#include <stdio.h>
#include "swapper.h"

#define ABS(val) ( (val) >= 0 ? (val) : -(val) )
#define ALIGN8(val) ( (((val) >> 3) << 3) )

union tmp {
    long int l;
    char c;
};

static int strlen_c(char *a)
{
    int len;

    for (len = 0; len < __SWAPPER_MAX_STR_LENGTH; len++) {
        if (a[len] == '\0')
            break;
    }

    return len;
}

int swapper_length_difference(char *a, char *b)
{
    int len_a = strlen_c(a);
    int len_b = strlen_c(b);

    return ABS(len_a - len_b);
}

void swapper_swap(char *a, char *b) {
    int len = strlen_c(a);

    union tmp t;

    for (int i = 0; i < (len >> 3); i++) {
        t.l = ((long int*) a)[i];
        ((long int*) a)[i] = ((long int*) b)[i];
        ((long int*) b)[i] = t.l;
    }

    for (int i = ALIGN8(len); i < len; i++) {
        t.c = a[i];
        a[i] = b[i];
        b[i] = t.c;
    }
}