Custom Post Types

private function register(): void
{
    register_post_type(Definitions::POST_TYPE_ARTIST, [
        'description'         => '',
        'public'              => true,
        'publicly_queryable'  => true,
        'show_in_nav_menus'   => true,
        'show_in_admin_bar'   => true,
        'exclude_from_search' => false,
        'show_in_rest'        => true,
        'show_ui'             => true,
        'show_in_menu'        => true,
        'menu_position'       => 21,
        'menu_icon'           => 'dashicons-id',
        'can_export'          => true,
        'delete_with_user'    => false,
        'hierarchical'        => false,
        'has_archive'         => 'artists',
        'query_var'           => Definitions::POST_TYPE_ARTIST,
        'capability_type'     => Definitions::POST_TYPE_ARTIST,
        'map_meta_cap'        => true,
        // ... capabilities and labels
    ]);
}

'capabilities' => [
    // meta caps (don't assign these to roles)
    'edit_post'              => 'edit_music_artist',
    'read_post'              => 'read_music_artist',
    'delete_post'            => 'delete_music_artist',

    // primitive/meta caps
    'create_posts'           => 'create_music_artists',

    // primitive caps used outside of map_meta_cap()
    'edit_posts'             => 'edit_music_artists',
    'edit_others_posts'      => 'edit_others_music_artists',
    'publish_posts'          => 'publish_music_artists',
    'read_private_posts'     => 'read_private_music_artists',

    // primitive caps used inside of map_meta_cap()
    'read'                   => 'read',
    'delete_posts'           => 'delete_music_artists',
    'delete_private_posts'   => 'delete_private_music_artists',
    'delete_published_posts' => 'delete_published_music_artists',
    'delete_others_posts'    => 'delete_others_music_artists',
    'edit_private_posts'     => 'edit_private_music_artists',
    'edit_published_posts'   => 'edit_published_music_artists'
],

'rewrite' => [
    'slug'       => 'artists',
    'with_front' => false,
    'pages'      => true,
    'feeds'      => true,
    'ep_mask'    => EP_PERMALINK,
],

'supports' => [
    'title',
    'editor',
    'excerpt',
    'author',
    'custom-fields',
    'thumbnail'
]

private function enterTitleHere(string $title, WP_Post $post): string
{
    return Definitions::POST_TYPE_ARTIST === $post->post_type
        ? esc_html__('Enter artist title', 'bifrost-music')
        : $title;
}

private function postUpdatedMessages(array $messages): array
{
    global $post, $post_ID;

    $artist_type = Definitions::POST_TYPE_ARTIST;

    if ($artist_type !== $post->post_type) {
        return $messages;
    }

    // Get permalink and preview URLs.
    $permalink   = get_permalink($post_ID);
    $preview_url = get_preview_post_link($post);

    // Post updated messages.
    $messages[$artist_type] = array(
        1 => esc_html__('Artist updated.', 'bifrost-music') . $view_link,
        6 => esc_html__('Artist published.', 'bifrost-music') . $view_link,
        // ... more messages
    );

    return $messages;
}

private function register(): void
{
    register_post_type(Definitions::POST_TYPE_ALBUM, [
        'description'         => '',
        'public'              => true,
        'show_in_rest'        => true,
        'show_ui'             => true,
        'menu_position'       => 22,
        'menu_icon'           => 'dashicons-playlist-audio',
        'has_archive'         => 'albums',
        'hierarchical'        => false,
        // ... rest of configuration
    ]);
}

private function restRegister(): void
{
    register_rest_field(Definitions::POST_TYPE_ALBUM, 'parent', [
        'get_callback'    => fn($post) => (int) $post['parent'],
        'update_callback' => fn($value, $post) => wp_update_post([
            'ID'          => $post->ID,
            'post_parent' => (int) $value
        ]),
        'schema' => [
            'description' => __('Parent Artist ID', 'bifrost-music'),
            'type'        => 'integer',
            'context'     => ['view', 'edit']
        ]
    ]);
}

private function addParentColumn(array $columns): array
{
    $new_columns = [];

    foreach ($columns as $key => $value) {
        $new_columns[$key] = $value;

        // Add parent column after title
        if ('title' === $key) {
            $new_columns['parent_artist'] = __( 'Artist', 'bifrost-music' );
        }
    }

    return $new_columns;
}

private function displayParentColumn(string $column, int $post_id): void
{
    if ('parent_artist' === $column) {
        $parent_id = wp_get_post_parent_id($post_id);

        if ($parent_id && $parent = get_post($parent_id)) {

            if (current_user_can('edit_post', $parent_id)) {
                printf(
                    '<a href="%s">%s</a>',
                    esc_url(get_edit_post_link($parent_id)),
                    esc_html($parent->post_title)
                );
                return;
            }

            echo esc_html($parent->post_title);
            return;
        }

        echo '&ndash;';
    }
}

private function sortParentColumn(array $columns): array
{
    $columns['parent_artist'] = 'parent';
    return $columns;
}

public static function activate(): void
{
    if ($role = get_role('administrator')) {
        // Artist caps.
        $role->add_cap('create_music_artists');
        $role->add_cap('edit_music_artists');
        $role->add_cap('edit_others_music_artists');
        $role->add_cap('publish_music_artists');
        // ... more capabilities

        // Album caps.
        $role->add_cap('create_music_albums');
        $role->add_cap('edit_music_albums');
        // ... more capabilities
    }
}

public static function uninstall(): void
{
    if ($role = get_role('administrator')) {
        // Remove Artist caps
        $role->remove_cap('create_music_artists');
        $role->remove_cap('edit_music_artists');
        // ... remove all capabilities
    }
}

public function register(): void
{
    $this->container->singleton(Album::class);
    $this->container->singleton(Artist::class);
    $this->container->singleton(Genre::class);
}

public function boot(): void
{
    $this->container->get(Album::class)->boot();
    $this->container->get(Artist::class)->boot();
    $this->container->get(Genre::class)->boot();
}