【ワードプレス】カテゴリを登録すると自動でスラッグの接尾辞にロケールを付与する【未完成】

gistfile1.php

add_action('create_term', function($term_id, $tt_id, $taxonomy){
	global $wpdb, $locale;
		
	$term = get_term( $term_id, $taxonomy, ARRAY_A );
	$locale = strtolower($locale);
	$slug   = sprintf("%s-%s", $term['slug'], $locale);
		
	if(preg_match("/-{$locale}$/i", $term['slug']))
		return;

	$duplicate_term = $wpdb->get_row( $wpdb->prepare( "SELECT t.term_id, tt.term_taxonomy_id FROM $wpdb->terms t INNER JOIN $wpdb->term_taxonomy tt ON ( tt.term_id = t.term_id ) WHERE t.slug = %s AND tt.parent = %d AND tt.taxonomy = %s AND t.term_id < %d AND tt.term_taxonomy_id != %d", $slug, $term['parent'], $taxonomy, $term_id, $tt_id ) );
	if ( $duplicate_term ) {
		$wpdb->delete( $wpdb->terms, array( 'term_id' => $term_id ) );
		$wpdb->delete( $wpdb->term_taxonomy, array( 'term_taxonomy_id' => $tt_id ) );
	} else {
		$wpdb->update($wpdb->terms, compact('slug'), compact( 'term_id' ));			
	}

}, 99, 3);

重複スラッグが登録できない。。