<?php
/**
 * CP Spinners - Public Frontend
 *
 * Handles frontend asset enqueueing and localized configuration for the
 * public loading overlay. Also provides admin-preview stylesheet support
 * without loading public overlay behavior in the WordPress dashboard.
 *
 * @package AeroSpin_CSS_Loading_Spinners
 */

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

/*
|--------------------------------------------------------------------------
| SECTION 1: Public Frontend Class
|--------------------------------------------------------------------------
|
| This class controls frontend stylesheet/script loading, external dynamic
| stylesheet delivery, and localized configuration for AeroSpin CSS Loading Spinners. Dynamic
| styling is compiled and served via a dedicated external stylesheet endpoint
| to eliminate frontend inline style injection, support strict Content
| Security Policy (CSP) environments, and leverage browser caching.
|
| Important:
| - This file must be saved as UTF-8 without BOM.
| - This file must not echo, print, var_dump, or close with a PHP closing tag.
| - Any unexpected output here can trigger WordPress activation/header warnings.
|
*/

if ( ! class_exists( 'ACLS_Public' ) ) {

	/**
	 * Public frontend controller for AeroSpin CSS Loading Spinners.
	 *
	 * @since 1.0.0
	 */
	final class ACLS_Public {

		/**
		 * Single class instance.
		 *
		 * @since 1.0.0
		 *
		 * @var ACLS_Public|null
		 */
		private static $instance = null;

		/**
		 * Frontend stylesheet handle.
		 *
		 * @since 1.1.4
		 *
		 * @var string
		 */
		private $frontend_style_handle = 'acls-style';

		/**
		 * Dynamic external stylesheet handle.
		 *
		 * @var string
		 */
		private $dynamic_style_handle = 'acls-dynamic-style';

		/**
		 * Admin preview stylesheet handle.
		 *
		 * @since 1.1.4
		 *
		 * @var string
		 */
		private $admin_preview_style_handle = 'acls-preview-style';

		/**
		 * Whether this request requires configuration markup for the public script.
		 *
		 * @var bool
		 */
		private $should_render_config = false;

		/**
		 * Frontend script handle.
		 *
		 * @since 1.1.4
		 *
		 * @var string
		 */
		private $frontend_script_handle = 'acls-script';

		/**
		 * Get the single class instance.
		 *
		 * @since 1.0.0
		 *
		 * @return ACLS_Public
		 */
		public static function get_instance() {
			// Instantiate the class only if it hasn't been instantiated yet.
			if ( null === self::$instance ) {
				self::$instance = new self();
			}

			return self::$instance;
		}

		/**
		 * Register public and admin-preview hooks.
		 *
		 * @since 1.0.0
		 */
		private function __construct() {
			// Hook into the frontend to load main assets.
			add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_assets' ) );

			// Hook into the admin to load preview styles for the settings page.
			add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_admin_preview_assets' ), 20 );
			add_action( 'wp_footer', array( $this, 'render_script_config' ), 1 );

			// Dynamic stylesheet endpoints: support both canonical, legacy, and documentation action names.
			add_action( 'admin_post_acls_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_nopriv_acls_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_AeroSpin_CSS_Loading_Spinners_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_nopriv_AeroSpin_CSS_Loading_Spinners_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_aerospin_css_loading_spinners_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_nopriv_aerospin_css_loading_spinners_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_Pure_CSS_Spinners_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_nopriv_Pure_CSS_Spinners_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_pure_css_spinners_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
			add_action( 'admin_post_nopriv_pure_css_spinners_dynamic_css', array( $this, 'render_dynamic_stylesheet' ) );
		}

		/**
		 * Prevent cloning.
		 *
		 * @since 1.0.0
		 *
		 * @return void
		 */
		private function __clone() {
			// Throw an error safely with escaped translation strings to comply with PHPCS.
			_doing_it_wrong(
				__FUNCTION__,
				esc_html__( 'Cloning this public controller is forbidden.', 'aerospin-css-loading-spinners' ),
				'1.0.0'
			);
		}

		/**
		 * Prevent unserializing.
		 *
		 * @since 1.0.0
		 *
		 * @return void
		 */
		public function __wakeup() {
			// Throw an error safely with escaped translation strings to comply with PHPCS.
			_doing_it_wrong(
				__FUNCTION__,
				esc_html__( 'Unserializing instances of this public controller is forbidden.', 'aerospin-css-loading-spinners' ),
				'1.0.0'
			);
		}

		/*
		|--------------------------------------------------------------------------
		| SECTION 2: Frontend Asset Enqueueing
		|--------------------------------------------------------------------------
		*/

		/**
		 * Enqueue frontend styles and scripts.
		 *
		 * @since 1.0.0
		 *
		 * @return void
		 */
		public function enqueue_assets() {
			// Retrieve normalized settings to verify if the plugin is active.
			$settings = $this->get_settings();

			// Bail early if the overlay is disabled globally.
			if ( empty( $settings['enabled'] ) ) {
				return;
			}

			// Validate request context to prevent loading on excluded pages or feeds.
			if ( $this->should_skip_current_request( $settings ) ) {
				return;
			}

			$plugin_url = defined( 'ACLS_PLUGIN_URL' ) ? ACLS_PLUGIN_URL : ( defined( 'Pure_CSS_Spinners_PLUGIN_URL' ) ? Pure_CSS_Spinners_PLUGIN_URL : plugin_dir_url( dirname( __DIR__ ) ) );
			$version    = defined( 'ACLS_VERSION' ) ? ACLS_VERSION : ( defined( 'Pure_CSS_Spinners_VERSION' ) ? Pure_CSS_Spinners_VERSION : '1.1.6' );

			// Enqueue the primary frontend stylesheet.
			wp_enqueue_style(
				$this->frontend_style_handle,
				$plugin_url . 'public/css/acls-spinners.css',
				array(),
				$version
			);

			// Enqueue the dynamic configuration styles via the external stylesheet endpoint.
			$dynamic_css = $this->get_dynamic_css( $settings );
			if ( ! empty( $dynamic_css ) ) {
				$dynamic_ver = substr( md5( $dynamic_css ), 0, 12 );
				wp_enqueue_style(
					$this->dynamic_style_handle,
					admin_url( 'admin-post.php?action=acls_dynamic_css' ),
					array( $this->frontend_style_handle ),
					$dynamic_ver
				);
			}

			// Enqueue the main frontend JavaScript file.
			wp_enqueue_script(
				$this->frontend_script_handle,
				$plugin_url . 'public/js/acls-public.js',
				array(),
				$version,
				true
			);

			// Apply the compatible loading strategy and render non-executable configuration markup.
			$this->add_defer_strategy( $this->frontend_script_handle );
			$this->should_render_config = true;
		}

		/**
		 * Enqueue public spinner CSS for the admin settings preview only.
		 *
		 * This intentionally does not enqueue the public JavaScript because the
		 * overlay behavior should not run throughout wp-admin.
		 *
		 * @since 1.0.0
		 *
		 * @param string $hook Current admin page hook.
		 * @return void
		 */
		public function enqueue_admin_preview_assets( $hook ) {
			// Only load the preview styles on the specific AeroSpin CSS Loading Spinners settings page.
			$valid_hooks = array(
				'toplevel_page_acls-settings',
				'settings_page_acls-settings',
				'toplevel_page_aerospin-css-loading-spinners',
				'settings_page_aerospin-css-loading-spinners',
				'settings_page_pure-css-spinners',
				'settings_page_clearpath-spinners',
				'settings_page_cp-spinners',
			);

			if ( ! in_array( $hook, $valid_hooks, true ) ) {
				return;
			}

			// Check to prevent duplicate enqueueing if the style is already loaded.
			if (
				wp_style_is( 'aerospin-css-loading-spinners-public', 'enqueued' )
				|| wp_style_is( 'acls-public', 'enqueued' )
				|| wp_style_is( $this->admin_preview_style_handle, 'enqueued' )
			) {
				return;
			}

			$plugin_url = defined( 'ACLS_PLUGIN_URL' ) ? ACLS_PLUGIN_URL : ( defined( 'Pure_CSS_Spinners_PLUGIN_URL' ) ? Pure_CSS_Spinners_PLUGIN_URL : plugin_dir_url( dirname( __DIR__ ) ) );
			$version    = defined( 'ACLS_VERSION' ) ? ACLS_VERSION : ( defined( 'Pure_CSS_Spinners_VERSION' ) ? Pure_CSS_Spinners_VERSION : '1.1.6' );

			// Enqueue the admin preview styles.
			wp_enqueue_style(
				$this->admin_preview_style_handle,
				$plugin_url . 'public/css/acls-spinners.css',
				array(),
				$version
			);
		}

		/*
		|--------------------------------------------------------------------------
		| SECTION 3: Script Localization
		|--------------------------------------------------------------------------
		*/

		/**
		 * Localize sanitized frontend configuration.
		 *
		 * @since 1.0.0
		 *
		 * @return void
		 */
		public function render_script_config() {
			if ( ! $this->should_render_config ) {
				return;
			}

			$script_json = wp_json_encode( $this->get_script_data( $this->get_settings() ), JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT );

			if ( ! is_string( $script_json ) || '' === $script_json ) {
				return;
			}
			?>
			<div id="acls-script-config" class="screen-reader-text" hidden data-acls-config="<?php echo esc_attr( $script_json ); ?>" data-cps-config="<?php echo esc_attr( $script_json ); ?>"></div>
			<?php
		}

		/**
		 * Generate sanitized dynamic CSS rules based on active user settings.
		 *
		 * @since 1.1.5
		 *
		 * @param array|null $settings Optional settings array.
		 * @return string
		 */
		public function get_dynamic_css( $settings = null ) {
			if ( null === $settings || ! is_array( $settings ) ) {
				$settings = $this->get_settings();
			}

			$opacity = $this->clamp_int( isset( $settings['overlay_opacity'] ) ? $settings['overlay_opacity'] : 85, 0, 100 ) / 100;
			$size    = $this->clamp_int( isset( $settings['spinner_size'] ) ? $settings['spinner_size'] : 60, 16, 240 );
			$z_index = $this->clamp_int( isset( $settings['z_index'] ) ? $settings['z_index'] : 99999, 1, 2147483647 );
			$fade    = $this->clamp_int( isset( $settings['fade_out_speed'] ) ? $settings['fade_out_speed'] : 400, 0, 5000 );
			$blur    = $this->clamp_int( isset( $settings['overlay_blur'] ) ? $settings['overlay_blur'] : 0, 0, 30 );

			return sprintf(
				'#acls-overlay,.acls-overlay,#cps-overlay,.cps-overlay{background-color:%1$s;z-index:%2$d;backdrop-filter:blur(%3$dpx);-webkit-backdrop-filter:blur(%3$dpx);transition-duration:%4$dms}.acls-spinner-wrap,.cps-spinner-wrap{--acls-color:%5$s;--acls-secondary:%6$s;--acls-size:%7$dpx;--cps-color:%5$s;--cps-secondary:%6$s;--cps-size:%7$dpx}',
				esc_attr( $this->get_overlay_rgba( isset( $settings['overlay_color'] ) ? $settings['overlay_color'] : '#ffffff', $opacity ) ),
				absint( $z_index ),
				absint( $blur ),
				absint( $fade ),
				esc_attr( $this->sanitize_color( isset( $settings['spinner_color'] ) ? $settings['spinner_color'] : '#4f46e5', '#4f46e5' ) ),
				esc_attr( $this->sanitize_color( isset( $settings['spinner_secondary'] ) ? $settings['spinner_secondary'] : '#e0e7ff', '#e0e7ff' ) ),
				absint( $size )
			);
		}

		/**
		 * Output the sanitized, settings-specific stylesheet as an external response.
		 *
		 * @return void
		 */
		public function render_dynamic_stylesheet() {
			$css  = $this->get_dynamic_css();
			$etag = '"' . md5( $css ) . '"';

			header( 'Content-Type: text/css; charset=UTF-8' );
			header( 'X-Content-Type-Options: nosniff' );
			header( 'Cache-Control: public, max-age=86400, stale-while-revalidate=604800' );
			header( 'ETag: ' . $etag );

			// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotValidated
			$if_none_match = isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) ? sanitize_text_field( wp_unslash( $_SERVER['HTTP_IF_NONE_MATCH'] ) ) : '';

			if ( '' !== $if_none_match && trim( $if_none_match ) === $etag ) {
				status_header( 304 );
				exit;
			}

			// phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- CSS generated and sanitized via get_dynamic_css().
			echo $css;
			exit;
		}

		/**
		 * Convert a validated hexadecimal or RGBA color to an rgba CSS value.
		 *
		 * @param mixed $color Hexadecimal or RGBA color.
		 * @param float $opacity Alpha channel value.
		 * @return string
		 */
		private function get_overlay_rgba( $color, $opacity ) {
			$sanitized = $this->sanitize_color( $color, '#ffffff' );

			// Check for valid RGBA color and apply the requested opacity.
			if ( preg_match( '/^rgba\(\s*(\d{1,3})\s*,\s*(\d{1,3})\s*,\s*(\d{1,3})\s*,\s*([0-9.]+)\s*\)$/i', $sanitized, $matches ) ) {
				$r = (int) $matches[1];
				$g = (int) $matches[2];
				$b = (int) $matches[3];

				return sprintf( 'rgba(%1$d,%2$d,%3$d,%4$s)', $r, $g, $b, (string) $opacity );
			}

			$hex = ltrim( $sanitized, '#' );

			if ( 3 === strlen( $hex ) ) {
				$hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
			}

			if ( 6 === strlen( $hex ) ) {
				return sprintf(
					'rgba(%1$d,%2$d,%3$d,%4$s)',
					hexdec( substr( $hex, 0, 2 ) ),
					hexdec( substr( $hex, 2, 2 ) ),
					hexdec( substr( $hex, 4, 2 ) ),
					(string) $opacity
				);
			}

			return sprintf( 'rgba(255,255,255,%s)', (string) $opacity );
		}

		/**
		 * Get safe frontend script data.
		 *
		 * WP localization helpers are intentionally avoided because this payload is
		 * configuration data, sanitized markup, and interface strings, not only
		 * localization strings.
		 *
		 * @since 1.1.4
		 *
		 * @param array $settings Normalized plugin settings.
		 * @return array
		 */
		private function get_script_data( $settings ) {
			// Determine the active spinner style with a fallback to 'ring'.
			$spinner_style = isset( $settings['spinner_style'] ) ? $this->sanitize_spinner_key( $settings['spinner_style'] ) : 'ring';

			return array(
				'spinnerStyle'     => $spinner_style,
				'spinnerColor'     => $this->sanitize_color( isset( $settings['spinner_color'] ) ? $settings['spinner_color'] : '#4f46e5', '#4f46e5' ),
				'spinnerSecondary' => $this->sanitize_color( isset( $settings['spinner_secondary'] ) ? $settings['spinner_secondary'] : '#e0e7ff', '#e0e7ff' ),
				'spinnerSize'      => $this->clamp_int( isset( $settings['spinner_size'] ) ? $settings['spinner_size'] : 60, 16, 240 ),
				'overlayColor'     => $this->sanitize_color( isset( $settings['overlay_color'] ) ? $settings['overlay_color'] : '#ffffff', '#ffffff' ),
				'overlayOpacity'   => $this->clamp_int( isset( $settings['overlay_opacity'] ) ? $settings['overlay_opacity'] : 85, 0, 100 ),
				'overlayBlur'      => $this->clamp_int( isset( $settings['overlay_blur'] ) ? $settings['overlay_blur'] : 0, 0, 30 ),
				'zIndex'           => $this->clamp_int( isset( $settings['z_index'] ) ? $settings['z_index'] : 99999, 1, 2147483647 ),
				'fadeOutSpeed'     => $this->clamp_int( isset( $settings['fade_out_speed'] ) ? $settings['fade_out_speed'] : 400, 0, 5000 ),
				'showOnExternal'   => ! empty( $settings['show_on_external'] ),
				'showOnAdminBar'   => ! empty( $settings['show_on_admin_bar'] ),
				'showOnForms'      => ! empty( $settings['show_on_forms'] ),
				'excludeSelectors' => isset( $settings['exclude_selectors'] ) ? $this->normalize_multiline_value( $settings['exclude_selectors'] ) : '',
				'excludePages'     => isset( $settings['exclude_pages'] ) ? $this->normalize_multiline_value( $settings['exclude_pages'] ) : '',
				'minDisplayTime'   => $this->clamp_int( isset( $settings['min_display_time'] ) ? $settings['min_display_time'] : 0, 0, 10000 ),
				'spinnerHtml'      => $this->get_spinner_html( $spinner_style ),
				'i18n'             => array(
					'loading' => esc_html__( 'Loading', 'aerospin-css-loading-spinners' ),
				),
			);
		}

		/**
		 * Add defer script strategy with compatibility fallback.
		 *
		 * @since 1.1.4
		 *
		 * @param string $handle Script handle.
		 * @return void
		 */
		private function add_defer_strategy( $handle ) {
			// Utilize WordPress 6.3+ script strategy loading methods when available.
			if ( function_exists( 'wp_script_add_data' ) ) {
				wp_script_add_data( $handle, 'strategy', 'defer' );
			}
		}

		/*
		|--------------------------------------------------------------------------
		| SECTION 4: Settings and Request Guards
		|--------------------------------------------------------------------------
		*/

		/**
		 * Get normalized settings.
		 *
		 * @since 1.1.4
		 *
		 * @return array
		 */
		private function get_settings() {
			// Look for the procedural or helper class function dynamically.
			if ( function_exists( 'aerospin_css_loading_spinners_get_settings' ) ) {
				$settings = aerospin_css_loading_spinners_get_settings();
			} elseif ( function_exists( 'Pure_CSS_Spinners_get_settings' ) ) {
				$settings = Pure_CSS_Spinners_get_settings();
			} elseif (
				class_exists( 'Pure_CSS_Spinners_Helpers' )
				&& is_callable( array( 'Pure_CSS_Spinners_Helpers', 'get_settings' ) )
			) {
				$settings = Pure_CSS_Spinners_Helpers::get_settings();
			} else {
				$settings = array();
			}

			// Apply sanitization safely if the helper functions exist.
			if ( function_exists( 'aerospin_css_loading_spinners_sanitize_settings' ) ) {
				$settings = aerospin_css_loading_spinners_sanitize_settings( $settings );
			} elseif ( function_exists( 'Pure_CSS_Spinners_sanitize_settings' ) ) {
				$settings = Pure_CSS_Spinners_sanitize_settings( $settings );
			} elseif (
				class_exists( 'Pure_CSS_Spinners_Helpers' )
				&& is_callable( array( 'Pure_CSS_Spinners_Helpers', 'sanitize_settings' ) )
			) {
				$settings = Pure_CSS_Spinners_Helpers::sanitize_settings( $settings );
			}

			return is_array( $settings ) ? $settings : array();
		}

		/**
		 * Determine whether assets should be skipped for the current request.
		 *
		 * @since 1.1.4
		 *
		 * @param array $settings Normalized plugin settings.
		 * @return bool
		 */
		private function should_skip_current_request( $settings ) {
			// Ignore backend, API requests, feeds, and embeds.
			if (
				is_admin()
				|| wp_doing_ajax()
				|| ( defined( 'REST_REQUEST' ) && REST_REQUEST )
				|| is_feed()
				|| is_robots()
				|| is_trackback()
				|| is_embed()
			) {
				return true;
			}

			// Skip WooCommerce pages known for heavy AJAX operations.
			if ( $this->is_woocommerce_sensitive_page() ) {
				return true;
			}

			$excluded_pages = isset( $settings['exclude_pages'] ) ? $settings['exclude_pages'] : '';
			$current_path   = $this->get_current_request_path();

			// If we have no active exclusions, do not skip.
			if ( '' === $current_path || '' === $excluded_pages ) {
				return false;
			}

			// Break lines into an array for processing.
			$paths = preg_split( '/\r\n|\r|\n/', $excluded_pages );

			if ( ! is_array( $paths ) ) {
				return false;
			}

			// Compare the current path against each rule line by line.
			foreach ( $paths as $path ) {
				$path = trim( (string) $path );

				if ( '' === $path ) {
					continue;
				}

				if ( $this->path_matches_rule( $current_path, $path ) ) {
					return true;
				}
			}

			return false;
		}

		/**
		 * Determine whether the current frontend request is a WooCommerce page
		 * where AJAX cart/checkout behavior is likely to conflict with a global
		 * navigation overlay.
		 *
		 * @since 1.1.4
		 *
		 * @return bool
		 */
		private function is_woocommerce_sensitive_page() {
			if ( ! class_exists( 'WooCommerce' ) ) {
				return false;
			}

			if ( function_exists( 'is_cart' ) && is_cart() ) {
				return true;
			}

			if ( function_exists( 'is_checkout' ) && is_checkout() ) {
				return true;
			}

			if ( function_exists( 'is_account_page' ) && is_account_page() ) {
				return true;
			}

			return false;
		}

		/**
		 * Check whether a current request path matches an exclusion rule.
		 *
		 * @since 1.1.4
		 *
		 * @param string $current_path Current path.
		 * @param string $rule         Exclusion rule.
		 * @return bool
		 */
		private function path_matches_rule( $current_path, $rule ) {
			// Normalize paths to ensure proper comparisons.
			$current_path = '/' . ltrim( (string) $current_path, '/' );
			$rule         = trim( (string) $rule );

			if ( '' === $rule ) {
				return false;
			}

			$rule_path = $rule;

			// If the rule contains a full URL, verify host matching and isolate path.
			if ( false !== strpos( $rule, '://' ) ) {
				$rule_host = wp_parse_url( $rule, PHP_URL_HOST );
				$site_host = wp_parse_url( home_url(), PHP_URL_HOST );

				if ( $rule_host && $site_host && strtolower( $rule_host ) !== strtolower( $site_host ) ) {
					return false;
				}

				$parsed_path = wp_parse_url( $rule, PHP_URL_PATH );

				if ( is_string( $parsed_path ) && '' !== $parsed_path ) {
					$rule_path = $parsed_path;
				}
			}

			$rule_path = '/' . ltrim( $rule_path, '/' );

			// Strip trailing slashes unless it represents the root path.
			if ( '/' !== $rule_path ) {
				$rule_path = untrailingslashit( $rule_path );
			}

			if ( '/' !== $current_path ) {
				$current_path = untrailingslashit( $current_path );
			}

			// Check for exact matching.
			if ( $current_path === $rule_path ) {
				return true;
			}

			// Treat root exclusion lightly; if it reaches here, no exact match was found.
			if ( '/' === $rule_path ) {
				return false;
			}

			// Partial path matching (e.g. /category/ matching /category/item).
			return 0 === strpos( $current_path, trailingslashit( $rule_path ) );
		}

		/**
		 * Get the current request path.
		 *
		 * @since 1.1.4
		 *
		 * @return string
		 */
		private function get_current_request_path() {
			// Enhancement: Added PHPCS ignore rule for InputNotValidated.
			// REQUEST_URI is a server routing variable mapped by the server itself,
			// making standard user input validation inapplicable. It is strictly sanitized below.

			// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotValidated
			$request_uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';

			if ( empty( $request_uri ) ) {
				return '';
			}

			// Isolate the actual path, safely dropping query strings and fragments.
			$path = wp_parse_url( $request_uri, PHP_URL_PATH );

			if ( ! is_string( $path ) || '' === $path ) {
				return '/';
			}

			// Ensure standard leading slash structure.
			return '/' . ltrim( $path, '/' );
		}

		/*
		|--------------------------------------------------------------------------
		| SECTION 5: Spinner Helpers
		|--------------------------------------------------------------------------
		*/

		/**
		 * Retrieve sanitized HTML markup for a specific spinner style.
		 *
		 * @since 1.0.0
		 *
		 * @param string $style Spinner style key.
		 * @return string
		 */
		private function get_spinner_html( $style ) {
			$style = $this->sanitize_spinner_key( $style );

			if ( function_exists( 'aerospin_css_loading_spinners_get_spinner' ) ) {
				$spinner = aerospin_css_loading_spinners_get_spinner( $style, 'ring' );

				if ( is_array( $spinner ) && isset( $spinner['html'] ) ) {
					return $this->sanitize_spinner_html( $spinner['html'] );
				}
			} elseif ( function_exists( 'Pure_CSS_Spinners_get_spinner' ) ) {
				$spinner = Pure_CSS_Spinners_get_spinner( $style, 'ring' );

				if ( is_array( $spinner ) && isset( $spinner['html'] ) ) {
					return $this->sanitize_spinner_html( $spinner['html'] );
				}
			} elseif ( function_exists( 'cp_spinners_get_spinner' ) ) {
				$spinner = cp_spinners_get_spinner( $style, 'ring' );

				if ( is_array( $spinner ) && isset( $spinner['html'] ) ) {
					return $this->sanitize_spinner_html( $spinner['html'] );
				}
			}

			$spinners = $this->get_spinners();

			if ( isset( $spinners[ $style ]['html'] ) ) {
				return $this->sanitize_spinner_html( $spinners[ $style ]['html'] );
			}

			if ( isset( $spinners['ring']['html'] ) ) {
				return $this->sanitize_spinner_html( $spinners['ring']['html'] );
			}

			return '';
		}

		/**
		 * Get sanitized spinner definitions.
		 *
		 * @since 1.1.4
		 *
		 * @return array
		 */
		private function get_spinners() {
			if ( function_exists( 'aerospin_css_loading_spinners_get_spinners' ) ) {
				$spinners = aerospin_css_loading_spinners_get_spinners();
			} elseif ( function_exists( 'Pure_CSS_Spinners_get_spinners' ) ) {
				$spinners = Pure_CSS_Spinners_get_spinners();
			} elseif (
				class_exists( 'Pure_CSS_Spinners_List' )
				&& is_callable( array( 'Pure_CSS_Spinners_List', 'get_spinners' ) )
			) {
				$spinners = Pure_CSS_Spinners_List::get_spinners();
			} else {
				$spinners = array();
			}

			return is_array( $spinners ) ? $spinners : array();
		}

		/**
		 * Sanitize spinner HTML using the narrow spinner allowlist.
		 *
		 * @since 1.1.4
		 *
		 * @param string $html Raw spinner HTML.
		 * @return string
		 */
		private function sanitize_spinner_html( $html ) {
			if ( function_exists( 'aerospin_css_loading_spinners_kses_spinner_html' ) ) {
				return aerospin_css_loading_spinners_kses_spinner_html( $html );
			} elseif ( function_exists( 'Pure_CSS_Spinners_kses_spinner_html' ) ) {
				return Pure_CSS_Spinners_kses_spinner_html( $html );
			}

			if (
				class_exists( 'Pure_CSS_Spinners_Helpers' )
				&& is_callable( array( 'Pure_CSS_Spinners_Helpers', 'kses_spinner_html' ) )
			) {
				return Pure_CSS_Spinners_Helpers::kses_spinner_html( $html );
			}

			// Apply strict tag stripping to output safe structural elements only.
			return wp_kses(
				$html,
				array(
					'div'  => array(
						'aria-hidden' => true,
						'class'       => true,
						'role'        => true,
					),
					'span' => array(
						'aria-hidden' => true,
						'class'       => true,
						'role'        => true,
					),
				)
			);
		}

		/**
		 * Sanitize a spinner key.
		 *
		 * @since 1.1.4
		 *
		 * @param mixed $style Raw spinner key.
		 * @return string
		 */
		private function sanitize_spinner_key( $style ) {
			if ( function_exists( 'aerospin_css_loading_spinners_sanitize_spinner_key' ) ) {
				return aerospin_css_loading_spinners_sanitize_spinner_key( $style, 'ring' );
			} elseif ( function_exists( 'Pure_CSS_Spinners_sanitize_spinner_key' ) ) {
				return Pure_CSS_Spinners_sanitize_spinner_key( $style, 'ring' );
			}

			if (
				class_exists( 'Pure_CSS_Spinners_Helpers' )
				&& is_callable( array( 'Pure_CSS_Spinners_Helpers', 'sanitize_spinner_key' ) )
			) {
				return Pure_CSS_Spinners_Helpers::sanitize_spinner_key( $style, 'ring' );
			}

			$style = sanitize_key( $this->safe_scalar( $style ) );

			return '' === $style ? 'ring' : $style;
		}

		/*
		|--------------------------------------------------------------------------
		| SECTION 6: Value Sanitizers
		|--------------------------------------------------------------------------
		*/

		/**
		 * Normalize a multiline setting for JavaScript configuration.
		 *
		 * @since 1.1.4
		 *
		 * @param mixed $value Raw multiline value.
		 * @return string
		 */
		private function normalize_multiline_value( $value ) {
			$value = $this->safe_scalar( $value );
			// Standardize line endings to a single character format.
			$value = str_replace( array( "\r\n", "\r" ), "\n", $value );

			return sanitize_textarea_field( $value );
		}

		/**
		 * Sanitize a color value.
		 *
		 * @since 1.1.4
		 *
		 * @param mixed  $value         Raw color value.
		 * @param string $default_value Fallback color.
		 * @return string
		 */
		private function sanitize_color( $value, $default_value ) {
			if ( function_exists( 'aerospin_css_loading_spinners_sanitize_color' ) ) {
				return aerospin_css_loading_spinners_sanitize_color( $value, $default_value );
			} elseif ( function_exists( 'Pure_CSS_Spinners_sanitize_color' ) ) {
				return Pure_CSS_Spinners_sanitize_color( $value, $default_value );
			}

			if (
				class_exists( 'Pure_CSS_Spinners_Helpers' )
				&& is_callable( array( 'Pure_CSS_Spinners_Helpers', 'sanitize_color' ) )
			) {
				return Pure_CSS_Spinners_Helpers::sanitize_color( $value, $default_value );
			}

			$color = sanitize_hex_color( $this->safe_scalar( $value ) );

			if ( $color ) {
				return $color;
			}

			$fallback = sanitize_hex_color( $this->safe_scalar( $default_value ) );

			return $fallback ? $fallback : '#ffffff';
		}

		/**
		 * Clamp an integer value.
		 *
		 * @since 1.1.4
		 *
		 * @param mixed $value Raw value.
		 * @param int   $min   Minimum.
		 * @param int   $max   Maximum.
		 * @return int
		 */
		private function clamp_int( $value, $min, $max ) {
			$value = is_numeric( $value ) ? (int) $value : (int) $min;

			return max( (int) $min, min( (int) $max, $value ) );
		}

		/**
		 * Safely cast scalar values to strings.
		 *
		 * @since 1.1.4
		 *
		 * @param mixed $value Raw value.
		 * @return string
		 */
		private function safe_scalar( $value ) {
			if ( is_array( $value ) || is_object( $value ) ) {
				return '';
			}

			return is_string( $value ) ? $value : (string) $value;
		}
	}
}

if ( ! class_exists( 'AeroSpin_CSS_Loading_Spinners_Public' ) ) {
	class_alias( 'ACLS_Public', 'AeroSpin_CSS_Loading_Spinners_Public' );
}
if ( ! class_exists( 'Pure_CSS_Spinners_Public' ) ) {
	class_alias( 'ACLS_Public', 'Pure_CSS_Spinners_Public' );
}
if ( ! class_exists( 'AreoSpin_Css_Loading_Spinners_Public' ) ) {
	class_alias( 'ACLS_Public', 'AreoSpin_Css_Loading_Spinners_Public' );
}

/*
|--------------------------------------------------------------------------
| SECTION 7: Initialize Public Controller
|--------------------------------------------------------------------------
*/

ACLS_Public::get_instance();