<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Content;

defined('ABSPATH') || exit;

trait VipServicePurchase {

    /** @var array<string,mixed>|null */
    private $vip_settings_cache = null;

    /** @var array<int,array<string,mixed>> */
    private $vip_member_cache = [];

    /** @var array<int,array<string,mixed>> */
    private $vip_catalog_cache = [];

    /** @var array<string,mixed>|null */
    private $vip_paid_display_cache = null;

    /**
     * Read payment settings once per request. The cache is kept on the
     * singleton instance and is never shared between users or requests.
     *
     * @return array<string,mixed>
     */
    private function get_vip_settings_context(): array {
        if (is_array($this->vip_settings_cache)) {
            return $this->vip_settings_cache;
        }

        $settings = class_exists('\AKSRT\Settings\Settings')
            ? \AKSRT\Settings\Settings::get_payment_vip_settings()
            : [];
        $this->vip_settings_cache = is_array($settings)
            ? $settings
            : ['enabled' => false, 'levels' => [], 'renew' => [], 'upgrade' => [], 'points_exchange' => []];
        return $this->vip_settings_cache;
    }

    /**
     * Read the current member state once per request and user.
     *
     * @return array{level:int,expires:int,is_permanent:bool,state:string,expires_label:string}
     */
    private function get_vip_member_context(int $user_id): array {
        $user_id = max(0, $user_id);
        if (array_key_exists($user_id, $this->vip_member_cache)) {
            return $this->vip_member_cache[$user_id];
        }

        $vip_state = $user_id > 0 && function_exists('aksrt_get_user_vip_state')
            ? aksrt_get_user_vip_state($user_id)
            : ['level' => 0, 'expires' => 0, 'state' => 'unopened', 'source' => 'none'];
        $level = (int) ($vip_state['level'] ?? 0);
        $expires = max(0, (int) ($vip_state['expires'] ?? 0));
        $member_state = 'unopened';
        if ($level > 0) {
            $member_state = $expires <= 0
                ? 'permanent'
                : ($expires < time() ? 'expired' : 'active');
        } elseif ($expires > 0 && $expires < time()) {
            // aksrt_get_user_vip_level() lazily clears expired levels; retain
            // the observable expired state for this response without reviving it.
            $member_state = 'expired';
        }
        $state = [
            'level' => max(0, $level),
            'expires' => $expires,
            'is_permanent' => $level > 0 && $expires <= 0,
            'state' => $member_state,
            'source' => (string) ($vip_state['source'] ?? 'none'),
            'expires_label' => $member_state === 'expired'
                ? __('已过期', 'aksrt')
                : $this->format_expires_label($expires, $level),
        ];
        $this->vip_member_cache[$user_id] = $state;
        return $state;
    }

    /**
     * Cache paid-content display settings alongside the VIP request context.
     *
     * @return array<string,mixed>
     */
    private function get_paid_display_context(): array {
        if (is_array($this->vip_paid_display_cache)) {
            return $this->vip_paid_display_cache;
        }
        $settings = class_exists('\AKSRT\Settings\Settings')
            ? \AKSRT\Settings\Settings::get_paid_content_settings()
            : [];
        $this->vip_paid_display_cache = is_array($settings) ? $settings : [];
        return $this->vip_paid_display_cache;
    }

    /**
     * @return array<string,mixed>
     */
    public function get_catalog(int $user_id = 0): array {
        $user_id = max(0, $user_id);
        if (array_key_exists($user_id, $this->vip_catalog_cache)) {
            return $this->vip_catalog_cache[$user_id];
        }

        $vip = $this->get_vip_settings_context();
        $member = $this->get_vip_member_context($user_id);
        $level = (int) $member['level'];
        $expires = (int) $member['expires'];
        $is_permanent = !empty($member['is_permanent']);
        $levels = is_array($vip['levels'] ?? null) ? $vip['levels'] : [];
        $renew = is_array($vip['renew'] ?? null) ? $vip['renew'] : [];
        $upgrade = is_array($vip['upgrade'] ?? null) ? $vip['upgrade'] : [];
        $points_ex = is_array($vip['points_exchange'] ?? null) ? $vip['points_exchange'] : [];
        $renew_enabled = !isset($renew['enabled']) || !empty($renew['enabled']);
        $upgrade_enabled = !isset($upgrade['enabled']) || !empty($upgrade['enabled']);
        $credits_enabled = !class_exists('\AKSRT\Settings\Settings') || \AKSRT\Settings\Settings::credits_enabled();
        $points_enabled = !empty($points_ex['enabled']) && $credits_enabled;

        $level_packages = [];
        foreach ([1, 2] as $lv) {
            if (empty($levels[$lv]['enabled'])) {
                continue;
            }
            // Cash products can be disabled per level.
            $product_s = !isset($levels[$lv]['product_s']) || !empty($levels[$lv]['product_s']);
            if ($is_permanent && $lv <= $level) {
                continue;
            }
            if ($level > 0 && $lv === $level && !$renew_enabled) {
                continue;
            }
            if ($level > 0 && $lv > $level && !$upgrade_enabled) {
                continue;
            }

            $name = (string) ($levels[$lv]['name'] ?? ('VIP' . $lv));
            $items = [];
            $packages = $product_s
                ? $this->parse_level_products((string) ($levels[$lv]['products_raw'] ?? ''))
                : [];
            foreach ($packages as $idx => $pkg) {
                $base_price = (float) $pkg['price'];
                $days = (int) $pkg['days'];
                $action = 'pay';
                if ($level > 0 && $lv === $level) {
                    $action = 'renew';
                } elseif ($level > 0 && $lv > $level) {
                    $action = 'upgrade';
                }

                $priced = $this->apply_action_price($base_price, $action, $renew, $upgrade, $lv, $level, $expires, $is_permanent, $days);
                if ($priced === null) {
                    continue;
                }

                $show_price = (float) ($priced['show_price'] ?? 0);
                if ($show_price <= 0 && !empty($pkg['show_price']) && $action === 'pay') {
                    $show_price = (float) $pkg['show_price'];
                }
                $discount_tag = (string) ($priced['tag'] ?? '');
                if ($discount_tag === '' && $action === 'pay' && !empty($pkg['tag'])) {
                    $discount_tag = (string) $pkg['tag'];
                }

                $days_label = __('永久', 'aksrt');
                if ((int) $pkg['time'] > 0) {
                    $days_label = ((string) ($pkg['unit'] ?? 'day') === 'month')
                        ? sprintf(__('%d 个月', 'aksrt'), (int) $pkg['time'])
                        : sprintf(__('%d 天', 'aksrt'), (int) $pkg['time']);
                }

                $items[] = [
                    'package_id'       => $this->encode_package_id($lv, $idx + 1),
                    'level'            => $lv,
                    'index'            => $idx + 1,
                    'action'           => $action,
                    'price'            => (float) $priced['price'],
                    'base_price'       => $base_price,
                    'show_price'       => $show_price,
                    'discount_tag'     => $discount_tag,
                    'days'             => $days,
                    'time'             => (int) ($pkg['time'] ?? 0),
                    'unit'             => (string) ($pkg['unit'] ?? 'day'),
                    'title'            => (string) $pkg['title'],
                    'price_label'      => $this->format_cash_label((float) $priced['price']),
                    'show_price_label' => $show_price > 0
                        ? $this->format_cash_label($show_price)
                        : '',
                    'days_label'       => $days_label,
                    'cta_label'        => $action === 'renew'
                        ? __('立即续费', 'aksrt')
                        : ($action === 'upgrade' ? __('立即升级', 'aksrt') : __('立即开通', 'aksrt')),
                ];
            }

            // Dedicated upgrade product: fixed or remaining-days unit price.
            if ($level === 1 && $lv === 2 && $upgrade_enabled) {
                $upgrade_items = $this->build_upgrade_items($user_id, $expires, $is_permanent, (string) ($upgrade['product'] ?? ''));
                foreach ($upgrade_items as $ui) {
                    $items[] = $ui;
                }
            }

            if ($items === []) {
                continue;
            }
            $level_packages[] = [
                'level'  => $lv,
                'name'   => $name,
                'action' => ($level > 0 && $lv === $level) ? 'renew' : (($level > 0 && $lv > $level) ? 'upgrade' : 'pay'),
                'items'  => $items,
            ];
        }

        $points_packages = [];
        if ($points_enabled) {
            $points_packages = $this->get_points_exchange_packages($vip, $levels);
            if ($level > 0) {
                $points_packages = array_values(array_filter(
                    $points_packages,
                    static function (array $package) use ($level, $is_permanent): bool {
                        $target_level = (int) ($package['level'] ?? 0);
                        return $target_level > $level || (!$is_permanent && $target_level === $level);
                    }
                ));
            }
        }

        $points_balance = ($user_id > 0 && class_exists('\AKSRT\Credits\Credits'))
            ? (int) \AKSRT\Credits\Credits::balance($user_id)
            : 0;
        $wallet_balance = ($user_id > 0 && class_exists('\AKSRT\Credits\Balance') && \AKSRT\Credits\Balance::enabled())
            ? (float) \AKSRT\Credits\Balance::balance($user_id)
            : 0.0;
        $methods = $this->available_payment_methods();
        $currency_name = class_exists('\AKSRT\Settings\Settings') ? \AKSRT\Settings\Settings::get_currency_name() : __('积分', 'aksrt');

        $catalog = [
            'enabled'            => !empty($vip['enabled']),
            'desc'               => (string) ($vip['desc'] ?? ''),
            'help_text'          => (string) ($vip['help_text'] ?? ''),
            'user_level'         => $level,
            'user_expires'       => $expires,
            'user_is_permanent'  => $is_permanent,
            'user_expires_label' => (string) ($member['expires_label'] ?? ''),
            'user_points'        => $points_balance,
            'wallet_balance'     => $wallet_balance,
            'currency_name'      => $currency_name,
            'renew_enabled'      => $renew_enabled,
            'upgrade_enabled'    => $upgrade_enabled,
            'credits_enabled'    => $credits_enabled,
            'renew_desc'         => (string) ($renew['desc'] ?? ''),
            'upgrade_desc'       => (string) ($upgrade['desc'] ?? ''),
            'level_packages'     => $level_packages,
            'points_exchange'    => [
                'enabled'  => $points_enabled,
                'desc'     => (string) ($points_ex['desc'] ?? ''),
                'packages' => $points_packages,
            ],
            'payment_methods'    => $methods,
            'vip_url'            => function_exists('aksrt_get_user_center_tab_url')
                ? aksrt_get_user_center_tab_url('credits')
                : (function_exists('aksrt_get_user_center_url') ? aksrt_get_user_center_url() : home_url('/')),
            'logged_in'          => $user_id > 0,
        ];
        $this->vip_catalog_cache[$user_id] = $catalog;
        return $catalog;
    }

    /**
     * Find a package in the server-derived catalog.
     *
     * The returned group name is request-local metadata used only for the
     * order subject; price and entitlement data remain server-derived.
     *
     * @param array<string,mixed> $catalog
     * @return array<string,mixed>|null
     */
    private function find_catalog_package(array $catalog, int $package_id): ?array {
        $groups = is_array($catalog['level_packages'] ?? null) ? $catalog['level_packages'] : [];
        foreach ($groups as $group) {
            if (!is_array($group)) {
                continue;
            }
            $group_name = (string) ($group['name'] ?? '');
            $items = is_array($group['items'] ?? null) ? $group['items'] : [];
            foreach ($items as $item) {
                if (!is_array($item) || (int) ($item['package_id'] ?? 0) !== $package_id) {
                    continue;
                }
                $item['_level_name'] = $group_name !== '' ? $group_name : ('VIP' . (int) ($item['level'] ?? 1));
                return $item;
            }
        }
        return null;
    }


    /**
     * @return array|\WP_Error
     */
    public function purchase(int $user_id, int $package_id, string $payment_method = 'balance') {
        if ($user_id <= 0) {
            return new \WP_Error('aksrt_need_login', __('请先登录后再开通会员。', 'aksrt'), ['status' => 401]);
        }

        $catalog = $this->get_catalog($user_id);
        if (empty($catalog['enabled'])) {
            return new \WP_Error('aksrt_vip_disabled', __('会员功能未启用', 'aksrt'), ['status' => 400]);
        }

        $pkg = $this->find_catalog_package($catalog, $package_id);
        if (!$pkg) {
            return new \WP_Error('aksrt_invalid_package', __('套餐不存在或当前不可购买', 'aksrt'), ['status' => 400]);
        }

        $level = (int) ($pkg['level'] ?? 0);
        $index = (int) ($pkg['index'] ?? 0);
        $action = sanitize_key((string) ($pkg['action'] ?? 'pay'));
        $amount = round((float) ($pkg['price'] ?? 0), 2);
        $base_price = (float) ($pkg['base_price'] ?? $amount);
        $days = (int) ($pkg['days'] ?? 0);
        $pkg_time = array_key_exists('time', $pkg) ? (int) $pkg['time'] : $days;
        $pkg_unit = sanitize_key((string) ($pkg['unit'] ?? 'day'));
        if (!in_array($pkg_unit, ['day', 'month'], true)) {
            $pkg_unit = 'day';
        }
        $discount_tag = (string) ($pkg['discount_tag'] ?? '');
        $upgrade_mode = sanitize_key((string) ($pkg['upgrade_mode'] ?? ''));
        if (in_array($upgrade_mode, ['jump', 'permanent'], true)) {
            $pkg_time = 0;
            $days = 0;
        }

        if ($level < 1 || $level > 2 || $index < 1 || $action === '') {
            return new \WP_Error('aksrt_invalid_package', __('套餐无效', 'aksrt'), ['status' => 400]);
        }

        if ($amount <= 0) {
            return new \WP_Error('aksrt_invalid_price', __('套餐价格无效', 'aksrt'), ['status' => 400]);
        }

        if (!class_exists('\AKSRT\Payment\Order') || !class_exists('\AKSRT\Payment\OrderRepository')) {
            return new \WP_Error('aksrt_pay_unavailable', __('支付系统不可用', 'aksrt'), ['status' => 500]);
        }

        $payment_method = sanitize_key($payment_method);
        if ($payment_method === '') {
            $payment_method = 'balance';
        }

        $note = wp_json_encode([
            'vip_pay' => 1,
            'level' => $level,
            'days' => $days,
            'time' => $pkg_time,
            'unit' => $pkg_unit,
            'package_index' => $index,
            'package_title' => (string) ($pkg['title'] ?? ''),
            'package_id' => $package_id,
            'action' => $action,
            'upgrade_mode' => $upgrade_mode,
            'base_price' => $base_price,
            'discount_tag' => $discount_tag,
        ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

        $expires_at = gmdate('Y-m-d H:i:s', time() + 30 * MINUTE_IN_SECONDS);
        $order_number = \AKSRT\Payment\OrderRepository::get_instance()->create([
            'user_id' => $user_id,
            'product_type' => \AKSRT\Core\DomainModel::ORDER_PRODUCT_VIP,
            'product_id' => $package_id,
            'amount' => $amount,
            'currency' => 'CNY',
            'status' => \AKSRT\Payment\Order::STATUS_PENDING,
            'payment_method' => $payment_method,
            'note' => is_string($note) ? $note : '',
            'expires_at' => $expires_at,
        ]);
        if ($order_number === '') {
            return new \WP_Error('aksrt_order_create_failed', __('创建订单失败', 'aksrt'), ['status' => 500]);
        }

        // Build the request-local order context from the same server-derived
        // package used for validation. PaymentOrchestrator still reloads the
        // persisted row under its attempt lock before touching the gateway.
        $level_name = (string) ($pkg['_level_name'] ?? ('VIP' . $level));
        $action_label = $action === 'renew' ? __('续费', 'aksrt') : ($action === 'upgrade' ? __('升级', 'aksrt') : __('开通', 'aksrt'));
        $order = [
            'order_number' => $order_number,
            'user_id' => $user_id,
            'product_type' => \AKSRT\Core\DomainModel::ORDER_PRODUCT_VIP,
            'product_id' => $package_id,
            'amount' => $amount,
            'currency' => 'CNY',
            'status' => \AKSRT\Payment\Order::STATUS_PENDING,
            'payment_method' => $payment_method,
            'note' => is_string($note) ? $note : '',
            'expires_at' => $expires_at,
            'subject' => sprintf(
                /* translators: 1: action 2: vip name 3: package title */
                __('%1$s%2$s · %3$s', 'aksrt'),
                $action_label,
                $level_name,
                (string) ($pkg['title'] ?? '')
            ),
        ];

        if (!class_exists('\AKSRT\Payment\Gateway')) {
            return new \WP_Error('aksrt_pay_unavailable', __('支付网关不可用', 'aksrt'), ['status' => 500]);
        }
        $resolved = \AKSRT\Payment\PaymentOrchestrator::resolve_gateway($payment_method);
        if (empty($resolved['gateway'])) {
            return new \WP_Error(
                (string) ($resolved['error_code'] ?? 'aksrt_gateway_unavailable'),
                (string) ($resolved['message'] ?? __('当前支付方式不可用', 'aksrt')),
                ['status' => 400, 'order_number' => $order_number]
            );
        }

        $payment_result = \AKSRT\Payment\PaymentOrchestrator::pay($resolved['gateway'], $order, [
            'paid_note' => __('用户完成会员开通支付。', 'aksrt'),
            'order_context' => $order,
        ]);
        if (empty($payment_result['success'])) {
            return new \WP_Error(
                (string) ($payment_result['code'] ?? 'aksrt_pay_failed'),
                (string) ($payment_result['message'] ?? __('支付失败', 'aksrt')),
                ['status' => 402, 'order_number' => $order_number]
            );
        }

        if (!empty($payment_result['redirect'])) {
            return [
                'success' => true,
                'data' => [
                    'redirect' => true,
                    'payment_url' => (string) ($payment_result['payment_url'] ?? ''),
                    'qr_content' => (string) ($payment_result['qr_content'] ?? ''),
                    'order_number' => $order_number,
                    'amount' => $amount,
                    'message' => $payment_result['message'],
                    'reload' => false,
                    'poll' => true,
                ],
            ];
        }

        return [
            'success' => true,
            'data' => [
                'order_number' => $order_number,
                'amount' => $amount,
                'level' => $level,
                'days' => $days,
                'action' => $action,
                'message' => $action === 'renew'
                    ? __('会员续费成功', 'aksrt')
                    : ($action === 'upgrade' ? __('会员升级成功', 'aksrt') : __('会员开通成功', 'aksrt')),
                'reload' => true,
            ],
        ];
    }


    /**
     * Activate VIP on paid order.
     *
     * @param string $order_number
     * @param array  $paid_order
     */
    public function on_order_paid(string $order_number, array $paid_order): void {
        if (sanitize_key((string) ($paid_order['product_type'] ?? '')) !== \AKSRT\Core\DomainModel::ORDER_PRODUCT_VIP) {
            return;
        }
        $user_id = (int) ($paid_order['user_id'] ?? 0);
        if ($user_id <= 0) {
            return;
        }

        $meta = [];
        if (!empty($paid_order['note']) && is_string($paid_order['note'])) {
            $decoded = json_decode($paid_order['note'], true);
            if (is_array($decoded)) {
                $meta = $decoded;
            }
        }
        if (empty($meta) && is_array($paid_order['meta_payload'] ?? null)) {
            $meta = $paid_order['meta_payload'];
        }

        $level = (int) ($meta['level'] ?? 0);
        $days = (int) ($meta['days'] ?? 0);
        $time = (int) ($meta['time'] ?? 0);
        $unit = sanitize_key((string) ($meta['unit'] ?? 'day'));
        if (!in_array($unit, ['day', 'month'], true)) {
            $unit = 'day';
        }
        $upgrade_mode = sanitize_key((string) ($meta['upgrade_mode'] ?? ''));
        if ($level <= 0) {
            $decoded = $this->decode_package_id((int) ($paid_order['product_id'] ?? 0));
            if ($decoded) {
                $level = (int) $decoded['level'];
            }
        }
        if ($level < 1) {
            $level = 1;
        }
        if ($level > 2) {
            $level = 2;
        }

        $previous_level = (int) get_user_meta($user_id, 'aksrt_vip_level', true);
        $previous_expiry = (int) get_user_meta($user_id, 'aksrt_vip_expires', true);
        $finite_duration = $time > 0 || $days > 0;
        if ($previous_level > 0 && $previous_expiry === 0 && $level > $previous_level && $finite_duration) {
            // Preserve a permanent lower tier while a finite higher-tier upgrade is active.
            update_user_meta($user_id, 'aksrt_vip_base_level', $previous_level);
            update_user_meta($user_id, 'aksrt_vip_base_expires', 0);
        } else {
            // Only a finite higher-tier upgrade may keep a layered base membership.
            delete_user_meta($user_id, 'aksrt_vip_base_level');
            delete_user_meta($user_id, 'aksrt_vip_base_expires');
        }
        $fulfilled = false;
        // unit upgrade: raise level only, keep current expiry (zibll).
        if ($upgrade_mode === 'unit') {
            $this->activate_vip($user_id, $level, 0, true);
            $fulfilled = (int) get_user_meta($user_id, 'aksrt_vip_level', true) >= $level;
        } elseif ($time > 0 || (isset($meta['time']) && (int) $meta['time'] === 0 && $days === 0)) {
            // Prefer calendar time+unit when present (including permanent time=0).
            $this->activate_vip_duration($user_id, $level, $time, $unit);
            $new_expiry = (int) get_user_meta($user_id, 'aksrt_vip_expires', true);
            $expected_base = max($previous_expiry, time());
            $expected_expiry = $time <= 0
                ? 0
                : strtotime('+' . $time . ' ' . ($unit === 'month' ? 'months' : 'days'), $expected_base);
            if ($expected_expiry === false) {
                $expected_expiry = $expected_base + ($this->duration_to_days($time, $unit) * DAY_IN_SECONDS);
            }
            $fulfilled = (int) get_user_meta($user_id, 'aksrt_vip_level', true) >= max($previous_level, $level)
                && ($new_expiry === 0 || ($time <= 0 ? $new_expiry === 0 : $new_expiry >= $expected_expiry));
        } else {
            $this->activate_vip($user_id, $level, $days, false);
            $new_expiry = (int) get_user_meta($user_id, 'aksrt_vip_expires', true);
            $fulfilled = (int) get_user_meta($user_id, 'aksrt_vip_level', true) >= max($previous_level, $level)
                && ($new_expiry === 0 || $days <= 0 || $new_expiry >= max($previous_expiry, time()) + ($days * DAY_IN_SECONDS));
        }
        if ($fulfilled && class_exists('\AKSRT\Payment\OrderRepository')) {
            \AKSRT\Payment\OrderRepository::get_instance()->update_status(
                $order_number,
                \AKSRT\Payment\Order::STATUS_COMPLETED,
                ['note' => __('会员权益已发放。', 'aksrt')]
            );
        }
    }


    /**
     * Apply membership meta.
     *
     * @param bool $keep_expiry When true (unit upgrade), only raise level and do not change expiry.
     *                          When days<=0 and keep_expiry=false, set permanent (expires=0).
     */
    public function activate_vip(int $user_id, int $level, int $days = 0, bool $keep_expiry = false): void {
        if ($user_id <= 0) {
            return;
        }
        $level = max(1, min(2, $level));
        $current_level = (int) get_user_meta($user_id, 'aksrt_vip_level', true);
        $new_level = max($current_level, $level);
        update_user_meta($user_id, 'aksrt_vip_level', $new_level);
        // Clear expired memory when re-granting.
        delete_user_meta($user_id, 'aksrt_vip_level_expired');

        // Unit upgrade (zibll): keep vip_exp_date, only raise level.
        if ($keep_expiry) {
            return;
        }

        if ($days <= 0) {
            // Permanent.
            delete_user_meta($user_id, 'aksrt_vip_base_level');
            delete_user_meta($user_id, 'aksrt_vip_base_expires');
            update_user_meta($user_id, 'aksrt_vip_expires', 0);
            return;
        }

        $current_exp = (int) get_user_meta($user_id, 'aksrt_vip_expires', true);
        if ($current_exp === 0 && $current_level > 0 && $level <= $current_level) {
            return; // keep an existing permanent level when not upgrading it
        }
        $base = max($current_exp, time());
        update_user_meta($user_id, 'aksrt_vip_expires', $base + ($days * DAY_IN_SECONDS));
    }

    /**
     * Activate VIP using calendar duration (zibll month/day).
     * time=0 → permanent. Extends from max(now, current_exp).
     */
    public function activate_vip_duration(int $user_id, int $level, int $time, string $unit = 'day'): void {
        if ($user_id <= 0) {
            return;
        }
        $level = max(1, min(2, $level));
        $unit = $unit === 'month' ? 'month' : 'day';
        $current_level = (int) get_user_meta($user_id, 'aksrt_vip_level', true);
        $new_level = max($current_level, $level);
        update_user_meta($user_id, 'aksrt_vip_level', $new_level);
        delete_user_meta($user_id, 'aksrt_vip_level_expired');

        if ($time <= 0) {
            delete_user_meta($user_id, 'aksrt_vip_base_level');
            delete_user_meta($user_id, 'aksrt_vip_base_expires');
            update_user_meta($user_id, 'aksrt_vip_expires', 0);
            return;
        }

        $current_exp = (int) get_user_meta($user_id, 'aksrt_vip_expires', true);
        if ($current_exp === 0 && $current_level > 0 && $level <= $current_level) {
            return; // keep an existing permanent level when not upgrading it
        }
        $base = max($current_exp, time());
        $modifier = $unit === 'month'
            ? ('+' . $time . ' months')
            : ('+' . $time . ' days');
        $new_exp = strtotime($modifier, $base);
        if ($new_exp === false) {
            $new_exp = $base + ($this->duration_to_days($time, $unit) * DAY_IN_SECONDS);
        }
        update_user_meta($user_id, 'aksrt_vip_expires', (int) $new_exp);
    }


    /**
     * Points exchange. Ordinary users can open a VIP; existing VIP users can
     * renew the same level or upgrade to a higher level with the exchanged term.
     *
     * @return array|\WP_Error
     */
    public function exchange_with_points(int $user_id, int $package_id) {
        if ($user_id <= 0) {
            return new \WP_Error('aksrt_need_login', __('请先登录后再兑换。', 'aksrt'), ['status' => 401]);
        }
        if (!class_exists('\AKSRT\Credits\Credits')) {
            return new \WP_Error('aksrt_credits_unavailable', __('积分系统不可用', 'aksrt'), ['status' => 500]);
        }
        $catalog = $this->get_catalog($user_id);
        if (array_key_exists('credits_enabled', $catalog) && empty($catalog['credits_enabled'])) {
            return new \WP_Error('aksrt_credits_disabled', __('积分功能未启用', 'aksrt'), ['status' => 400]);
        }
        $points_ex = is_array($catalog['points_exchange'] ?? null) ? $catalog['points_exchange'] : [];
        if (empty($points_ex['enabled'])) {
            return new \WP_Error('aksrt_points_exchange_disabled', __('积分兑换会员未启用', 'aksrt'), ['status' => 400]);
        }

        $match = null;
        $packages = is_array($points_ex['packages'] ?? null) ? $points_ex['packages'] : [];
        foreach ($packages as $pkg) {
            if (is_array($pkg) && (int) ($pkg['package_id'] ?? 0) === $package_id) {
                $match = $pkg;
                break;
            }
        }
        if (!$match) {
            return new \WP_Error('aksrt_invalid_package', __('兑换套餐不存在', 'aksrt'), ['status' => 400]);
        }

        if ((int) ($catalog['user_level'] ?? 0) > 0) {
            $current_level = (int) ($catalog['user_level'] ?? 0);
            $target_level = (int) ($match['level'] ?? 0);
            $is_permanent = !empty($catalog['user_is_permanent']);
            if ($target_level < $current_level || ($target_level === $current_level && $is_permanent)) {
                return new \WP_Error('aksrt_vip_package_unavailable', __('当前会员状态无法兑换该套餐。', 'aksrt'), ['status' => 400]);
            }
        }

        $cost = (int) ($match['points'] ?? 0);
        $level = (int) ($match['level'] ?? 1);
        $days = (int) ($match['days'] ?? 0);
        if ($cost <= 0) {
            return new \WP_Error('aksrt_invalid_price', __('兑换积分无效', 'aksrt'), ['status' => 400]);
        }

        $balance = (int) ($catalog['user_points'] ?? 0);
        if ($balance < $cost) {
            return new \WP_Error('aksrt_credits_insufficient', __('积分不足，暂时无法兑换', 'aksrt'), [
                'status' => 402,
                'balance' => $balance,
                'cost' => $cost,
            ]);
        }

        if (!class_exists('\AKSRT\Payment\Order') || !class_exists('\AKSRT\Payment\OrderRepository')) {
            return new \WP_Error('aksrt_pay_unavailable', __('订单系统不可用', 'aksrt'), ['status' => 500]);
        }

        $note = wp_json_encode([
            'vip_pay' => 1,
            'vip_pay_type' => 'points_exchange',
            'level' => $level,
            'days' => $days,
            'points' => $cost,
            'package_id' => $package_id,
            'package_title' => (string) ($match['title'] ?? ''),
            'action' => 'points_exchange',
        ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

        $order_number = \AKSRT\Payment\OrderRepository::get_instance()->create([
            'user_id' => $user_id,
            'product_type' => \AKSRT\Core\DomainModel::ORDER_PRODUCT_VIP,
            'product_id' => $package_id,
            'amount' => (float) $cost,
            'currency' => 'points',
            'status' => \AKSRT\Payment\Order::STATUS_PENDING,
            'payment_method' => 'points',
            'note' => is_string($note) ? $note : '',
            'expires_at' => gmdate('Y-m-d H:i:s', time() + 30 * MINUTE_IN_SECONDS),
        ]);
        if ($order_number === '') {
            return new \WP_Error('aksrt_order_create_failed', __('创建订单失败', 'aksrt'), ['status' => 500]);
        }

        $lock = class_exists('\AKSRT\Payment\PaymentAttemptLock')
            ? \AKSRT\Payment\PaymentAttemptLock::acquire($order_number)
            : false;
        if ($lock === false) {
            return new \WP_Error('aksrt_pay_locked', __('该订单正在发起支付，请稍后重试。', 'aksrt'), ['status' => 409]);
        }

        try {
            $deducted = \AKSRT\Credits\Credits::deduct(
                $user_id,
                $cost,
                'vip_points_exchange',
                ['order' => $order_number, 'level' => $level, 'days' => $days],
                sprintf(__('积分兑换会员 · %s', 'aksrt'), (string) ($match['title'] ?? ''))
            );
            if (is_wp_error($deducted) || $deducted === false) {
                \AKSRT\Payment\Order::get_instance()->update_status($order_number, \AKSRT\Payment\Order::STATUS_CANCELLED, [
                    'note' => __('积分扣除失败，自动取消', 'aksrt'),
                ]);
                $msg = is_wp_error($deducted) ? $deducted->get_error_message() : __('积分扣除失败', 'aksrt');
                return new \WP_Error('aksrt_credits_deduct_failed', $msg ?: __('积分扣除失败', 'aksrt'), ['status' => 400]);
            }

            $paid = \AKSRT\Payment\Order::get_instance()->update_status($order_number, \AKSRT\Payment\Order::STATUS_PAID, [
                'payment_method' => 'points',
                'payment_transaction_id' => 'points_' . $order_number,
                'note' => sprintf(__('积分兑换会员 %d 积分。', 'aksrt'), $cost),
                'require_transition' => true,
            ]);
            if (!$paid) {
                \AKSRT\Credits\Credits::add(
                    $user_id,
                    $cost,
                    'vip_points_exchange_refund',
                    ['order' => $order_number],
                    __('会员兑换失败退款', 'aksrt')
                );
                return new \WP_Error('aksrt_order_confirm_failed', __('兑换确认失败，已尝试退回积分', 'aksrt'), ['status' => 500]);
            }
        } finally {
            \AKSRT\Payment\PaymentAttemptLock::release($order_number, $lock);
        }

        return [
            'success' => true,
            'data' => [
                'order_number' => $order_number,
                'points' => $cost,
                'level' => $level,
                'days' => $days,
                'balance' => \AKSRT\Credits\Credits::balance($user_id),
                'message' => __('兑换成功', 'aksrt'),
                'reload' => true,
            ],
        ];
    }

}