#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <cs50.h>
#include <unistd.h>
#include <crypt.h>
#define _XOPEN_SOURCE

char *crackh(char *current, char *encrypt, char *salt, int i, int limit);
char *crack(char *encrypt, char *salt, int len);

int main(int argsc, char *argsv[])
{
    if (argsc != 2)
    {
        printf("Expected 1 command line argument");
        return 1;
    }
    char salt[3];
    salt[0] = argsv[1][0];
    salt[1] = argsv[1][1];
    salt[2] = '\0';
    //printf("");
    printf("%s\n", crack(argsv[1], salt, 4));
    return 0;
}

char *crackh(char *s, char *encrypt, char *salt, int i, int limit)
{
    for (char c = 'a'; c < 'z'; c++)
    {
        //Runs each letter twice; Uppercase and lowercase
        for (int u = 0; u < 2; u++)
        {
            if (u == 0)
            {
                s[i] = c;
            }
            else
            {
                s[i] = toupper(c);
            }
            //This means that it is looking at passwords of the correct length and should start testing them
            if (i == limit)
            {
                if (strcmp(crypt(s, salt), encrypt) == 0)
                {
                    return s;
                }
            }
            //If you aren't at the correct length of password, go deeper
            else
            {
                char *plain = crackh(s, encrypt, salt, i + 1, limit);
                if (strcmp(plain, "") != 0)
                {
                    return plain;
                }
            }
        }
    }
    return "";
}

char *crack(char *encrypt, char *salt, int len)
{
    char s[len + 2];
    //Calls crack for a 1 digit password, than a 2 digit password...
    for (int i = 0; i < len; i++)
    {
        //Sets \0 to be 1 after the last character that will be changed.
        s[i + 1] = '\0';
        char *plainText = crackh(s, encrypt, salt, 0, i);
        //If plaintext is "" crack couldn't find a password
        if (strcmp(plainText, "") != 0)
        {
            return plainText;
        }
    }
    return "";
}