#include <cs50.h>
#include <ctype.h>
#include <stdio.h>
// #include <stdlib.h>
#include <string.h>

string encipher(string plaintext, string cipher);

int main(int argc, string argv[])
{
    //string cipher = argv[1];

    //Validate the key
    bool hasRepeats = false;
    bool nonletters = false;

    //Make sure theres a key
    if (argc != 2)
    {
        printf("Usage: ./substitution key\n");
        return 1;
    }

    for (int i = 0, n = strlen(argv[1]); i < n; i++)
    {
        for (int j = 0, m = strlen(argv[1]); j < n; j++)
        {
            if (i == j)
            {
                //comparing to self, do nothing
            }
            else
            {
                // Check for repeated letters
                if ((toupper(argv[1][i])) == toupper(argv[1][j]))
                {
                    hasRepeats = true;
                }
            }
            //return 0;
        }
        // Check for numbers in the argv[1]
        if (isalpha(argv[1][i]) == 0)
        {
            nonletters = true;
        }
    }

    if (argc == 2 && strlen(argv[1]) != 26)
    {
        printf("Key must contain 26 characters.\n");
        return 1;
    }
    else if (nonletters == true)
    {
        printf("Key must only contain alphabetic characters.\n");
        return 1;
    }
    else if (hasRepeats == true)
    {
        printf("Key must not contain repeated characters.\n");
        return 1;
    }
    else
    {
        // printf("Looks good, baby!\n");
    }

    //Ask for the user text
    string plaintext = get_string("plaintext: \n");

    //Encipher the text
    string ciphertext = encipher(plaintext, argv[1]);

    //Print the ciphertext
    printf("ciphertext: %s\n", ciphertext);

    return 0;
}

string encipher(string plaintext, string cipher)
{
    char encoded[strlen(plaintext)];

    for (int i = 0, n = strlen(plaintext); i < n; i++)
    {
        bool lowerCase = false;

        if (isalpha(plaintext) == true)
        {
            if (islower(plaintext[i]) == true)
            {
                lowerCase = true;
            }

            int position = toupper(plaintext[i]) - 65;

            encoded[i] = cipher[position];

            //correct to lowercase
            if (lowerCase == true)
            {
                encoded[i] = tolower(encoded[i]);
            }
        }
        else
        {
            encoded[i] = plaintext[i];
        }
    }
    return encoded;
}