<?php

declare( strict_types=1 );

namespace Rooster\Core;

defined( 'ABSPATH' ) || exit;

final class Defer {

	public const QUERY       = 'rooster_layer';
	public const PLACEHOLDER = 'rooster/defer-placeholder';

	
	public const READER = 2;

	
	public const CSS = 'rooster_css';

	
	private static bool $layer_css = false;

	
	public const HEIGHTS_ACTION = 'rooster_defer_heights';

	
	private const HEIGHTS_AGREE = 24;

	
	private const HEIGHTS_MAX = 3000;

	
	private const HEIGHTS_RATE = 60;

	
	public const WARM_COOKIE = 'rooster_dh_warm';

	
	private static ?array $learned = null;

	
	private const ACTION_ARGS = [ 'add-to-cart', 'added-to-cart', 'quantity', 'variation_id', 'remove_item', 'undo_item', 'order_again', 'cancel_order', 'download_file', '_wpnonce', '_wp_http_referer' ];

	
	private const SUPPORTED = [
		'core/group'                     => '320px',
		'core/columns'                   => '320px',
		'core/details'                   => '48px',
		'core/template-part'             => '400px',
		'core/pattern'                   => '320px',
		'core/comments'                  => '320px',
		'core/query'                     => '480px',
		'core/cover'                     => '400px',
		'woocommerce/product-collection' => '420px',
		'woocommerce/product-reviews'    => '360px',
	];

	
	private static array $registered = [];

	private static int $counter = 0;

	
	private static int $nav_counter = 0;

	
	private static array $menu_seen = [];

	private static bool $placeholders = false;

	private static bool $enqueued = false;

	public static function boot(): void {
		add_action( 'init', [ self::class, 'collect_regions' ], 0 );
		add_filter( 'register_block_type_args', [ self::class, 'add_support' ], 10, 2 );
		add_action( 'init', [ self::class, 'register' ] );
		
		add_action( 'wp_ajax_nopriv_' . self::HEIGHTS_ACTION, [ self::class, 'record_heights' ] );
		add_action( 'wp_ajax_' . self::HEIGHTS_ACTION, [ self::class, 'record_heights' ] );
		if ( defined( 'WP_CLI' ) && WP_CLI ) {
			\WP_CLI::add_command( 'aieo heights warm', [ self::class, 'cli_warm' ], [ 'shortdesc' => 'Print a short-lived token whose signed-out height reports count at once.' ] );
			\WP_CLI::add_command( 'aieo heights show', [ self::class, 'cli_show' ], [ 'shortdesc' => 'Show the learned placeholder heights of a page.' ] );
		}
		if ( is_admin() ) {
			return;
		}
		add_action( 'shutdown', [ self::class, 'keep_session' ], 0 );
		add_filter( 'render_block_data', [ self::class, 'walk' ], 20, 3 );
		add_filter( 'render_block', [ self::class, 'late' ], 20, 2 );
		add_filter( 'render_block_core/navigation', [ self::class, 'hidden_nav_menu' ], 30, 2 );
		add_filter( 'render_block_core/navigation', [ self::class, 'nav_submenus' ], 31, 2 );
		add_action( 'send_headers', [ self::class, 'headers' ] );
		add_action( 'template_redirect', [ self::class, 'layer_status' ], 0 );
		add_action( 'template_redirect', [ self::class, 'in_place_headers' ], 0 );
		add_action( 'wp_enqueue_scripts', [ self::class, 'enqueue_for_stubs' ], 999 );
		add_filter( 'wp_speculation_rules_href_exclude_paths', [ self::class, 'exclude_layer_from_speculation' ] );
	}

	public static function is_full(): bool {
		if ( null === self::$full ) {
			self::$full = 'full' === ( $_GET[ self::QUERY ] ?? '' ); 
		}
		return self::$full;
	}

	
	public static function keep_session(): void {
		if ( ! self::is_full() || ! function_exists( 'WC' ) ) {
			return;
		}
		$wc = WC();
		if ( is_object( $wc ) && isset( $wc->session ) && is_object( $wc->session ) ) {
			remove_action( 'shutdown', [ $wc->session, 'save_data' ], 20 );
		}
	}

	
	private static ?bool $full = null;

	
	private static ?bool $in_place = null;

	
	public static function in_place(): bool {
		if ( null !== self::$in_place ) {
			return self::$in_place;
		}
		if ( ! did_action( 'wp' ) ) {
			return false; 
		}
		$listing = function_exists( 'is_shop' ) && ( is_shop() || is_product_taxonomy() || ( is_search() && 'product' === get_query_var( 'post_type' ) ) );
		
		self::$in_place = self::script_fetch() && (bool) apply_filters( 'rooster/defer/in_place', $listing );
		return self::$in_place;
	}

	
	private static function script_fetch(): bool {
		$header = static fn ( string $name ): string => strtolower( trim( (string) ( $_SERVER[ $name ] ?? '' ) ) ); 
		return 'empty' === $header( 'HTTP_SEC_FETCH_DEST' )
			&& in_array( $header( 'HTTP_SEC_FETCH_MODE' ), [ 'cors', 'same-origin' ], true )
			&& 'same-origin' === $header( 'HTTP_SEC_FETCH_SITE' )
			&& 'GET' === strtoupper( (string) ( $_SERVER['REQUEST_METHOD'] ?? 'GET' ) ) 
			&& ! self::is_full()
			&& ! isset( $_GET['rooster_part'] ); 
	}

	
	public static function renders_whole(): bool {
		return self::is_full() || self::in_place();
	}

	
	public static function in_place_headers(): void {
		if ( ! self::in_place() || headers_sent() ) {
			return;
		}
		header( 'X-Rooster-In-Place: 1' );
		header( 'X-Rooster-No-Cache: 1' );
		header( 'Vary: Sec-Fetch-Dest', false );
		if ( ! defined( 'DONOTCACHEPAGE' ) ) {
			define( 'DONOTCACHEPAGE', true ); 
		}
	}

	
	public static function capture(): void {
		if ( ! self::is_full() ) {
			return;
		}
		self::$layer_css = isset( $_GET[ self::CSS ] ); 
		unset( $_GET[ self::QUERY ], $_REQUEST[ self::QUERY ], $_GET[ self::CSS ], $_REQUEST[ self::CSS ] );
		if ( isset( $_SERVER['REQUEST_URI'] ) ) {
			$_SERVER['REQUEST_URI'] = remove_query_arg( [ self::QUERY, self::CSS ], (string) $_SERVER['REQUEST_URI'] );
			$_SERVER['QUERY_STRING'] = (string) wp_parse_url( $_SERVER['REQUEST_URI'], PHP_URL_QUERY );
		}
	}

	
	public static function layer_css(): bool {
		return self::$layer_css;
	}

	public static function enabled(): bool {
		static $enabled = null;
		if ( null === $enabled ) {
			$enabled = (bool) \AIEO_Engine_Settings::get( 'defer', true ) && ! is_admin() && ! wp_is_json_request() && ! ( defined( 'REST_REQUEST' ) && REST_REQUEST );
		}
		return $enabled;
	}

	
	public static function collect_regions(): void {
		$registrar = new class() {
			
			public function register( $name, $args = [] ): void {
				Defer::add_region( (string) $name, (array) $args );
			}
		};
		do_action( 'rooster/defer/register_region', $registrar );
	}

	public static function add_region( string $name, array $args ): void {
		$height = (string) ( $args['height'] ?? '320px' );
		self::$registered[ $name ] = preg_match( '/^[0-9.]+(px|rem|em|vh|dvh|%)$/', $height ) ? $height : '320px';
	}

	
	public static function add_support( $args, $name ) {
		$height = self::SUPPORTED[ $name ] ?? self::$registered[ $name ] ?? null;
		if ( null !== $height && ! isset( $args['supports']['rooster']['defer'] ) ) {
			$args['supports']['rooster']['defer'] = [ 'allowed' => true, 'height' => $height, 'default' => 'inline' ];
			
			$args['attributes']['roosterDefer'] ??= [ 'type' => 'object' ];
		}
		return $args;
	}

	
	public static function register(): void {
		\WP_Block_Supports::get_instance()->register(
			'rooster-defer',
			[
				'register_attribute' => static function ( \WP_Block_Type $block_type ): void {
					if ( empty( $block_type->supports['rooster']['defer']['allowed'] ) ) {
						return;
					}
					if ( ! is_array( $block_type->attributes ) ) {
						$block_type->attributes = [];
					}
					$block_type->attributes['roosterDefer'] ??= [ 'type' => 'object' ];
				},
			]
		);
		register_block_type(
			self::PLACEHOLDER,
			[
				'api_version'     => 3,
				'title'           => __( 'Deferred region placeholder', 'ai-eshop-optimizer' ),
				'attributes'      => [
					'id'      => [ 'type' => 'string' ],
					'height'  => [ 'type' => 'string' ],
					'label'   => [ 'type' => 'string' ],
					'trigger' => [ 'type' => 'string' ],
					'align'   => [ 'type' => 'string' ],
				],
				'supports'        => [ 'inserter' => false, 'html' => false ],
				'render_callback' => [ self::class, 'render_placeholder' ],
			]
		);
		if ( ! is_admin() ) {
			
			$relative = defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ? 'assets/js/modules/defer.js' : 'assets/js/modules/defer.min.js';
			wp_register_script_module(
				'rooster-defer',
				AIEO_ENGINE_URL . '/' . $relative,
				[ '@wordpress/interactivity', [ 'id' => '@wordpress/interactivity-router', 'import' => 'dynamic' ] ],
				(string) filemtime( AIEO_ENGINE_DIR . '/' . $relative )
			);
		}
	}

	

	
	public static function walk( $parsed_block, $source_block = null, $parent_block = null ) {
		if ( null !== $parent_block || ! is_array( $parsed_block ) || ! self::enabled() ) {
			return $parsed_block;
		}
		return self::walk_tree( $parsed_block );
	}

	private static function walk_tree( array $block ): array {
		if ( self::is_deferred( $block ) && empty( $block['attrs']['roosterDefer']['id'] ) ) {
			$id = self::region_id();
			if ( ! self::renders_whole() ) {
				return self::placeholder_block( $block, $id );
			}
			$block['attrs']['roosterDefer']['id'] = $id;
			
			return $block;
		}
		if ( ! empty( $block['innerBlocks'] ) ) {
			foreach ( $block['innerBlocks'] as $i => $inner ) {
				$block['innerBlocks'][ $i ] = self::walk_tree( $inner );
			}
		}
		return $block;
	}

	private static function placeholder_block( array $block, string $id ): array {
		return [
			'blockName'    => self::PLACEHOLDER,
			'attrs'        => [
				'id'      => $id,
				'height'  => self::placeholder_height( $block, $id ),
				'label'   => self::label( $block ),
				'trigger' => (string) ( $block['attrs']['roosterDefer']['trigger'] ?? 'layer' ),
				'align'   => (string) ( $block['attrs']['align'] ?? '' ),
			],
			'innerBlocks'  => [],
			'innerHTML'    => '',
			'innerContent' => [],
		];
	}

	
	private static function is_deferred( array $block ): bool {
		$defer = $block['attrs']['roosterDefer'] ?? null;
		if ( ! is_array( $defer ) || empty( $defer['enabled'] ) || self::PLACEHOLDER === ( $block['blockName'] ?? '' ) ) {
			return false;
		}
		
		
		
		
		if ( function_exists( 'is_cart' ) && ( is_cart() || is_checkout() ) && '0px' !== self::height( $block ) && 'intent' !== ( $defer['trigger'] ?? '' ) ) {
			return false;
		}
		
		if ( ! is_user_logged_in() && in_array( (string) ( $block['blockName'] ?? '' ), (array) apply_filters( 'rooster/defer/in_place_for_guests', [ 'rooster-lms/lesson-qa' ] ), true ) ) {
			return false;
		}
		
		return (bool) apply_filters( 'rooster/defer/is_deferred', true, $block );
	}

	private static function region_id(): string {
		++self::$counter;
		return 'rooster-defer-' . self::$counter;
	}

	private static function height( array $block ): string {
		$h = (string) ( $block['attrs']['roosterDefer']['height'] ?? '' );
		if ( '' === $h ) {
			$type = \WP_Block_Type_Registry::get_instance()->get_registered( (string) ( $block['blockName'] ?? '' ) );
			$h    = (string) ( $type->supports['rooster']['defer']['height'] ?? '320px' );
		}
		return preg_match( '/^[0-9.]+(px|rem|em|vh|dvh|%)$/', $h ) ? $h : '320px';
	}

	

	
	private static function placeholder_height( array $block, string $id ): string {
		$learned = self::learned_height( $id );
		return null !== $learned ? $learned . 'px' : self::height( $block );
	}

	
	public static function learned_height( string $id ): ?int {
		if ( null === self::$learned ) {
			$row           = get_transient( self::heights_key( self::heights_path( 'http://x' . (string) ( $_SERVER['REQUEST_URI'] ?? '/' ) ), DeviceClass::current() ) ); 
			self::$learned = is_array( $row ) && is_array( $row['value'] ?? null ) ? $row['value'] : [];
		}
		return isset( self::$learned[ $id ] ) ? (int) self::$learned[ $id ] : null;
	}

	
	private static function heights_path( string $url ): string {
		$path  = (string) wp_parse_url( $url, PHP_URL_PATH );
		$query = (string) wp_parse_url( $url, PHP_URL_QUERY );
		parse_str( $query, $args );
		foreach ( array_keys( (array) $args ) as $key ) {
			if ( self::QUERY === $key || str_starts_with( (string) $key, 'utm_' ) || in_array( $key, [ 'fbclid', 'gclid', 'msclkid', 'srsltid', 'ttclid' ], true ) ) {
				unset( $args[ $key ] );
			}
		}
		ksort( $args );
		return ( '' !== $path ? $path : '/' ) . ( $args ? '?' . http_build_query( $args ) : '' );
	}

	private static function heights_key( string $path, string $device ): string {
		return 'rooster_dh_' . md5( $path . '|' . $device );
	}

	
	public static function record_heights(): void {
		if ( ! check_ajax_referer( self::HEIGHTS_ACTION, 'nonce', false ) ) {
			wp_send_json_error( null, 403 );
		}
		if ( is_user_logged_in() ) {
			wp_send_json_error( null, 403 ); 
		}
		
		$warm    = isset( $_COOKIE[ self::WARM_COOKIE ] ) ? (string) $_COOKIE[ self::WARM_COOKIE ] : ''; 
		$trusted = '' !== $warm && false !== get_transient( 'rooster_dh_warm_' . hash( 'sha256', $warm ) );
		$addr = hash_hmac( 'sha256', (string) ( $_SERVER['REMOTE_ADDR'] ?? '' ), wp_salt( 'nonce' ) );
		$rate = 'rooster_dh_rate_' . substr( $addr, 0, 20 );
		$sent = (int) get_transient( $rate );
		if ( ! $trusted && $sent >= self::HEIGHTS_RATE ) {
			wp_send_json_error( null, 429 );
		}
		set_transient( $rate, $sent + 1, HOUR_IN_SECONDS );

		$raw    = wp_unslash( $_POST ); 
		$path   = is_string( $raw['path'] ?? null ) ? (string) $raw['path'] : '';
		$device = in_array( $raw['device'] ?? '', [ 'mobile', 'desktop' ], true ) ? (string) $raw['device'] : '';
		$sizes  = json_decode( is_string( $raw['h'] ?? null ) ? (string) $raw['h'] : '', true );
		if ( '' === $device || ! str_starts_with( $path, '/' ) || str_starts_with( $path, '//' ) || strlen( $path ) > 300 || ! is_array( $sizes ) || count( $sizes ) > 20 ) {
			wp_send_json_error( null, 400 );
		}
		$key = self::heights_key( self::heights_path( 'http://x' . $path ), $device ); 
		$row = get_transient( $key );
		$row = is_array( $row ) ? $row : [ 'value' => [], 'reports' => [] ];
		$was = $row;
		$now = time();
		foreach ( $sizes as $id => $h ) {
			if ( ! preg_match( '/^(rooster-defer-\d{1,3}|aieo-mount-[a-z0-9_]{1,40})$/', (string) $id ) || ! is_numeric( $h ) ) {
				continue;
			}
			$h = (int) round( (float) $h );
			if ( $h < 0 || $h > self::HEIGHTS_MAX ) {
				continue;
			}
			if ( $trusted ) {
				$row['value'][ $id ]   = $h;
				$row['reports'][ $id ] = [];
				continue;
			}
			
			$reports = array_values( array_filter( (array) ( $row['reports'][ $id ] ?? [] ), static fn ( $r ) => is_array( $r ) && $now - (int) ( $r[2] ?? 0 ) < WEEK_IN_SECONDS && ( $r[1] ?? '' ) !== $addr ) );
			$reports[] = [ $h, $addr, $now ];
			$reports   = array_slice( $reports, -8 );
			$row['reports'][ $id ] = $reports;
			
			$agree = array_values( array_filter( $reports, static fn ( $r ) => abs( (int) $r[0] - $h ) <= self::HEIGHTS_AGREE ) );
			if ( count( $agree ) >= 2 ) {
				$heights = array_map( static fn ( $r ) => (int) $r[0], $agree );
				sort( $heights );
				$row['value'][ $id ] = $heights[ intdiv( count( $heights ), 2 ) ];
			}
		}
		if ( $row !== $was ) {
			set_transient( $key, $row, 30 * DAY_IN_SECONDS );
		}
		if ( $trusted ) {
			self::warm_log( 'report', self::heights_path( 'http://x' . $path ), $device, count( $sizes ) );
		}
		wp_send_json_success();
	}

	
	private static function warm_log( string $event, string $path, string $device, int $count ): void {
		$log   = (array) get_option( 'rooster_dh_warm_log', [] );
		$log[] = [ gmdate( 'c' ), $event, $path, $device, $count ];
		update_option( 'rooster_dh_warm_log', array_slice( $log, -200 ), false );
	}

	
	public static function cli_warm( $args, $assoc ): void {
		$minutes = max( 1, min( 60, (int) ( $assoc['minutes'] ?? 15 ) ) );
		$token   = wp_generate_password( 32, false );
		set_transient( 'rooster_dh_warm_' . hash( 'sha256', $token ), time() + $minutes * MINUTE_IN_SECONDS, $minutes * MINUTE_IN_SECONDS );
		self::warm_log( 'minted', '', '', $minutes );
		\WP_CLI::line( $token );
		\WP_CLI::success( sprintf( 'Send it as the cookie %s from a signed-out browser: its height reports count at once for %d minutes.', self::WARM_COOKIE, $minutes ) );
	}

	
	public static function cli_show( $args, $assoc ): void {
		$path   = self::heights_path( 'http://x' . (string) ( $args[0] ?? '/' ) );
		$device = in_array( $assoc['device'] ?? '', [ 'mobile', 'desktop' ], true ) ? (string) $assoc['device'] : 'desktop';
		$row    = get_transient( self::heights_key( $path, $device ) );
		\WP_CLI::line( $path . ' (' . $device . '): ' . wp_json_encode( is_array( $row ) ? [ 'value' => $row['value'] ?? [], 'reports' => array_map( 'count', (array) ( $row['reports'] ?? [] ) ) ] : null ) );
	}

	private static function label( array $block ): string {
		return (string) ( $block['attrs']['roosterDefer']['label'] ?? $block['attrs']['metadata']['name'] ?? __( 'More content', 'ai-eshop-optimizer' ) );
	}

	

	
	public static function render_placeholder( $attributes ): string {
		$id = (string) ( $attributes['id'] ?? self::region_id() );
		if ( ! self::$placeholders ) {
			self::$placeholders = true;
			self::enqueue(); 
		}
		$label = (string) ( $attributes['label'] ?? __( 'More content', 'ai-eshop-optimizer' ) );
		return sprintf(
			'<div class="rooster-defer%7$s" data-wp-interactive="rooster/defer" data-wp-router-region="%1$s" id="%1$s" data-rooster-defer="%2$s" role="region" aria-label="%3$s" aria-busy="true"%8$s style="--rooster-defer-height:%4$s"><noscript><a class="rooster-defer__link" href="%5$s">%6$s</a></noscript></div>',
			esc_attr( $id ),
			esc_attr( (string) ( $attributes['trigger'] ?? 'layer' ) ),
			esc_attr( $label ),
			esc_attr( (string) ( $attributes['height'] ?? '320px' ) ),
			esc_url( self::layer_url() . '#' . $id ),
			
			esc_html( sprintf( __( 'Show %s', 'ai-eshop-optimizer' ), $label ) ),
			esc_attr( self::align_class( (array) $attributes ) ),
			
			null !== self::learned_height( $id ) ? ' data-rooster-learned' : ''
		);
	}

	
	public static function late( $html, $block ): string {
		if ( ! self::enabled() || ! self::is_deferred( $block ) ) {
			return (string) $html;
		}
		$id = (string) ( $block['attrs']['roosterDefer']['id'] ?? '' );
		if ( '' === $id ) {
			$id = self::region_id();
			if ( ! self::renders_whole() ) {
				return self::render_placeholder( [ 'id' => $id, 'height' => self::placeholder_height( $block, $id ), 'label' => self::label( $block ), 'trigger' => (string) ( $block['attrs']['roosterDefer']['trigger'] ?? 'layer' ), 'align' => (string) ( $block['attrs']['align'] ?? '' ) ] );
			}
		}
		if ( ! self::renders_whole() ) {
			return (string) $html; 
		}
		if ( ! self::is_full() ) {
			self::enqueue(); 
		}
		
		
		if ( str_contains( (string) $html, 'data-wp-router-region="' . esc_attr( $id ) . '"' ) ) {
			return (string) $html;
		}
		return sprintf(
			'<div class="rooster-defer is-loaded%3$s" data-wp-interactive="rooster/defer" data-wp-router-region="%1$s" id="%1$s">%2$s</div>',
			esc_attr( $id ),
			(string) $html,
			esc_attr( self::align_class( (array) ( $block['attrs'] ?? [] ) ) )
		);
	}

	
	public static function hidden_nav_menu( $html, $block ): string {
		$html = (string) $html;
		if ( ! self::enabled() || 'desktop' !== DeviceClass::current() ) {
			return $html;
		}
		$tags = new \WP_HTML_Tag_Processor( $html );
		if ( ! $tags->next_tag( 'nav' ) || ! $tags->has_class( 'wp-block-hidden-desktop' ) ) {
			return $html;
		}
		if ( str_contains( $html, 'disable-default-overlay' ) && str_contains( $html, 'wp-block-navigation__overlay-container' ) ) {
			return $html;
		}
		$content = strpos( $html, 'wp-block-navigation__responsive-container-content' );
		$start   = false === $content ? false : strpos( $html, '<ul', $content );
		if ( false === $start ) {
			return $html;
		}
		
		$depth = 0;
		$at    = $start;
		$end   = false;
		while ( preg_match( '#<(/?)ul\b#i', $html, $m, PREG_OFFSET_CAPTURE, $at ) ) {
			$depth += '/' === $m[1][0] ? -1 : 1;
			$at     = $m[0][1] + 3;
			if ( 0 === $depth ) {
				$end = strpos( $html, '>', $m[0][1] ) + 1;
				break;
			}
		}
		if ( false === $end ) {
			return $html;
		}
		$id   = 'rooster-defer-nav-' . ( ++self::$nav_counter );
		$list = substr( $html, $start, $end - $start );
		if ( self::renders_whole() ) {
			$region = sprintf( '<div class="rooster-defer is-loaded" data-wp-interactive="rooster/defer" data-wp-router-region="%1$s" id="%1$s" style="display:contents">%2$s</div>', esc_attr( $id ), $list );
		} else {
			$region = self::render_placeholder( [ 'id' => $id, 'height' => '0px', 'label' => __( 'Menu', 'ai-eshop-optimizer' ), 'trigger' => 'intent' ] );
		}
		return substr( $html, 0, $start ) . $region . substr( $html, $end );
	}

	
	public static function nav_submenus( $html, $block ): string {
		$html = (string) $html;
		if ( ! self::enabled() || ! DeviceClass::enabled() || 'desktop' !== DeviceClass::current() || ! str_contains( $html, 'wp-block-navigation__submenu-container' ) || str_contains( $html, 'open-always' ) ) {
			return $html;
		}
		$tags = new \WP_HTML_Tag_Processor( $html );
		if ( ! $tags->next_tag( 'nav' ) || $tags->has_class( 'wp-block-hidden-desktop' ) ) {
			return $html;
		}
		$full  = self::renders_whole();
		$out   = '';
		$at    = 0; 
		$pos   = 0; 
		$depth = 0; 
		$cut   = 0;
		while ( preg_match( '#<(/?)ul\b[^>]*>#i', $html, $m, PREG_OFFSET_CAPTURE, $pos ) ) {
			$tag   = $m[0][0];
			$start = $m[0][1];
			$pos   = $start + strlen( $tag );
			if ( '/' === $m[1][0] ) {
				--$depth;
				continue;
			}
			if ( 2 !== ++$depth || ! str_contains( $tag, 'wp-block-navigation__submenu-container' ) ) {
				continue;
			}
			
			$inner = 1;
			$scan  = $pos;
			$close = false;
			while ( preg_match( '#<(/?)ul\b[^>]*>#i', $html, $n, PREG_OFFSET_CAPTURE, $scan ) ) {
				$scan   = $n[0][1] + strlen( $n[0][0] );
				$inner += '/' === $n[1][0] ? -1 : 1;
				if ( 0 === $inner ) {
					$close = $n[0][1];
					break;
				}
			}
			if ( false === $close ) {
				return $html;
			}
			$open = new \WP_HTML_Tag_Processor( $tag );
			if ( ! $open->next_tag( 'ul' ) || null !== $open->get_attribute( 'id' ) ) {
				continue;
			}
			
			$basis = (string) preg_replace( '/\s+aria-current="[^"]*"|\s*\bcurrent[-_](?:menu|page)[-_](?:item|parent|ancestor)\b/', '', substr( $html, $pos, $close - $pos ) );
			$key   = substr( md5( $basis ), 0, 10 );
			$nth   = self::$menu_seen[ $key ] = ( self::$menu_seen[ $key ] ?? 0 ) + 1;
			$id    = 'rooster-defer-menu-' . $key . ( $nth > 1 ? '-' . $nth : '' );
			
			$item  = strrpos( substr( $html, 0, $start ), '<li' );
			$of    = false !== $item && preg_match( '/<a\b[^>]*\bhref="([^"]*)"/', substr( $html, $item, $start - $item ), $link ) ? html_entity_decode( $link[1], ENT_QUOTES ) : '';
			$open->add_class( 'rooster-defer' );
			if ( $full ) {
				$open->add_class( 'is-loaded' );
			}
			$open->set_attribute( 'id', $id );
			$open->set_attribute( 'data-wp-router-region', $id );
			
			
			if ( null === $open->get_attribute( 'data-wp-interactive' ) ) {
				$open->set_attribute( 'data-wp-interactive', 'core/navigation' );
			}
			$open->set_attribute( 'data-rooster-defer', 'menu' );
			if ( '' !== $of ) {
				$open->set_attribute( 'data-rooster-menu-of', $of );
			}
			
			$out .= substr( $html, $at, $start - $at ) . $open->get_updated_html() . ( $full ? substr( $html, $pos, $close - $pos ) : '' );
			$at   = $close;
			$pos  = $close; 
			++$cut;
		}
		if ( ! $cut ) {
			return $html;
		}
		if ( ! $full ) {
			self::enqueue(); 
		}
		return $out . substr( $html, $at );
	}

	public static function headers(): void {
		if ( self::is_full() && ! headers_sent() ) {
			header( 'X-Robots-Tag: noindex, nofollow', true );
		}
	}

	
	public static function layer_status(): void {
		if ( self::is_full() && is_404() && ! headers_sent() ) {
			status_header( 200 );
		}
	}

	
	private static function align_class( array $attributes ): string {
		$align = (string) ( $attributes['align'] ?? '' );
		return in_array( $align, [ 'full', 'wide' ], true ) ? ' align' . $align : '';
	}

	
	public static function enqueue_for_stubs(): void {
		if ( self::$enqueued ) {
			return;
		}
		if ( Performance::registered() || Performance::delays_any() ) {
			self::enqueue();
			return;
		}
		foreach ( array_keys( Performance::handles() ) as $handle ) {
			if ( wp_script_is( $handle, 'enqueued' ) ) {
				self::enqueue();
				return;
			}
		}
	}

	
	public static function later_image( string $html ): string {
		$tags = new \WP_HTML_Tag_Processor( $html );
		if ( ! $tags->next_tag( 'img' ) ) {
			return $html;
		}
		$src = (string) $tags->get_attribute( 'src' );
		if ( '' === $src || str_starts_with( $src, 'data:' ) ) {
			return $html;
		}
		$width  = max( 1, (int) $tags->get_attribute( 'width' ) );
		$height = max( 1, (int) $tags->get_attribute( 'height' ) );
		$tags->set_attribute( 'data-rooster-later', true );
		$tags->set_attribute( 'data-rooster-later-src', $src );
		$tags->remove_attribute( 'src' );
		foreach ( [ 'srcset', 'sizes' ] as $name ) {
			$value = $tags->get_attribute( $name );
			if ( is_string( $value ) && '' !== $value ) {
				$tags->set_attribute( 'data-rooster-later-' . $name, $value );
				$tags->remove_attribute( $name );
			}
		}
		self::enqueue();
		
		$blank = 'data:image/svg+xml,' . rawurlencode( sprintf( '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 %d %d"/>', $width, $height ) );
		return (string) preg_replace( '/^(\s*<img)\b/i', '$1 src="' . esc_attr( $blank ) . '"', $tags->get_updated_html(), 1 );
	}

	public static function enqueue(): void {
		if ( self::$enqueued ) {
			return;
		}
		self::$enqueued = true;
		wp_enqueue_script_module( 'rooster-defer' );
		$state = [
			'fullUrl' => self::layer_url(),
			'human'   => false,
			'loaded'  => false,
		];
		
		$heights = self::heights_config();
		if ( $heights ) {
			$state['heights'] = $heights;
		}
		wp_interactivity_state( 'rooster/defer', $state );
	}

	
	public static function heights_config(): array {
		if ( is_user_logged_in() ) {
			return [];
		}
		return [
			'url'    => admin_url( 'admin-ajax.php' ),
			'nonce'  => wp_create_nonce( self::HEIGHTS_ACTION ),
			'device' => DeviceClass::current(),
		];
	}

	
	public static function exclude_layer_from_speculation( $paths ): array {
		$paths   = (array) $paths;
		$paths[] = '/*\\?*' . self::QUERY . '=*';
		return $paths;
	}

	public static function current_url(): string {
		$uri = (string) ( $_SERVER['REQUEST_URI'] ?? '/' );
		return remove_query_arg( self::QUERY, home_url( $uri ) );
	}

	
	public static function layer_url(): string {
		$url  = self::current_url();
		$args = array_map( 'strval', (array) apply_filters( 'rooster/defer/action_args', self::ACTION_ARGS ) );
		parse_str( (string) wp_parse_url( $url, PHP_URL_QUERY ), $present );
		foreach ( array_keys( (array) $present ) as $key ) {
			if ( str_starts_with( (string) $key, 'attribute_' ) ) {
				$args[] = (string) $key;
			}
		}
		$args[] = self::CSS;
		$layer  = [ self::QUERY => 'full' ];
		if ( class_exists( UsedCss::class ) && UsedCss::active() ) {
			$layer[ self::CSS ] = '1';
		}
		return add_query_arg( $layer, remove_query_arg( $args, $url ) );
	}
}