#include <stdio.h>
#include <cs50.h>
#include <string.h>
#include "bmp.h"

int main(int argc, char *argv[])
{
    //Tests command line input for correct # of inputs
    if (argc != 4)
    {
        printf("Usage: ./resize n infile outfile\n");
        return 1;
    }

    //Add pointers for factor & file names of infile and outfile
    int rFactor = atoi(argv[1]);
    char *infile = argv[2];
    char *outfile = argv[3];

    //Tests rFactor input for integers between 1 and 100 inclusive
    if (rFactor < 1 || rFactor > 100)
    {
        printf("Resize factor needs to be a value between 1 and 100, inclusive.\n");
        return 1;
    }
    //Open infile and check for NULL
    FILE *inptr = fopen(infile, "r");
    if (inptr == NULL)
    {
        printf("Could not open %s.\n", infile);
        return 2;
    }

    //Open or create output file
    FILE *outptr = fopen(outfile, "w");
    if (outptr == NULL)
    {
        printf("Could not create %s.\n", outfile);
        return 3;
    }

    //Read infile BITMAPFILEHEADER
    BITMAPFILEHEADER bf;
    fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);

    //Read infile BITMAPINFOHEADER
    BITMAPINFOHEADER bi;
    fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);

    //Ensure file is 24-bit uncompressed BMP 4.0
    if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 || bi.biBitCount != 24 || bi.biCompression != 0)
    {
        fclose(inptr);
        fclose(outptr);
        printf("Unsupported File Format.\n");
        return 4;
    }

    int inptWidth = bi.biWidth;
    int inptHeight = bi.biHeight;

    //Modify width/height of BITMAPINFOHEADER
    bi.biWidth = bi.biWidth * rFactor;
    bi.biHeight = bi.biHeight * rFactor;

    //Write outfile BITMAPFILEHEADER
    fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);

    //Write outfile BITMAPINFOHEADER
    fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);

    //Determine padding for input scanlines
    int inpt_padding = (4 - (inptWidth * sizeof(RGBTRIPLE)) % 4) % 4;

    //Determine padding for output scanlines
    int outpt_padding = (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;

    //iterate over infile height
    for (int h = 0; h < abs(inptHeight); h++)
    {
        //create temp array to store RGBTRIPLE
        RGBTRIPLE *row = malloc(bi.biWidth * sizeof(RGBTRIPLE));

        //iterate over pixels in scanline
        for (int i = 0; i < bi.biWidth; i+= rFactor)
        {
            //Create temp var to store RGBTRIPLE
            RGBTRIPLE triple;

            //Read RGBTRIPLE from infile and store in temp var
            fread(&triple, sizeof(RGBTRIPLE), 1, inptr);

            //Store temp var in array
            row[i] = triple;

            //iterate pixel for rFactor scaling
            for (int j = i + 1; j < bi.biWidth; j++)
                row[j] = triple;
        }

        for (int x = 0; x < bi.biWidth; x++)
            printf("%i, %i, %i | ", row[x].rgbtRed, row[x].rgbtGreen, row[x].rgbtBlue);
        printf("\n");

        //write array to outfile
        for (int k = 0; k < rFactor; k++)
        {
            for (int l = 0; l < bi.biWidth; l++)
                fwrite(&row[l], sizeof(RGBTRIPLE), 1, outptr);
            for (int m = 0; m < outpt_padding; m++)
                fputc(0x00, outptr);
        }

        //Skip infile padding
        fseek(inptr, inpt_padding, SEEK_CUR);

        //free up memory
        free(row);
    }

    //Close infile
    fclose(inptr);

    //Close outfile
    fclose(outptr);

    //Sucess
    return 0;
}