ap_update_qameta_terms( integer $question_id )

function ap_update_qameta_terms( $question_id ) {
	$terms = array();

	if ( taxonomy_exists( 'question_category' ) ) {
		$categories = get_the_terms( $question_id, 'question_category' );

		if ( $categories ) {
			$terms = $terms + $categories;
		}
	}

	if ( taxonomy_exists( 'question_tag' ) ) {
		$tags = get_the_terms( $question_id, 'question_tag' );

		if ( $tags ) {
			$terms = $terms + $tags;
		}
	}

	if ( taxonomy_exists( 'question_label' ) ) {
		$labels = get_the_terms( $question_id, 'question_label' );

		if ( $labels ) {
			$terms = $terms + $labels;
		}
	}

	$term_ids = array();

	foreach ( (array) $terms as $term ) {
		$term_ids[] = $term->term_id;
	}

	if ( ! empty( $term_ids ) ) {
		ap_insert_qameta( $question_id, array( 'terms' => $term_ids ) );
	}

	return $term_ids;
}