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

#include "spn.h"

int main(int argc, char const *argv[])
{
    if (argc < 6) {
        printf("Usage: %s <key> <subst> <perm> <decoded> <coded>\n", argv[0]);
        return 1;
    }

    unsigned short key;
    unsigned char perm[8], subst[16];

    FILE* keyFile = fopen(argv[1], "r");
    if (fread(&key, 2, 1, keyFile) != 1) {
        printf("Unable to read key file\n");
        return 1;
    } else fclose(keyFile);

    FILE* substFile = fopen(argv[2], "r");
    if (fread(&subst, 1, 16, substFile) != 16) {
        printf("Unable to read subst file\n");
        return 1;
    } else fclose(substFile);

    FILE* permFile = fopen(argv[3], "r");
    if (fread(&perm, 1, 8, permFile) != 8) {
        printf("Unable to read permutation file\n");
        return 1;
    } else fclose(permFile);


    FILE* decoded = fopen(argv[4], "r");
    FILE* encoded = fopen(argv[5], "w");

    if (!decoded || !encoded) {
        printf("Unable to read/write content into files\n");
        return 1;
    }
    
    char w;
    while (fread(&w, 1, 1, decoded)) {
        w = encrypt(w, key, perm, subst);
        
        if (!fwrite(&w, 1, 1, encoded)) {
            printf("Error during writing\n");
            return 1;
        }
    }

    return 0;
}