#include "my_strtok_r.h"

#include <stddef.h>

static int is_delim(char c, const char *delims)
{
    for (const char *d = delims; *d; d++)
    {
        if (*d == c)
            return 1;
    }
    return 0;
}

char *my_strtok_r(char *str, const char *delim, char **saveptr)
{
    if (str == NULL)
    {
        if (*saveptr == NULL)
        {
            return NULL;
        }
        str = *saveptr;
    }

    size_t i = 0;
    while (str[i] != '\0' && is_delim(str[i], delim))
    {
        i++;
    }
    if (str[i] == '\0')
    {
        *saveptr = NULL;
        return NULL;
    }

    char *res = str + i;

    while (str[i] != '\0' && !is_delim(str[i], delim))
    {
        i++;
    }
    if (str[i] == '\0')
    {
        *saveptr = NULL;
        return res;
    }
    *saveptr = str + i + 1;
    str[i] = '\0';
    return res;
}