#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>

FILE* fileIn;
FILE* fileOut;

double pi = 3.1415926535897932384626433832795;
double sigma = 0.6;

void inputCheck(int argc, char* argv[])
{
    if (argc != 4 || !(strcmp(argv[2], "Averaging") == 0 || strcmp(argv[2], "Gauss3") == 0 || strcmp(argv[2], "Gauss5") == 0 || strcmp(argv[2], "Sobel") == 0
        || strcmp(argv[2], "SobelX") == 0 || strcmp(argv[2], "SobelY") == 0 || strcmp(argv[2], "ColorWB") == 0) || fopen_s(&fileIn, argv[1], "rb") != 0)
    {
        printf("Invalid input. Try again.");
        exit(0);
    }
}

#pragma pack(push, 1)
struct BITMAPFILEHEADER
{
    unsigned short  bfType;
    unsigned int bfSize;
    unsigned short bfReserved1;
    unsigned short bfReserved2;
    unsigned int bfOffBits;
};

struct BITMAPINFOHEADER {
    unsigned int biSize;
    unsigned int  biWidth;
    unsigned int  biHeight;
    unsigned short  biPlanes;
    unsigned short  biBitCount;
    unsigned int biCompression;
    unsigned int biSizeImage;
    unsigned int  biXPelsPerMeter;
    unsigned int  biYPelsPerMeter;
    unsigned int biClrUsed;
    unsigned int biClrImportant;
};
#pragma pack(pop)

void convolution(unsigned char* bitMapImage, int height, int width, char* mode)
{
    if (strcmp(mode, "ColorWB") == 0)
    {
        for (int i = 0; i < height * width; i++)
        {
            unsigned char result = (299 * bitMapImage[i * 3] + 587 * bitMapImage[i * 3 + 1] + 114 * bitMapImage[i * 3 + 2]) / 1000;
            bitMapImage[i * 3] = result;
            bitMapImage[i * 3 + 1] = result;
            bitMapImage[i * 3 + 2] = result;
        }
        return;
    }

    unsigned char* bitMapImageCopy = (unsigned char*)malloc(3 * height * width * sizeof(unsigned char));
    for (int i = 0; i < 3 * height * width; i++)
        bitMapImageCopy[i] = bitMapImage[i];

    int* steps = (int*)malloc(18 * sizeof(int));

    for (int i = -1; i <= 1; i++)
        for (int j = -1; j <= 1; j++)
        {
            steps[(i + 1) * 9 + j + 1] = i;
            steps[(i + 1) * 9 + j + 2] = j;
        }

    double* matrix = (double*)malloc(9 * sizeof(double));
    int size = 1;
    if (strcmp(mode, "Gauss5") == 0)
    {
        steps = (int*)realloc(steps, 50 * sizeof(int));
        printf("asfgd\n");
        for (int i = -2; i <= 2; i++)
            for (int j = -2; j <= 2; j++)
            {
                steps[(i + 2) * 25 + j + 1] = i;
                steps[(i + 2) * 25 + j + 2] = j;
            }

        size = 2;

        matrix = (double*)realloc(matrix, 25 * sizeof(double));
        for (int x = -2; x < 2 + 1; x++)
            for (int y = -2; y < 2 + 1; y++)
                matrix[(x + 2) * 5 + y + 2] = 1 / sqrt(2 * pi * sigma) * exp(-(x * x + y * y) / (2 * sigma * sigma));
    }
    else if (strcmp(mode, "Averaging") == 0)
    {
        double source[9] = { 1, 1, 1, 1, 1, 1, 1, 1, 1 };
        for (int i = 0; i < 9; i++)
            matrix[i] = source[i];
    }
    else if (strcmp(mode, "Gauss3") == 0)
    {
        for (int x = -1; x < 1 + 1; x++)
            for (int y = -1; y < 1 + 1; y++)
                matrix[(x + 1) * 3 + y + 1] = 1 / sqrt(2 * pi * sigma) * exp(-(x * x + y * y) / (2 * sigma * sigma));
    }
    else if (strcmp(mode, "SobelX") == 0)
    {
        int source[9] = { -1, 0, 1, -2, 0, 2, -1, 0, 1 };
        for (int i = 0; i < 9; i++)
            matrix[i] = source[i];
    }
    else if (strcmp(mode, "SobelY") == 0)
    {
        int source[9] = { -1, -2, -1, 0, 0, 0, 1, 2, 1 };
        for (int i = 0; i < 9; i++)
            matrix[i] = source[i];
    }

    for (int i = 0; i < 9; i++)
        printf("%f ", matrix[i]);

    for (int i = 0; i < height; i++)
        for (int j = 0; j < width; j++)
        {
            double result[3] = { 0, 0, 0 };
            double divisor = 0;

            for (int step = 0; step < (2 * size + 1) * (2 * size + 1); step++)
                if (i + steps[step * 2] >= 0 && i + steps[step * 2] < height && j + steps[step * 2 + 1] >= 0 && j + steps[step * 2 + 1] < width)
                {
                    result[0] += bitMapImage[((i + steps[step * 2]) * width + j + steps[step * 2 + 1]) * 3] * matrix[(steps[step * 2] + 1) * (2 * size + 1) + steps[step * 2 + 1] + 1];
                    result[1] += bitMapImage[((i + steps[step * 2]) * width + j + steps[step * 2 + 1]) * 3 + 1] * matrix[(steps[step * 2] + 1) * (2 * size + 1) + steps[step * 2 + 1] + 1];
                    result[2] += bitMapImage[((i + steps[step * 2]) * width + j + steps[step * 2 + 1]) * 3 + 2] * matrix[(steps[step * 2] + 1) * (2 * size + 1) + steps[step * 2 + 1] + 1];
                    divisor += matrix[(steps[step * 2] + 1) * (2 * size + 1) + steps[step * 2 + 1] + 1];
                }

            bitMapImageCopy[(i * width + j) * 3] = (unsigned char)(result[0] / divisor);
            bitMapImageCopy[(i * width + j) * 3 + 1] = (unsigned char)(result[1] / divisor);
            bitMapImageCopy[(i * width + j) * 3 + 2] = (unsigned char)(result[2] / divisor);
            //printf("%f\n", divisor);
        }

    if (strcmp(mode, "SobelX") == 0 || strcmp(mode, "SobelY") == 0)
    {
        for (int i = 0; i < height * width * 3; i++)
            bitMapImage[i] = abs(bitMapImageCopy[i]) > 400 ? 255 : 0;
    }
    else
    {
        for (int i = 0; i < height * width * 3; i++)
            bitMapImage[i] = bitMapImageCopy[i];
    }

    free(steps);
    free(matrix);
    free(bitMapImageCopy);
}

int main()
{
    //inputCheck(argc, argv);
    //Source C : \Users\David\source\repos\Task8\Task8\fileIn.bmp ColorWB C : \Users\David\source\repos\Task8\Task8\fileOut.bmp
    fopen_s(&fileIn, "fileIn.bmp", "rb");
    fopen_s(&fileOut, "fileOut.bmp", "wb");

    struct BITMAPFILEHEADER bitMapFileHeader;
    struct BITMAPINFOHEADER bitMapInfoHeader;

    fread(&bitMapFileHeader, sizeof(bitMapFileHeader), 1, fileIn);
    fread(&bitMapInfoHeader, sizeof(bitMapInfoHeader), 1, fileIn);

    unsigned char* bitMapImage = (unsigned char*)malloc(bitMapInfoHeader.biSizeImage);

    fseek(fileIn, bitMapFileHeader.bfOffBits, SEEK_SET);
    fread(bitMapImage, 1, bitMapInfoHeader.biSizeImage, fileIn);

    convolution(bitMapImage, bitMapInfoHeader.biHeight, bitMapInfoHeader.biWidth, "Gauss3");

    fwrite(&bitMapFileHeader, sizeof(bitMapFileHeader), 1, fileOut);
    fwrite(&bitMapInfoHeader, sizeof(bitMapInfoHeader), 1, fileOut);

    for (int i = 0; i < bitMapInfoHeader.biSizeImage; i++)
        fwrite(&bitMapImage[i], 1, 1, fileOut);

    printf("The program worked successfully");
    free(bitMapImage);
    fclose(fileIn);
    fclose(fileOut);
    return 0;
}