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

#define ASCII_TO_ALPHA(x) x - 65
#define ALPHA_TO_ASCII(x) x + 65

int main(int argc, char *argv[]){

    FILE *txtFile = fopen(argv[1], "r"); // open file that was dragged into exe

    int alphabetCount[26] = { 0 };
    char buffer;

    if (txtFile){
        while ( (buffer = toupper(fgetc(txtFile)) ) != EOF){
            if (buffer >= 'A' && buffer <= 'Z'){
                alphabetCount[ASCII_TO_ALPHA(buffer)]++;
            }
        }
    }

    gnu_writeAsHistogram(&alphabetCount);

    fclose(txtFile);

    return 0;
}

void gnu_writeAsHistogram(int *alphabetCount){
    int som = 0;
    float alphabetPerc[26] = { 0 };

    for (int i = 0; i < 26; i++)
        som += alphabetCount[i];

    for (int i = 0; i < 26; i++)
        alphabetPerc[i] = (float)alphabetCount[i]/som * 100;

    FILE *gnuplotPipe = popen("C:\\Users\\Zain\\Documents\\Github\\GNUCPlotter\\gnuplot\\bin\\gnuplot.exe -persistent", "w");
    fprintf(gnuplotPipe,
        "set multiplot\n"
        "set xrange [1:26]\n"
        "set autoscale\n"
        "show autoscale\n"
        "set grid\n"
        "set style data histogram\n"
        "set style histogram cluster gap 1\n"
        "set style fill solid border -1\n"
        "set boxwidth 0.9\n"
        "set xtic('A' 1, 'B' 2, 'C' 3, 'D' 4, 'E' 5, 'F' 6, 'G' 7, 'H' 8, 'I' 9, 'J' 10, 'K' 11, 'L' 12, 'M' 13, 'N' 14, 'O' 15, 'P' 16, 'Q' 17, 'R' 18, 'S' 19, 'T' 20, 'U' 21, 'V' 22, 'W' 23, 'X' 24, 'Y' 25, 'Z' 26)\n"
        "set xtic rotate by -45 scale 0\n");

    fprintf(gnuplotPipe, "$myData << EOD\n");

    for (int i = 0; i < 26; i++){
        fprintf(gnuplotPipe, "%d %.2f\n", i+1, alphabetPerc[i]);
    }

    fprintf(gnuplotPipe, "EOD\n");
    fprintf(gnuplotPipe, "stats $myData u 1:2\n");
    fprintf(gnuplotPipe, "plot $myData u 1:2 with boxes notitle, $myData u 1:2:2 with labels offset char 0,1\n");

    fclose(gnuplotPipe);
}