/**
 * 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
    char* infile = argv[2];
    char* outfile = argv[3];
    int n = atoi(argv[1]);
    if(n>100 || n<1)
   {
    printf("can resize between 1 - 100 ");
    return 2;
   }

    // 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(&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 x = bi.biHeight;
    int y = bi.biWidth;

     bf.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + (bi.biSizeImage * n);
    bi.biHeight *= n;
    bi.biWidth  *= n;
    // write outfile's BITMAPFILEHEADER
    fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);

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

    // determine padding for scanlines
    int padding =  (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
    int outpadding =  (4 - (y * sizeof(RGBTRIPLE)) % 4) % 4;
    // iterate over infile's scanlines
    for (int i = 0, absx = abs(x); i < absx; i++)
    {

        //write scanline [resize_multiple] times
        for(int m = 0; m < n; m++)
        {
            // fseek back to beginning of scanline if m < resize_multiple


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

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

                //write RGB [resize_multiple] times
                for(int l = 0; l < n; l++)
                {
                    // 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 < outpadding; k++)
                fputc(0x00, outptr);
        }
    }


    // close infile
    fclose(inptr);

    // close outfile
    fclose(outptr);

    // that's all folks
    return 0;
}