Drupal: migration from NodeHierarchy to Taxonomy

function misc_menu() {
  $items = array();
  $items['taxonomy-transform'] = array(
    'page callback' => 'misc_taxonomy_transform',
    'access arguments' => array('administer nodes'),
    'type' => MENU_CALLBACK,
  );

  return $items;
}

function misc_taxonomy_transform() {
    ob_start();

    echo '<pre>';

/*  $stranky = db_query('DELETE FROM term_data WHERE vid = 5'); */
/*  $stranky = db_query('TRUNCATE TABLE term_hierarchy'); */

/*
    $test = node_load(1246, NULL, TRUE);
    _misc_generate_taxonomy($test);
*/

    $stranky = db_query('SELECT n.nid as nid FROM {node} n WHERE n.type = "stranka" ');
    while($stranka = db_fetch_array($stranky)) {
        $node = node_load($stranka['nid'], NULL, TRUE);
        $term = _misc_generate_taxonomy($node);
        $node->taxonomy[] = $term;
/*      print_r($term); */
        node_save($node);

        echo '<br>' . $node->title;
        $i++;
    }
    echo '<br><br>hotovo ' . $i;

    echo '</pre>';

    $res = ob_get_contents();
    ob_end_clean();
    return $res;
}

function _misc_generate_taxonomy($node, $depth = 0) {

    $parent_nid = $node->nodehierarchy_menu_links[0]['pnid'];
    $weight = $node->nodehierarchy_menu_links[0]['weight'];
    $parent = node_load($parent_nid, NULL, TRUE);

    $last_tid = !empty($parent) ? _misc_generate_taxonomy($parent, ++$depth) : 0; // Pokud jsme na nejvyssi urovni, rodic je 0, jinak rekurze a rodic je TID posledniho vlozeneho terminu
    $depth--;

    $new_term = array(
        'vid' => 5, // Voacabulary ID
    'name' => $node->title, // Term Name
    'parent' => $last_tid,
    'weight' => $weight
    );

    if($depth == 0) {
        // vratim pole taxonomickeho terminu
        $new_term['tid'] = $last_tid;
        $new_term['name'] = $parent->title;
        return $new_term;
    }

    if($depth > 0) {
        $existing_term = db_result(db_query('SELECT d.tid FROM {term_data} d LEFT JOIN {term_hierarchy} h ON d.tid = h.tid WHERE d.name = "%s" AND h.parent = %d', $node->title, $last_tid));// Zkontroluju, jestli již existuje
        if(!empty($existing_term)) {
            $tid = $existing_term;
        } else {
            taxonomy_save_term($new_term); // ulozim
            $tid = db_result(db_query('SELECT tid FROM {term_data} ORDER BY tid DESC LIMIT 1'));
        }
        return $tid;// vratim posledni tid

    }
}