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

string strtolower(string text);
string strtoupper(string text);
bool is_alphabetical(string text);

int main(int argc, string argv[])
{
    // if user gives too few or too many args
    if (argc < 2 || argc > 2)
    {
        printf("Usage: ./substitution key\n");
        return 1;
    }
    else
    {
        string key = argv[1];
        int key_length = strlen(key);
        // if user gives a key of incorrect length
        if (key_length < 26 || key_length > 26)
        {
            printf("Key must contain 26 characters.\n");
        }
        else
        {
            string key_upper = strtoupper(key);
            string key_lower = strtolower(key);
            printf("%s\n", key_upper);
            printf("%s\n", key_lower);
            printf("%s\n", strtoupper(key));
            if (is_alphabetical(key))
            {
                printf("is alpha\n");
            }
            else
            {
                printf("is not alpha\n");
            }

            /* check if key contains non-alphabetic characters
            ** or contains a character more than once
            */

            // get message from user

            /* iterate over each char
            ** if is upper, substitute using key_upper
            ** if is lower, substitute using key_lower
            */
        }
    }
}

string strtolower(string text)
{
    int length = strlen(text);
    for (int i = 0; i < length; i++)
    {
        text[i] = tolower(text[i]);
    }
    return text;
}

string strtoupper(string text)
{
    int length = strlen(text);
    for (int i = 0; i < length; i++)
    {
        text[i] = toupper(text[i]);
    }
    return text;
}

bool is_alphabetical(string text)
{
    int length = strlen(text);
    for (int i = 0; i < length; i++)
    {
        if (!isalpha(text[i]))
        {
            return false;
        }
        return true;
    }
}