<?php
namespace Elastica\Query;

use Elastica\Query as BaseQuery;

/**
 * Runs the child query with an estimated hits size, and out of the hit docs, aggregates it into parent docs.
 *
 * @author Wu Yang <darkyoung@gmail.com>
 *
 * @link https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-top-children-query.html
 */
class TopChildren extends AbstractQuery
{
    /**
     * Construct topChildren query.
     *
     * @param string|\Elastica\Query|\Elastica\Query\AbstractQuery $query
     * @param string                                               $type  Parent document type
     */
    public function __construct($query, $type = null)
    {
        $this->setQuery($query);
        $this->setType($type);
    }

    /**
     * Sets query object.
     *
     * @param string|\Elastica\Query|\Elastica\Query\AbstractQuery $query
     *
     * @return $this
     */
    public function setQuery($query)
    {
        return $this->setParam('query', BaseQuery::create($query));
    }

    /**
     * Set type of the parent document.
     *
     * @param string $type Parent document type
     *
     * @return $this
     */
    public function setType($type)
    {
        return $this->setParam('type', $type);
    }
}
