package com.thealgorithms.dynamicprogramming;

/**
 * Java program for Boundary fill algorithm.
 * @author Akshay Dubey (https://github.com/itsAkshayDubey)
 */
public class BoundaryFill {

    /**
     * Get the color at the given co-odrinates of a 2D image
     *
     * @param image The image to be filled
     * @param x_co_ordinate The x co-ordinate of which color is to be obtained
     * @param y_co_ordinate The y co-ordinate of which color is to be obtained
     */
    public static int getPixel(int[][] image, int x_co_ordinate, int y_co_ordinate) {
        return image[x_co_ordinate][y_co_ordinate];
    }

    /**
     * Put the color at the given co-odrinates of a 2D image
     *
     * @param image The image to be filed
     * @param x_co_ordinate The x co-ordinate at which color is to be filled
     * @param y_co_ordinate The y co-ordinate at which color is to be filled
     */
    public static void putPixel(int[][] image, int x_co_ordinate, int y_co_ordinate, int new_color) {
        image[x_co_ordinate][y_co_ordinate] = new_color;
    }

    /**
     * Fill the 2D image with new color
     *
     * @param image The image to be filed
     * @param x_co_ordinate The x co-ordinate at which color is to be filled
     * @param y_co_ordinate The y co-ordinate at which color is to be filled
     * @param new_color The new color which to be filled in the image
     * @param boundary_color The old color which is to be replaced in the image
     */
    public static void boundaryFill(int[][] image, int x_co_ordinate, int y_co_ordinate, int new_color, int boundary_color) {
        if (x_co_ordinate >= 0 && y_co_ordinate >= 0 && getPixel(image, x_co_ordinate, y_co_ordinate) != new_color && getPixel(image, x_co_ordinate, y_co_ordinate) != boundary_color) {
            putPixel(image, x_co_ordinate, y_co_ordinate, new_color);
            boundaryFill(image, x_co_ordinate + 1, y_co_ordinate, new_color, boundary_color);
            boundaryFill(image, x_co_ordinate - 1, y_co_ordinate, new_color, boundary_color);
            boundaryFill(image, x_co_ordinate, y_co_ordinate + 1, new_color, boundary_color);
            boundaryFill(image, x_co_ordinate, y_co_ordinate - 1, new_color, boundary_color);
            boundaryFill(image, x_co_ordinate + 1, y_co_ordinate - 1, new_color, boundary_color);
            boundaryFill(image, x_co_ordinate - 1, y_co_ordinate + 1, new_color, boundary_color);
            boundaryFill(image, x_co_ordinate + 1, y_co_ordinate + 1, new_color, boundary_color);
            boundaryFill(image, x_co_ordinate - 1, y_co_ordinate - 1, new_color, boundary_color);
        }
    }

    /**
     * This method will print the 2D image matrix
     *
     * @param image The image to be printed on the console
     */
    public static void printImageArray(int[][] image) {
        for (int i = 0; i < image.length; i++) {
            for (int j = 0; j < image[0].length; j++) {
                System.out.print(image[i][j] + "  ");
            }

            System.out.println();
        }
    }

    // Driver Program
    public static void main(String[] args) {
        // Input 2D image matrix
        int[][] image = {
            {0, 0, 0, 0, 0, 0, 0},
            {0, 3, 3, 3, 3, 0, 0},
            {0, 3, 0, 0, 3, 0, 0},
            {0, 3, 0, 0, 3, 3, 3},
            {0, 3, 3, 3, 0, 0, 3},
            {0, 0, 0, 3, 0, 0, 3},
            {0, 0, 0, 3, 3, 3, 3},
        };

        boundaryFill(image, 2, 2, 5, 3);

        /* Output ==>
                 * 0  0  0  0  0  0  0
                   0  3  3  3  3  0  0
                   0  3  5  5  3  0  0
           0  3  5  5  3  3  3
           0  3  3  3  5  5  3
           0  0  0  3  5  5  3
           0  0  0  3  3  3  3
                 * */

        // print 2D image matrix
        printImageArray(image);
    }
}