<?php
/**
 * agent-toolbelt/purge-all-caches (spec §3.1).
 *
 * Clears the page cache (12 supported plugins, ported from the verified PBC 3.1
 * table — same guards, same try/catch isolation), the object cache, and expired
 * transients. OPcache is out of scope (research verdict): reported as skipped.
 */

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

if ( ! class_exists( 'ATB_Operation_Purge_All_Caches' ) ) {
    class ATB_Operation_Purge_All_Caches extends ATB_Operation
    {
        public function slug()
        {
            return 'purge-all-caches';
        }

        public function describe()
        {
            return array(
                'slug'        => $this->slug(),
                'risk'        => 'low',
                'summary'     => "Clears the site's server-side caches so visitors see current content: "
                    . 'the page cache (12 supported plugins), the object cache, and expired transients. '
                    . 'Call after content or configuration changes when stale output is suspected. '
                    . 'Dry-run lists which cache layers are detected without clearing anything.',
                'annotations' => array(
                    'destructive' => false,
                    'idempotent'  => true,
                ),
                'input_schema' => array(
                    'type'       => 'object',
                    'properties' => array(
                        'dry_run' => array(
                            'type'    => 'boolean',
                            'default' => false,
                        ),
                    ),
                ),
            );
        }

        public function dry_run( $atb_input )
        {
            return $this->build_output( false );
        }

        public function run( $atb_input )
        {
            return $this->build_output( true );
        }

        /**
         * Builds the common output for either a dry run or a real execution.
         * Every layer is evaluated the same way regardless of mode; only
         * $atb_execute decides whether purge calls actually fire.
         *
         * @param bool $atb_execute
         * @return array
         */
        protected function build_output( $atb_execute )
        {
            $atb_layers = array(
                $this->page_cache_layer( $atb_execute ),
                $this->object_cache_layer( $atb_execute ),
                $this->transients_layer( $atb_execute ),
                $this->opcache_layer(),
            );

            $atb_performed = false;
            foreach ( $atb_layers as $atb_layer ) {
                if ( ! empty( $atb_layer['purged'] ) ) {
                    $atb_performed = true;
                    break;
                }
            }

            return $this->output( $atb_performed, ! $atb_execute, array( 'layers' => $atb_layers ) );
        }

        /* --------------------------------------------------------------------
         * Layers
         * ------------------------------------------------------------------ */

        protected function page_cache_layer( $atb_execute )
        {
            $atb_plugin = self::detect_page_cache_plugin();

            if ( '' === $atb_plugin ) {
                return array(
                    'layer'    => 'page-cache',
                    'detected' => false,
                    'purged'   => false,
                    'reason'   => 'no supported page cache plugin detected',
                );
            }

            if ( ! $atb_execute ) {
                return array(
                    'layer'    => 'page-cache',
                    'detected' => true,
                    'purged'   => false,
                    'reason'   => 'detected: ' . $atb_plugin,
                );
            }

            try {
                $atb_purged = self::dispatch_page_cache_purge( $atb_plugin );
            } catch ( \Throwable $atb_e ) {
                // A misbehaving cache plugin must never break the caller.
                return array(
                    'layer'    => 'page-cache',
                    'detected' => true,
                    'purged'   => false,
                    'reason'   => 'purge failed: ' . $atb_plugin,
                );
            }

            return array(
                'layer'    => 'page-cache',
                'detected' => true,
                'purged'   => $atb_purged,
                'reason'   => $atb_purged ? ( 'purged: ' . $atb_plugin ) : ( 'purge function unavailable: ' . $atb_plugin ),
            );
        }

        protected function object_cache_layer( $atb_execute )
        {
            $atb_detected = function_exists( 'wp_using_ext_object_cache' ) && wp_using_ext_object_cache();

            if ( ! $atb_execute ) {
                return array(
                    'layer'    => 'object-cache',
                    'detected' => (bool) $atb_detected,
                    'purged'   => false,
                    'reason'   => $atb_detected ? 'external object cache detected' : 'no external object cache detected',
                );
            }

            $atb_purged = function_exists( 'wp_cache_flush' ) ? (bool) wp_cache_flush() : false;

            return array(
                'layer'    => 'object-cache',
                'detected' => (bool) $atb_detected,
                'purged'   => $atb_purged,
                'reason'   => $atb_purged ? 'flushed' : 'wp_cache_flush unavailable',
            );
        }

        protected function transients_layer( $atb_execute )
        {
            if ( ! $atb_execute ) {
                return array(
                    'layer'    => 'transients',
                    'detected' => true,
                    'purged'   => false,
                    'reason'   => 'would delete expired transients',
                );
            }

            if ( function_exists( 'delete_expired_transients' ) ) {
                delete_expired_transients();

                return array(
                    'layer'    => 'transients',
                    'detected' => true,
                    'purged'   => true,
                    'reason'   => 'expired transients deleted',
                );
            }

            return array(
                'layer'    => 'transients',
                'detected' => true,
                'purged'   => false,
                'reason'   => 'delete_expired_transients unavailable',
            );
        }

        protected function opcache_layer()
        {
            return array(
                'layer'    => 'opcache',
                'detected' => function_exists( 'opcache_reset' ),
                'purged'   => false,
                'reason'   => 'skipped',
            );
        }

        /* --------------------------------------------------------------------
         * Page-cache detection + dispatch — ported from
         * Prevent_Browser_Caching::get_active_page_cache_plugin() /
         * Prevent_Browser_Caching_Integrations::dispatch_purge(), verified
         * against current wp.org releases (v3.1-planning/03-research §2).
         * ------------------------------------------------------------------ */

        /**
         * Returns the display name of the first detected page-cache plugin, or
         * '' if none of the 12 supported plugins is active.
         *
         * @return string
         */
        public static function detect_page_cache_plugin()
        {
            $atb_known = array(
                'WP Rocket'            => defined( 'WP_ROCKET_VERSION' ),
                'LiteSpeed Cache'      => defined( 'LSCWP_V' ),
                'W3 Total Cache'       => defined( 'W3TC' ),
                'WP Super Cache'       => function_exists( 'wp_cache_serve_cache_file' ) || defined( 'WPCACHEHOME' ),
                'WP Fastest Cache'     => class_exists( 'WpFastestCache' ),
                'WP-Optimize'          => class_exists( 'WP_Optimize' ),
                'Breeze'               => defined( 'BREEZE_VERSION' ),
                'Cache Enabler'        => class_exists( 'Cache_Enabler' ),
                'Hummingbird'          => class_exists( 'Hummingbird\\WP_Hummingbird' ) || class_exists( 'WP_Hummingbird' ),
                'SiteGround Optimizer' => defined( 'SiteGround_Optimizer\\VERSION' ),
                'Swift Performance'    => class_exists( 'Swift_Performance' ) || class_exists( 'Swift_Performance_Lite' ),
                'Comet Cache'          => class_exists( 'comet_cache' ),
            );

            foreach ( $atb_known as $atb_name => $atb_active ) {
                if ( $atb_active ) {
                    return $atb_name;
                }
            }

            return '';
        }

        /**
         * Dispatches the verified purge call for a detected plugin name.
         *
         * @param string $atb_plugin
         * @return bool True when a purge call ran.
         */
        public static function dispatch_page_cache_purge( $atb_plugin )
        {
            switch ( $atb_plugin ) {
                case 'WP Rocket':
                    if ( function_exists( 'rocket_clean_domain' ) ) {
                        rocket_clean_domain();
                        return true;
                    }
                    break;

                case 'LiteSpeed Cache':
                    if ( has_action( 'litespeed_purge_all' ) ) {
                        // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- third-party cache plugin's own purge hook.
                        do_action( 'litespeed_purge_all', 'Agent Toolbelt' );
                        return true;
                    }
                    break;

                case 'W3 Total Cache':
                    // Page cache only; flush_all would also wipe minify/object/CDN.
                    if ( function_exists( 'w3tc_flush_posts' ) ) {
                        w3tc_flush_posts();
                        return true;
                    }
                    break;

                case 'WP Super Cache':
                    if ( function_exists( 'wp_cache_clear_cache' ) ) {
                        wp_cache_clear_cache();
                        return true;
                    }
                    break;

                case 'WP Fastest Cache':
                    if ( has_action( 'wpfc_clear_all_cache' ) ) {
                        // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- third-party cache plugin's own purge hook.
                        do_action( 'wpfc_clear_all_cache' );
                        return true;
                    }
                    break;

                case 'WP-Optimize':
                    if ( function_exists( 'WP_Optimize' ) ) {
                        $atb_wpo = WP_Optimize();

                        if ( is_object( $atb_wpo ) && method_exists( $atb_wpo, 'get_page_cache' ) ) {
                            $atb_cache = $atb_wpo->get_page_cache();

                            if ( is_object( $atb_cache ) && method_exists( $atb_cache, 'purge' ) ) {
                                $atb_cache->purge();
                                return true;
                            }
                        }
                    }
                    break;

                case 'Breeze':
                    if ( has_action( 'breeze_clear_all_cache' ) ) {
                        // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- third-party cache plugin's own purge hook.
                        do_action( 'breeze_clear_all_cache' );
                        return true;
                    }
                    break;

                case 'Cache Enabler':
                    if ( method_exists( 'Cache_Enabler', 'clear_complete_cache' ) ) {
                        Cache_Enabler::clear_complete_cache();
                        return true;
                    }
                    break;

                case 'Hummingbird':
                    if ( has_action( 'wphb_clear_page_cache' ) ) {
                        // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- third-party cache plugin's own purge hook.
                        do_action( 'wphb_clear_page_cache' );
                        return true;
                    }
                    break;

                case 'SiteGround Optimizer':
                    if ( function_exists( 'sg_cachepress_purge_cache' ) ) {
                        sg_cachepress_purge_cache();
                        return true;
                    }
                    break;

                case 'Swift Performance':
                    if ( class_exists( 'Swift_Performance_Cache' ) && method_exists( 'Swift_Performance_Cache', 'clear_all_cache' ) ) {
                        Swift_Performance_Cache::clear_all_cache();
                        return true;
                    }
                    break;

                case 'Comet Cache':
                    // clear() = current site; wipe() = whole network (don't).
                    if ( method_exists( 'comet_cache', 'clear' ) ) {
                        comet_cache::clear();
                        return true;
                    }
                    break;
            }

            return false;
        }
    }
}