/**
 * 将 max-video-preview 修改为 100。
 *
 * @param string $output       原始输出字符串的字符串表示。
 * @param object $presentation 包含必要数据的呈现对象。
 *
 * @return string Googlebot 元标签。
 */
function change_robots_video_preview_settings( $output, $presentation ) {
    $robots = $presentation->robots;

    $values = \array_map( function( $item ) {
        if ( strpos( $item, 'max-video-preview' ) !== false ) {
            $item = 'max-video-preview:100';
        }

        return $item;
    }, $robots );

    return \implode( ', ', $values );
}

add_filter( 'wpseo_robots', 'change_robots_video_preview_settings', 10, 2 );

/**
 * Changes title for a specific category.
 *
 * @param string $title        The current title.
 * @param object $presentation The presentation object containing the necessary data.
 *
 * @return string The altered title tag.
 */
function change_category_title( $title, $presentation ) {
    $categories = \get_the_category( $presentation->model->object_id );

    foreach ( $categories as $category ) {
        if ( $category->slug === 'books' ) {
            return sprintf( '%s - %s', $title, $category->name );
        }

        return $title;
    }
}

add_filter( 'wpseo_title', 'change_category_title', 10, 2 );

use Yoast\WP\SEO\Presenters\Abstract_Indexable_Presenter;

/**
 * Adds a custom my_meta_tag tag.
 */
class My_Custom_Presenter extends Abstract_Indexable_Presenter {
    /**
     * This output the full meta tag you want to add.
     */
    public function present() {
        return '<meta name="my_meta_tag" content="' . esc_attr( $this->get() ) . '" />';
    }

    /**
     * Returns the value of our new tag.
     *
     * @return string The value of our meta tag.
     */
    public function get() {
        return ( $this->presentation->open_graph_locale === 'nl_NL' ) ? 'Dutch' : 'Not dutch';
    }
}

use Yoast\WP\SEO\Presenters\Abstract_Indexable_Tag_Presenter;

/**
 * Adds a custom my_meta_tag tag.
 */
class My_Custom_Presenter extends Abstract_Indexable_Tag_Presenter {

    /**
     * The tag format including placeholders.
     *
     * @var string
     */
    protected $tag_format = '<meta name="my_meta_tag" content="%s" />';

    /**
     * Returns the value of our new tag.
     *
     * @return string The value of our meta tag.
     */
    public function get() {
        return ( $this->presentation->open_graph_locale === 'nl_NL' ) ? 'Dutch' : 'Not dutch';
    }
}

/**
 * 将我们的自定义呈现器添加到呈现器数组中。
 *
 * @param array $presenters 当前的呈现器数组。
 *
 * @return array 添加了自定义呈现器后的呈现器数组。
 */
function add_my_custom_presenter( $presenters ) {
    $presenters[] = new My_Custom_Presenter();

    return $presenters;
}

add_filter( 'wpseo_frontend_presenters', 'add_my_custom_presenter' );

/**
 * 从展示器中移除规范 URL。
 *
 * @param array $presenters 已注册的展示器。
 *
 * @return array 剩余的展示器。
 */
function remove_canonical_presenter( $presenters ) {
    return array_map( function( $presenter ) {
        if ( ! $presenter instanceof Canonical_Presenter ) {
            return $presenter;
        }
    }, $presenters );
}

add_action( 'wpseo_frontend_presenters', 'remove_canonical_presenter' );