ipt>';

		foreach ( $tags_match[0] as $i => $tag ) {
			// Strip query args.
			$path = wp_parse_url( $tags_match[2][ $i ], PHP_URL_PATH );

			// Check if this file should be deferred.
			if ( isset( $excluded_css[ $path ] ) ) {
				continue;
			}

			if ( preg_match( '/media\s*=\s*[\'"]print[\'"]/i', $tags_match[0][ $i ] ) ) {
				continue;
			}

			$preload = str_replace( 'stylesheet', 'preload', $tags_match[1][ $i ] );
			$onload  = preg_replace( '~' . preg_quote( $tags_match[3][ $i ], '~' ) . '~iU', ' data-rocket-async="style" as="style" onload="" onerror="this.removeAttribute(\'data-rocket-async\')" ' . $tags_match[3][ $i ] . '>', $tags_match[3][ $i ] );
			$tag     = str_replace( $tags_match[3][ $i ] . '>', $onload, $tag );
			$tag     = str_replace( $tags_match[1][ $i ], $preload, $tag );
			$tag     = str_replace( 'onload=""', 'onload="this.onload=null;this.rel=\'stylesheet\'"', $tag );
			$tag     = preg_replace( '/(id\s*=\s*[\"\'](?:[^\"\']*)*[\"\'])/i', '', $tag );
			$buffer  = str_replace( $tags_match[0][ $i ], $tag, $buffer );

			$noscripts .= $tags_match[0][ $i ];
		}

		$noscripts .= '</noscript>';

		return str_replace( '</body>', $noscripts . '</body>', $buffer );
	}

	/**
	 * Regenerates the CPCSS when switching theme if the option is active.
	 *
	 * @since 3.3
	 */
	public function maybe_regenerate_cpcss() {
		if ( ! $this->options->get( 'async_css' ) ) {
			return;
		}

		if ( ! $this->is_mobile_cpcss_active() ) {
			$this->critical_css->process_handler( 'default', 'all' );
			return;
		}

		$this->critical_css->process_handler( 'all' );
	}

	/**
	 * Checks if mobile CPCSS is active.
	 *
	 * @since 3.6
	 *
	 * @return boolean CPCSS active or not.
	 */
	private function is_mobile_cpcss_active() {
		return (
			$this->options->get( 'async_css', 0 )
			&&
			$this->options->get( 'cache_mobile', 0 )
			&&
			$this->options->get( 'do_caching_mobile_files', 0 )
		)
		&&
		$this->options->get( 'async_css_mobile', 0 );
	}

	/**
	 * Checks if we should async CSS
	 *
	 * @since 3.6.2.1
	 *
	 * @return boolean
	 */
	private function should_async_css() {
		if ( rocket_get_constant( 'DONOTROCKETOPTIMIZE' ) ) {
			return false;
		}

		if ( ! $this->options->get( 'async_css', 0 ) ) {
			return false;
		}

		return ! is_rocket_post_excluded_option( 'async_css' );
	}

	/**
	 * Stops the critical CSS generation.
	 *
	 * @since 3.10
	 *
	 * @return void
	 */
	public function stop_critical_css_generation() {

		$this->critical_css->stop_generation();
		delete_transient( 'rocket_critical_css_generation_process_running' );
		delete_transient( 'rocket_critical_css_generation_process_complete' );
	}

	/**
	 * Stops the critical CSS generation when deactivating the async CSS option via CLI and remove the notices.
	 *
	 * @note CL.
	 * @since 3.12.6
	 */
	public function stop_process_on_cli_deactivation() {
		$this->stop_critical_css_generation();
	}

	/**
	 * Sanitizes options
	 *
	 * @param array                                     $input    Array of values submitted from the form.
	 * @param \WP_Rocket\Engine\Admin\Settings\Settings $settings Settings class instance.
	 *
	 * @note CL
	 * @return array
	 */
	public function sanitize_options( $input, $settings ) : array {
		$is_wp2_env = ( function_exists( 'clsop_is_wp2_environment' ) && clsop_is_wp2_environment() );

		// WP2 branch: checkbox only toggles OCD and triggers clwpos-user; no async_css* normalization.
		if ( $is_wp2_env ) {
			// Only record intended action; do not change unrelated options here.
			$this->cpcss_toggle_action = null;

			$option_key = rocket_get_constant( 'WP_ROCKET_SLUG', 'wp_rocket_settings' );
			$posted     = filter_input( INPUT_POST, $option_key, FILTER_DEFAULT, FILTER_REQUIRE_ARRAY ); // phpcs:ignore WordPress.Security.NonceVerification.Missing
			if ( ! is_array( $posted ) && isset( $_POST[ $option_key ] ) && is_array( $_POST[ $option_key ] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Missing
				$posted = array_map( 'sanitize_text_field', wp_unslash( $_POST[ $option_key ] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Missing
			}
			$posted = is_array( $posted ) ? $posted : [];

			if ( array_key_exists( 'optimize_css_delivery', $posted ) ) {
				$raw_value                 = $posted['optimize_css_delivery'];
				$ocd_checked               = (int) sanitize_text_field( (string) $raw_value ) === 1;
				$this->cpcss_toggle_action = $ocd_checked ? 'enable' : 'disable';
				set_transient( 'clsop_ui_cpcss_toggle_action', $this->cpcss_toggle_action, MINUTE_IN_SECONDS );

				return array_merge( (array) $input, [ 'optimize_css_delivery' => $ocd_checked ? '1' : 0 ] );
			}

			// Unchecked: payload exists but field is absent.
			if ( is_array( $posted ) && ! empty( $posted ) && ! array_key_exists( 'optimize_css_delivery', $posted ) ) {
				$this->cpcss_toggle_action = 'disable';
				set_transient( 'clsop_ui_cpcss_toggle_action', $this->cpcss_toggle_action, MINUTE_IN_SECONDS );
				return array_merge( (array) $input, [ 'optimize_css_delivery' => 0 ] );
			}

			// Fallback to sanitized input if POST is unavailable in this context.
			if ( array_key_exists( 'optimize_css_delivery', $input ) ) {
				$ocd_checked               = (int) sanitize_text_field( (string) $input['optimize_css_delivery'] ) === 1;
				$this->cpcss_toggle_action = $ocd_checked ? 'enable' : 'disable';
				set_transient( 'clsop_ui_cpcss_toggle_action', $this->cpcss_toggle_action, MINUTE_IN_SECONDS );
				return array_merge( (array) $input, [ 'optimize_css_delivery' => $ocd_checked ? '1' : 0 ] );
			}

			return $input;
		}

		// Non-WP2 branch.
		$feature_enabled = (int) get_rocket_option( 'async_css', 0 ) === 1;
		$uuid            = (string) get_rocket_option( 'ccss_awp_unique_id', '' );

		// CL: In standalone mode, allow user to toggle the checkbox via UI.
		// Preserve existing uuid if any.
		if ( function_exists( 'clsop_is_standalone' ) && clsop_is_standalone() ) {
			if ( ! empty( $input['async_css'] ) || ! empty( $input['optimize_css_delivery'] ) ) {
				$input['ccss_awp_unique_id'] = $uuid; // Preserve existing, not used for API auth.
				$input['async_css']          = 1;
				$input['async_css_mobile']   = 1;
			}
			return $input;
		}

		// CLOS mode: preserve legacy normalization (managed by CLI).
		if ( ! $feature_enabled ) {
			// No normalization when feature disabled; keep input as-is.
			return $input;
		}

		// If input is empty: UUID first (if any), then enforced keys in fixed order.
		if ( empty( $input ) || ! is_array( $input ) ) {
			$normalized = [];
			if ( '' !== $uuid ) {
				$normalized['ccss_awp_unique_id'] = $uuid;
			}
			$normalized += [
				'async_css'             => 1,
				'async_css_mobile'      => 1,
				'remove_unused_css'     => 0,
				'optimize_css_delivery' => '1',
			];
			return array_merge( (array) $input, $normalized );
		}

		// Non-empty input: enforce values and put UUID last to match fixtures.
		$normalized = [
			'async_css'             => 1,
			'async_css_mobile'      => 1,
			'remove_unused_css'     => 0,
			'optimize_css_delivery' => '1',
		];
		if ( '' !== $uuid ) {
			$normalized['ccss_awp_unique_id'] = $uuid;
		}
		return array_merge( (array) $input, $normalized );
	}

	/**
	 * After options are saved, if OCD was checked in WP2, enable hosting feature via clwpos-user.
	 *
	 * @param array $value New options.
	 * @return void
	 */
	public function on_options_changed_after_ui( $value ) {
		// Retrieve recorded action from transient if property is not set.
		if ( null === $this->cpcss_toggle_action ) {
			$this->cpcss_toggle_action = get_transient( 'clsop_ui_cpcss_toggle_action' );
			delete_transient( 'clsop_ui_cpcss_toggle_action' );
		}
		if ( null === $this->cpcss_toggle_action ) {
			return;
		}

		$env_is_wp2 = ( function_exists( 'clsop_is_wp2_environment' ) && clsop_is_wp2_environment() );

		// Allow direct override of the client (e.g., tests) before consulting the container.
		$client = apply_filters( 'rocket_awp_clwpos_user_client', null ); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
		if ( ! is_object( $client ) ) {
			$container = apply_filters( 'rocket_container', null ); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound
			if ( ! is_object( $container ) || ! method_exists( $container, 'get' ) ) {
				return;
			}
			$client = $container->get( 'awp_clwpos_user' );
		}
		if ( ! is_object( $client ) ) {
			return;
		}

		// Only proceed if WP2 env OR the client/binary is available.
		if ( ! $env_is_wp2 ) {
			if ( ! method_exists( $client, 'is_available' ) || ! $client->is_available() ) {
				return;
			}
		}

		if ( 'disable' === $this->cpcss_toggle_action && method_exists( $client, 'disable_critical_css_current_site' ) ) {
			$client->disable_critical_css_current_site();
		} elseif ( 'enable' === $this->cpcss_toggle_action && method_exists( $client, 'enable_critical_css_current_site' ) ) {
			$client->enable_critical_css_current_site();
		}

		// Reset the recorded action.
		$this->cpcss_toggle_action = null;
	}

	/**
	 * Display a notice to pass from CPCSS to RUCSS.
	 *
	 * @return void
	 */
	public function switch_to_rucss_notice() {
		// CL: removed.
	}

	/**
	 * Switch to RUCSS.
	 *
	 * @return void
	 */
	public function switch_to_rucss() {
		// CL: removed.
	}

	/**
	 * CL: Enable inline CSS for Google Fonts on mobile when aggressive optimization is active.
	 *
	 * This eliminates render-blocking font CSS requests on mobile devices by inlining
	 * the font-face declarations directly into the HTML.
	 *
	 * @since 3.x
	 *
	 * @param bool $inline Whether to inline Google Fonts CSS.
	 * @return bool True to inline fonts CSS on mobile with aggressive optimization.
	 */
	public function maybe_inline_fonts_on_mobile( $inline ) {
		// Already enabled by another filter.
		if ( $inline ) {
			return $inline;
		}

		// Check if Critical CSS (async_css) is enabled.
		if ( ! $this->options->get( 'async_css', 0 ) ) {
			return $inline;
		}

		// Check if aggressive mobile optimization is enabled.
		if ( ! $this->options->get( 'async_css_mobile_aggressive', 0 ) ) {
			return $inline;
		}

		// Only apply on mobile devices.
		if ( ! wp_is_mobile() ) {
			return $inline;
		}

		return true;
	}

	/**
	 * CL: Filter CSS exclusions for aggressive mobile optimization.
	 *
	 * Reduces the list of CSS files excluded from async loading on mobile devices,
	 * keeping only critical patterns like admin-bar and dashicons.
	 *
	 * @since 3.x
	 *
	 * @param array $exclusions Current list of CSS files excluded from async loading.
	 * @return array Reduced list of exclusions for mobile optimization.
	 */
	public function aggressive_mobile_css_optimization( $exclusions ) {
		if ( ! is_array( $exclusions ) || empty( $exclusions ) ) {
			return $exclusions;
		}

		/**
		 * Filter the list of CSS patterns to keep excluded even in aggressive mobile mode.
		 *
		 * Some CSS files should remain excluded from async loading even on mobile
		 * to prevent layout shifts or critical functionality issues.
		 *
		 * @since 3.x
		 *
		 * @param array $keep_excluded Patterns of CSS files to keep excluded.
		 */
		$keep_excluded = (array) apply_filters(
			'rocket_aggressive_mobile_css_keep_excluded',
			[
				'admin-bar',
				'dashicons',
				'wp-admin',
			]
		);

		if ( empty( $keep_excluded ) ) {
			return [];
		}

		$filtered_exclusions = [];

		foreach ( $exclusions as $exclusion ) {
			foreach ( $keep_excluded as $pattern ) {
				if ( false !== strpos( $exclusion, $pattern ) ) {
					$filtered_exclusions[] = $exclusion;
					break;
				}
			}
		}

		return $filtered_exclusions;
	}
}