#include <lib/string.h>

#include <stddef.h>

char* strtok_r(char *s, const char *delim, char **saveptr) {
    char *token;

    if (!saveptr) {
        return NULL;
    }

    if (!s) {
        s = *saveptr;
    }

    if (!s || *s == '\0') {
        *saveptr = s;
        return NULL;
    }

    while (*s != '\0') {
        const char *d = delim;
        int is_delim = 0;
        while (*d != '\0') {
            if (*s == *d) {
                is_delim = 1;
                break;
            }
            d++;
        }
        if (!is_delim) {
            break;
        }
        s++;
    }

    if (*s == '\0') {
        *saveptr = s;
        return NULL;
    }

    token = s;

    while (*s != '\0') {
        const char *d = delim;
        int is_delim = 0;
        while (*d != '\0') {
            if (*s == *d) {
                is_delim = 1;
                break;
            }
            d++;
        }
        if (is_delim) {
            *s = '\0';
            *saveptr = s + 1;
            return token;
        }
        s++;
    }

    *saveptr = s;
    return token;
}