<?php
/**
 * Batch 21 — LiteSpeed Cache deep (Pro-equivalent, net-new).
 *
 * Deeper LiteSpeed control beyond the generic b17 cache family: version/detect,
 * read & set LiteSpeed options (with reversible backup), and granular purge
 * (all / by URL / by post / by tag). Uses LiteSpeed's documented action hooks
 * and its `litespeed.conf.*` option store. Guarded by LSCWP_V / LSCWP_CUR_V.
 * GPL-2.0-or-later. See NOTICE.md.
 */

namespace AskTamMCP\Extensions;

defined('ABSPATH') || exit;

class Batch21 {

    private const OPT_PREFIX = 'litespeed.conf.';
    private const BACKUP = 'amp_ls_backup';

    public static function register($registry): void {
        if (!defined('LSCWP_V') && !defined('LSCWP_CUR_V')) return;

        $def = function (string $name, string $desc, array $props, array $required, string $scope, string $method) {
            $schema = ['type' => 'object', 'properties' => $props];
            if ($required) $schema['required'] = $required;
            return ['name' => $name, 'description' => $desc, 'scope' => $scope,
                    'handler' => 'AskTamMCP\\Extensions\\Batch21::' . $method, 'inputSchema' => $schema];
        };

        $registry->register($def('litespeed_detect', 'Report LiteSpeed Cache version and whether object cache / crawler are active.',
            [], [], 'read', 'detect'));

        $registry->register($def('litespeed_list_options', 'List LiteSpeed Cache settings (litespeed.conf.* options), optionally filtered by key substring.',
            ['filter' => ['type' => 'string'], 'limit' => ['type' => 'integer', 'default' => 200]], [], 'read', 'listOptions'));

        $registry->register($def('litespeed_set_option', 'Set one LiteSpeed Cache setting. key may be given with or without the litespeed.conf. prefix. value is parsed as JSON when valid. Prior value auto-backed-up for litespeed_restore_option.',
            ['key' => ['type' => 'string'], 'value' => ['type' => 'string']], ['key', 'value'], 'write', 'setOption'));

        $registry->register($def('litespeed_restore_option', 'Restore one LiteSpeed setting to the value saved before the last litespeed_set_option.',
            ['key' => ['type' => 'string']], ['key'], 'write', 'restoreOption'));

        $registry->register($def('litespeed_purge', 'Purge LiteSpeed cache. scope = all (default) | url | post | tag. Provide url, post_id, or tag accordingly.',
            ['scope' => ['type' => 'string', 'enum' => ['all', 'url', 'post', 'tag']], 'url' => ['type' => 'string'], 'post_id' => ['type' => 'integer'], 'tag' => ['type' => 'string']],
            [], 'write', 'purge'));
    }

    private static function fullKey(string $key): string {
        return strpos($key, self::OPT_PREFIX) === 0 ? $key : self::OPT_PREFIX . $key;
    }

    public static function detect(array $args): array {
        return [
            'version' => defined('LSCWP_V') ? LSCWP_V : (defined('LSCWP_CUR_V') ? LSCWP_CUR_V : 'unknown'),
            'object_cache' => wp_using_ext_object_cache(),
            'crawler' => (bool) get_option(self::OPT_PREFIX . 'crawler', false),
        ];
    }

    public static function listOptions(array $args): array {
        global $wpdb;
        $filter = isset($args['filter']) ? (string) $args['filter'] : '';
        $limit = max(1, (int) ($args['limit'] ?? 200));
        $like = self::OPT_PREFIX . '%';
        $rows = $wpdb->get_results($wpdb->prepare(
            "SELECT option_name, option_value FROM {$wpdb->options} WHERE option_name LIKE %s ORDER BY option_name LIMIT %d",
            $like, $limit
        ), ARRAY_A);
        $out = [];
        foreach ((array) $rows as $r) {
            $k = substr($r['option_name'], strlen(self::OPT_PREFIX));
            if ($filter !== '' && stripos($k, $filter) === false) continue;
            $v = maybe_unserialize($r['option_value']);
            $out[] = ['key' => $k, 'value' => is_scalar($v) ? $v : $v];
        }
        return ['count' => count($out), 'options' => $out];
    }

    public static function setOption(array $args): array {
        $key = (string) ($args['key'] ?? '');
        if ($key === '') throw new \RuntimeException('key required.');
        $opt = self::fullKey($key);
        $raw = (string) ($args['value'] ?? '');
        $decoded = json_decode($raw, true);
        $value = (json_last_error() === JSON_ERROR_NONE && ($raw === 'null' || $decoded !== null)) ? $decoded : $raw;

        $had = (get_option($opt, '__amp_absent__') !== '__amp_absent__');
        $prior = $had ? get_option($opt) : null;
        $backup = get_option(self::BACKUP, []);
        if (!is_array($backup)) $backup = [];
        $backup[$opt] = ['had' => $had, 'value' => $prior];
        update_option(self::BACKUP, $backup, false);

        update_option($opt, $value);
        if (defined('LSCWP_V')) do_action('litespeed_purge_all');
        return ['key' => $key, 'stored_as' => $opt, 'value' => $value, 'backed_up' => true, 'previously_set' => $had];
    }

    public static function restoreOption(array $args): array {
        $key = (string) ($args['key'] ?? '');
        if ($key === '') throw new \RuntimeException('key required.');
        $opt = self::fullKey($key);
        $backup = get_option(self::BACKUP, []);
        if (!is_array($backup) || !array_key_exists($opt, $backup)) {
            throw new \RuntimeException('No backup recorded for key: ' . $key);
        }
        $entry = $backup[$opt];
        if (!empty($entry['had'])) { update_option($opt, $entry['value']); $action = 'restored'; }
        else { delete_option($opt); $action = 'removed'; }
        unset($backup[$opt]);
        update_option(self::BACKUP, $backup, false);
        if (defined('LSCWP_V')) do_action('litespeed_purge_all');
        return ['key' => $key, 'action' => $action];
    }

    public static function purge(array $args): array {
        $scope = (string) ($args['scope'] ?? 'all');
        switch ($scope) {
            case 'url':
                $url = (string) ($args['url'] ?? '');
                if ($url === '') throw new \RuntimeException('url required for scope=url.');
                do_action('litespeed_purge_url', $url);
                return ['scope' => 'url', 'url' => $url, 'purged' => true];
            case 'post':
                $pid = (int) ($args['post_id'] ?? 0);
                if (!$pid) throw new \RuntimeException('post_id required for scope=post.');
                do_action('litespeed_purge_post', $pid);
                return ['scope' => 'post', 'post_id' => $pid, 'purged' => true];
            case 'tag':
                $tag = (string) ($args['tag'] ?? '');
                if ($tag === '') throw new \RuntimeException('tag required for scope=tag.');
                do_action('litespeed_purge', $tag);
                return ['scope' => 'tag', 'tag' => $tag, 'purged' => true];
            default:
                do_action('litespeed_purge_all');
                return ['scope' => 'all', 'purged' => true];
        }
    }
}