// Command libraries
#include <cs50.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <math.h>

// Main program
int main(void)
{
    // Prompting user for text
    string text_prompt = get_string("Enter text for evaluation: ");

    // Count of TOTAL characters in string (anything)
    int total_length = strlen(text_prompt);

    // Setting up and implementing the counters
    int letter_count = 0;
    int word_count = 1;
    int sentence_count = 0;
    for(int n = 0; n < total_length; n++)
    {
        if (isalpha(text_prompt[n]))
        {
            letter_count++;
        }
        if (isblank(text_prompt[n]))
        {
            word_count++;
        }
        if ((text_prompt[n] == '!') || (text_prompt[n] == '?') || (text_prompt[n] == '.'))
        {
            sentence_count++;
        }
    }

    // Setting up grade level calculation
    float avg_letters = (100 * letter_count) / word_count;
    float avg_sentences = (100 * sentence_count) / word_count;
    int index = round(((0.0588 * avg_letters) - (0.296 * avg_sentences) - 15.8));

    // Printing result to user
    if (index > 16)
    {
        printf("Grade 16+\n");
    }
    else if (index < 1)
    {
        printf("Before Grade 1\n");
    }
    else
    {
        printf("Grade %d\n", index);
    }
}