<?php
/**
 * Admin surfaces: settings page and read-only coverage viewer.
 *
 * v1.0.6 replaces the default WordPress admin styling with a hand-crafted
 * design system that matches Schema Monster (Mega). CSS lives in
 * assets/css/admin.css and is enqueued only on this plugin's admin pages
 * so it never leaks into other plugin screens.
 *
 * The upgrade card (Yoast-style upsell to Mega) renders on both Settings
 * and Coverage. See class-upgrade-card.php for the card itself.
 *
 * @package SchemaMonsterFree
 */

namespace SchemaMonsterFree;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Admin controller.
 */
final class Admin {

	const MENU_SLUG    = 'schema-monster';
	const CAPABILITY   = 'manage_options';
	const ASSET_HANDLE = 'smfree-admin';

	/**
	 * Register admin hooks.
	 */
	public static function init(): void {
		add_action( 'admin_menu', array( __CLASS__, 'register_menu' ) );
		add_action( 'admin_init', array( __CLASS__, 'register_settings' ) );
		add_action( 'admin_enqueue_scripts', array( __CLASS__, 'enqueue_assets' ) );
		add_filter( 'plugin_action_links_' . plugin_basename( SMFREE_PLUGIN_FILE ), array( __CLASS__, 'plugin_action_links' ) );
	}

	/**
	 * Register the top-level menu page. Uses the Schema Monster monster
	 * icon (PNG) for the sidebar rather than a generic Dashicon.
	 */
	public static function register_menu(): void {
		// WordPress admin sidebars use a dark navy background, so a colored
		// icon disappears into it. WP core plugins and every major third-
		// party plugin use a white/monochrome variant for exactly this
		// reason. The white_ice variant renders correctly on the dark
		// sidebar; the full-color monster is used for the header wordmark
		// (on light card backgrounds) where color reads correctly.
		$icon_url = SMFREE_PLUGIN_URL . 'assets/images/schema-monster-menu-icon-white.png';

		add_menu_page(
			__( 'Schema Monster', 'schema-monster' ),
			__( 'Schema Monster', 'schema-monster' ),
			self::CAPABILITY,
			self::MENU_SLUG,
			array( __CLASS__, 'render_settings_page' ),
			$icon_url,
			70
		);

		add_submenu_page(
			self::MENU_SLUG,
			__( 'Settings', 'schema-monster' ),
			__( 'Settings', 'schema-monster' ),
			self::CAPABILITY,
			self::MENU_SLUG,
			array( __CLASS__, 'render_settings_page' )
		);

		add_submenu_page(
			self::MENU_SLUG,
			__( 'Coverage', 'schema-monster' ),
			__( 'Coverage', 'schema-monster' ),
			self::CAPABILITY,
			self::MENU_SLUG . '-coverage',
			array( __CLASS__, 'render_coverage_page' )
		);
	}

	/**
	 * Enqueue admin assets.
	 *
	 * The full admin design system CSS loads only on this plugin's pages.
	 * A small sidebar-icon fixup CSS loads on every wp-admin page (because
	 * the sidebar renders everywhere) but is scoped to only affect our own
	 * menu item — it never touches any other plugin's icon.
	 *
	 * @param string $hook Current admin page hook.
	 */
	public static function enqueue_assets( string $hook ): void {
		// Sidebar icon CSS — load admin-wide since the sidebar is on every
		// wp-admin page. Scoped by #toplevel_page_schema-monster
		// selectors, so it cannot affect any other plugin.
		wp_enqueue_style(
			self::ASSET_HANDLE . '-menu',
			SMFREE_PLUGIN_URL . 'assets/css/admin-menu.css',
			array(),
			SMFREE_VERSION
		);

		// Full design system — only on our plugin's pages.
		$our_hooks = array(
			'toplevel_page_' . self::MENU_SLUG,
			'schema-monster_page_' . self::MENU_SLUG . '-coverage',
		);
		if ( ! in_array( $hook, $our_hooks, true ) ) {
			return;
		}

		wp_enqueue_style(
			self::ASSET_HANDLE,
			SMFREE_PLUGIN_URL . 'assets/css/admin.css',
			array(),
			SMFREE_VERSION
		);
	}

	/**
	 * Register plugin settings.
	 */
	public static function register_settings(): void {
		register_setting(
			'smfree_settings_group',
			SMFREE_OPTION_PREFIX . 'enabled',
			array(
				'type'              => 'boolean',
				'sanitize_callback' => static function ( $value ) {
					return (int) (bool) $value;
				},
				'default'           => 1,
			)
		);

		register_setting(
			'smfree_settings_group',
			SMFREE_OPTION_PREFIX . 'coexistence_mode',
			array(
				'type'              => 'string',
				'sanitize_callback' => array( __CLASS__, 'sanitize_coexistence_mode' ),
				'default'           => Coexistence::MODE_MERGE,
			)
		);

		register_setting(
			'smfree_settings_group',
			SMFree_FAQ_Detector::OPTION_ENABLED,
			array(
				'type'              => 'boolean',
				'sanitize_callback' => array( __CLASS__, 'sanitize_checkbox' ),
				'default'           => 1,
			)
		);

		register_setting(
			'smfree_settings_group',
			SMFree_FAQ_Detector::OPTION_DEBUG,
			array(
				'type'              => 'boolean',
				'sanitize_callback' => array( __CLASS__, 'sanitize_checkbox' ),
				'default'           => 0,
			)
		);
	}

	/**
	 * Sanitize a checkbox setting to 0/1.
	 *
	 * @param mixed $value Raw input.
	 */
	public static function sanitize_checkbox( $value ): int {
		return (int) (bool) $value;
	}

	/**
	 * Sanitize the coexistence mode setting.
	 *
	 * @param mixed $value Raw input.
	 */
	public static function sanitize_coexistence_mode( $value ): string {
		return smfree_normalize_coexistence_mode( is_string( $value ) ? sanitize_key( $value ) : '' );
	}

	/**
	 * Add a Settings link on the Plugins list row.
	 *
	 * @param array<int,string> $links Existing links.
	 * @return array<int,string>
	 */
	public static function plugin_action_links( array $links ): array {
		$settings_url = admin_url( 'admin.php?page=' . self::MENU_SLUG );
		$upgrade_url  = 'https://schemamonster.com/pricing/';

		$prepend = array(
			sprintf( '<a href="%s">%s</a>', esc_url( $settings_url ), esc_html__( 'Settings', 'schema-monster' ) ),
			sprintf( '<a href="%s" target="_blank" rel="noopener" style="color: #6D5AEA; font-weight: 600;">%s</a>', esc_url( $upgrade_url ), esc_html__( 'Upgrade to Mega', 'schema-monster' ) ),
		);

		return array_merge( $prepend, $links );
	}

	// ------------------------------------------------------------------
	// Shared header, footer, wrapper.
	// ------------------------------------------------------------------

	/**
	 * Render the plugin's header (wordmark + version badge).
	 */
	private static function render_header(): void {
		$logo_url = SMFREE_PLUGIN_URL . 'assets/images/schema-monster-logo.png';
		?>
		<div class="smf-header">
			<div class="smf-header-brand">
				<img
					src="<?php echo esc_url( $logo_url ); ?>"
					alt="<?php esc_attr_e( 'Schema Monster', 'schema-monster' ); ?>"
				/>
			</div>
			<div class="smf-header-badge">
				<?php esc_html_e( 'Free', 'schema-monster' ); ?>
				<strong>v<?php echo esc_html( SMFREE_VERSION ); ?></strong>
			</div>
		</div>
		<?php
	}

	/**
	 * Render the plugin's footer.
	 */
	private static function render_footer(): void {
		?>
		<div class="smf-footer">
			<?php
			printf(
				/* translators: %s: link to schemamonster.com */
				esc_html__( 'Powered by %s', 'schema-monster' ),
				'<a href="https://schemamonster.com/" target="_blank" rel="noopener">Schema Monster</a>'
			);
			?>
		</div>
		<?php
	}

	// ------------------------------------------------------------------
	// Settings page.
	// ------------------------------------------------------------------

	/**
	 * Render the settings page.
	 */
	public static function render_settings_page(): void {
		if ( ! current_user_can( self::CAPABILITY ) ) {
			return;
		}

		$enabled = (int) get_option( SMFREE_OPTION_PREFIX . 'enabled', 1 );
		$mode    = smfree_get_coexistence_mode();
		$faq_on  = (int) SMFree_FAQ_Detector::enabled();
		$faq_dbg = (int) SMFree_FAQ_Detector::debug_enabled();
		?>
		<div class="wrap smf-wrap">
			<?php self::render_header(); ?>

			<?php Upgrade_Card::render( 'settings' ); ?>

			<div class="smf-card">
				<div class="smf-card-header">
					<h2><?php esc_html_e( 'Schema Output', 'schema-monster' ); ?></h2>
					<p class="smf-card-subtitle">
						<?php esc_html_e( 'Control how Schema Monster emits JSON-LD and coexists with other SEO plugins.', 'schema-monster' ); ?>
					</p>
				</div>

				<form method="post" action="options.php">
					<?php settings_fields( 'smfree_settings_group' ); ?>

					<div class="smf-form-row">
						<div class="smf-form-label">
							<label for="smfree_enabled"><?php esc_html_e( 'Enable schema output', 'schema-monster' ); ?></label>
						</div>
						<div class="smf-form-body">
							<div class="smf-toggle-row">
								<input
									type="checkbox"
									id="smfree_enabled"
									name="<?php echo esc_attr( SMFREE_OPTION_PREFIX . 'enabled' ); ?>"
									value="1"
									<?php checked( 1, $enabled ); ?>
								/>
								<label for="smfree_enabled">
									<?php esc_html_e( 'Emit JSON-LD schema in the <head> of qualifying pages.', 'schema-monster' ); ?>
								</label>
							</div>
							<p class="description">
								<?php esc_html_e( 'Disable to stop schema output plugin-wide without deactivating the plugin.', 'schema-monster' ); ?>
							</p>
						</div>
					</div>

					<div class="smf-form-row">
						<div class="smf-form-label">
							<label for="smfree_coexistence_mode"><?php esc_html_e( 'Coexistence mode', 'schema-monster' ); ?></label>
						</div>
						<div class="smf-form-body">
							<select
								id="smfree_coexistence_mode"
								name="<?php echo esc_attr( SMFREE_OPTION_PREFIX . 'coexistence_mode' ); ?>"
							>
								<option value="<?php echo esc_attr( Coexistence::MODE_MERGE ); ?>" <?php selected( Coexistence::MODE_MERGE, $mode ); ?>>
									<?php esc_html_e( 'Merge — drop our duplicates (recommended)', 'schema-monster' ); ?>
								</option>
								<option value="<?php echo esc_attr( Coexistence::MODE_SUPPRESS ); ?>" <?php selected( Coexistence::MODE_SUPPRESS, $mode ); ?>>
									<?php esc_html_e( 'Suppress third-party — only Schema Monster emits', 'schema-monster' ); ?>
								</option>
								<option value="<?php echo esc_attr( Coexistence::MODE_EMIT ); ?>" <?php selected( Coexistence::MODE_EMIT, $mode ); ?>>
									<?php esc_html_e( 'Emit alongside — no deduplication (advanced)', 'schema-monster' ); ?>
								</option>
							</select>
							<p class="description">
								<strong><?php esc_html_e( 'Merge:', 'schema-monster' ); ?></strong>
								<?php esc_html_e( 'Before output, Schema Monster checks the JSON-LD other plugins print on the page. If another plugin already emits a schema type (for example WebSite, Organization, or WebPage), Schema Monster leaves its own copy out, so no type appears twice. Other plugins\' output is never changed.', 'schema-monster' ); ?>
							</p>
							<p class="description">
								<strong><?php esc_html_e( 'Suppress third-party:', 'schema-monster' ); ?></strong>
								<?php esc_html_e( 'Suppresses Yoast SEO and Rank Math schema output. Other SEO plugins are not affected.', 'schema-monster' ); ?>
							</p>
							<p class="description" style="color: #B45309;">
								<?php esc_html_e( 'Warning: This may affect rich result eligibility if other SEO plugins were handling schema previously.', 'schema-monster' ); ?>
							</p>
							<p class="description">
								<strong><?php esc_html_e( 'Emit alongside:', 'schema-monster' ); ?></strong>
								<?php esc_html_e( 'Schema Monster and other plugins all emit their full output. This produces duplicate schema by design; use it only to compare outputs.', 'schema-monster' ); ?>
							</p>
						</div>
					</div>

					<div class="smf-form-row">
						<div class="smf-form-label">
							<label for="smfree_faq_autodetect"><?php esc_html_e( 'Auto-detect FAQ accordions', 'schema-monster' ); ?></label>
						</div>
						<div class="smf-form-body">
							<div class="smf-toggle-row">
								<input
									type="checkbox"
									id="smfree_faq_autodetect"
									name="<?php echo esc_attr( SMFree_FAQ_Detector::OPTION_ENABLED ); ?>"
									value="1"
									<?php checked( 1, $faq_on ); ?>
								/>
								<label for="smfree_faq_autodetect">
									<?php esc_html_e( 'Add FAQPage schema when a page contains two or more questions and answers.', 'schema-monster' ); ?>
								</label>
							</div>
							<p class="description">
								<?php esc_html_e( 'Detects Elementor Accordion, Toggle, and Nested Accordion widgets, Details blocks, and question headings under an "FAQ" heading.', 'schema-monster' ); ?>
							</p>
						</div>
					</div>

					<div class="smf-form-row">
						<div class="smf-form-label">
							<label for="smfree_debug_faq_detection"><?php esc_html_e( 'Debug FAQ detection', 'schema-monster' ); ?></label>
						</div>
						<div class="smf-form-body">
							<div class="smf-toggle-row">
								<input
									type="checkbox"
									id="smfree_debug_faq_detection"
									name="<?php echo esc_attr( SMFree_FAQ_Detector::OPTION_DEBUG ); ?>"
									value="1"
									<?php checked( 1, $faq_dbg ); ?>
								/>
								<label for="smfree_debug_faq_detection">
									<?php esc_html_e( 'Log FAQ auto-detection results for each page view.', 'schema-monster' ); ?>
								</label>
							</div>
							<p class="description">
								<?php
								printf(
									/* translators: %s: log directory path inside wp-content */
									esc_html__( 'Writes daily logs to %s (kept for 7 days). Leave off in production.', 'schema-monster' ),
									'<code>' . esc_html( 'wp-content/uploads/' . SMFree_FAQ_Detector::LOG_DIR . '/' ) . '</code>'
								);
								?>
							</p>
						</div>
					</div>

					<div style="margin-top: 24px; padding-top: 16px; border-top: 1px solid #F1F5F9;">
						<?php submit_button( __( 'Save Changes', 'schema-monster' ), 'primary', 'submit', false ); ?>
					</div>
				</form>
			</div>

			<div class="smf-card">
				<div class="smf-card-header">
					<h2><?php esc_html_e( 'Schema Types Emitted', 'schema-monster' ); ?></h2>
					<p class="smf-card-subtitle">
						<?php esc_html_e( 'These schema.org types are produced on qualifying pages, deterministically from your existing content.', 'schema-monster' ); ?>
					</p>
				</div>

				<ul class="smf-schema-types">
					<li><?php esc_html_e( 'WebSite with Sitelinks Search Box', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'Organization', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'WebPage with entity references', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'BreadcrumbList (non-homepage)', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'BlogPosting (posts only)', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'FAQPage (Yoast/Rank Math blocks, auto-detected accordions, and consolidated third-party FAQ)', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'HowTo (Yoast/Rank Math HowTo blocks)', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'VideoObject (YouTube or Vimeo URL in content)', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'SiteNavigationElement (homepage only)', 'schema-monster' ); ?></li>
					<li><?php esc_html_e( 'Product with Offer (WooCommerce)', 'schema-monster' ); ?></li>
				</ul>
			</div>

			<?php self::render_footer(); ?>
		</div>
		<?php
	}

	// ------------------------------------------------------------------
	// Coverage page.
	// ------------------------------------------------------------------

	/**
	 * Render the coverage viewer.
	 */
	public static function render_coverage_page(): void {
		if ( ! current_user_can( self::CAPABILITY ) ) {
			return;
		}

		$post_types = get_post_types( array( 'public' => true ), 'names' );
		$blocklist  = self::internal_post_type_blocklist();
		foreach ( $blocklist as $slug ) {
			unset( $post_types[ $slug ] );
		}
		unset( $post_types['attachment'] );

		/**
		 * Filter: modify the list of post types shown on the Coverage page.
		 * Return an array of post type slugs.
		 *
		 * @param array<int|string,string> $post_types Post type slugs to include.
		 */
		$post_types = (array) apply_filters( 'smfree_coverage_post_types', $post_types );
		// Deprecated pre-1.0.15 name, kept for back-compat.
		// phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
		$post_types = (array) apply_filters_deprecated( 'smf_coverage_post_types', array( $post_types ), '1.0.15', 'smfree_coverage_post_types' );

		$candidates = get_posts(
			array(
				'post_type'      => array_values( $post_types ),
				'post_status'    => 'publish',
				'posts_per_page' => 100,
				'orderby'        => 'modified',
				'order'          => 'DESC',
				'no_found_rows'  => true,
			)
		);

		$posts = array();
		foreach ( $candidates as $candidate ) {
			if ( self::is_excluded_from_coverage( $candidate ) ) {
				continue;
			}
			$posts[] = $candidate;
			if ( count( $posts ) >= 50 ) {
				break;
			}
		}
		?>
		<div class="wrap smf-wrap">
			<?php self::render_header(); ?>

			<?php Upgrade_Card::render( 'coverage' ); ?>

			<div class="smf-card">
				<div class="smf-card-header">
					<h2><?php esc_html_e( 'Coverage', 'schema-monster' ); ?></h2>
					<p class="smf-card-subtitle">
						<?php
						printf(
							/* translators: %d: post count */
							esc_html__( 'The last %d modified indexable posts, with the schema types the plugin will emit for each.', 'schema-monster' ),
							50
						);
						?>
					</p>
				</div>

				<p class="smf-freshness">
					<?php
					printf(
						/* translators: %s: timestamp of when data was computed */
						esc_html__( 'Data current as of %s. Reload this page to recompute.', 'schema-monster' ),
						esc_html( wp_date( 'F j, Y \a\t g:i a', current_time( 'timestamp' ) ) )
					);
					?>
				</p>
				<p class="smf-footnote">
					<?php
					esc_html_e(
						'Excludes internal template stores (Elementor library, CartFlows steps), password-protected posts, and posts marked noindex by Yoast, Rank Math, or All in One SEO.',
						'schema-monster'
					);
					?>
				</p>

				<?php if ( empty( $posts ) ) : ?>
					<p><em><?php esc_html_e( 'No indexable posts found.', 'schema-monster' ); ?></em></p>
				<?php else : ?>
					<table class="smf-table">
						<thead>
							<tr>
								<th><?php esc_html_e( 'Title', 'schema-monster' ); ?></th>
								<th><?php esc_html_e( 'Type', 'schema-monster' ); ?></th>
								<th><?php esc_html_e( 'Schema types emitted', 'schema-monster' ); ?></th>
								<th><?php esc_html_e( 'Modified', 'schema-monster' ); ?></th>
							</tr>
						</thead>
						<tbody>
							<?php foreach ( $posts as $post ) : ?>
								<?php
								$graph = Engine::build_graph( (int) $post->ID );
								$types = self::extract_types( $graph );
								?>
								<tr>
									<td>
										<a href="<?php echo esc_url( get_edit_post_link( $post->ID ) ); ?>">
											<?php echo esc_html( get_the_title( $post ) ); ?>
										</a>
									</td>
									<td>
										<span class="smf-post-type"><?php echo esc_html( $post->post_type ); ?></span>
									</td>
									<td>
										<?php if ( empty( $types ) ) : ?>
											<em style="color: #94A3B8;"><?php esc_html_e( 'None', 'schema-monster' ); ?></em>
										<?php else : ?>
											<?php echo esc_html( implode( ', ', $types ) ); ?>
										<?php endif; ?>
									</td>
									<td><?php echo esc_html( get_the_modified_date( 'Y-m-d H:i', $post ) ); ?></td>
								</tr>
							<?php endforeach; ?>
						</tbody>
					</table>

					<p style="margin-top: 16px; color: #94A3B8; font-size: 12px; font-style: italic;">
						<?php esc_html_e( 'Regenerate, exclude, and refresh actions arrive in v1.1.', 'schema-monster' ); ?>
					</p>
				<?php endif; ?>
			</div>

			<?php self::render_footer(); ?>
		</div>
		<?php
	}

	// ------------------------------------------------------------------
	// Helper methods (unchanged from v1.0.5).
	// ------------------------------------------------------------------

	/**
	 * Post type slugs that get excluded from Coverage regardless of their
	 * public/publicly_queryable registration flags.
	 *
	 * @return array<int,string>
	 */
	private static function internal_post_type_blocklist(): array {
		$default = array(
			// Elementor and its addon ecosystem.
			'elementor_library',
			'e-landing-page',
			'elementskit_content',        // ElementsKit widget templates.
			'elementskit_template',       // ElementsKit page templates.
			'ua-templates',               // Ultimate Addons for Elementor.
			'ha-templates',               // Happy Addons templates.
			'jet-engine',                 // JetEngine content types (often internal).
			// CartFlows.
			'cartflows_step',
			'cartflows_flow',
			// Themes.
			'oceanwp_library',
			'astra-advanced-hook',
			'astra_adv_header',
			'brizy_template',
			// Form plugins.
			'wpforms',
			'gravityforms',
			'wpcf7_contact_form',
			// ACF.
			'acf-field',
			'acf-field-group',
			// WooCommerce internals.
			'shop_order',
			'shop_coupon',
			'shop_order_refund',
			'product_variation',
			// WordPress core internals.
			'nav_menu_item',
			'revision',
		);

		/**
		 * Filter: modify the list of internal post type slugs excluded from
		 * Coverage.
		 *
		 * @param array<int,string> $default Default blocklist.
		 */
		$internal = (array) apply_filters( 'smfree_coverage_internal_post_types', $default );
		// Deprecated pre-1.0.15 name, kept for back-compat.
		// phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
		return (array) apply_filters_deprecated( 'smf_coverage_internal_post_types', array( $internal ), '1.0.15', 'smfree_coverage_internal_post_types' );
	}

	/**
	 * True when a post should not appear on the Coverage viewer because a
	 * search engine wouldn't index it.
	 *
	 * @param \WP_Post $post Post to check.
	 */
	private static function is_excluded_from_coverage( \WP_Post $post ): bool {
		if ( '' !== (string) $post->post_password ) {
			return true;
		}

		$yoast_noindex = get_post_meta( (int) $post->ID, '_yoast_wpseo_meta-robots-noindex', true );
		if ( '1' === (string) $yoast_noindex ) {
			return true;
		}

		$rm_robots = get_post_meta( (int) $post->ID, 'rank_math_robots', true );
		if ( is_array( $rm_robots ) && in_array( 'noindex', $rm_robots, true ) ) {
			return true;
		}

		$aioseo_new = get_post_meta( (int) $post->ID, '_aioseo_noindex', true );
		$aioseo_old = get_post_meta( (int) $post->ID, '_aioseop_noindex', true );
		if ( in_array( (string) $aioseo_new, array( 'on', '1' ), true ) ) {
			return true;
		}
		if ( in_array( (string) $aioseo_old, array( 'on', '1' ), true ) ) {
			return true;
		}

		/**
		 * Filter: allow a site to exclude additional posts from Coverage.
		 *
		 * @param bool     $excluded Current exclusion decision.
		 * @param \WP_Post $post     The post being evaluated.
		 */
		$excluded = (bool) apply_filters( 'smfree_coverage_exclude_post', false, $post );
		// Deprecated pre-1.0.15 name, kept for back-compat.
		// phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
		return (bool) apply_filters_deprecated( 'smf_coverage_exclude_post', array( $excluded, $post ), '1.0.15', 'smfree_coverage_exclude_post' );
	}

	/**
	 * Flatten @type values from a graph into a comma-friendly list.
	 *
	 * @param array<string,mixed> $graph JSON-LD graph.
	 * @return array<int,string>
	 */
	private static function extract_types( array $graph ): array {
		if ( empty( $graph['@graph'] ) || ! is_array( $graph['@graph'] ) ) {
			return array();
		}
		$types = array();
		foreach ( $graph['@graph'] as $node ) {
			if ( ! is_array( $node ) || empty( $node['@type'] ) ) {
				continue;
			}
			$node_types = is_array( $node['@type'] ) ? $node['@type'] : array( $node['@type'] );
			foreach ( $node_types as $t ) {
				if ( is_string( $t ) && '' !== $t ) {
					$types[] = $t;
				}
			}
		}
		return array_values( array_unique( $types ) );
	}
}