#include <stdio.h>
#include <stdlib.h>
#include <cs50.h>

#include "bmp.h"

int main(int argc, char *argv[])
{
    // ensure proper usage
    if (argc != 4)
    {
        fprintf(stderr, "Usage: copy infile outfile\n");
        return 1;
    }

    int n = atoi(argv[1]);

    // remember filenames
    char *infile = argv[2];
    char *outfile = argv[3];

    // open input file
    FILE *inptr = fopen(infile, "r");
    if (inptr == NULL)
    {
        fprintf(stderr, "Could not open %s.\n", infile);
        return 2;
    }

    // open output file
    FILE *outptr = fopen(outfile, "w");
    if (outptr == NULL)
    {
        fclose(inptr);
        fprintf(stderr, "Could not create %s.\n", outfile);
        return 3;
    }

    // read infile's BITMAPFILEHEADER
    BITMAPFILEHEADER bf;
    fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);

    // read infile's BITMAPINFOHEADER
    BITMAPINFOHEADER bi;
    fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);

    // ensure infile is (likely) a 24-bit uncompressed BMP 4.0
    if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 ||
        bi.biBitCount != 24 || bi.biCompression != 0)
    {
        fclose(outptr);
        fclose(inptr);
        fprintf(stderr, "Unsupported file format.\n");
        return 4;
    }

    int oldWidth = bi.biWidth;
    int oldHeight ;
    oldHeight = bi.biHeight;


    bi.biWidth = bi.biWidth * n ;
    bi.biHeight = bi.biHeight * n;

    // determine padding for scanlines
    int originalpadding;
    originalpadding =  (4 - (oldWidth * sizeof(RGBTRIPLE)) % 4) % 4;
    int padding = (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;

    bi.biSizeImage = abs(bi.biHeight) * ((bi.biWidth * sizeof (RGBTRIPLE)) + padding);
    bf.bfSize = bi.biSizeImage + sizeof (BITMAPFILEHEADER) + sizeof (BITMAPINFOHEADER);

    for (int m = 0; m < n; m++)
    {
    // write outfile's BITMAPFILEHEADER
    fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);

    // write outfile's BITMAPINFOHEADER
    fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);
    }




    // iterate over infile's scanlines
    for (int i = 0, bibiHeight = abs(bi.biHeight); i < bibiHeight; i++)
    {
        for (int d = 0; d < n; d++)
        {

            // iterate over pixels in scanline
            for (int j = 0; j < bi.biWidth; j++)
            {
                // temporary storage
                RGBTRIPLE triple;

                // read RGB triple from infile
                fread(&triple, sizeof(RGBTRIPLE), 1, inptr);

                for (int s = 0; s < n; s++)
                {
                    // write RGB triple to outfile
                    fwrite(&triple, sizeof(RGBTRIPLE), 1, outptr);
                }
            }
        }

        // skip over padding, if any
        fseek(inptr, padding, SEEK_CUR);

        // then add it back (to demonstrate how)
        for (int k = 0; k < padding; k++)
        {
            fputc(0x00, outptr);
        }

    }

    // close infile
    fclose(inptr);

    // close outfile
    fclose(outptr);

    // success
    return 0;
}