using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using OpenCVForUnity.CoreModule;
using OpenCVForUnity.ImgprocModule;
using System.Linq;
using Vuforia;

public class detection_script : MonoBehaviour
{
    Mat cameraImageMat;
    Mat stylizedMat = new Mat();
    Mat greyMat = new Mat();


    int width = 400;
    int height = 400;

    Texture2D outputTexture;
    MatOfPoint2f dstPoints;

    // Start is called before the first frame update
    void Start()
    {
        dstPoints = new MatOfPoint2f();
        dstPoints.alloc(4);
        dstPoints.put(3, 0, width, height);
        dstPoints.put(2, 0, 0, height);
        dstPoints.put(1, 0, width, 0);
        dstPoints.put(0, 0, 0, 0);
        outputTexture = new Texture2D(width, height, TextureFormat.RGBA32, false);
    }

    // Update is called once per frame
    void Update()
    {
        MatDisplay.SetCameraFoV(41.5f);

        Image cameraImage = CameraDevice.Instance.GetCameraImage(Image.PIXEL_FORMAT.RGBA8888);

        if (cameraImage != null)
        {
            if (cameraImageMat == null)
            {
                cameraImageMat = new Mat(cameraImage.Height, cameraImage.Width, CvType.CV_8UC4);
            }
            cameraImageMat.put(0, 0, cameraImage.Pixels);

            Imgproc.cvtColor(cameraImageMat, greyMat, Imgproc.COLOR_RGB2GRAY);


            Imgproc.threshold(greyMat, stylizedMat, 69, 255, Imgproc.THRESH_BINARY);


            List<MatOfPoint> contourList = new List<MatOfPoint>();
            Mat hierarchy = new Mat();
            Imgproc.findContours(stylizedMat, contourList, hierarchy, Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);

            //Imgproc.drawContours(cameraImageMat, contourList, -1, new Scalar(255,0,0), 2);

            List<MatOfPoint> squareContours = new List<MatOfPoint>();
            foreach (var contour in contourList)
            {
                MatOfPoint2f contour2f = new MatOfPoint2f();
                contour.convertTo(contour2f, CvType.CV_32FC2);

                double epsilon = 0.01f * Imgproc.arcLength(contour2f, true);
                MatOfPoint2f approx = new MatOfPoint2f();
                Imgproc.approxPolyDP(contour2f, approx, epsilon, true);

                if (approx.toList().Count == 4)
                {
                    Imgproc.drawContours(cameraImageMat, new List<MatOfPoint> { contour }, -1, new Scalar(255,0,0), 2);
                    squareContours.Add(contour);
                }
            }


            MatOfPoint square = findSquare(squareContours);
            if (square == null)
            {
                MatDisplay.DisplayMat(cameraImageMat, MatDisplaySettings.FULL_BACKGROUND);
                // TODO: Maybe display cam first
                return;
            }

            Imgproc.drawContours(cameraImageMat, new List<MatOfPoint> { square }, -1, new Scalar(0, 255, 0), 2);



            MatDisplay.DisplayMat(cameraImageMat, MatDisplaySettings.FULL_BACKGROUND);
            
        }
    }

    MatOfPoint findSquare (List<MatOfPoint> squareContours)
    {
        foreach (var outer_square in squareContours)
        {
            var outer_maxX = outer_square.toList().Max(point => point.x);
            var outer_maxY = outer_square.toList().Max(point => point.y);

            var outer_minX = outer_square.toList().Min(point => point.x);
            var outer_minY = outer_square.toList().Min(point => point.y);

            foreach (var inner_square in squareContours)
            {
                var inner_maxX = inner_square.toList().Max(point => point.x);
                var inner_maxY = inner_square.toList().Max(point => point.y);

                var inner_minX = inner_square.toList().Min(point => point.x);
                var inner_minY = inner_square.toList().Min(point => point.y);

                if (outer_minX < inner_minX &&
                    outer_minY < inner_minY &&
                    outer_maxX > inner_maxX &&
                    outer_maxY > inner_maxY)
                {
                    return outer_square;
                }
            }
        }
        return null;
    }
}