如何通过在运行"wp_insert_post"之前检查帖子标题是否存在来防止重复发帖？

$title = '帖子标题';
$existing_post = get_page_by_title( $title, OBJECT, 'post' );

if ( ! $existing_post ) {
    $post_id = wp_insert_post( array(
        'post_title' => $title,
        'post_content' => '帖子内容',
        'post_status' => 'publish',
        'post_type' => 'post',
    ) );
}

function check_duplicate_title( $query ) {
    if ( $query->is_main_query() && $query->is_search ) {
        $query->set( 'post_title', '帖子标题' );
    }
}
add_action( 'pre_get_posts', 'check_duplicate_title' );

function check_duplicate_title_before_save( $post_id ) {
    $title = get_the_title( $post_id );
    $existing_post = get_page_by_title( $title, OBJECT, 'post' );

    if ( $existing_post && $existing_post->ID != $post_id ) {
        wp_delete_post( $post_id, true );
    }
}
add_action( 'save_post', 'check_duplicate_title_before_save' );