protected function searchTopics()
    {
        $query = Thread::find();
        if (Podium::getInstance()->user->isGuest) {
            $query->joinWith(['forum' => function ($q) {
                $q->andWhere([Forum::tableName() . '.visible' => 1])->joinWith(['category' => function ($q) {
                    $q->andWhere([Category::tableName() . '.visible' => 1]);
                }]);
            }]);
        }
        if (!empty($this->query)) {
            $words = explode(' ', preg_replace('/\s+/', ' ', $this->query));
            foreach ($words as $word) {
                if ($this->match == 'all') {
                    $query->andWhere(['like', Thread::tableName() . '.name', $word]);
                } else {
                    $query->orWhere(['like', Thread::tableName() . '.name', $word]);
                }
            }
        }
        $this->prepareQuery($query, true);
        $sort = [
            'defaultOrder' => [Thread::tableName() . '.id' => SORT_DESC],
            'attributes' => [
                Thread::tableName() . '.id' => [
                    'asc' => [Thread::tableName() . '.id' => SORT_ASC],
                    'desc' => [Thread::tableName() . '.id' => SORT_DESC],
                    'default' => SORT_DESC,
                ],
            ]
        ];
        return new ActiveDataProvider([
            'query' => $query,
            'sort' => $sort,
        ]);
    }