package domain.image.processing.outline;

import domain.image.GrayScaleMatrix;
import domain.image.Image;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;

public class LinearOutline {
    public static GrayScaleMatrix prewittGradient(Image image, int direction) {
        Mat kernel = new Mat(3, 3, CvType.CV_64F);
        if (direction == 1) {
            kernel.put(0, 0, -1, -1, -1, 0, 0, 0, 1, 1, 1);
        } else if (direction == 2) {
            kernel.put(0, 0, -1, 0, 1, -1, 0, 1, -1, 0, 1);
        } else {
            kernel.release();
            throw new IllegalArgumentException("Direction must be 1 or 2");
        }
        return applyKernel(image, kernel);
    }

    public static GrayScaleMatrix sobelGradient(Image image, int direction) {
        Mat kernel = new Mat(3, 3, CvType.CV_64F);
        if (direction == 1) {
            kernel.put(0, 0, -1, -2, -1, 0, 0, 0, 1, 2, 1);
        } else if (direction == 2) {
            kernel.put(0, 0, -1, 0, 1, -2, 0, 2, -1, 0, 1);
        } else {
            kernel.release();
            throw new IllegalArgumentException("Direction must be 1 or 2");
        }
        return applyKernel(image, kernel);
    }

    public static GrayScaleMatrix laplacian4(Image image) {
        Mat kernel = new Mat(3, 3, CvType.CV_64F);
        kernel.put(0, 0, 0, -1, 0, -1, 4, -1, 0, -1, 0);
        return applyKernel(image, kernel);
    }

    public static GrayScaleMatrix laplacian8(Image image) {
        Mat kernel = new Mat(3, 3, CvType.CV_64F);
        kernel.put(0, 0, -1, -1, -1, -1, 8, -1, -1, -1, -1);
        return applyKernel(image, kernel);
    }

    private static GrayScaleMatrix applyKernel(Image image, Mat kernel) {
        GrayScaleMatrix gray = image.toGrayScale();
        Mat input = new Mat(gray.getHeight(), gray.getWidth(), CvType.CV_64F);
        double[][] data = gray.getRawData();
        for (int y = 0; y < gray.getHeight(); y++) {
            input.put(y, 0, data[y]);
        }
        Mat result = new Mat();
        Imgproc.filter2D(input, result, CvType.CV_64F, kernel);
        double[][] output = new double[result.rows()][result.cols()];
        for (int y = 0; y < result.rows(); y++) {
            result.get(y, 0, output[y]);
        }
        input.release();
        result.release();
        kernel.release();
        return new GrayScaleMatrix(output);
    }
}