// 65-90 A-Z, 97-122 a-z , upper 32 apart from lowercase
//Declare pre-processor directives
#include <cs50.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>

//Declare caesar cipher function
char encipher(char cae, int k);


//// (1) inline comments are actually a kind of "code" smell
//// if you follow some guidelines, like using speaking variable names and use functions where possible to keep your main and other functions small,
//// your code should be easy to understand, so no comments are needed

//Declare main function
int main(int argc, string argv[])
{
    //Declare variables
	//// (2) always use "speaking" variable names
    string p;
    //// int n; see (4)

    /////if-else to check for 2 valid command line arguments (0-1)
    if (argc == 1)
    {
        printf("You entered no command line arguments, exiting the program\n");
        return 1;
    }

	// (3) else if not needed here
    if (argc > 2)
    {
        printf("Only one positive integer is accepted, exiting the program\n");
        return 1;
    }

    //Convert string argv[1] to int and initialize the value to variable k
	////same as (2)
    int k = atoi(argv[1]);

    //Do-while loop until user enters valid string

	//// (4) put variables as close as possible where needed
	/// int n; actually not needed at all, see (5)
    do
    {
        p = get_string("plaintext: ");
    }
    while (strlen(p) == 0); //// (5)

	//// (6) could be extracted into a function
    //For loop to encipher text
    for (int i = 0; i < n; i++)
    {
        p[i] = encipher(p[i], k);
    }

    //print output
    printf("ciphertext: %s\n", p);

    //return error code of 0
    return 0;
}

//Caesar Cipher
char encipher(char cae, int k) 	////same as (2)
{
    //Check if alphabetical
    if (isalpha(cae))
    {
        //Check if lowercase
        if (islower(cae))
        {
            cae = ((cae - 'a') + k) % 26 + 'a';
        }

        //Check if uppercase
        else if (isupper(cae))
        {
            cae = ((cae - 'A') + k) % 26 + 'A';
        }
    }

    return cae;
}