<?php
/**
 * Keeps the Stand widget out of script optimizers.
 *
 * @package StandChat
 */

namespace StandChat;

defined( 'ABSPATH' ) || exit;

/**
 * Optimizer exclusions.
 *
 * Combining, minifying, delaying or deferring the widget breaks it: it loads
 * its interface relative to its own script address, and the inline
 * configuration must run before it. The script tags also carry attributes that
 * optimizers honor (data-cfasync, data-no-optimize, data-no-defer, nowprocket);
 * these filters cover the rest. Filters of plugins that aren't installed never
 * run.
 */
final class Optimizers {

	/**
	 * Keywords that identify the widget and its configuration.
	 */
	const KEYWORDS = array( 'cdn.stand.chat/widget', 'widget/stand.js', 'StandChatConfig', 'StandChatWordPress', 'stand-chat/build/frontend.js' );

	/**
	 * Hooks.
	 */
	public function register(): void {
		// WP Rocket: Delay JavaScript execution, minify/combine, and Load JavaScript deferred.
		add_filter( 'rocket_delay_js_exclusions', array( $this, 'add_keywords' ) );
		add_filter( 'rocket_exclude_js', array( $this, 'add_keywords' ) );
		add_filter( 'rocket_exclude_inline_js', array( $this, 'add_keywords' ) );
		add_filter( 'rocket_exclude_defer_js', array( $this, 'add_keywords' ) );

		// Autoptimize: comma-separated exclusion string.
		add_filter( 'autoptimize_filter_js_exclude', array( $this, 'autoptimize' ) );

		// LiteSpeed Cache: JS minify/combine and defer/delay exclusions.
		add_filter( 'litespeed_optimize_js_excludes', array( $this, 'add_keywords' ) );
		add_filter( 'litespeed_optm_js_defer_exc', array( $this, 'add_keywords' ) );

		// SiteGround Speed Optimizer works with script handles.
		add_filter( 'sgo_javascript_combine_exclude', array( $this, 'add_handles' ) );
		add_filter( 'sgo_js_minify_exclude', array( $this, 'add_handles' ) );
		add_filter( 'sgo_js_async_exclude', array( $this, 'add_handles' ) );
		add_filter( 'sgo_javascript_combine_excluded_inline_content', array( $this, 'add_keywords' ) );
	}

	/**
	 * Adds the widget keywords to an exclusion list.
	 *
	 * @param mixed $exclusions Existing exclusions.
	 * @return array<int, string>
	 */
	public function add_keywords( $exclusions ) {
		$exclusions = is_array( $exclusions ) ? $exclusions : array();
		return array_values( array_unique( array_merge( $exclusions, self::KEYWORDS ) ) );
	}

	/**
	 * Adds the widget's script handles to an exclusion list.
	 *
	 * @param mixed $handles Existing handles.
	 * @return array<int, string>
	 */
	public function add_handles( $handles ) {
		$handles = is_array( $handles ) ? $handles : array();
		return array_values( array_unique( array_merge( $handles, array( Frontend::WIDGET_HANDLE, Frontend::HELPER_HANDLE ) ) ) );
	}

	/**
	 * Autoptimize's comma-separated exclusions.
	 *
	 * @param mixed $exclusions Existing exclusions.
	 */
	public function autoptimize( $exclusions ): string {
		$exclusions = is_string( $exclusions ) ? $exclusions : '';
		$items      = array_filter( array_map( 'trim', explode( ',', $exclusions ) ) );
		return implode( ', ', array_unique( array_merge( $items, self::KEYWORDS ) ) );
	}

	/**
	 * Optimizers detected on this site, for the Chat widget screen and support.
	 *
	 * @return array<int, array{name: string, handled: bool}>
	 */
	public static function detected(): array {
		$found  = array();
		$checks = array(
			'WP Rocket'            => defined( 'WP_ROCKET_VERSION' ),
			'Autoptimize'          => defined( 'AUTOPTIMIZE_PLUGIN_VERSION' ),
			'LiteSpeed Cache'      => defined( 'LSCWP_V' ),
			'SiteGround Optimizer' => defined( 'SiteGround_Optimizer\VERSION' ),
			'W3 Total Cache'       => defined( 'W3TC' ),
			'Perfmatters'          => defined( 'PERFMATTERS_VERSION' ),
			'WP Fastest Cache'     => class_exists( 'WpFastestCache' ),
			'Jetpack Boost'        => defined( 'JETPACK_BOOST_VERSION' ),
		);
		foreach ( $checks as $name => $active ) {
			if ( $active ) {
				$found[] = array(
					'name'    => $name,
					'handled' => in_array( $name, array( 'WP Rocket', 'Autoptimize', 'LiteSpeed Cache', 'SiteGround Optimizer' ), true ),
				);
			}
		}
		return $found;
	}
}