<?php

class DibiExtensions extends Nette\Object {

    public static function register()
    {
        \DibiFluent::extensionMethod('fetchTree', callback(__CLASS__, 'fetchTree'));
        \DibiResult::extensionMethod('fetchTree', callback(__CLASS__, 'fetchTree'));
    }


    public static function fetchTree(DibiObject $obj, $id, $parent_id) {
        if ($obj instanceof DibiFluent) {
                $result = $obj->execute();

        } elseif ($obj instanceof DibiResult) {
                $result = $obj;

        } else {
                throw new Nette\MemberAccessException("fetchTree cant be called on " . get_class($obj));
        }

        // nahradit $obj za $result

        $result->seek(0);
        $row = $result->fetch(FALSE);
        if (!$row)
            return array();  // empty resultset

            $refs = array();
        $data = NULL;

        if (!array_key_exists($id, $row) ||
                !array_key_exists($parent_id, $row)) {
            throw new \Nette\InvalidArgumentException("Column '$id' or '$parent_id' is not in record");
        }

        do {
            $ref = &$refs[$row[$id]];

            $ref[$parent_id] = $row[$parent_id];
            $ref = array_merge((array) $ref, (array) $row);

            if ($row[$parent_id] == 0 || $row[$parent_id] == NULL) {
                $data[$row[$id]] = &$ref;
            } else {
                $refs[$row[$parent_id]]['children'][$row[$id]] = &$ref;
            }
        } while ($row = $result->fetch(FALSE));

        unset($ref);
        unset($refs);
        return $data;
    }

}