#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>


static int uc_mkdir(const char *full_path, mode_t mode)
{
    struct stat st;
    int rc;

    rc = stat(full_path, &st);
    if (rc == -1 && errno == ENOENT) {
        rc = mkdir(full_path, mode);
        if (rc == -1 && errno != EEXIST) {
            return -1;
        }
    } else if (rc == 0) {
        if (!S_ISDIR(st.st_mode)) {
            errno = ENOTDIR;
            return -1;
        }
    } else {
        return -1;
    }

    return 0;
}

int uc_mkdir_p(const char *full_path, mode_t mode)
{
    struct stat st;
    int rc;
    char *path;
    char *p;
    int create_final = 1;

    if (full_path == NULL || full_path[0] == 0) {
        errno = EINVAL;
        return -1;
    }

    rc = stat(full_path, &st);
    if (rc == 0) { //already exists
        if (!S_ISDIR(st.st_mode)) {
            errno = ENOTDIR;
            return -1;
        }

        return 0;
    }

    path = strdup(full_path);
    if (path == NULL) {
        return -1;
    }

    //skip leading /
    for (p = path; *p == '/'; p++)
        ;

    for (;;) {
        p = strchr(p, '/');
        if (p == NULL) {
            break;
        }

        *p = 0;

        rc = uc_mkdir(path, mode);
        if (rc != 0) {
            free(path);
            return -1;
        }

        *p = '/';
        //in case of multiple / , e.g. foo//bar
        for (; *p == '/'; p++)
            ;

        if (*p == 0) {
            create_final = 0;
            break;
        }
    }

    //last part, in case full_path does not end with a /
    if (create_final) {
        rc = uc_mkdir(path, mode);
    } else {
        rc = 0;
    }

    free(path);

    return rc;
}