#include<stdio.h>

#pragma pack(push, 1)

typedef struct BITMAPFILEHEADER{
    unsigned short int bfType;
    unsigned long int bfSize;
    unsigned short int bfReserved1;
    unsigned short int bfReserved2;
    unsigned long int bfOffBits;
} BITMAPFILEHEADER;

typedef struct BITMAPINFOHEADER{
    unsigned long int biSize;
    long int biWidth;
    long int biHeight;
    unsigned short int biPlanes;
    unsigned short int biBitCount;
    unsigned long int biCompression;
    unsigned long int biSizeImage;
    long int biXPelsPerMeter;
    long int biYPelsPerMeter;
    unsigned long int biClrUsed;
    unsigned long int biClrImportant;
} BITMAPINFOHEADER;

typedef struct RGBTRIPLE {
    char rgbtBlue;
    char rgbtGreen;
    char rgbtRed;
} RGBTRIPLE;
#pragma pack(pop)

void printInfo(BITMAPFILEHEADER filehdr, BITMAPINFOHEADER infohdr){

    printf("%x\n",filehdr.bfType);
	printf("%li\n",filehdr.bfSize);
	printf("%d\n",filehdr.bfReserved1);
	printf("%d\n",filehdr.bfReserved2);
	printf("%li\n\n",filehdr.bfOffBits);

	printf("%li\n", infohdr.biSize);
    printf("%li\n", infohdr.biWidth);
    printf("%li\n", infohdr.biHeight);
    printf("%d\n", infohdr.biPlanes);
    printf("%d\n", infohdr.biBitCount);
    printf("%li\n", infohdr.biCompression);
    printf("%li\n", infohdr.biSizeImage);
    printf("%li\n", infohdr.biXPelsPerMeter);
    printf("%li\n", infohdr.biYPelsPerMeter);
    printf("%li\n", infohdr.biClrUsed);
    printf("%li\n", infohdr.biClrImportant);
}

int checkCoordinates(int x0, int y0, int x1, int y1, int height, int width) { //возвращает 1, если координаты некорректны
                                                                              //возвращает 0, если данные введены верно
    if (x0 < 0 || y0 < 0 || x1 < 0|| y1 < 0) {

        return 1;
    }
    if (x0 > width || y0 > height || x1 > width || y1 > height ) {

        return 1;
    }
    return 0;
}

void rot(long int x0, long int y0, long int x1, long int y1, RGBTRIPLE** rgb) {

    RGBTRIPLE swapRgb [y1-y0+1][x1-x0+1];
    long int i, j, m = 0, k = 0;

    for ( i = x0; i <= y1; i ++ , k ++) {
        for ( j = y0; j <= x1; j++, m ++) {

            swapRgb[m][k] = rgb[i][j];
        }
    }

    for ( i = x0; i < y1; i ++ , m ++) {
        for ( j = y0; j < x1; j++, k ++) {

            rgb[i][j] = swapRgb[m][k];
        }
    }
}

int main(){

    BITMAPFILEHEADER filehdr;
    BITMAPINFOHEADER infohdr;
    RGBTRIPLE rgbChange;
    RGBTRIPLE rgbZero = {'0','0','0'};

    char inputFile[10];
    long int x0, y0, x1, y1, height, width, i, j, k = 0;
    int emptyBytes = 0, flagChange = 0; // flagChange == 1, если строка была отражена

    printf("Enter file name: ");
    scanf("%s", &inputFile);
    printf("Enter x0: ");
    scanf("%li", &x0);
    printf("Enter y0: ");
    scanf("%li", &y0);
    printf("Enter x1: ");
    scanf("%li", &x1);
    printf("Enter y1: ");
    scanf("%li", &y1);
    FILE* f = fopen(inputFile, "rb");

    if (!f){

        printf("Fail with file\n");
        return 0;
    }

    fread(&filehdr, sizeof(struct BITMAPFILEHEADER), 1, f);
    fread(&infohdr, sizeof(struct BITMAPINFOHEADER), 1, f);

    height = infohdr.biHeight;
    width = infohdr.biWidth;

    if (checkCoordinates(x0, y0, x1, y1, height, width)) {

        printf("Fail with coordinates\n");
        return 0;
    }

    FILE* newf = fopen("new.bmp", "wb");

    fwrite(&filehdr, sizeof(BITMAPFILEHEADER), 1, newf);
    fwrite(&infohdr, sizeof(BITMAPINFOHEADER), 1, newf);

    if ( (width * 3) % 4 ){

        emptyBytes = 4 - (width * 3) % 4;
    }

    RGBTRIPLE rgb[height][width];

    for (i = 0; i < height ; i++) {

        for (j = 0; j < width; j++) {

            fread(&rgb[i][j], sizeof(RGBTRIPLE), 1, f);
        }

        if (emptyBytes) {

            fread(&rgbChange, emptyBytes, 1, f);
        }
    }

    rot(x0, height - y0, x1, height - y1 , rgb);

    for (i = 0; i < height ; i++) {

        for (j = 0; j < width; j++ ) {

            fwrite(&rgb[i][j], sizeof(RGBTRIPLE), 1, newf);
        }

        if (emptyBytes) {

            fwrite(&rgbZero, emptyBytes, 1, newf);
        }
    }

    printf("Look new.bmp");
    fclose(f);
    fclose(newf);
	return 0;
}