<?php
/**
 * AJAX Loading admin dashboard.
 *
 * Settings screen (Settings → AJAX Loading), quick actions, admin notices and
 * plugin-list links.
 *
 * @author  Mahesh Thorat
 * @link    https://maheshthorat.web.app
 * @package Ajax_loading
 * @since   2.0.0
 */

defined( 'ABSPATH' ) || exit;

require_once __DIR__ . '/views/class-ajax-loading-admin-fields.php';

/**
 * Admin controller.
 */
class WPAJXL_Admin {

	/**
	 * Settings page slug (unchanged since 1.x).
	 */
	const PAGE_SLUG = 'ajax-loading-admin';

	/**
	 * Slug used by 0.x releases; redirected to PAGE_SLUG.
	 */
	const LEGACY_PAGE_SLUG = 'wp-ajax-loading-admin';

	/**
	 * Settings API option group.
	 */
	const OPTION_GROUP = 'ajax_loading';

	/**
	 * Settings option name.
	 */
	const OPTION = '_wp_ajax_loading';

	/**
	 * admin-post.php action for quick actions.
	 */
	const ACTION = 'ajax_loading_action';

	/**
	 * Nonce action for quick actions.
	 */
	const NONCE_ACTION = 'ajax_loading_admin_action';

	/**
	 * Capability required for everything on this screen.
	 */
	const CAPABILITY = 'manage_options';

	/**
	 * Maximum size of an imported settings file (bytes).
	 */
	const IMPORT_MAX_BYTES = 102400;

	/**
	 * Option holding the last client diagnostics summary (written by the REST API).
	 */
	const DIAGNOSTICS_OPTION = '_wp_ajax_loading_diagnostics';

	/**
	 * "Say Thanks" link.
	 */
	const THANKS_URL = 'https://buymeacoffee.com/maheshmthorat';

	/**
	 * Result notices of quick actions that change what visitors get; with a page cache they only take
	 * effect on cached pages after a purge, so these notices say so.
	 */
	const PAGE_CACHE_NOTICE_CODES = array( 'enabled', 'disabled', 'safe_mode_on', 'safe_mode_off', 'visibility_admins', 'visibility_everyone', 'paused', 'resumed', 'cache_cleared', 'reset', 'imported' );

	/**
	 * Plugin identifier.
	 *
	 * @var string
	 */
	protected $plugin_name;

	/**
	 * Plugin version (asset cache busting).
	 *
	 * @var string
	 */
	protected $version;

	/**
	 * Hook suffix of the settings screen ('' until admin_menu ran).
	 *
	 * @var string
	 */
	protected $hook_suffix = '';

	/**
	 * Memoised sample URLs.
	 *
	 * @var array|null
	 */
	protected $sample_urls = null;

	/**
	 * Constructor (legacy 1.x signature).
	 *
	 * @param string $plugin_name Plugin identifier.
	 * @param string $version     Plugin version.
	 */
	public function __construct( $plugin_name = 'ajax-loading', $version = '' ) {
		$this->plugin_name = is_string( $plugin_name ) && '' !== $plugin_name ? $plugin_name : 'ajax-loading';
		if ( ! is_string( $version ) || '' === $version ) {
			$version = defined( 'WPAJXL_PLUGIN_VERSION' ) ? WPAJXL_PLUGIN_VERSION : '2.0.0';
		}
		$this->version = $version;
	}

	/**
	 * Register all admin hooks.
	 *
	 * @return void
	 */
	public function register() {
		if ( ! class_exists( 'WPAJXL_Settings' ) ) {
			return;
		}
		add_action( 'admin_menu', array( $this, 'add_menu' ) );
		add_action( 'admin_init', array( $this, 'register_settings' ) );
		add_action( 'admin_page_access_denied', array( $this, 'maybe_redirect_legacy_slug' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_assets' ) );
		add_action( 'admin_post_' . self::ACTION, array( $this, 'handle_action' ) );
		add_action( 'admin_notices', array( $this, 'admin_notices' ) );
		add_filter( 'plugin_action_links_' . $this->plugin_basename(), array( $this, 'action_links' ) );
		add_filter( 'removable_query_args', array( $this, 'removable_query_args' ) );
	}

	/*
	 * ---------------------------------------------------------------------
	 * Hooks
	 * ---------------------------------------------------------------------
	 */

	/**
	 * Add Settings → AJAX Loading.
	 *
	 * @return void
	 */
	public function add_menu() {
		$suffix = add_options_page(
			__( 'AJAX Loading', 'ajax-loading' ),
			__( 'AJAX Loading', 'ajax-loading' ),
			self::CAPABILITY,
			self::PAGE_SLUG,
			array( $this, 'render_page' )
		);
		$this->hook_suffix = is_string( $suffix ) ? $suffix : '';
	}

	/**
	 * Register the option with the Settings API (options.php handles saving).
	 *
	 * @return void
	 */
	public function register_settings() {
		register_setting(
			self::OPTION_GROUP,
			self::OPTION,
			array(
				'type'              => 'array',
				'sanitize_callback' => array( WPAJXL_Settings::instance(), 'sanitize_option_input' ),
				'show_in_rest'      => false,
			)
		);
	}

	/**
	 * Redirect the 0.x page slug to the current settings screen.
	 *
	 * Runs on 'admin_page_access_denied', which WordPress fires for the
	 * unregistered legacy slug right before it would show "not allowed".
	 *
	 * @return void
	 */
	public function maybe_redirect_legacy_slug() {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only routing.
		$page = isset( $_GET['page'] ) ? sanitize_key( wp_unslash( $_GET['page'] ) ) : '';
		if ( self::LEGACY_PAGE_SLUG !== $page || ! current_user_can( self::CAPABILITY ) ) {
			return;
		}
		wp_safe_redirect( $this->page_url() );
		exit;
	}

	/**
	 * Enqueue admin assets on the plugin screen only.
	 *
	 * @param string $hook_suffix Current admin page hook suffix.
	 * @return void
	 */
	public function enqueue_assets( $hook_suffix ) {
		if ( '' === $this->hook_suffix || $hook_suffix !== $this->hook_suffix ) {
			return;
		}

		$tab = $this->current_tab();

		wp_enqueue_style( 'wp-color-picker' );

		if ( 'loading' === $tab ) {
			// Logo picker and live preview are only on the Loading Experience tab.
			wp_enqueue_media();
			wp_enqueue_style( 'ajax-loading-preview', $this->asset_url( 'frontend', 'css' ), array(), $this->asset_version( 'frontend', 'css' ) );
		}

		wp_enqueue_style( 'ajax-loading-admin', $this->asset_url( 'admin', 'css' ), array( 'wp-color-picker' ), $this->asset_version( 'admin', 'css' ) );
		wp_enqueue_script(
			'ajax-loading-admin',
			$this->asset_url( 'admin', 'js' ),
			array( 'jquery', 'wp-color-picker' ),
			$this->asset_version( 'admin', 'js' ),
			array( 'in_footer' => true )
		);

		$json = wp_json_encode( $this->script_data( $tab ), JSON_HEX_TAG | JSON_HEX_AMP | JSON_UNESCAPED_SLASHES );
		wp_add_inline_script( 'ajax-loading-admin', 'window.ajaxLoadingAdmin = ' . ( false === $json ? '{}' : $json ) . ';', 'before' );
	}

	/**
	 * Quick actions (admin-post.php?action=ajax_loading_action).
	 *
	 * @return void
	 */
	public function handle_action() {
		if ( ! current_user_can( self::CAPABILITY ) ) {
			wp_die(
				esc_html__( 'Sorry, you are not allowed to manage AJAX Loading.', 'ajax-loading' ),
				esc_html__( 'Forbidden', 'ajax-loading' ),
				array(
					'response'  => 403,
					'back_link' => true,
				)
			);
		}

		$method = isset( $_SERVER['REQUEST_METHOD'] ) ? strtoupper( sanitize_text_field( wp_unslash( $_SERVER['REQUEST_METHOD'] ) ) ) : '';
		if ( 'POST' !== $method ) {
			wp_die(
				esc_html__( 'This action must be submitted from the AJAX Loading settings screen.', 'ajax-loading' ),
				esc_html__( 'Method not allowed', 'ajax-loading' ),
				array(
					'response'  => 405,
					'back_link' => true,
				)
			);
		}

		check_admin_referer( self::NONCE_ACTION );

		$do = '';
		if ( isset( $_POST['do'] ) ) {
			$do = sanitize_key( wp_unslash( $_POST['do'] ) );
		} elseif ( isset( $_GET['do'] ) ) {
			$do = sanitize_key( wp_unslash( $_GET['do'] ) );
		}
		$tab    = isset( $_POST['ajxl_tab'] ) ? sanitize_key( wp_unslash( $_POST['ajxl_tab'] ) ) : 'overview';
		$return = ( isset( $_POST['ajxl_return'] ) && 'plugins' === sanitize_key( wp_unslash( $_POST['ajxl_return'] ) ) ) ? 'plugins' : 'page';

		if ( 'export' === $do ) {
			$this->send_export( $tab );
		}

		$notice = 'action_failed';
		try {
			$notice = $this->run_action( $do );
		} catch ( Throwable $e ) {
			self::debug_log( 'quick action "' . $do . '" failed: ' . $e->getMessage() );
			$notice = 'action_failed';
		}

		$this->redirect_after_action( $tab, $notice, $return );
	}

	/**
	 * Admin notices: action results and state warnings (own screen + Plugins screen).
	 *
	 * @return void
	 */
	public function admin_notices() {
		if ( ! current_user_can( self::CAPABILITY ) || ! function_exists( 'get_current_screen' ) ) {
			return;
		}
		$screen = get_current_screen();
		if ( ! $screen ) {
			return;
		}
		$own     = ( '' !== $this->hook_suffix && $screen->id === $this->hook_suffix );
		$plugins = ( 'plugins' === $screen->id );
		if ( ! $own && ! $plugins ) {
			return;
		}

		$code = $this->notice_code();
		if ( '' !== $code ) {
			$this->print_result_notice( $code );
		} elseif ( $own && $this->settings_were_saved() && class_exists( 'WPAJXL_Compat' ) && method_exists( 'WPAJXL_Compat', 'has_page_cache' ) && WPAJXL_Compat::has_page_cache() ) {
			printf( '<div class="notice notice-info is-dismissible ajxl-notice"><p>%s</p></div>', esc_html( self::page_cache_hint() ) );
		}
		$this->print_state_notices( $own, $code );
	}

	/**
	 * Whether this request follows a successful save of the settings form (options.php redirect).
	 *
	 * @return bool
	 */
	protected function settings_were_saved() {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- display only.
		return isset( $_GET['settings-updated'] ) && 'true' === sanitize_key( wp_unslash( $_GET['settings-updated'] ) );
	}

	/**
	 * Advice shown after a change that only reaches page-cached pages once the cache is purged.
	 *
	 * @return string
	 */
	protected static function page_cache_hint() {
		return __( 'A page cache is active on this site: purge it, otherwise visitors keep getting cached pages built with the previous settings.', 'ajax-loading' );
	}

	/**
	 * Plugin list links: Settings first, then Say Thanks.
	 *
	 * @param array $links Existing links.
	 * @return array
	 */
	public function action_links( $links ) {
		$links = is_array( $links ) ? $links : array();
		$mine  = array(
			'ajxl-settings' => sprintf( '<a href="%1$s">%2$s</a>', esc_url( $this->page_url() ), esc_html__( 'Settings', 'ajax-loading' ) ),
			'ajxl-thanks'   => sprintf(
				'<a href="%1$s" target="_blank" rel="noopener noreferrer">%2$s<span class="screen-reader-text"> %3$s</span></a>',
				esc_url( self::THANKS_URL ),
				esc_html__( 'Say Thanks', 'ajax-loading' ),
				esc_html__( '(opens in a new tab)', 'ajax-loading' )
			),
		);
		return array_merge( $mine, $links );
	}

	/**
	 * Strip one-time notice codes from the address bar after display.
	 *
	 * @param array $args Removable query args.
	 * @return array
	 */
	public function removable_query_args( $args ) {
		$args   = is_array( $args ) ? $args : array();
		$args[] = 'ajxl_notice';
		return $args;
	}

	/*
	 * ---------------------------------------------------------------------
	 * Page rendering
	 * ---------------------------------------------------------------------
	 */

	/**
	 * Render the settings screen.
	 *
	 * @return void
	 */
	public function render_page() {
		if ( ! current_user_can( self::CAPABILITY ) ) {
			wp_die( esc_html__( 'Sorry, you are not allowed to manage AJAX Loading.', 'ajax-loading' ), 403 );
		}

		$tab    = $this->current_tab();
		$tabs   = $this->tabs();
		$status = $this->navigation_status();
		?>
		<div class="wrap ajxl-admin" data-ajxl-tab="<?php echo esc_attr( $tab ); ?>">
			<div class="ajxl-header">
				<div class="ajxl-header__brand">
					<span class="ajxl-header__icon dashicons dashicons-controls-forward" aria-hidden="true"></span>
					<h1 class="ajxl-header__title">
						<?php esc_html_e( 'AJAX Loading', 'ajax-loading' ); ?>
						<span class="ajxl-version"><?php echo esc_html( $this->version ); ?></span>
					</h1>
				</div>
				<div class="ajxl-header__status">
					<?php echo self::pill( $status['status'], $status['label'] ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- pill() escapes. ?>
					<?php foreach ( $status['flags'] as $flag ) : ?>
						<?php echo self::pill( 'info', $flag ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- pill() escapes. ?>
					<?php endforeach; ?>
				</div>
			</div>
			<hr class="wp-header-end" />

			<nav class="nav-tab-wrapper ajxl-tabs" aria-label="<?php esc_attr_e( 'AJAX Loading settings sections', 'ajax-loading' ); ?>">
				<?php foreach ( $tabs as $slug => $info ) : ?>
					<a href="<?php echo esc_url( $this->tab_url( $slug ) ); ?>" class="nav-tab<?php echo $slug === $tab ? ' nav-tab-active' : ''; ?>"<?php echo $slug === $tab ? ' aria-current="page"' : ''; ?> data-ajxl-tab-link>
						<span class="dashicons <?php echo esc_attr( $info['icon'] ); ?>" aria-hidden="true"></span>
						<span class="ajxl-tabs__label"><?php echo esc_html( $info['label'] ); ?></span>
					</a>
				<?php endforeach; ?>
			</nav>

			<div class="ajxl-panel ajxl-panel--<?php echo esc_attr( $tab ); ?>">
				<?php $this->load_view( $tab ); ?>
			</div>

			<?php $this->render_action_forms( $tab ); ?>
		</div>
		<?php
	}

	/**
	 * Include a tab partial with its context variables.
	 *
	 * Variables available in views: $admin (this object), $settings
	 * (WPAJXL_Settings), $values (stored settings), $schema (settings schema),
	 * $tab (current tab slug).
	 *
	 * @param string $view View name.
	 * @return void
	 */
	protected function load_view( $view ) {
		$tabs = $this->tabs();
		if ( ! isset( $tabs[ $view ] ) ) {
			return;
		}
		$file = __DIR__ . '/views/' . $view . '.php';
		if ( ! is_readable( $file ) ) {
			return;
		}
		$admin    = $this;
		$settings = $this->settings();
		$values   = $this->values();
		$schema   = $this->schema();
		$tab      = $view;
		include $file;
	}

	/**
	 * Open the options.php settings form for a tab.
	 *
	 * @param string $tab Tab slug.
	 * @return void
	 */
	public function open_settings_form( $tab ) {
		printf( '<form method="post" action="%s" class="ajxl-settings-form" id="ajxl-settings-form" data-ajxl-settings-form>', esc_url( admin_url( 'options.php' ) ) );
		settings_fields( self::OPTION_GROUP );
		// A clean return URL (the current request may carry a one-time ajxl_notice); the later field wins.
		printf( '<input type="hidden" name="_wp_http_referer" value="%s" />', esc_attr( $this->relative_tab_url( $tab ) ) );
		printf( '<input type="hidden" name="%s" value="%s" />', esc_attr( WPAJXL_Admin_Fields::name( '_ajxl_tab' ) ), esc_attr( $tab ) );
	}

	/**
	 * Close the settings form with a sticky save bar.
	 *
	 * @return void
	 */
	public function close_settings_form() {
		echo '<div class="ajxl-form-footer">';
		submit_button( __( 'Save Changes', 'ajax-loading' ), 'primary', 'submit', false );
		echo '<span class="ajxl-form-footer__dirty ajxl-needs-js" data-ajxl-dirty-note hidden>' . esc_html__( 'You have unsaved changes.', 'ajax-loading' ) . '</span>';
		echo '</div></form>';
	}

	/**
	 * Render every schema field of a tab (grouped in cards).
	 *
	 * @param string $tab Tab slug.
	 * @return void
	 */
	public function render_fields( $tab ) {
		WPAJXL_Admin_Fields::render_tab( $tab, $this->schema(), $this->values() );
	}

	/**
	 * Echo a submit button bound to a hidden quick-action form.
	 *
	 * @param string $do    Action.
	 * @param string $label Button text.
	 * @param array  $args  { class, name, value, confirm, icon, data (name => value, without the data- prefix) }.
	 * @return void
	 */
	public function action_button( $do, $label, array $args = array() ) {
		$args  = wp_parse_args(
			$args,
			array(
				'class'   => 'button',
				'name'    => '',
				'value'   => '',
				'confirm' => '',
				'icon'    => '',
				'data'    => array(),
			)
		);
		$extra = '';
		if ( '' !== $args['name'] ) {
			$extra .= sprintf( ' name="%s" value="%s"', esc_attr( $args['name'] ), esc_attr( $args['value'] ) );
		}
		if ( '' !== $args['confirm'] ) {
			$extra .= sprintf( ' data-ajxl-confirm="%s"', esc_attr( $args['confirm'] ) );
		}
		foreach ( (array) $args['data'] as $data_name => $data_value ) {
			$extra .= sprintf( ' data-%s="%s"', esc_attr( sanitize_key( $data_name ) ), esc_attr( (string) $data_value ) );
		}
		$icon = '' !== $args['icon'] ? sprintf( '<span class="dashicons %s" aria-hidden="true"></span> ', esc_attr( $args['icon'] ) ) : '';
		printf(
			'<button type="submit" form="%1$s" class="%2$s"%3$s>%4$s%5$s</button>',
			esc_attr( 'ajxl-action-' . sanitize_key( $do ) ),
			esc_attr( $args['class'] ),
			$extra, // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped when built.
			$icon, // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped when built.
			esc_html( $label )
		);
	}

	/**
	 * Echo the hidden fields of a quick-action form.
	 *
	 * @param string $do     Action.
	 * @param string $tab    Tab to return to.
	 * @param string $return 'page' or 'plugins'.
	 * @return void
	 */
	public function action_fields( $do, $tab, $return = 'page' ) {
		printf( '<input type="hidden" name="action" value="%s" />', esc_attr( self::ACTION ) );
		printf( '<input type="hidden" name="do" value="%s" />', esc_attr( $do ) );
		printf( '<input type="hidden" name="ajxl_tab" value="%s" />', esc_attr( $tab ) );
		printf( '<input type="hidden" name="_wpnonce" value="%s" />', esc_attr( wp_create_nonce( self::NONCE_ACTION ) ) );
		if ( 'plugins' === $return ) {
			echo '<input type="hidden" name="ajxl_return" value="plugins" />';
		}
	}

	/**
	 * Open a visible quick-action form (used for import/reset/export).
	 *
	 * @param string $do        Action.
	 * @param string $tab       Tab to return to.
	 * @param array  $attrs     Extra attributes: class, enctype, confirm.
	 * @return void
	 */
	public function open_action_form( $do, $tab, array $attrs = array() ) {
		$extra = '';
		if ( ! empty( $attrs['enctype'] ) ) {
			$extra .= sprintf( ' enctype="%s"', esc_attr( $attrs['enctype'] ) );
		}
		if ( ! empty( $attrs['confirm'] ) ) {
			$extra .= sprintf( ' data-ajxl-confirm="%s"', esc_attr( $attrs['confirm'] ) );
		}
		printf(
			'<form method="post" action="%1$s" class="%2$s"%3$s>',
			esc_url( admin_url( 'admin-post.php' ) ),
			esc_attr( trim( 'ajxl-action-form ' . ( isset( $attrs['class'] ) ? $attrs['class'] : '' ) ) ),
			$extra // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped when built.
		);
		$this->action_fields( $do, $tab );
	}

	/**
	 * Hidden forms targeted by action_button() (forms cannot be nested in the settings form).
	 *
	 * @param string $tab Current tab.
	 * @return void
	 */
	protected function render_action_forms( $tab ) {
		$actions = array( 'toggle_enable', 'toggle_safe_mode', 'toggle_visibility', 'pause', 'resume', 'clear_cache', 'clear_log' );
		echo '<div class="ajxl-action-forms" hidden>';
		foreach ( $actions as $do ) {
			printf( '<form method="post" action="%1$s" id="%2$s">', esc_url( admin_url( 'admin-post.php' ) ), esc_attr( 'ajxl-action-' . $do ) );
			$this->action_fields( $do, $tab );
			echo '</form>';
		}
		echo '</div>';
	}

	/*
	 * ---------------------------------------------------------------------
	 * Data helpers used by views
	 * ---------------------------------------------------------------------
	 */

	/**
	 * Tabs: slug => [ label, icon, form ].
	 *
	 * @return array
	 */
	public function tabs() {
		return array(
			'overview'    => array(
				'label' => __( 'Overview', 'ajax-loading' ),
				'icon'  => 'dashicons-dashboard',
			),
			'general'     => array(
				'label' => __( 'General', 'ajax-loading' ),
				'icon'  => 'dashicons-admin-generic',
			),
			'loading'     => array(
				'label' => __( 'Loading Experience', 'ajax-loading' ),
				'icon'  => 'dashicons-update',
			),
			'performance' => array(
				'label' => __( 'Performance', 'ajax-loading' ),
				'icon'  => 'dashicons-performance',
			),
			'seo'         => array(
				'label' => __( 'SEO & Integrations', 'ajax-loading' ),
				'icon'  => 'dashicons-chart-line',
			),
			'exclusions'  => array(
				'label' => __( 'Exclusions', 'ajax-loading' ),
				'icon'  => 'dashicons-shield',
			),
			'tools'       => array(
				'label' => __( 'Tools & Diagnostics', 'ajax-loading' ),
				'icon'  => 'dashicons-admin-tools',
			),
			'about'       => array(
				'label' => __( 'About', 'ajax-loading' ),
				'icon'  => 'dashicons-editor-help',
			),
			'thanks'      => array(
				'label' => __( 'Say Thanks', 'ajax-loading' ),
				'icon'  => 'dashicons-heart',
			),
		);
	}

	/**
	 * Current tab from the query string (legacy &con=about|donate supported).
	 *
	 * @return string
	 */
	public function current_tab() {
		// phpcs:disable WordPress.Security.NonceVerification.Recommended -- read-only view routing.
		$tab = isset( $_GET['tab'] ) ? sanitize_key( wp_unslash( $_GET['tab'] ) ) : '';
		if ( '' === $tab && isset( $_GET['con'] ) ) {
			$legacy = sanitize_key( wp_unslash( $_GET['con'] ) );
			if ( 'about' === $legacy ) {
				$tab = 'about';
			} elseif ( 'donate' === $legacy ) {
				$tab = 'thanks';
			}
		}
		// phpcs:enable
		$tabs = $this->tabs();
		return isset( $tabs[ $tab ] ) ? $tab : 'overview';
	}

	/**
	 * Settings page URL (no tab).
	 *
	 * @return string
	 */
	public function page_url() {
		return add_query_arg( 'page', self::PAGE_SLUG, admin_url( 'options-general.php' ) );
	}

	/**
	 * URL of a tab.
	 *
	 * @param string $tab      Tab slug.
	 * @param array  $args     Extra query args.
	 * @param string $fragment Optional #fragment (without '#').
	 * @return string
	 */
	public function tab_url( $tab, array $args = array(), $fragment = '' ) {
		$url = add_query_arg(
			array_merge(
				array(
					'page' => self::PAGE_SLUG,
					'tab'  => sanitize_key( $tab ),
				),
				$args
			),
			admin_url( 'options-general.php' )
		);
		return '' === $fragment ? $url : $url . '#' . rawurlencode( $fragment );
	}

	/**
	 * Root-relative URL of a tab (used as the options.php return address).
	 *
	 * @param string $tab Tab slug.
	 * @return string
	 */
	protected function relative_tab_url( $tab ) {
		$path = wp_parse_url( admin_url( 'options-general.php' ), PHP_URL_PATH );
		$path = is_string( $path ) && '' !== $path ? $path : '/wp-admin/options-general.php';
		return $path . '?page=' . rawurlencode( self::PAGE_SLUG ) . '&tab=' . rawurlencode( sanitize_key( $tab ) );
	}

	/**
	 * Settings service.
	 *
	 * @return WPAJXL_Settings
	 */
	public function settings() {
		return WPAJXL_Settings::instance();
	}

	/**
	 * Stored settings merged over defaults.
	 *
	 * @return array
	 */
	public function values() {
		$values = $this->settings()->all();
		return is_array( $values ) ? $values : array();
	}

	/**
	 * Settings schema.
	 *
	 * @return array
	 */
	public function schema() {
		$schema = $this->settings()->schema();
		return is_array( $schema ) ? $schema : array();
	}

	/**
	 * One stored value with a fallback.
	 *
	 * @param string $key      Setting key.
	 * @param mixed  $fallback Fallback.
	 * @return mixed
	 */
	public function value( $key, $fallback = null ) {
		$values = $this->values();
		return array_key_exists( $key, $values ) ? $values[ $key ] : $fallback;
	}

	/**
	 * Boolean view of a stored value.
	 *
	 * @param string $key Setting key.
	 * @return bool
	 */
	public function flag( $key ) {
		return WPAJXL_Admin_Fields::to_bool( $this->value( $key, false ) );
	}

	/**
	 * Human label of a setting's current (or given) choice.
	 *
	 * @param string      $key   Setting key.
	 * @param string|null $value Value (null = current).
	 * @return string
	 */
	public function choice_label( $key, $value = null ) {
		$schema = $this->schema();
		$value  = null === $value ? $this->value( $key, '' ) : $value;
		return WPAJXL_Admin_Fields::choice_label( $key, is_scalar( $value ) ? (string) $value : '', isset( $schema[ $key ] ) && is_array( $schema[ $key ] ) ? $schema[ $key ] : array() );
	}

	/**
	 * Navigation state for the header pill, overview card and notices.
	 *
	 * @return array { status, label, detail, flags[] }
	 */
	public function navigation_status() {
		$settings = $this->settings();
		$flags    = array();

		if ( 'on' !== $this->value( 'enable_plugin', 'off' ) ) {
			return array(
				'status' => 'error',
				'label'  => __( 'Off', 'ajax-loading' ),
				'detail' => __( 'AJAX navigation is turned off. Every page loads normally.', 'ajax-loading' ),
				'flags'  => array(),
			);
		}

		if ( $this->flag( 'safe_mode' ) ) {
			$flags[] = __( 'Safe mode', 'ajax-loading' );
		}

		if ( $settings->is_paused() ) {
			return array(
				'status' => 'warning',
				'label'  => __( 'Paused', 'ajax-loading' ),
				'detail' => sprintf(
					/* translators: %s: date and time. */
					__( 'Paused until %s. Pages load normally until then.', 'ajax-loading' ),
					$this->format_time( (int) $this->value( 'pause_until', 0 ) )
				),
				'flags'  => $flags,
			);
		}

		if ( 'admins' === $this->value( 'visibility', 'everyone' ) ) {
			return array(
				'status' => 'info',
				'label'  => __( 'Administrators only', 'ajax-loading' ),
				'detail' => __( 'Test mode: only logged-in administrators get AJAX navigation. Visitors get normal page loads.', 'ajax-loading' ),
				'flags'  => $flags,
			);
		}

		return array(
			'status' => 'ok',
			'label'  => __( 'Active', 'ajax-loading' ),
			'detail' => empty( $flags )
				? __( 'AJAX navigation is active for all visitors.', 'ajax-loading' )
				: __( 'AJAX navigation is active for all visitors, with conservative safe-mode behaviour.', 'ajax-loading' ),
			'flags'  => $flags,
		);
	}

	/**
	 * Recent client errors (newest first).
	 *
	 * @param int $limit 0 = all.
	 * @return array
	 */
	public function log_entries( $limit = 0 ) {
		$entries = self::invoke( 'WPAJXL_Logger', 'get', array(), array() );
		if ( ! is_array( $entries ) ) {
			return array();
		}
		$entries = array_values( array_filter( $entries, 'is_array' ) );
		usort(
			$entries,
			static function ( $a, $b ) {
				$ta = isset( $a['time'] ) ? (int) $a['time'] : 0;
				$tb = isset( $b['time'] ) ? (int) $b['time'] : 0;
				return $tb - $ta;
			}
		);
		return $limit > 0 ? array_slice( $entries, 0, (int) $limit ) : $entries;
	}

	/**
	 * Environment report items, normalised.
	 *
	 * @return array List of [ id, status, label, message ].
	 */
	public function environment_report() {
		$items = self::invoke( 'WPAJXL_Compat', 'environment_report', array(), array() );
		$out   = array();
		if ( ! is_array( $items ) ) {
			return $out;
		}
		foreach ( $items as $index => $item ) {
			if ( ! is_array( $item ) ) {
				continue;
			}
			$status = isset( $item['status'] ) ? (string) $item['status'] : 'info';
			$out[]  = array(
				'id'      => isset( $item['id'] ) ? (string) $item['id'] : (string) $index,
				'status'  => in_array( $status, array( 'ok', 'info', 'warning', 'error' ), true ) ? $status : 'info',
				'label'   => isset( $item['label'] ) ? (string) $item['label'] : '',
				'message' => isset( $item['message'] ) ? (string) $item['message'] : '',
			);
		}
		return $out;
	}

	/**
	 * Last client diagnostics summary stored by the REST API.
	 *
	 * @return array { time, ok, checks[], counts{ok,info,warning,error} } or empty array.
	 */
	public function last_diagnostics() {
		$stored = get_option( self::DIAGNOSTICS_OPTION, array() );
		if ( ! is_array( $stored ) || empty( $stored['time'] ) ) {
			return array();
		}
		$checks = isset( $stored['checks'] ) && is_array( $stored['checks'] ) ? array_values( array_filter( $stored['checks'], 'is_array' ) ) : array();
		$counts = array(
			'ok'      => 0,
			'info'    => 0,
			'warning' => 0,
			'error'   => 0,
		);
		foreach ( $checks as $check ) {
			$status = isset( $check['status'] ) ? (string) $check['status'] : 'info';
			if ( isset( $counts[ $status ] ) ) {
				++$counts[ $status ];
			}
		}
		return array(
			'time'   => (int) $stored['time'],
			'ok'     => ! empty( $stored['ok'] ),
			'checks' => $checks,
			'counts' => $counts,
		);
	}

	/**
	 * Built-in safety rules (read-only) as [ label, detail ] pairs.
	 *
	 * @return array
	 */
	public function safety_rules() {
		$rules = self::invoke( 'WPAJXL_Exclusions', 'readonly_safety_rules', array(), array() );
		$out   = array();
		if ( ! is_array( $rules ) ) {
			return $out;
		}
		foreach ( $rules as $key => $rule ) {
			if ( is_string( $rule ) && '' !== $rule ) {
				$out[] = array(
					'label'  => $rule,
					'detail' => '',
				);
			} elseif ( is_array( $rule ) ) {
				$label  = '';
				$detail = '';
				foreach ( array( 'label', 'title', 'name' ) as $field ) {
					if ( ! empty( $rule[ $field ] ) && is_string( $rule[ $field ] ) ) {
						$label = $rule[ $field ];
						break;
					}
				}
				foreach ( array( 'description', 'detail', 'message' ) as $field ) {
					if ( ! empty( $rule[ $field ] ) && is_string( $rule[ $field ] ) ) {
						$detail = $rule[ $field ];
						break;
					}
				}
				if ( ! empty( $rule['patterns'] ) && is_array( $rule['patterns'] ) ) {
					$detail = trim( $detail . ' ' . implode( ', ', array_filter( $rule['patterns'], 'is_string' ) ) );
				}
				if ( '' === $label && is_string( $key ) ) {
					$label = $key;
				}
				if ( '' !== $label || '' !== $detail ) {
					$out[] = array(
						'label'  => '' !== $label ? $label : $detail,
						'detail' => '' !== $label ? $detail : '',
					);
				}
			}
		}
		return $out;
	}

	/**
	 * Summary of exclusion rules for the Overview tab.
	 *
	 * @return array { urls, selectors, post_types, sets, total }
	 */
	public function exclusion_summary() {
		$urls       = $this->count_lines( $this->value( 'exclude_urls', '' ) );
		$selectors  = $this->count_lines( $this->value( 'exclude_selectors', '' ) );
		$post_types = $this->value( 'exclude_post_types', array() );
		$post_types = is_array( $post_types ) ? count( array_filter( $post_types, 'strlen' ) ) : 0;
		$sets       = 1; // WordPress system paths (admin, login, feeds, REST, files) are always excluded.
		if ( $this->flag( 'exclude_woocommerce' ) && class_exists( 'WooCommerce' ) ) {
			++$sets;
		}
		if ( $this->flag( 'exclude_membership' ) ) {
			++$sets;
		}
		return array(
			'urls'       => $urls,
			'selectors'  => $selectors,
			'post_types' => $post_types,
			'sets'       => $sets,
			'total'      => $urls + $selectors + $post_types + $sets,
		);
	}

	/**
	 * Count non-empty lines of a "lines" value.
	 *
	 * @param mixed $value String or list.
	 * @return int
	 */
	public function count_lines( $value ) {
		if ( is_array( $value ) ) {
			$lines = $value;
		} elseif ( is_string( $value ) ) {
			$lines = preg_split( '/\r\n|\r|\n/', $value );
		} else {
			return 0;
		}
		$count = 0;
		foreach ( (array) $lines as $line ) {
			if ( is_scalar( $line ) && '' !== trim( (string) $line ) ) {
				++$count;
			}
		}
		return $count;
	}

	/**
	 * Sample front-end URLs for diagnostics (home, latest post, a page, a category, search).
	 *
	 * @return array List of [ id, label, url ].
	 */
	public function sample_urls() {
		if ( null !== $this->sample_urls ) {
			return $this->sample_urls;
		}
		$urls   = array();
		$urls[] = array(
			'id'    => 'home',
			'label' => __( 'Home page', 'ajax-loading' ),
			'url'   => home_url( '/' ),
		);

		$posts = get_posts(
			array(
				'post_type'      => 'post',
				'post_status'    => 'publish',
				'posts_per_page' => 1,
				'has_password'   => false,
				'orderby'        => 'date',
				'order'          => 'DESC',
				'fields'         => 'ids',
				'no_found_rows'  => true,
			)
		);
		if ( ! empty( $posts ) ) {
			$link = get_permalink( (int) $posts[0] );
			if ( $link ) {
				$urls[] = array(
					'id'    => 'post',
					/* translators: %s: post title. */
					'label' => sprintf( __( 'Latest post: %s', 'ajax-loading' ), $this->plain_title( (int) $posts[0] ) ),
					'url'   => $link,
				);
			}
		}

		$skip  = array_filter( array( (int) get_option( 'page_on_front' ), (int) get_option( 'page_for_posts' ) ) );
		$pages = get_posts(
			array(
				'post_type'      => 'page',
				'post_status'    => 'publish',
				'posts_per_page' => 1,
				'has_password'   => false,
				'post__not_in'   => $skip, // phpcs:ignore WordPressVIPMinimum.Performance.WPQueryParams.PostNotIn_post__not_in -- at most two ids, admin only.
				'orderby'        => array(
					'menu_order' => 'ASC',
					'date'       => 'DESC',
				),
				'fields'         => 'ids',
				'no_found_rows'  => true,
			)
		);
		if ( ! empty( $pages ) ) {
			$link = get_permalink( (int) $pages[0] );
			if ( $link ) {
				$urls[] = array(
					'id'    => 'page',
					/* translators: %s: page title. */
					'label' => sprintf( __( 'Page: %s', 'ajax-loading' ), $this->plain_title( (int) $pages[0] ) ),
					'url'   => $link,
				);
			}
		}

		$terms = get_terms(
			array(
				'taxonomy'   => 'category',
				'number'     => 1,
				'hide_empty' => true,
				'orderby'    => 'count',
				'order'      => 'DESC',
			)
		);
		if ( ! is_wp_error( $terms ) && ! empty( $terms ) && $terms[0] instanceof WP_Term ) {
			$link = get_term_link( $terms[0] );
			if ( ! is_wp_error( $link ) ) {
				$urls[] = array(
					'id'    => 'category',
					/* translators: %s: category name. */
					'label' => sprintf( __( 'Category: %s', 'ajax-loading' ), wp_strip_all_tags( $terms[0]->name ) ),
					'url'   => $link,
				);
			}
		}

		$urls[] = array(
			'id'    => 'search',
			'label' => __( 'Search results', 'ajax-loading' ),
			'url'   => add_query_arg( 's', 'a', home_url( '/' ) ),
		);

		$this->sample_urls = $urls;
		return $urls;
	}

	/**
	 * Plain-text title of a post.
	 *
	 * @param int $post_id Post id.
	 * @return string
	 */
	protected function plain_title( $post_id ) {
		$title = trim( wp_strip_all_tags( html_entity_decode( get_the_title( $post_id ), ENT_QUOTES, 'UTF-8' ) ) );
		/* translators: %d: post id. */
		return '' !== $title ? $title : sprintf( __( '#%d (no title)', 'ajax-loading' ), $post_id );
	}

	/**
	 * Format a unix timestamp in the site's date/time format.
	 *
	 * @param int $timestamp Unix timestamp.
	 * @return string
	 */
	public function format_time( $timestamp ) {
		$timestamp = (int) $timestamp;
		if ( $timestamp <= 0 ) {
			return '';
		}
		$format = trim( get_option( 'date_format', 'Y-m-d' ) . ' ' . get_option( 'time_format', 'H:i' ) );
		$output = wp_date( $format, $timestamp );
		return is_string( $output ) ? $output : gmdate( 'Y-m-d H:i', $timestamp );
	}

	/**
	 * "5 minutes ago" style relative time.
	 *
	 * @param int $timestamp Unix timestamp.
	 * @return string
	 */
	public function time_ago( $timestamp ) {
		$timestamp = (int) $timestamp;
		if ( $timestamp <= 0 ) {
			return '';
		}
		/* translators: %s: human-readable time difference. */
		return sprintf( __( '%s ago', 'ajax-loading' ), human_time_diff( $timestamp, time() ) );
	}

	/**
	 * Human labels of navigation error codes.
	 *
	 * @return array code => label
	 */
	public function error_code_labels() {
		return array(
			'network'               => __( 'Network error', 'ajax-loading' ),
			'timeout'               => __( 'Request timed out', 'ajax-loading' ),
			'http_status'           => __( 'Server returned an error status', 'ajax-loading' ),
			'invalid_content_type'  => __( 'Response was not an HTML page', 'ajax-loading' ),
			'parse_error'           => __( 'Page could not be parsed', 'ajax-loading' ),
			'marker_missing'        => __( 'Destination page is not served by AJAX Loading (cached copy or plugin inactive there)', 'ajax-loading' ),
			'bypass'                => __( 'Destination page is excluded', 'ajax-loading' ),
			'container_mismatch'    => __( 'Content area not found on both pages', 'ajax-loading' ),
			'layout_mismatch'       => __( 'Pages use different layouts', 'ajax-loading' ),
			'cross_origin_redirect' => __( 'Redirected to another site', 'ajax-loading' ),
			'excluded_redirect'     => __( 'Redirected to an excluded URL', 'ajax-loading' ),
			'integration_excluded'  => __( 'Page uses an integration set to reload', 'ajax-loading' ),
			'interactive_content'   => __( 'Page contains interactive blocks', 'ajax-loading' ),
			'exception'             => __( 'Unexpected script error', 'ajax-loading' ),
			'circuit_open'          => __( 'Automatic fallback active for this visitor', 'ajax-loading' ),
			'prevented'             => __( 'Cancelled by a site script', 'ajax-loading' ),
			'device_disabled'       => __( 'Disabled for this device type', 'ajax-loading' ),
			'language_changed'      => __( 'Page is in another language', 'ajax-loading' ),
			'asset_changed'         => __( 'Tracked assets changed', 'ajax-loading' ),
			'personalized'          => __( 'Personalised page', 'ajax-loading' ),
			'unsupported_charset'   => __( 'Unsupported character set', 'ajax-loading' ),
		);
	}

	/**
	 * Human label of an error code.
	 *
	 * @param string $code Error code.
	 * @return string
	 */
	public function error_code_label( $code ) {
		$labels = $this->error_code_labels();
		return isset( $labels[ $code ] ) ? $labels[ $code ] : (string) $code;
	}

	/**
	 * Status pill markup (escaped).
	 *
	 * @param string $status ok|info|warning|error|neutral.
	 * @param string $label  Text.
	 * @return string
	 */
	public static function pill( $status, $label ) {
		$status = in_array( $status, array( 'ok', 'info', 'warning', 'error', 'neutral' ), true ) ? $status : 'neutral';
		return sprintf( '<span class="ajxl-pill ajxl-pill--%1$s">%2$s</span>', esc_attr( $status ), esc_html( $label ) );
	}

	/**
	 * Human label of a diagnostic status.
	 *
	 * @param string $status Status.
	 * @return string
	 */
	public static function status_label( $status ) {
		$labels = array(
			'ok'      => __( 'OK', 'ajax-loading' ),
			'info'    => __( 'Info', 'ajax-loading' ),
			'warning' => __( 'Warning', 'ajax-loading' ),
			'error'   => __( 'Problem', 'ajax-loading' ),
		);
		return isset( $labels[ $status ] ) ? $labels[ $status ] : $labels['info'];
	}

	/**
	 * Call a method of another plugin module whether it is static or an instance method.
	 *
	 * Keeps the dashboard working (with the fallback) if a module is missing or throws.
	 *
	 * @param string $class    Class name.
	 * @param string $method   Method name.
	 * @param array  $args     Arguments.
	 * @param mixed  $fallback Returned on any failure.
	 * @return mixed
	 */
	public static function invoke( $class, $method, array $args = array(), $fallback = null ) {
		if ( ! class_exists( $class ) || ! method_exists( $class, $method ) ) {
			return $fallback;
		}
		try {
			$ref = new ReflectionMethod( $class, $method );
			if ( ! $ref->isPublic() ) {
				return $fallback;
			}
			if ( $ref->isStatic() ) {
				return call_user_func_array( array( $class, $method ), $args );
			}
			if ( method_exists( $class, 'instance' ) ) {
				$instance = call_user_func( array( $class, 'instance' ) );
			} else {
				$class_ref = new ReflectionClass( $class );
				if ( ! $class_ref->isInstantiable() ) {
					return $fallback;
				}
				$ctor     = $class_ref->getConstructor();
				$required = $ctor ? $ctor->getNumberOfRequiredParameters() : 0;
				if ( 0 === $required ) {
					$instance = new $class();
				} elseif ( 1 === $required && class_exists( 'WPAJXL_Settings' ) ) {
					$instance = new $class( WPAJXL_Settings::instance() );
				} else {
					return $fallback;
				}
			}
			return is_object( $instance ) ? call_user_func_array( array( $instance, $method ), $args ) : $fallback;
		} catch ( Throwable $e ) {
			self::debug_log( $class . '::' . $method . ' failed: ' . $e->getMessage() );
			return $fallback;
		}
	}

	/**
	 * Log a message when WP_DEBUG is on.
	 *
	 * @param string $message Message.
	 * @return void
	 */
	protected static function debug_log( $message ) {
		if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
			error_log( '[AJAX Loading] ' . $message ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log -- debug only.
		}
	}

	/*
	 * ---------------------------------------------------------------------
	 * Quick actions
	 * ---------------------------------------------------------------------
	 */

	/**
	 * Run a quick action and return the notice code.
	 *
	 * @param string $do Action.
	 * @return string
	 */
	protected function run_action( $do ) {
		// Nonce verified in handle_action().
		// phpcs:disable WordPress.Security.NonceVerification.Missing
		$settings = $this->settings();

		switch ( $do ) {
			case 'toggle_enable':
				$enable = ( 'on' !== $this->value( 'enable_plugin', 'off' ) );
				$settings->update( array( 'enable_plugin' => $enable ? 'on' : 'off' ) );
				return $enable ? 'enabled' : 'disabled';

			case 'toggle_safe_mode':
				$on = ! $this->flag( 'safe_mode' );
				$settings->update( array( 'safe_mode' => $on ) );
				return $on ? 'safe_mode_on' : 'safe_mode_off';

			case 'toggle_visibility':
				$admins = ( 'admins' !== $this->value( 'visibility', 'everyone' ) );
				$settings->update( array( 'visibility' => $admins ? 'admins' : 'everyone' ) );
				return $admins ? 'visibility_admins' : 'visibility_everyone';

			case 'pause':
				$duration = isset( $_POST['duration'] ) ? absint( wp_unslash( $_POST['duration'] ) ) : 3600;
				$duration = in_array( $duration, array( HOUR_IN_SECONDS, DAY_IN_SECONDS ), true ) ? $duration : HOUR_IN_SECONDS;
				$settings->pause( $duration );
				return 'paused';

			case 'resume':
				$settings->resume();
				return 'resumed';

			case 'clear_cache':
				$settings->bump_cache_version();
				return 'cache_cleared';

			case 'reset':
				if ( empty( $_POST['ajxl_confirm_reset'] ) ) {
					return 'reset_unconfirmed';
				}
				$settings->reset();
				return 'reset';

			case 'import':
				return $this->handle_import();

			case 'clear_log':
				self::invoke( 'WPAJXL_Logger', 'clear' );
				return 'log_cleared';
		}
		// phpcs:enable
		return 'action_failed';
	}

	/**
	 * Validate the uploaded settings file and import it.
	 *
	 * @return string Notice code.
	 */
	protected function handle_import() {
		// Nonce verified in handle_action(); every part of the upload is validated below.
		// phpcs:disable WordPress.Security.NonceVerification.Missing, WordPress.Security.ValidatedSanitizedInput.InputNotSanitized, WordPress.Security.ValidatedSanitizedInput.MissingUnslash
		if ( empty( $_FILES['ajxl_import_file'] ) || ! is_array( $_FILES['ajxl_import_file'] ) ) {
			return 'import_no_file';
		}
		$file  = $_FILES['ajxl_import_file'];
		$error = isset( $file['error'] ) ? (int) $file['error'] : UPLOAD_ERR_NO_FILE;
		// phpcs:enable

		if ( UPLOAD_ERR_NO_FILE === $error ) {
			return 'import_no_file';
		}
		if ( UPLOAD_ERR_INI_SIZE === $error || UPLOAD_ERR_FORM_SIZE === $error ) {
			return 'import_too_large';
		}
		if ( UPLOAD_ERR_OK !== $error || empty( $file['tmp_name'] ) || ! is_string( $file['tmp_name'] ) ) {
			return 'import_failed';
		}

		$size = isset( $file['size'] ) ? (int) $file['size'] : 0;
		if ( $size > self::IMPORT_MAX_BYTES ) {
			return 'import_too_large';
		}
		if ( $size <= 0 ) {
			return 'import_invalid';
		}

		$name = isset( $file['name'] ) && is_string( $file['name'] ) ? sanitize_file_name( $file['name'] ) : '';
		if ( 'json' !== strtolower( (string) pathinfo( $name, PATHINFO_EXTENSION ) ) ) {
			return 'import_wrong_type';
		}
		if ( ! is_uploaded_file( $file['tmp_name'] ) ) {
			return 'import_failed';
		}

		// phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- reading PHP's own upload temp file.
		$raw = file_get_contents( $file['tmp_name'], false, null, 0, self::IMPORT_MAX_BYTES + 1 );
		if ( false === $raw ) {
			return 'import_failed';
		}
		if ( strlen( $raw ) > self::IMPORT_MAX_BYTES ) {
			return 'import_too_large';
		}
		if ( 0 === strpos( $raw, "\xEF\xBB\xBF" ) ) {
			$raw = substr( $raw, 3 );
		}

		$data = json_decode( $raw, true );
		if ( ! is_array( $data ) ) {
			return 'import_invalid';
		}

		$result = $this->settings()->import( $data );
		if ( is_wp_error( $result ) ) {
			set_transient( $this->import_error_key(), $result->get_error_message(), 5 * MINUTE_IN_SECONDS );
			return 'import_invalid';
		}
		return $result ? 'imported' : 'import_invalid';
	}

	/**
	 * Stream the settings export as a JSON download and exit.
	 *
	 * @param string $tab Tab to return to on failure.
	 * @return void
	 */
	protected function send_export( $tab ) {
		$data = $this->settings()->export();
		$json = is_array( $data ) ? wp_json_encode( $data, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE ) : false;
		if ( false === $json ) {
			$this->redirect_after_action( $tab, 'action_failed', 'page' );
		}

		$host = wp_parse_url( home_url(), PHP_URL_HOST );
		$file = sanitize_file_name( 'ajax-loading-settings-' . ( is_string( $host ) ? $host . '-' : '' ) . gmdate( 'Y-m-d' ) . '.json' );

		nocache_headers();
		header( 'Content-Type: application/json; charset=utf-8' );
		header( 'Content-Disposition: attachment; filename="' . $file . '"' );
		header( 'X-Content-Type-Options: nosniff' );
		header( 'Content-Length: ' . strlen( $json ) );
		echo $json; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- JSON file download, not HTML.
		exit;
	}

	/**
	 * Redirect back after a quick action.
	 *
	 * @param string $tab    Tab slug.
	 * @param string $notice Notice code.
	 * @param string $return 'page' or 'plugins'.
	 * @return void
	 */
	protected function redirect_after_action( $tab, $notice, $return ) {
		$tabs = $this->tabs();
		if ( 'plugins' === $return ) {
			$url = add_query_arg( 'ajxl_notice', $notice, admin_url( 'plugins.php' ) );
		} else {
			$url = $this->tab_url( isset( $tabs[ $tab ] ) ? $tab : 'overview', array( 'ajxl_notice' => $notice ) );
		}
		wp_safe_redirect( $url );
		exit;
	}

	/**
	 * Transient key for the last import error of the current user.
	 *
	 * @return string
	 */
	protected function import_error_key() {
		return 'ajxl_import_error_' . get_current_user_id();
	}

	/*
	 * ---------------------------------------------------------------------
	 * Notices
	 * ---------------------------------------------------------------------
	 */

	/**
	 * Whitelisted notice code from the query string.
	 *
	 * @return string
	 */
	protected function notice_code() {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- display only, whitelisted.
		$code     = isset( $_GET['ajxl_notice'] ) ? sanitize_key( wp_unslash( $_GET['ajxl_notice'] ) ) : '';
		$messages = $this->notice_messages();
		return isset( $messages[ $code ] ) ? $code : '';
	}

	/**
	 * Notice code => [ type, message ].
	 *
	 * @return array
	 */
	protected function notice_messages() {
		return array(
			'enabled'             => array( 'success', __( 'AJAX navigation is now enabled.', 'ajax-loading' ) ),
			'disabled'            => array( 'warning', __( 'AJAX navigation is now disabled. Every page loads normally.', 'ajax-loading' ) ),
			'safe_mode_on'        => array( 'success', __( 'Safe mode is on.', 'ajax-loading' ) ),
			'safe_mode_off'       => array( 'success', __( 'Safe mode is off.', 'ajax-loading' ) ),
			'visibility_admins'   => array( 'success', __( 'Test mode is on: only administrators get AJAX navigation.', 'ajax-loading' ) ),
			'visibility_everyone' => array( 'success', __( 'AJAX navigation is now active for all visitors.', 'ajax-loading' ) ),
			'paused'              => array( 'success', __( 'AJAX navigation is paused.', 'ajax-loading' ) ),
			'resumed'             => array( 'success', __( 'AJAX navigation has resumed.', 'ajax-loading' ) ),
			'cache_cleared'       => array( 'success', __( 'Navigation cache cleared. Visitors\' browsers discard their cached pages the next time they load a page from your server, or when the cache lifetime ends.', 'ajax-loading' ) ),
			'reset'               => array( 'success', __( 'All settings were restored to their defaults.', 'ajax-loading' ) ),
			'reset_unconfirmed'   => array( 'error', __( 'Please confirm that you want to restore the default settings.', 'ajax-loading' ) ),
			'imported'            => array( 'success', __( 'Settings imported.', 'ajax-loading' ) ),
			'import_no_file'      => array( 'error', __( 'Choose a settings file to import.', 'ajax-loading' ) ),
			'import_too_large'    => array( 'error', __( 'The settings file is larger than 100 KB.', 'ajax-loading' ) ),
			'import_wrong_type'   => array( 'error', __( 'Please choose a .json file exported by AJAX Loading.', 'ajax-loading' ) ),
			'import_failed'       => array( 'error', __( 'The file could not be uploaded. Please try again.', 'ajax-loading' ) ),
			'import_invalid'      => array( 'error', __( 'This file is not a valid AJAX Loading settings export. Nothing was changed.', 'ajax-loading' ) ),
			'log_cleared'         => array( 'success', __( 'Recent errors cleared.', 'ajax-loading' ) ),
			'action_failed'       => array( 'error', __( 'That action could not be completed.', 'ajax-loading' ) ),
		);
	}

	/**
	 * Print the result notice of a quick action.
	 *
	 * @param string $code Notice code.
	 * @return void
	 */
	protected function print_result_notice( $code ) {
		$messages = $this->notice_messages();
		list( $type, $message ) = $messages[ $code ];

		if ( 'paused' === $code && $this->settings()->is_paused() ) {
			$message = sprintf(
				/* translators: %s: date and time. */
				__( 'AJAX navigation is paused until %s. Pages load normally until then.', 'ajax-loading' ),
				$this->format_time( (int) $this->value( 'pause_until', 0 ) )
			);
		}

		if ( in_array( $code, self::PAGE_CACHE_NOTICE_CODES, true ) && class_exists( 'WPAJXL_Compat' ) && method_exists( 'WPAJXL_Compat', 'has_page_cache' ) && WPAJXL_Compat::has_page_cache() ) {
			$message .= ' ' . self::page_cache_hint();
		}

		$detail = '';
		if ( 'import_invalid' === $code ) {
			$stored = get_transient( $this->import_error_key() );
			if ( is_string( $stored ) && '' !== $stored ) {
				$detail = $stored;
				delete_transient( $this->import_error_key() );
			}
		}

		printf(
			'<div class="notice notice-%1$s is-dismissible ajxl-notice"><p>%2$s%3$s</p></div>',
			esc_attr( $type ),
			esc_html( $message ),
			'' !== $detail ? ' <span class="ajxl-notice__detail">' . esc_html( $detail ) . '</span>' : ''
		);
	}

	/**
	 * Persistent notices for paused / safe mode / administrators-only states.
	 *
	 * @param bool   $own  On the plugin's own screen.
	 * @param string $code Result notice already shown (to avoid repeating it).
	 * @return void
	 */
	protected function print_state_notices( $own, $code ) {
		if ( 'on' !== $this->value( 'enable_plugin', 'off' ) ) {
			return;
		}
		$return = $own ? 'page' : 'plugins';
		$tab    = $own ? $this->current_tab() : 'overview';

		if ( $this->settings()->is_paused() && 'paused' !== $code ) {
			$this->print_state_notice(
				'warning',
				sprintf(
					/* translators: %s: date and time. */
					__( 'AJAX Loading is paused until %s. Visitors get normal page loads until then.', 'ajax-loading' ),
					$this->format_time( (int) $this->value( 'pause_until', 0 ) )
				),
				'resume',
				__( 'Resume now', 'ajax-loading' ),
				$tab,
				$return
			);
		}

		if ( $this->flag( 'safe_mode' ) && 'safe_mode_on' !== $code ) {
			$this->print_state_notice(
				'info',
				__( 'AJAX Loading safe mode is on: prefetching, caching and page builder support are limited while you troubleshoot.', 'ajax-loading' ),
				'toggle_safe_mode',
				__( 'Turn off safe mode', 'ajax-loading' ),
				$tab,
				$return
			);
		}

		if ( 'admins' === $this->value( 'visibility', 'everyone' ) && 'visibility_admins' !== $code ) {
			$this->print_state_notice(
				'info',
				__( 'AJAX Loading is in test mode: only administrators get AJAX navigation.', 'ajax-loading' ),
				'toggle_visibility',
				__( 'Enable for everyone', 'ajax-loading' ),
				$tab,
				$return
			);
		}
	}

	/**
	 * One state notice with an inline action form.
	 *
	 * @param string $type    notice type.
	 * @param string $message Message.
	 * @param string $do      Quick action.
	 * @param string $button  Button label.
	 * @param string $tab     Tab to return to.
	 * @param string $return  'page' or 'plugins'.
	 * @return void
	 */
	protected function print_state_notice( $type, $message, $do, $button, $tab, $return ) {
		printf( '<div class="notice notice-%1$s ajxl-notice ajxl-state-notice"><p>%2$s</p>', esc_attr( $type ), esc_html( $message ) );
		printf( '<form method="post" action="%s" class="ajxl-inline-form"><p>', esc_url( admin_url( 'admin-post.php' ) ) );
		$this->action_fields( $do, $tab, $return );
		printf( '<button type="submit" class="button button-small">%s</button>', esc_html( $button ) );
		if ( 'plugins' === $return ) {
			printf( ' <a href="%1$s">%2$s</a>', esc_url( $this->page_url() ), esc_html__( 'Open AJAX Loading settings', 'ajax-loading' ) );
		}
		echo '</p></form></div>';
	}

	/*
	 * ---------------------------------------------------------------------
	 * Assets
	 * ---------------------------------------------------------------------
	 */

	/**
	 * Plugin basename (works when the folder is renamed).
	 *
	 * @return string
	 */
	protected function plugin_basename() {
		if ( defined( 'WPAJXL_PLUGIN_BASENAME' ) && WPAJXL_PLUGIN_BASENAME ) {
			return WPAJXL_PLUGIN_BASENAME;
		}
		return plugin_basename( dirname( __DIR__ ) . '/ajax-loading.php' );
	}

	/**
	 * Plugin root URL with trailing slash.
	 *
	 * @return string
	 */
	public function plugin_url() {
		if ( defined( 'WPAJXL_PLUGIN_URL' ) && WPAJXL_PLUGIN_URL ) {
			return trailingslashit( WPAJXL_PLUGIN_URL );
		}
		return plugin_dir_url( __DIR__ );
	}

	/**
	 * Plugin root path with trailing slash.
	 *
	 * @return string
	 */
	protected function plugin_path() {
		return trailingslashit( dirname( __DIR__ ) );
	}

	/**
	 * Relative path of a built asset (.min unless SCRIPT_DEBUG; falls back to the unminified build).
	 *
	 * @param string $name Base name (admin|frontend).
	 * @param string $ext  js|css.
	 * @return string
	 */
	protected function asset_path( $name, $ext ) {
		$plain = 'assets/dist/' . $name . '.' . $ext;
		$min   = 'assets/dist/' . $name . '.min.' . $ext;
		if ( defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ) {
			return file_exists( $this->plugin_path() . $plain ) ? $plain : $min;
		}
		return file_exists( $this->plugin_path() . $min ) ? $min : $plain;
	}

	/**
	 * URL of a built asset.
	 *
	 * @param string $name Base name.
	 * @param string $ext  Extension.
	 * @return string
	 */
	protected function asset_url( $name, $ext ) {
		return $this->plugin_url() . $this->asset_path( $name, $ext );
	}

	/**
	 * Asset version (plugin version; file time added while SCRIPT_DEBUG is on).
	 *
	 * @param string $name Base name.
	 * @param string $ext  Extension.
	 * @return string
	 */
	protected function asset_version( $name, $ext ) {
		if ( defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ) {
			$mtime = @filemtime( $this->plugin_path() . $this->asset_path( $name, $ext ) ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- missing build file is not an error.
			if ( $mtime ) {
				return $this->version . '.' . $mtime;
			}
		}
		return $this->version;
	}

	/**
	 * Front-end config (§5) used by the preview and diagnostics.
	 *
	 * @return array
	 */
	protected function frontend_config() {
		$config = self::invoke( 'WPAJXL_Frontend', 'get_config', array(), array() );
		return is_array( $config ) ? $config : array();
	}

	/**
	 * Data for window.ajaxLoadingAdmin.
	 *
	 * @param string $tab Current tab.
	 * @return array
	 */
	protected function script_data( $tab ) {
		$schema = $this->schema();
		return array(
			'tab'        => $tab,
			'restUrl'    => esc_url_raw( rest_url( 'ajax-loading/v1/' ) ),
			'restNonce'  => wp_create_nonce( 'wp_rest' ),
			'config'     => $this->frontend_config(),
			'types'      => WPAJXL_Admin_Fields::types( $schema ),
			'sampleUrls' => 'tools' === $tab ? $this->sample_urls() : array(),
			'logging'    => $this->flag( 'error_logging' ),
			'visibility' => (string) $this->value( 'visibility', 'everyone' ),
			'protect'    => array(
				'woocommerce' => $this->flag( 'exclude_woocommerce' ),
				'membership'  => $this->flag( 'exclude_membership' ),
			),
			'importMax'  => self::IMPORT_MAX_BYTES,
			'errorCodes' => $this->error_code_labels(),
			'i18n'       => $this->script_i18n(),
		);
	}

	/**
	 * Translated strings for the admin script.
	 *
	 * @return array
	 */
	protected function script_i18n() {
		return array(
			// Generic.
			'statusOk'           => self::status_label( 'ok' ),
			'statusInfo'         => self::status_label( 'info' ),
			'statusWarning'      => self::status_label( 'warning' ),
			'statusError'        => self::status_label( 'error' ),
			'loading'            => __( 'Loading…', 'ajax-loading' ),
			/* translators: %s: error message. */
			'requestFailed'      => __( 'The request failed: %s', 'ajax-loading' ),
			'unsavedLeave'       => __( 'You have unsaved changes on this tab. Leave without saving?', 'ajax-loading' ),
			'copied'             => __( 'Copied', 'ajax-loading' ),
			'copyFailed'         => __( 'Press Ctrl+C (or Cmd+C) to copy.', 'ajax-loading' ),
			'importTooLarge'     => __( 'The settings file is larger than 100 KB.', 'ajax-loading' ),
			'importWrongType'    => __( 'Please choose a .json file exported by AJAX Loading.', 'ajax-loading' ),
			'importNoFile'       => __( 'Choose a settings file to import.', 'ajax-loading' ),

			// Media picker.
			'mediaTitle'         => __( 'Choose a logo for the loading indicator', 'ajax-loading' ),
			'mediaButton'        => __( 'Use this image', 'ajax-loading' ),
			'mediaNone'          => __( 'No image selected', 'ajax-loading' ),
			'mediaSelected'      => __( 'Logo image selected.', 'ajax-loading' ),

			// Preview.
			'previewPlaying'     => __( 'Playing preview…', 'ajax-loading' ),
			'previewDone'        => __( 'Preview finished.', 'ajax-loading' ),
			/* translators: %s: error message. */
			'previewFailed'      => __( 'The preview could not run: %s', 'ajax-loading' ),
			'reducedMotionOn'    => __( 'Your device asks for reduced motion and "Respect reduced motion" is on, so animations are skipped here, exactly as for visitors with this preference.', 'ajax-loading' ),
			'reducedMotionOff'   => __( 'Your device asks for reduced motion, but "Respect reduced motion" is off: visitors with this preference will still see animations.', 'ajax-loading' ),

			// Diagnostics.
			'running'            => __( 'Running checks…', 'ajax-loading' ),
			/* translators: 1: start page path, 2: destination page path. */
			'testTitle'          => __( 'Navigation test: %1$s → %2$s', 'ajax-loading' ),
			'selectorsTitle'     => __( 'Content selectors on sample pages', 'ajax-loading' ),
			'invalidUrl'         => __( 'Enter a full URL of a page on this site.', 'ajax-loading' ),
			/* translators: %s: site origin (scheme and host). */
			'notSameOrigin'      => __( 'Only pages on this site (%s) can be tested.', 'ajax-loading' ),
			/* translators: 1: HTTP status code, 2: size in KB, 3: duration in milliseconds. */
			'fetchOk'            => __( 'HTTP %1$s, %2$s KB in %3$s ms', 'ajax-loading' ),
			/* translators: %s: error message. */
			'fetchFailed'        => __( 'Could not load the page: %s', 'ajax-loading' ),
			/* translators: %s: HTTP status code. */
			'fetchStatus'        => __( 'The server answered with HTTP %s.', 'ajax-loading' ),
			/* translators: %s: content type. */
			'fetchType'          => __( 'The response is not an HTML page (%s).', 'ajax-loading' ),
			/* translators: %s: URL path. */
			'fetchRedirect'      => __( 'Redirected to %s.', 'ajax-loading' ),
			'fetchTimeout'       => __( 'The request timed out.', 'ajax-loading' ),
			/* translators: %s: URL path. */
			'labelFetch'         => __( 'Load %s', 'ajax-loading' ),
			/* translators: %s: URL path. */
			'labelMarker'        => __( 'Plugin marker on %s', 'ajax-loading' ),
			'markerEnabled'      => __( 'AJAX Loading is active on this page.', 'ajax-loading' ),
			'markerBypass'       => __( 'This page is excluded on the server (for example cart, checkout, login or an excluded post type). Links to it load normally.', 'ajax-loading' ),
			'markerMissing'      => __( 'The marker tag is missing: the plugin is off, paused, in test mode for other users, or a page cache serves a copy from before activation. Navigation to this page falls back to a normal load.', 'ajax-loading' ),
			/* translators: 1: plugin version found in the page, 2: installed plugin version. */
			'markerVersion'      => __( 'The page was rendered by AJAX Loading %1$s but this site runs %2$s. Clear your page cache.', 'ajax-loading' ),
			'labelLinkRule'      => __( 'Link rules for the destination', 'ajax-loading' ),
			'linkOk'             => __( 'A link to this URL is handled with AJAX.', 'ajax-loading' ),
			/* translators: %s: technical reason code. */
			'linkSkipped'        => __( 'A link to this URL loads normally (%s).', 'ajax-loading' ),
			'labelPrefetch'      => __( 'Prefetch for visitors', 'ajax-loading' ),
			'prefetchOk'         => __( 'Visitors may prefetch this URL.', 'ajax-loading' ),
			/* translators: %s: technical reason code. */
			'prefetchSkipped'    => __( 'Visitors never prefetch this URL (%s).', 'ajax-loading' ),
			'prefetchOff'        => __( 'Prefetching is turned off.', 'ajax-loading' ),
			'labelDetect'        => __( 'Content to replace', 'ajax-loading' ),
			/* translators: 1: detection mode, 2: list of regions. */
			'detectOk'           => __( 'Mode "%1$s": %2$s', 'ajax-loading' ),
			/* translators: 1: error code, 2: explanation. */
			'detectFailed'       => __( 'No matching content area (%1$s): %2$s', 'ajax-loading' ),
			/* translators: %s: CSS selector. */
			'regionContent'      => __( 'content %s', 'ajax-loading' ),
			/* translators: %s: CSS selector. */
			'regionHeader'       => __( 'header %s', 'ajax-loading' ),
			/* translators: %s: CSS selector. */
			'regionFooter'       => __( 'footer %s', 'ajax-loading' ),
			'regionBody'         => __( 'whole body', 'ajax-loading' ),
			'labelHead'          => __( 'Head tags that will be updated', 'ajax-loading' ),
			/* translators: 1: page title, 2: number of tags, 3: list of tag names. */
			'headSummary'        => __( 'Title "%1$s"; %2$s tag(s) replaced: %3$s', 'ajax-loading' ),
			/* translators: %s: page title. */
			'headTitleOnly'      => __( 'Title "%s"; head tag syncing is off or there is nothing to sync.', 'ajax-loading' ),
			'labelScripts'       => __( 'Scripts and styles', 'ajax-loading' ),
			/* translators: 1: number of scripts, 2: number of scripts, 3: number of stylesheets. */
			'scriptsSummary'     => __( '%1$s script(s) inside the new content, %2$s new external script(s), %3$s new stylesheet(s).', 'ajax-loading' ),
			'scriptsNoExec'      => __( 'Scripts inside the new content are not executed ("Run scripts inside new content" is off).', 'ajax-loading' ),
			'documentWrite'      => __( 'An inline script uses document.write and will be skipped after AJAX navigation.', 'ajax-loading' ),
			'labelLinks'         => __( 'Links on the start page', 'ajax-loading' ),
			/* translators: 1: number of links, 2: total number of links, 3: list of reasons. */
			'linksSummary'       => __( '%1$s of %2$s links load with AJAX. Others: %3$s', 'ajax-loading' ),
			'linksNone'          => __( 'No links found on the start page.', 'ajax-loading' ),
			'labelWarnings'      => __( 'Things that force a normal page load', 'ajax-loading' ),
			'warnInteractive'    => __( 'The destination content uses Interactivity API blocks, so it loads normally ("Interactive blocks" is set to reload).', 'ajax-loading' ),
			'warnInteractiveSwap' => __( 'The destination content uses Interactivity API blocks; they are swapped with AJAX and may not work.', 'ajax-loading' ),
			'warnRouter'         => __( 'The start page loads the WordPress Interactivity router, so AJAX Loading stays inactive on it.', 'ajax-loading' ),
			/* translators: 1: language code of the start page, 2: language code of the destination. */
			'warnLanguage'       => __( 'The pages are in different languages (%1$s → %2$s), so this navigation reloads the page.', 'ajax-loading' ),
			/* translators: %s: list of CSS class names. */
			'warnBodyClass'      => __( 'The destination is a protected page (%s), so it loads normally.', 'ajax-loading' ),
			/* translators: %s: integration key. */
			'warnIntegrationExcluded' => __( 'The destination contains content of the "%s" integration, which is set to "Exclude (full page load)", so it loads normally.', 'ajax-loading' ),
			'warnTracked'        => __( 'Assets marked with data-ajax-loading-track="reload" differ between the pages, so this navigation reloads.', 'ajax-loading' ),
			'warnPersonalized'   => __( 'The destination is personalised for you (logged in, cart or comment cookies). It is never prefetched or cached.', 'ajax-loading' ),
			'warnVisibility'     => __( 'Test mode is on: visitors do not get AJAX navigation yet.', 'ajax-loading' ),
			'noWarnings'         => __( 'Nothing forces a normal page load.', 'ajax-loading' ),
			'testPassed'         => __( 'This navigation will use AJAX.', 'ajax-loading' ),
			'testFailed'         => __( 'This navigation will fall back to a normal page load.', 'ajax-loading' ),
			'asVisitorNote'      => __( 'Pages are fetched with your logged-in session; visitors may see slightly different markup.', 'ajax-loading' ),
			'colPage'            => __( 'Page', 'ajax-loading' ),
			'colContent'         => __( 'Content area', 'ajax-loading' ),
			'colHeader'          => __( 'Header', 'ajax-loading' ),
			'colFooter'          => __( 'Footer', 'ajax-loading' ),
			'colMarker'          => __( 'Marker', 'ajax-loading' ),
			/* translators: %s: page name. */
			'colFromFirst'       => __( 'Navigation from %s', 'ajax-loading' ),
			'notFound'           => __( 'Not found', 'ajax-loading' ),
			'markerShortEnabled' => __( 'Active', 'ajax-loading' ),
			'markerShortBypass'  => __( 'Excluded', 'ajax-loading' ),
			'markerShortMissing' => __( 'Missing', 'ajax-loading' ),
			/* translators: 1: CSS selector, 2: number of matches. */
			'selectorsCustom'    => __( 'Custom selector %1$s: %2$s', 'ajax-loading' ),
			/* translators: %s: number of matches. */
			'matchCount'         => __( '%s match(es)', 'ajax-loading' ),
			'sameAsFirst'        => __( 'Start page', 'ajax-loading' ),
			'noSamples'          => __( 'No sample pages are available.', 'ajax-loading' ),
			'saved'              => __( 'Results saved. They appear on the Overview tab.', 'ajax-loading' ),
			/* translators: %s: error message. */
			'saveFailed'         => __( 'The results could not be saved: %s', 'ajax-loading' ),

			// Environment and log.
			'envEmpty'           => __( 'No environment information is available.', 'ajax-loading' ),
			'envRefreshed'       => __( 'Environment report refreshed.', 'ajax-loading' ),
			/* translators: 1: date and time, 2: result summary. */
			'lastClientRun'      => __( 'Last compatibility check: %1$s (%2$s)', 'ajax-loading' ),
			'clientOk'           => __( 'no problems found', 'ajax-loading' ),
			'clientIssues'       => __( 'issues found', 'ajax-loading' ),
			'logEmpty'           => __( 'No navigation errors recorded.', 'ajax-loading' ),
			'logRefreshed'       => __( 'Recent errors refreshed.', 'ajax-loading' ),
			'logCleared'         => __( 'Recent errors cleared.', 'ajax-loading' ),
			'confirmClearLog'    => __( 'Delete all recorded navigation errors?', 'ajax-loading' ),
		);
	}
}

if ( ! class_exists( 'WP_ajax_loading_Admin', false ) ) {
	class_alias( 'WPAJXL_Admin', 'WP_ajax_loading_Admin' );
}