#include <stdio.h>
#include <stdlib.h> /* for memory allocation functions */
#include <ctype.h> /* for isalnum function */

#define LINE 80 /* Characters in each line */
#define MEM_SIZE 100 /* Initial memory size */

/*gets a char input with an undefined size, counting each char and checking if it's an alpha-numeric char */
char *getInput(int *counter, int *counteran);
/*prints the user input in a symmetric way*/
void printInput(char *input);

/* This program reads user input with an undefined size, store it in memory according to its size, and prints input in a symmetric way
    then, it prints the total number of char in input, and the number of alpha-numeric chars. */

int main()
{
    char *mainInput; /* pointer to the dynamic array, will later be initalized */
    int cnt = 0;     /* characters counter */
    int cntan = 0;   /* alpha-numeric characters counter */
    printf("Please enter your text:\n");
    mainInput = getInput(&cnt, &cntan); /* sending addresses then storing in them the processed data */
    if (mainInput == NULL)
    {
        return 1;
    }

    printf("\n");
    printf("------------------------------ OUTPUT ------------------------------\n\n");
    printInput(mainInput);
    printf("\n");
    printf("Total Characters: %d\n", cnt);
    printf("Total Alpha-Numeric Characters: %d\n",cntan);
    free(mainInput);
    return 0;
}

char *getInput(int *counter, int *counterAN)
{
    int cntan = 0;
    char *p = (char *)malloc(MEM_SIZE * sizeof(char));
    char *q = p; /*backup pointer, if realloc fails to allocate, function will return last address values stored*/
    int c;
    long current = 0, last = MEM_SIZE - 1;
    while ((c = getchar()) != EOF)
    {
        if (current >= last) /* if reached last bit */
        {
            q = p;
            p = (char *)realloc(q, last + (MEM_SIZE * sizeof(char))); /* attempting to add more bits */
            if (p == NULL)
            {
                printf("Memory allocation failed, printing only stored values \n");
                return q;
            }
            last += MEM_SIZE;
        }

        p[current] = c;
        ++current;
        if (isalnum(c)) /* checking if current char is alpha-numeric */
            cntan++;
    }
    p[current] = '\0';
    (*counter) = current; /* index equals to number of charaters, transfering it through address */
    (*counterAN) = cntan; /* transfering value through address */
    return p;
}

void printInput(char *input)
{
    int line_index = 0, i = 0;
    while (input[i] != '\0') /* until not reached end of input */
    {
        while (line_index < LINE && (input[i] != '\0')) /* printing lines in a symmetric way */
        {
            line_index++;
            putchar(input[i]);
            i++;
        }
        line_index = 0;
        putchar('\n');
    }
}