        {
            return new OpenCvSharp.Point(pointf.X, pointf.Y);
        }
        static PointF[] Calculate(float[] pos1, float[] pos2, float[] pos3, float[] pos4)
        {
            // Your 4 detected points (change the names if needed)
            PointF p1 = new PointF(pos1[0], pos1[1]);
            PointF p2 = new PointF(pos2[0], pos2[1]);
            PointF p3 = new PointF(pos3[0], pos3[1]);
            PointF p4 = new PointF(pos4[0], pos4[1]);

            // 1. Find the center of the QR
            float centerX = (p1.X + p2.X + p3.X + p4.X) / 4f;
            float centerY = (p1.Y + p2.Y + p3.Y + p4.Y) / 4f;
            PointF center = new PointF(centerX, centerY);

            // 2. How much bigger you want the box (1.0 = exact size, 1.15 = 15% bigger)
            float scale = 1.35f;   // ← change this value

            // 3. Move every corner away from the center
            PointF Expand(PointF p)
            {
                float dx = p.X - center.X;
                float dy = p.Y - center.Y;
                return new PointF(center.X + dx * scale, center.Y + dy * scale);
            }

            float scaleLB = 1.75f;   // ← change this value
            PointF ExpandLB(PointF p)
            {
                float dx = p.X - center.X;
                float dy = p.Y - center.Y;
                return new PointF(center.X + dx * scaleLB, center.Y + dy * scaleLB);
            }

            PointF topLeft = Expand(p3);   // change order if needed
            PointF topRight = Expand(p2);
            PointF bottomRight = ExpandLB(p4);
            PointF bottomLeft = Expand(p1);
            PointF[] Location = new PointF[] { topLeft, topRight, bottomLeft, bottomRight };
            return Location;
            // 4. Now draw the 4 lines
            // Example with System.Drawing or Unity or whatever you use:

        }
        static void DrawLine(PointF p1, PointF p2)
        {
            Cv2.Line(frame, (int)p1.X, (int)p1.Y, (int)p2.X, (int)p2.Y, Scalar.Red, 2);

        }
        static void DrawLine(PointF[] Location)
        {
            DrawLine(Location[0], Location[1]);


            DrawLine(Location[1], Location[2]);
            DrawLine(Location[2], Location[3]);
            DrawLine(Location[3], Location[0]);

        }
        static void DrawLine(float x1, float y1, float x2, float y2)
        {
            Cv2.Line(frame, (int)x1, (int)y1, (int)x2, (int)y2, Scalar.Red, 2);
        }
        static Mat frame = new Mat();

        static Result ReadQrCode(Mat frame)
        {

            QRCodeReader reader = new QRCodeReader();
            Result result = reader.decode(MatToBinaryBitmap(frame));
            return result;
        }
        static BinaryBitmap MatToBinaryBitmap(Mat frame)
        {
            if (frame.Empty())
                throw new ArgumentException("The Mat is empty.", nameof(frame));

            using var rgb = new Mat();

            // OpenCV uses BGR; ZXing RGBLuminanceSource expects RGB.
            Cv2.CvtColor(
                frame,
                rgb,
                ColorConversionCodes.BGR2RGB
            );

            // Clone ensures contiguous pixel memory.
            using var contiguous = rgb.Clone();

            int width = contiguous.Width;
            int height = contiguous.Height;

            int byteCount = checked(
                (int)(contiguous.Total() * contiguous.ElemSize())
            );

            byte[] pixels = new byte[byteCount];

            Marshal.Copy(
                contiguous.Data,
                pixels,
                0,
                pixels.Length
            );

            var luminanceSource = new RGBLuminanceSource(
                pixels,
                width,
                height,
                RGBLuminanceSource.BitmapFormat.RGB24
            );

            return new BinaryBitmap(
                new HybridBinarizer(luminanceSource)
            );
        }
    }
}