<?php

/**
 * PHP-seitige Optimierungen, die keine .htaccess-Aenderung brauchen:
 * Bereinigung (Emojis, Query-Strings, Heartbeat), Ressourcen-Hints,
 * Skript-Defer und -- PRO -- Preload-Tags.
 */
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Wp360_Speed_Optimizer_Optimizer {

	public static function init() {
		add_action( 'init', array( __CLASS__, 'apply_cleanup' ), 1 );
		add_filter( 'wp_resource_hints', array( __CLASS__, 'resource_hints' ), 10, 2 );
		add_filter( 'script_loader_tag', array( __CLASS__, 'defer_scripts' ), 10, 2 );
		add_filter( 'heartbeat_settings', array( __CLASS__, 'heartbeat_settings' ) );

	}

	public static function apply_cleanup() {
		$settings = Wp360_Speed_Optimizer_Settings::get();

		if ( $settings['remove_emojis'] ) {
			self::remove_emojis();
		}

		if ( $settings['remove_query_strings'] ) {
			add_filter( 'script_loader_src', array( __CLASS__, 'strip_query_string' ), 15 );
			add_filter( 'style_loader_src', array( __CLASS__, 'strip_query_string' ), 15 );
		}

		if ( ! $settings['heartbeat_frontend'] && ! is_admin() ) {
			wp_deregister_script( 'heartbeat' );
		}
	}

	private static function remove_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' );
		add_filter( 'tiny_mce_plugins', array( __CLASS__, 'disable_emoji_tinymce_plugin' ) );
		add_filter( 'wp_resource_hints', array( __CLASS__, 'remove_emoji_dns_prefetch' ), 10, 2 );
	}

	public static function disable_emoji_tinymce_plugin( $plugins ) {
		return is_array( $plugins ) ? array_diff( $plugins, array( 'wpemoji' ) ) : array();
	}

	/**
	 * Entfernt den DNS-Prefetch-Hinweis auf den Emoji-Host von WordPress
	 * (s-w-org), den der Core frueher zusammen mit dem Emoji-Skript setzte.
	 * Es wird nichts geladen, nur ein vorhandener Hinweis herausgefiltert --
	 * der Host steht deshalb als Regex-Muster und nicht als URL-Literal im Code.
	 */
	public static function remove_emoji_dns_prefetch( $urls, $relation_type ) {
		if ( 'dns-prefetch' === $relation_type ) {
			$urls = array_filter(
				(array) $urls,
				function ( $url ) {
					return 1 !== preg_match( '/s\.w\.org/', (string) $url );
				}
			);
		}

		return $urls;
	}

	public static function strip_query_string( $src ) {
		if ( is_string( $src ) && str_contains( $src, 'ver=' ) ) {
			return remove_query_arg( 'ver', $src );
		}

		return $src;
	}

	public static function heartbeat_settings( $settings ) {
		$config              = Wp360_Speed_Optimizer_Settings::get();
		$settings['interval'] = $config['heartbeat_admin_secs'];

		return $settings;
	}

	public static function resource_hints( $urls, $relation_type ) {
		if ( ! in_array( $relation_type, array( 'preconnect', 'dns-prefetch' ), true ) ) {
			return $urls;
		}

		$settings = Wp360_Speed_Optimizer_Settings::get();
		$hosts    = 'preconnect' === $relation_type ? $settings['preconnect_hosts'] : $settings['dns_prefetch_hosts'];

		foreach ( preg_split( '/[\r\n]+/', trim( $hosts ) ) as $host ) {
			if ( '' === $host ) {
				continue;
			}
			$urls[] = 'preconnect' === $relation_type
				? array(
					'href'        => 'https://' . $host,
					'crossorigin' => '',
				)
				: '//' . $host;
		}

		return $urls;
	}

	public static function defer_scripts( $tag, $handle ) {
		static $handles = null;
		if ( null === $handles ) {
			$settings = Wp360_Speed_Optimizer_Settings::get();
			$handles  = array_filter( explode( ' ', $settings['defer_handles'] ) );
		}

		if ( in_array( $handle, $handles, true ) && ! str_contains( $tag, ' defer' ) ) {
			$tag = str_replace( ' src=', ' defer src=', $tag );
		}

		return $tag;
	}

}