#include <cs50.h>
#include <stdio.h>
#include <crypt.h>
#include <string.h>

bool crack(char *hash, char *guess, char *salt);

int main(int argc, string argv[])
{
    ///argv[1] is hashed password input. First two characters are salt for crypt()
    if(argc != 2)
    {
        printf("Usage: ./crack hash\n");
        return 1;
    }

    ///put user input into array "hash" and salt into array "salt"
    char *hash = argv[1];
    char salt[] = {hash[0], hash[1]};

    ///establishes array alpha to iterate through given no non-alpha chars
    char alpha[52] ={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};

    //iterates through alpha[] testing for single char passwords
    //iterate variables correspond to array locations (a, b, c, d, e)
    char pw1[2];
    for(int a1 = 0; a1 < 52; a1++)
    {
        pw1[0] = alpha[a1];
        pw1[1] = '\0';

        if(crack(hash, pw1, salt))
        {
            printf("%s\n", pw1);
            return 0;
        }
    }

    //iterates through alpha[] testing for two char passwords
    char pw2[3];
    for(int b1 = 0; b1 < 52; b1++)
    {
        for (int a1 = 0; a1 < 52; a1++)
        {
            pw2[0] = alpha[b1];
            pw2[1] = alpha[a1];
            pw2[2] = '\0';

            if(crack(hash, pw2, salt))
            {
                printf("%s\n", pw2);
                return 0;
            }
        }
    }

    //iterate through alpha testing for three char passwords
    char pw3[4];
    for(int c1 = 0; c1 < 52; c1++)
    {
        for(int b1 = 0; b1 < 52; b1++)
        {
            for(int a1 = 0; a1 < 52; a1++)
            {
                pw3[0] = alpha[c1];
                pw3[1] = alpha[b1];
                pw3[2] = alpha[a1];
                pw3[3] = '\0';

                if(crack(hash, pw3, salt))
                {
                    printf("%s\n", pw3);
                    return 0;
                }
            }
        }
    }

    //iterate through alpha testing for four char passwords
    char pw4[5];
    for(int d1 = 0; d1 < 52; d1++)
    {
        for(int c1 = 0; c1 < 52; c1++)
        {
            for(int b1 = 0; b1 < 52; b1++)
            {
                for(int a1 = 0; a1 < 52; a1++)
                {
                    pw4[0] = alpha[d1];
                    pw4[1] = alpha[c1];
                    pw4[2] = alpha[b1];
                    pw4[3] = alpha[a1];
                    pw4[4] = '\0';

                    if(crack(hash, pw4, salt))
                    {
                        printf("%s\n", pw4);
                        return 0;
                    }
                }
            }
        }
    }

    //iterate through alpha testing for five char passwords
    char pw5[6];
    for(int e1 = 0; e1 < 52; e1++)
    {
        for(int d1 = 0; d1 < 52; d1++)
        {
            for(int c1 = 0; c1 < 52; c1++)
            {
                for(int b1 = 0; b1 < 52; b1++)
                {
                    for(int a1 = 0; a1 < 52; a1++)
                    {
                        pw5[0] = alpha[e1];
                        pw5[1] = alpha[d1];
                        pw5[2] = alpha[c1];
                        pw5[3] = alpha[b1];
                        pw5[4] = alpha[a1];
                        pw5[5] = '\0';

                        if(crack(hash, pw5, salt))
                        {
                            printf("%s\n", pw5);
                            return 0;
                        }
                    }
                }
            }
        }
    }
}

///boolean function for comparing crypt output to hash provided by user
bool crack(char *hash, char *guess, char *salt)
{
    char *encrypt_guess = crypt(guess, salt);
    if(strcmp(encrypt_guess, hash) == 0)
    {
        return true;
    }
    return false;
}