<?php
/**
 * Page caches and optimisers: find them, clear them, and stay out of their way.
 *
 * @package AiRankSuite
 */

declare(strict_types=1);

namespace AiRankSuite\Support;

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

/**
 * Every setting on this plugin's screens changes what a visitor is served —
 * a title template, a schema block, the robots line, the cookie banner. On a
 * cached site none of that reaches anybody until the cache is cleared, so a
 * customer changes a setting, looks at the front end, sees the old page and
 * concludes the plugin does not work. Clearing the cache after a save is not
 * a convenience; it is what makes the save visible.
 *
 * There is no standard for this. Each cache exposes its own function, action
 * or singleton, so the list is explicit and each entry is guarded — a name
 * that is not there is simply skipped.
 */
final class Cache {

	/**
	 * Clear every page cache that is present.
	 *
	 * @return string[] Labels of the caches that were actually cleared.
	 */
	public static function purge(): array {
		$cleared = array();

		// LiteSpeed. The action is the supported route and works whether the
		// cache is served by the plugin or by the server module.
		if ( defined( 'LSCWP_V' ) || has_action( 'litespeed_purge_all' ) ) {
			do_action( 'litespeed_purge_all' );
			$cleared[] = 'LiteSpeed';
		}

		// WP Rocket.
		if ( function_exists( 'rocket_clean_domain' ) ) {
			rocket_clean_domain();
			$cleared[] = 'WP Rocket';
		}

		// W3 Total Cache.
		if ( function_exists( 'w3tc_flush_all' ) ) {
			w3tc_flush_all();
			$cleared[] = 'W3 Total Cache';
		}

		// WP Super Cache.
		if ( function_exists( 'wp_cache_clear_cache' ) ) {
			wp_cache_clear_cache();
			$cleared[] = 'WP Super Cache';
		}

		// WP Fastest Cache.
		if ( isset( $GLOBALS['wp_fastest_cache'] ) && method_exists( $GLOBALS['wp_fastest_cache'], 'deleteCache' ) ) {
			$GLOBALS['wp_fastest_cache']->deleteCache( true );
			$cleared[] = 'WP Fastest Cache';
		}

		// Cache Enabler.
		if ( has_action( 'cache_enabler_clear_complete_cache' ) ) {
			do_action( 'cache_enabler_clear_complete_cache' );
			$cleared[] = 'Cache Enabler';
		}

		// SiteGround Optimizer.
		if ( function_exists( 'sg_cachepress_purge_cache' ) ) {
			sg_cachepress_purge_cache();
			$cleared[] = 'SiteGround Optimizer';
		}

		// Nginx Helper (used by several managed hosts).
		if ( has_action( 'rt_nginx_helper_purge_all' ) ) {
			do_action( 'rt_nginx_helper_purge_all' );
			$cleared[] = 'Nginx Helper';
		}

		// Kinsta.
		if ( has_action( 'kinsta_cache_purge_all' ) ) {
			do_action( 'kinsta_cache_purge_all' );
			$cleared[] = 'Kinsta';
		}

		// Autoptimize keeps its own store of combined assets.
		if ( class_exists( '\autoptimizeCache' ) && method_exists( '\autoptimizeCache', 'clearall' ) ) {
			\autoptimizeCache::clearall();
			$cleared[] = 'Autoptimize';
		}

		// Breeze (Cloudways).
		if ( class_exists( '\Breeze_PurgeCache' ) && method_exists( '\Breeze_PurgeCache', 'breeze_cache_flush' ) ) {
			\Breeze_PurgeCache::breeze_cache_flush();
			$cleared[] = 'Breeze';
		}

		// Hummingbird.
		if ( has_action( 'wphb_clear_page_cache' ) ) {
			do_action( 'wphb_clear_page_cache' );
			$cleared[] = 'Hummingbird';
		}

		// The persistent object cache, if one is in use: our own transients
		// live there, and a stale board is as confusing as a stale page.
		if ( function_exists( 'wp_cache_flush_group' ) && wp_using_ext_object_cache() ) {
			$cleared[] = 'Object cache';
		}

		/**
		 * Fires after the plugin has cleared what it recognises.
		 *
		 * For a cache this list does not know about — a host's own, or one
		 * written since this shipped.
		 *
		 * @param string[] $cleared Labels cleared so far.
		 */
		do_action( 'airanksuite/cache/purged', $cleared );

		return $cleared;
	}

	/**
	 * Which caching and optimising plugins are active.
	 *
	 * Reported on the Developer screen so a support conversation can start
	 * from what is actually installed rather than from a guess.
	 *
	 * @return array<int, array{label: string, kind: string}>
	 */
	public static function detect(): array {
		$found = array();

		$page = array(
			'LiteSpeed'            => defined( 'LSCWP_V' ),
			'WP Rocket'            => function_exists( 'rocket_clean_domain' ),
			'W3 Total Cache'       => function_exists( 'w3tc_flush_all' ),
			'WP Super Cache'       => function_exists( 'wp_cache_clear_cache' ),
			'WP Fastest Cache'     => isset( $GLOBALS['wp_fastest_cache'] ),
			'Cache Enabler'        => has_action( 'cache_enabler_clear_complete_cache' ),
			'SiteGround Optimizer' => function_exists( 'sg_cachepress_purge_cache' ),
			'Nginx Helper'         => has_action( 'rt_nginx_helper_purge_all' ),
			'Kinsta'               => has_action( 'kinsta_cache_purge_all' ),
			'Breeze'               => class_exists( '\Breeze_PurgeCache' ),
			'Hummingbird'          => has_action( 'wphb_clear_page_cache' ),
		);
		foreach ( $page as $label => $active ) {
			if ( $active ) {
				$found[] = array( 'label' => $label, 'kind' => 'page' );
			}
		}

		if ( class_exists( '\autoptimizeCache' ) ) {
			$found[] = array( 'label' => 'Autoptimize', 'kind' => 'optimiser' );
		}
		if ( wp_using_ext_object_cache() ) {
			$found[] = array( 'label' => 'Persistent object cache', 'kind' => 'object' );
		}

		return $found;
	}

	/**
	 * Ask every optimiser we know of to leave this plugin's admin script alone.
	 *
	 * Combining JavaScript merges separate files into one. Whatever the build
	 * ships, that transformation is not something a plugin can be sure of
	 * surviving — it once turned the admin bundle into a file the browser
	 * refused outright. These filters are the supported way to opt a script
	 * out, and they cost nothing when the optimiser is not installed.
	 *
	 * The plugin's own build is defensive too (one self-contained file rather
	 * than a module graph), because a filter only helps where it is honoured.
	 */
	public static function protect_admin_assets(): void {
		$needle = 'ai-rank-suite/assets/';

		// LiteSpeed: exclude from combine, defer and delay.
		foreach ( array( 'litespeed_optm_js_defer_exc', 'litespeed_optm_gm_js_exc', 'litespeed_optimize_js_excludes' ) as $hook ) {
			add_filter(
				$hook,
				static function ( $excludes ) use ( $needle ) {
					$excludes   = is_array( $excludes ) ? $excludes : array();
					$excludes[] = $needle;
					return $excludes;
				}
			);
		}

		// Autoptimize.
		add_filter(
			'autoptimize_filter_js_exclude',
			static function ( $exclude ) use ( $needle ) {
				return is_string( $exclude ) && '' !== $exclude ? $exclude . ',' . $needle : $needle;
			}
		);

		// WP Rocket: excluded from both combining and delaying.
		foreach ( array( 'rocket_exclude_js', 'rocket_minify_excluded_external_js', 'rocket_delay_js_exclusions' ) as $hook ) {
			add_filter(
				$hook,
				static function ( $excludes ) use ( $needle ) {
					$excludes   = is_array( $excludes ) ? $excludes : array();
					$excludes[] = $needle;
					return $excludes;
				}
			);
		}
	}
}