#include "helpers.h"
#include <math.h>

void blur(int height, int width, RGBTRIPLE image[height][width])
{
    // make a copy
    RGBTRIPLE copy[height][width];
    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            copy[i][j].rgbtRed = image[i][j].rgbtRed;
            copy[i][j].rgbtGreen = image[i][j].rgbtGreen;
            copy[i][j].rgbtBlue = image[i][j].rgbtBlue;
        }
    }

    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            int pixelCount = 1, sumRed = 0, sumGreen = 0, sumBlue = 0, avgRed, avgGreen, avgBlue;
            for (int a = i - 1; a < i + 2; a++)
            {
                for (int b = j - 1; b < j + 2; b++)
                {
                    // check whether the pixel lies inside the image
                    if (a < 0 || a > height - 1 || b < 0 || b > width - 1)
                    {
                        continue;
                    }
                    // add values of each channel
                    sumRed += copy[a][b].rgbtRed;
                    sumGreen += copy[a][b].rgbtGreen;
                    sumBlue += copy[a][b].rgbtBlue;
                    pixelCount++;
                }
            }
            // calculate the average
            avgRed = round(sumRed / (float) pixelCount);
            avgGreen = round(sumBlue / (float) pixelCount);
            avgBlue = round(sumGreen / (float) pixelCount);

            // change the values of each pixel
            image[i][j].rgbtRed = avgRed;
            image[i][j].rgbtGreen = avgGreen;
            image[i][j].rgbtBlue = avgBlue;
        }
    }
    return;
}