roi-theme/wp-content/themes/apus-theme/inc/performance.php

<?php
/**
 * Performance Optimization Functions
 *
 * Functions to remove WordPress bloat and improve performance.
 *
 * NOTA: Versión reducida con solo optimizaciones seguras después de
 * resolver problemas de memory exhaustion en Issue #22.
 *
 * @package Apus_Theme
 * @since 1.0.0
 */

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Disable WordPress Emojis
 *
 * Removes emoji detection scripts and styles from WordPress.
 * These scripts are loaded on every page but rarely used.
 *
 * @since 1.0.0
 */
function apus_disable_emojis() {
	remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
	remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
	remove_action( 'wp_print_styles', 'print_emoji_styles' );
	remove_action( 'admin_print_styles', 'print_emoji_styles' );
	remove_filter( 'the_content_feed', 'wp_staticize_emoji' );
	remove_filter( 'comment_text_rss', 'wp_staticize_emoji' );
	remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' );

	// Remove from TinyMCE.
	add_filter( 'tiny_mce_plugins', 'apus_disable_emojis_tinymce' );
}
add_action( 'init', 'apus_disable_emojis' );

/**
 * Filter function used to remove emoji plugin from TinyMCE
 *
 * @since 1.0.0
 * @param array $plugins An array of default TinyMCE plugins.
 * @return array Modified array of TinyMCE plugins without emoji plugin.
 */
function apus_disable_emojis_tinymce( $plugins ) {
	if ( is_array( $plugins ) ) {
		return array_diff( $plugins, array( 'wpemoji' ) );
	}

	return array();
}

/**
 * Disable WordPress oEmbed
 *
 * Removes oEmbed discovery links and scripts.
 * Only disable if you don't need to embed content from other sites.
 *
 * @since 1.0.0
 */
function apus_disable_oembed() {
	// Remove oEmbed discovery links.
	remove_action( 'wp_head', 'wp_oembed_add_discovery_links' );

	// Remove oEmbed-specific JavaScript from the front-end and back-end.
	remove_action( 'wp_head', 'wp_oembed_add_host_js' );

	// Remove all embeds rewrite rules.
	add_filter( 'rewrite_rules_array', 'apus_disable_oembed_rewrites' );

	// Remove filter of the oEmbed result before any HTTP requests are made.
	remove_filter( 'pre_oembed_result', 'wp_filter_pre_oembed_result', 10 );
}
add_action( 'init', 'apus_disable_oembed', 9999 );

/**
 * Remove all rewrite rules related to embeds
 *
 * @since 1.0.0
 * @param array $rules WordPress rewrite rules.
 * @return array Modified rewrite rules.
 */
function apus_disable_oembed_rewrites( $rules ) {
	foreach ( $rules as $rule => $rewrite ) {
		if ( false !== strpos( $rewrite, 'embed=true' ) ) {
			unset( $rules[ $rule ] );
		}
	}
	return $rules;
}

/**
 * Disable wp-embed.js script
 *
 * Dequeues the wp-embed.js script that WordPress loads by default.
 * This script is used for embedding WordPress posts on other sites.
 *
 * @since 1.0.0
 */
function apus_dequeue_embed_script() {
	wp_deregister_script( 'wp-embed' );
}
add_action( 'wp_footer', 'apus_dequeue_embed_script' );

/**
 * Disable WordPress Feeds
 *
 * Removes RSS, RDF, and Atom feeds.
 * Only disable if you don't need feed functionality.
 *
 * @since 1.0.0
 */
function apus_disable_feeds() {
	wp_die(
		esc_html__( 'No feed available, please visit our homepage!', 'apus' ),
		esc_html__( 'Feed Not Available', 'apus' ),
		array(
			'response'  => 404,
			'back_link' => true,
		)
	);
}

/**
 * Remove feed links and redirect feed URLs
 *
 * @since 1.0.0
 */
function apus_disable_feed_links() {
	// Remove feed links from header.
	remove_action( 'wp_head', 'feed_links', 2 );
	remove_action( 'wp_head', 'feed_links_extra', 3 );

	// Redirect feed URLs to homepage.
	add_action( 'do_feed', 'apus_disable_feeds', 1 );
	add_action( 'do_feed_rdf', 'apus_disable_feeds', 1 );
	add_action( 'do_feed_rss', 'apus_disable_feeds', 1 );
	add_action( 'do_feed_rss2', 'apus_disable_feeds', 1 );
	add_action( 'do_feed_atom', 'apus_disable_feeds', 1 );
	add_action( 'do_feed_rss2_comments', 'apus_disable_feeds', 1 );
	add_action( 'do_feed_atom_comments', 'apus_disable_feeds', 1 );
}
add_action( 'init', 'apus_disable_feed_links' );

/**
 * Disable RSD and Windows Live Writer Manifest
 *
 * Really Simple Discovery (RSD) and Windows Live Writer (WLW) manifest
 * are rarely used and can be safely removed.
 *
 * @since 1.0.0
 */
function apus_disable_rsd_wlw() {
	// Remove RSD link.
	remove_action( 'wp_head', 'rsd_link' );

	// Remove Windows Live Writer manifest link.
	remove_action( 'wp_head', 'wlwmanifest_link' );
}
add_action( 'init', 'apus_disable_rsd_wlw' );

/**
 * Disable Dashicons for non-logged users
 *
 * Dashicons are only needed in the admin area and for logged-in users.
 * This removes them from the front-end for visitors.
 *
 * @since 1.0.0
 */
function apus_disable_dashicons() {
	if ( ! is_user_logged_in() ) {
		wp_deregister_style( 'dashicons' );
	}
}
add_action( 'wp_enqueue_scripts', 'apus_disable_dashicons' );

/**
 * Disable Block Library CSS
 *
 * Removes the default WordPress block library styles.
 * Only disable if you're not using the block editor or if you're
 * providing your own block styles.
 *
 * @since 1.0.0
 */
function apus_disable_block_library_css() {
	// Remove default block library styles.
	wp_dequeue_style( 'wp-block-library' );
	wp_dequeue_style( 'wp-block-library-theme' );

	// Remove inline global styles.
	wp_dequeue_style( 'global-styles' );

	// Remove classic theme styles (if not using classic editor).
	wp_dequeue_style( 'classic-theme-styles' );
}
add_action( 'wp_enqueue_scripts', 'apus_disable_block_library_css', 100 );

/**
 * Remove WordPress version from head and feeds
 *
 * Removes the WordPress version number for security reasons.
 *
 * @since 1.0.0
 */
function apus_remove_wp_version() {
	return '';
}
add_filter( 'the_generator', 'apus_remove_wp_version' );

/**
 * Disable XML-RPC
 *
 * XML-RPC is often targeted by brute force attacks.
 * Disable if you don't need remote publishing functionality.
 *
 * @since 1.0.0
 * @return bool
 */
function apus_disable_xmlrpc() {
	return false;
}
add_filter( 'xmlrpc_enabled', 'apus_disable_xmlrpc' );

/**
 * Remove jQuery Migrate
 *
 * jQuery Migrate is used for backwards compatibility but adds extra overhead.
 * Only remove if you've verified all scripts work without it.
 *
 * @since 1.0.0
 * @param WP_Scripts $scripts WP_Scripts object.
 */
function apus_remove_jquery_migrate( $scripts ) {
	if ( ! is_admin() && isset( $scripts->registered['jquery'] ) ) {
		$script = $scripts->registered['jquery'];

		if ( $script->deps ) {
			// Remove jquery-migrate from dependencies.
			$script->deps = array_diff( $script->deps, array( 'jquery-migrate' ) );
		}
	}
}
add_action( 'wp_default_scripts', 'apus_remove_jquery_migrate' );

/**
 * Optimize WordPress Database Queries
 *
 * Removes unnecessary meta queries for better performance.
 *
 * @since 1.0.0
 */
function apus_optimize_queries() {
	// Remove unnecessary post meta from queries
	remove_action( 'wp_head', 'adjacent_posts_rel_link_wp_head', 10 );
	remove_action( 'wp_head', 'wp_shortlink_wp_head', 10 );
}
add_action( 'init', 'apus_optimize_queries' );

/**
 * Disable WordPress Admin Bar for Non-Admins
 *
 * Reduces HTTP requests for non-admin users.
 *
 * @since 1.0.0
 */
function apus_disable_admin_bar() {
	if ( ! current_user_can( 'administrator' ) && ! is_admin() ) {
		show_admin_bar( false );
	}
}
add_action( 'after_setup_theme', 'apus_disable_admin_bar' );

/**
 * ============================================================================
 * RESOURCE HINTS: DNS PREFETCH, PRECONNECT, PRELOAD
 * ============================================================================
 */

/**
 * Agregar DNS Prefetch y Preconnect para recursos externos
 *
 * DNS Prefetch: Resuelve DNS antes de que se necesite el recurso
 * Preconnect: Establece conexión completa (DNS + TCP + TLS) por anticipado
 *
 * @since 1.0.0
 * @param array  $urls          Array of resource URLs.
 * @param string $relation_type The relation type (dns-prefetch, preconnect, etc.).
 * @return array Modified array of resource URLs.
 */
function apus_add_resource_hints( $urls, $relation_type ) {
	// DNS Prefetch para recursos externos que no son críticos
	if ( 'dns-prefetch' === $relation_type ) {
		// CDN de Bootstrap Icons (ya usado en enqueue-scripts.php)
		$urls[] = 'https://cdn.jsdelivr.net';

		// Google Analytics (si se usa)
		$urls[] = 'https://www.google-analytics.com';
		$urls[] = 'https://www.googletagmanager.com';

		// Google AdSense (si se usa)
		$urls[] = 'https://pagead2.googlesyndication.com';
		$urls[] = 'https://adservice.google.com';
		$urls[] = 'https://googleads.g.doubleclick.net';
	}

	// Preconnect para recursos críticos externos
	if ( 'preconnect' === $relation_type ) {
		// CDN de Bootstrap Icons - recurso crítico usado en el header
		$urls[] = array(
			'href'        => 'https://cdn.jsdelivr.net',
			'crossorigin' => 'anonymous',
		);
	}

	return $urls;
}
add_filter( 'wp_resource_hints', 'apus_add_resource_hints', 10, 2 );

/**
 * Preload de recursos críticos para mejorar LCP
 *
 * Preload indica al navegador que descargue recursos críticos lo antes posible.
 * Útil para fuentes, CSS crítico, y imágenes hero.
 *
 * @since 1.0.0
 */
function apus_preload_critical_resources() {
	// Preload de fuentes críticas
	$fonts = array(
		'inter-var.woff2',
		'inter-var-italic.woff2',
	);

	foreach ( $fonts as $font ) {
		$font_url = get_template_directory_uri() . '/assets/fonts/' . $font;
		printf(
			'<link rel="preload" href="%s" as="font" type="font/woff2" crossorigin="anonymous">' . "\n",
			esc_url( $font_url )
		);
	}

	// Preload del CSS de Bootstrap (crítico para el layout)
	$bootstrap_css = get_template_directory_uri() . '/assets/vendor/bootstrap/css/bootstrap.min.css';
	printf(
		'<link rel="preload" href="%s" as="style">' . "\n",
		esc_url( $bootstrap_css )
	);

	// Preload del CSS de fuentes (crítico para evitar FOIT/FOUT)
	$fonts_css = get_template_directory_uri() . '/assets/css/fonts.css';
	printf(
		'<link rel="preload" href="%s" as="style">' . "\n",
		esc_url( $fonts_css )
	);
}
add_action( 'wp_head', 'apus_preload_critical_resources', 2 );

/**
 * ============================================================================
 * OPTIMIZACIÓN DE SCRIPTS Y ESTILOS
 * ============================================================================
 */

/**
 * Agregar atributos async/defer a scripts específicos
 *
 * Los scripts con defer se descargan en paralelo pero se ejecutan en orden
 * después de que el DOM esté listo.
 *
 * @since 1.0.0
 * @param string $tag    The script tag.
 * @param string $handle The script handle.
 * @return string Modified script tag.
 */
function apus_add_script_attributes( $tag, $handle ) {
	// Scripts que deben tener async (no dependen de otros ni del DOM)
	$async_scripts = array(
		// Google Analytics u otros scripts de tracking
		'google-analytics',
		'gtag',
	);

	// Scripts que ya tienen defer via strategy en wp_enqueue_script
	// No necesitamos modificarlos aquí ya que WordPress 6.3+ lo maneja

	if ( in_array( $handle, $async_scripts, true ) ) {
		// Agregar async solo si no tiene defer
		if ( false === strpos( $tag, 'defer' ) ) {
			$tag = str_replace( ' src', ' async src', $tag );
		}
	}

	return $tag;
}
add_filter( 'script_loader_tag', 'apus_add_script_attributes', 10, 2 );

/**
 * Remover query strings de assets estáticos para mejorar caching
 *
 * Algunos proxies y CDNs no cachean recursos con query strings.
 * WordPress agrega ?ver= por defecto.
 *
 * @since 1.0.0
 * @param string $src The source URL.
 * @return string Modified source URL without query strings.
 */
function apus_remove_query_strings_from_static_resources( $src ) {
	// Solo remover de nuestros propios assets
	if ( strpos( $src, get_template_directory_uri() ) !== false ) {
		$src = remove_query_arg( 'ver', $src );
	}

	return $src;
}
add_filter( 'style_loader_src', 'apus_remove_query_strings_from_static_resources', 10, 1 );
add_filter( 'script_loader_src', 'apus_remove_query_strings_from_static_resources', 10, 1 );

/**
 * Optimizar el Heartbeat API de WordPress
 *
 * El Heartbeat API hace llamadas AJAX periódicas que pueden afectar el rendimiento.
 * Lo desactivamos en el frontend y lo ralentizamos en el admin.
 *
 * @since 1.0.0
 */
function apus_optimize_heartbeat() {
	// Desactivar completamente en el frontend
	if ( ! is_admin() ) {
		wp_deregister_script( 'heartbeat' );
	}
}
add_action( 'init', 'apus_optimize_heartbeat', 1 );

/**
 * Modificar configuración del Heartbeat en admin
 *
 * @since 1.0.0
 * @param array $settings Heartbeat settings.
 * @return array Modified settings.
 */
function apus_modify_heartbeat_settings( $settings ) {
	// Cambiar intervalo de 15 segundos (default) a 60 segundos
	$settings['interval'] = 60;
	return $settings;
}
add_filter( 'heartbeat_settings', 'apus_modify_heartbeat_settings' );

/**
 * ============================================================================
 * OPTIMIZACIÓN DE BASE DE DATOS Y QUERIES
 * ============================================================================
 */

/**
 * Limitar revisiones de posts para reducir tamaño de BD
 *
 * Esto se debe configurar en wp-config.php, pero lo documentamos aquí:
 * define('WP_POST_REVISIONS', 5);
 *
 * @since 1.0.0
 */

/**
 * Optimizar WP_Query para posts relacionados y listados
 *
 * @since 1.0.0
 * @param WP_Query $query The WP_Query instance.
 */
function apus_optimize_main_query( $query ) {
	// Solo en queries principales en el frontend
	if ( is_admin() || ! $query->is_main_query() ) {
		return;
	}

	// En archivos, limitar posts por página para mejorar rendimiento
	if ( $query->is_archive() || $query->is_home() ) {
		// No cargar meta innecesaria
		$query->set( 'update_post_meta_cache', true );
		$query->set( 'update_post_term_cache', true );

		// Limitar posts por página si no está configurado
		if ( ! $query->get( 'posts_per_page' ) ) {
			$query->set( 'posts_per_page', 12 );
		}
	}
}
add_action( 'pre_get_posts', 'apus_optimize_main_query' );

/**
 * Deshabilitar self-pingbacks
 *
 * Los self-pingbacks ocurren cuando un post enlaza a otro post del mismo sitio.
 * Son innecesarios y generan queries adicionales.
 *
 * @since 1.0.0
 * @param array $links An array of post links to ping.
 * @return array Modified array without self-pings.
 */
function apus_disable_self_pingbacks( &$links ) {
	$home = get_option( 'home' );
	foreach ( $links as $l => $link ) {
		if ( 0 === strpos( $link, $home ) ) {
			unset( $links[ $l ] );
		}
	}
}
add_action( 'pre_ping', 'apus_disable_self_pingbacks' );

/**
 * ============================================================================
 * OPTIMIZACIÓN DE RENDER Y LAYOUT
 * ============================================================================
 */

/**
 * Agregar display=swap a Google Fonts para evitar FOIT
 *
 * Ya no usamos Google Fonts (fuentes locales), pero dejamos la función
 * por si se necesita en el futuro.
 *
 * @since 1.0.0
 * @param string $src The source URL.
 * @return string Modified source URL.
 */
function apus_add_font_display_swap( $src ) {
	if ( strpos( $src, 'fonts.googleapis.com' ) !== false ) {
		$src = add_query_arg( 'display', 'swap', $src );
	}
	return $src;
}
add_filter( 'style_loader_src', 'apus_add_font_display_swap' );

/**
 * Agregar width y height a imágenes para prevenir CLS
 *
 * WordPress 5.5+ agrega automáticamente width/height, pero aseguramos que esté activo.
 *
 * @since 1.0.0
 * @return bool
 */
function apus_enable_image_dimensions() {
	return true;
}
add_filter( 'wp_lazy_loading_enabled', 'apus_enable_image_dimensions' );

/**
 * Optimizar buffer de salida HTML
 *
 * Habilita compresión GZIP si está disponible y no está ya habilitada.
 *
 * @since 1.0.0
 */
function apus_enable_gzip_compression() {
	// Solo en frontend
	if ( is_admin() ) {
		return;
	}

	// Verificar si GZIP ya está habilitado
	if ( ! ini_get( 'zlib.output_compression' ) && 'ob_gzhandler' !== ini_get( 'output_handler' ) ) {
		// Verificar si la extensión está disponible
		if ( function_exists( 'gzencode' ) && extension_loaded( 'zlib' ) ) {
			// Verificar headers
			if ( ! headers_sent() ) {
				// Habilitar compresión
				ini_set( 'zlib.output_compression', 'On' );
				ini_set( 'zlib.output_compression_level', '6' ); // Balance entre compresión y CPU
			}
		}
	}
}
add_action( 'template_redirect', 'apus_enable_gzip_compression', 0 );

/**
 * ============================================================================
 * FUNCIONES AUXILIARES
 * ============================================================================
 */

/**
 * Limpiar caché de transients expirados periódicamente
 *
 * Los transients expirados se acumulan en la base de datos.
 *
 * @since 1.0.0
 */
function apus_cleanup_expired_transients() {
	global $wpdb;

	// Eliminar transients expirados (solo los del tema)
	$wpdb->query(
		$wpdb->prepare(
			"DELETE FROM {$wpdb->options} WHERE option_name LIKE %s AND option_value < %d",
			$wpdb->esc_like( '_transient_timeout_apus_' ) . '%',
			time()
		)
	);
}
// Ejecutar limpieza semanalmente
add_action( 'apus_weekly_cleanup', 'apus_cleanup_expired_transients' );

// Registrar evento cron si no existe
if ( ! wp_next_scheduled( 'apus_weekly_cleanup' ) ) {
	wp_schedule_event( time(), 'weekly', 'apus_weekly_cleanup' );
}

/*
 * NOTA: Funciones previamente deshabilitadas han sido reimplementadas
 * con mejoras para evitar loops infinitos y problemas de memoria.
 *
 * - Resource hints (dns-prefetch, preconnect) - REACTIVADO
 * - Preload de recursos críticos - REACTIVADO
 * - Optimización del Heartbeat API - REACTIVADO
 * - Remoción de query strings - REACTIVADO (solo para assets propios)
 * - Script attributes (defer/async) - REACTIVADO
 */