/****************************************************************************
 * copy.c
 *
 * Computer Science 50
 * Problem Set 5
 *
 * Copies a BMP piece by piece, just because.
 ***************************************************************************/

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

#include "bmp.h"



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

    // remember filenames
    int n = atoi(argv[1]);
    char *infile = argv[2];
    char *outfile = argv[3];

    //resize number n should be an integer less than or equal to 100
    if(n > 100)
    {
        printf("n shoule be an integer less than or equal to 100!!");
        return 4;
    }
    // open input file
    FILE *inptr = fopen(infile, "r");
    if (inptr == NULL)
    {
        printf("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(&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;
    }

    // write outfile's BITMAPFILEHEADER
    fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);

    // write outfile's BITMAPINFOHEADER
    BITMAPINFOHEADER nbi;
    nbi = bi;
    nbi.biWidth = n * nbi.biWidth;
    nbi.biHeight = n * nbi.biHeight;
    fwrite(&nbi, sizeof(BITMAPINFOHEADER), 1, outptr);

    // determine padding for scanlines
    int outpadding =  (4 - (nbi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
//    int inpadding =  (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;

    RGBTRIPLE buffer[nbi.biWidth];

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

            // write RGB triple to outfile
            fwrite(&triple, sizeof(RGBTRIPLE), 1 * n, outptr);

            // assign buffer
            for(int k = 0; k < n; k++)
            {
                buffer[j * n + k] = triple;
            }
        }
        for(int l = 0; l < n; l++)
        {
            fwrite(&buffer, sizeof(buffer), 1, outptr);
            fseek(inptr, outpadding, SEEK_CUR);
            for (int k = 0; k < outpadding; k++)
                fputc(0x00, outptr);
        }

        //copy n times of entire row
       // fwrite(&buffer, sizeof(buffer), 1 * n, outptr);

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

        // write padding to outfile
       // for (int k = 0; k < padding; k++)
           // fputc(0x00, outptr);
    }
    // close infile
    fclose(inptr);

    // close outfile
    fclose(outptr);

    // that's all folks
    return 0;
}