<?php
/**
 * AKSRT VIP Service — package parse, purchase, activate membership.
 *
 * product_type = ORDER_PRODUCT_VIP
 * product_id encodes package: level * 1000 + index (1-based)
 *
 * packages_raw line format: price|days|title  (days 0 = permanent)
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Vip_Service {

    private static $instance = null;

    public static function get_instance(): self {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    public function init(): void {
        add_action('rest_api_init', [$this, 'register_routes']);
        add_action('aksrt_order_paid', [$this, 'on_order_paid'], 20, 2);
    }

    public function register_routes(): void {
        register_rest_route('aksrt/v1', '/pay/vip', [
            [
                'methods'             => 'GET',
                'callback'            => [$this, 'rest_catalog'],
                'permission_callback' => [$this, 'check_rest_nonce'],
            ],
            [
                'methods'             => 'POST',
                'callback'            => [$this, 'rest_purchase'],
                'permission_callback' => [$this, 'check_rest_nonce'],
            ],
        ]);
    }

    /**
     * @param WP_REST_Request $request
     * @return true|WP_Error
     */
    public function check_rest_nonce(WP_REST_Request $request) {
        $nonce = $request->get_header('x-wp-nonce');
        if (!$nonce) {
            return new WP_Error('aksrt_rest_no_nonce', __('缺少安全令牌', 'aksrt'), ['status' => 403]);
        }
        if (!wp_verify_nonce($nonce, 'wp_rest')) {
            return new WP_Error('aksrt_rest_bad_nonce', __('安全令牌已过期，请刷新页面', 'aksrt'), ['status' => 403]);
        }
        return true;
    }

    /**
     * GET /pay/vip
     */
    public function rest_catalog(WP_REST_Request $request) {
        $uid = get_current_user_id();
        return new WP_REST_Response($this->get_catalog($uid), 200);
    }

    /**
     * POST /pay/vip
     * body: { package_id: int, payment_method?: string }
     */
    public function rest_purchase(WP_REST_Request $request) {
        $uid = get_current_user_id();
        if ($uid <= 0) {
            return new WP_Error('aksrt_need_login', __('请先登录后再开通会员。', 'aksrt'), [
                'status' => 401,
                'login_url' => function_exists('aksrt_get_login_url') ? aksrt_get_login_url() : wp_login_url(),
            ]);
        }

        $params = $request->get_json_params();
        if (!is_array($params)) {
            $params = $request->get_params();
        }
        $package_id = (int) ($params['package_id'] ?? 0);
        $payment_method = sanitize_key((string) ($params['payment_method'] ?? 'balance'));
        if ($payment_method === '' || $payment_method === 'cash') {
            $payment_method = 'balance';
        }

        $result = $this->purchase($uid, $package_id, $payment_method);
        if (is_wp_error($result)) {
            return $result;
        }
        if (empty($result['success'])) {
            return new WP_Error(
                sanitize_key((string) ($result['code'] ?? 'aksrt_vip_pay_failed')),
                (string) ($result['message'] ?? __('开通失败', 'aksrt')),
                ['status' => (int) ($result['status'] ?? 400)]
            );
        }
        return new WP_REST_Response($result, 200);
    }

    /**
     * @return array<string,mixed>
     */
    public function get_catalog(int $user_id = 0): array {
        $vip = class_exists('AKSRT_Settings')
            ? AKSRT_Settings::get_payment_vip_settings()
            : ['enabled' => false, 'packages_raw' => '', 'levels' => []];

        $level = function_exists('aksrt_get_user_vip_level') ? aksrt_get_user_vip_level($user_id) : 0;
        $expires = $user_id > 0 ? (int) get_user_meta($user_id, 'aksrt_vip_expires', true) : 0;
        $packages = $this->parse_packages((string) ($vip['packages_raw'] ?? ''));
        $levels = is_array($vip['levels'] ?? null) ? $vip['levels'] : [];

        $level_packages = [];
        foreach ([1, 2] as $lv) {
            if (empty($levels[$lv]['enabled'])) {
                continue;
            }
            $name = (string) ($levels[$lv]['name'] ?? ('VIP' . $lv));
            $items = [];
            foreach ($packages as $idx => $pkg) {
                $items[] = [
                    'package_id'  => $this->encode_package_id($lv, $idx + 1),
                    'level'       => $lv,
                    'index'       => $idx + 1,
                    'price'       => (float) $pkg['price'],
                    'days'        => (int) $pkg['days'],
                    'title'       => (string) $pkg['title'],
                    'price_label' => $this->format_cash_label((float) $pkg['price']),
                    'days_label'  => ((int) $pkg['days'] <= 0)
                        ? __('永久', 'aksrt')
                        : sprintf(
                            /* translators: %d: days */
                            __('%d 天', 'aksrt'),
                            (int) $pkg['days']
                        ),
                ];
            }
            if ($items === []) {
                continue;
            }
            $level_packages[] = [
                'level' => $lv,
                'name'  => $name,
                'items' => $items,
            ];
        }

        $methods = $this->available_payment_methods();

        return [
            'enabled'         => !empty($vip['enabled']),
            'desc'            => (string) ($vip['desc'] ?? ''),
            'help_text'       => (string) ($vip['help_text'] ?? ''),
            'user_level'      => $level,
            'user_expires'    => $expires,
            'user_expires_label' => $this->format_expires_label($expires, $level),
            'level_packages'  => $level_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,
        ];
    }

    /**
     * @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]);
        }

        $decoded = $this->decode_package_id($package_id);
        if (!$decoded) {
            return new WP_Error('aksrt_invalid_package', __('套餐无效', 'aksrt'), ['status' => 400]);
        }
        $level = (int) $decoded['level'];
        $index = (int) $decoded['index'];

        $vip = class_exists('AKSRT_Settings')
            ? AKSRT_Settings::get_payment_vip_settings()
            : ['enabled' => false, 'packages_raw' => '', 'levels' => []];
        if (empty($vip['enabled'])) {
            return new WP_Error('aksrt_vip_disabled', __('会员功能未启用', 'aksrt'), ['status' => 400]);
        }
        $levels = is_array($vip['levels'] ?? null) ? $vip['levels'] : [];
        if (empty($levels[$level]['enabled'])) {
            return new WP_Error('aksrt_vip_level_disabled', __('该会员等级未启用', 'aksrt'), ['status' => 400]);
        }

        $packages = $this->parse_packages((string) ($vip['packages_raw'] ?? ''));
        $pkg = $packages[$index - 1] ?? null;
        if (!$pkg) {
            return new WP_Error('aksrt_invalid_package', __('套餐不存在', 'aksrt'), ['status' => 400]);
        }

        $amount = round((float) $pkg['price'], 2);
        if ($amount <= 0) {
            return new WP_Error('aksrt_invalid_price', __('套餐价格无效', 'aksrt'), ['status' => 400]);
        }

        if (!class_exists('AKSRT_Order') || !class_exists('AKSRT_Order_Repository')) {
            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';
        }

        $days = (int) $pkg['days'];
        $note = wp_json_encode([
            'vip_pay' => 1,
            'level' => $level,
            'days' => $days,
            'package_index' => $index,
            'package_title' => (string) $pkg['title'],
            'package_id' => $package_id,
        ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

        $order_number = AKSRT_Order_Repository::get_instance()->create([
            'user_id' => $user_id,
            'product_type' => AKSRT_Domain_Model::ORDER_PRODUCT_VIP,
            'product_id' => $package_id,
            'amount' => $amount,
            'currency' => 'CNY',
            'status' => AKSRT_Order::STATUS_PENDING,
            'payment_method' => $payment_method,
            'note' => is_string($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]);
        }

        $order = AKSRT_Order_Repository::get_instance()->get($order_number);
        if (!$order) {
            return new WP_Error('aksrt_order_create_failed', __('创建订单失败', 'aksrt'), ['status' => 500]);
        }

        $level_name = (string) ($levels[$level]['name'] ?? ('VIP' . $level));
        $order['subject'] = sprintf(
            /* translators: 1: vip name 2: package title */
            __('开通%s · %s', 'aksrt'),
            $level_name,
            (string) $pkg['title']
        );
        $order['payment_method'] = $payment_method;

        if (!class_exists('AKSRT_Payment_Gateway')) {
            return new WP_Error('aksrt_pay_unavailable', __('支付网关不可用', 'aksrt'), ['status' => 500]);
        }
        $gateway = AKSRT_Payment_Gateway::get_instance()->get_gateway($payment_method);
        if (!$gateway) {
            return new WP_Error('aksrt_gateway_unavailable', __('当前支付方式不可用', 'aksrt'), [
                'status' => 400,
                'order_number' => $order_number,
            ]);
        }
        if (method_exists($gateway, 'is_configured') && !$gateway->is_configured()) {
            return new WP_Error('aksrt_gateway_unconfigured', __('该支付方式尚未配置，请联系站长。', 'aksrt'), [
                'status' => 400,
                'order_number' => $order_number,
            ]);
        }

        $payment_result = $gateway->create_payment($order);
        if (empty($payment_result['success'])) {
            $msg = (string) ($payment_result['message'] ?? __('支付失败', 'aksrt'));
            $code = ($payment_method === 'balance' && (str_contains($msg, '余额') || str_contains($msg, '不足')))
                ? 'aksrt_balance_insufficient'
                : 'aksrt_pay_failed';
            return new WP_Error($code, $msg, [
                'status' => 402,
                'order_number' => $order_number,
            ]);
        }

        $code_url = (string) ($payment_result['payment_data']['code_url'] ?? '');
        $payment_url = (string) ($payment_result['payment_url'] ?? '');
        if ($payment_url !== '' || $code_url !== '') {
            return [
                'success' => true,
                'data' => [
                    'redirect' => true,
                    'payment_url' => $payment_url,
                    'qr_content' => $code_url,
                    'order_number' => $order_number,
                    'amount' => $amount,
                    'message' => $payment_result['message'] ?? __('请在新页面完成支付。', 'aksrt'),
                    'reload' => false,
                    'poll' => true,
                ],
            ];
        }

        $paid = AKSRT_Order::get_instance()->update_status($order_number, AKSRT_Order::STATUS_PAID, [
            'payment_method' => $payment_method,
            'payment_transaction_id' => sanitize_text_field((string) ($payment_result['transaction_id'] ?? '')),
            'note' => __('用户完成会员开通支付。', 'aksrt'),
        ]);
        if (!$paid) {
            return new WP_Error('aksrt_order_confirm_failed', __('订单确认失败', 'aksrt'), ['status' => 500]);
        }

        return [
            'success' => true,
            'data' => [
                'order_number' => $order_number,
                'amount' => $amount,
                'level' => $level,
                'days' => $days,
                'message' => __('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_Domain_Model::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);
        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;
        }

        $this->activate_vip($user_id, $level, $days);
    }

    /**
     * Apply membership meta.
     */
    public function activate_vip(int $user_id, int $level, int $days = 0): void {
        if ($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);

        if ($days <= 0) {
            // Permanent.
            update_user_meta($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) {
            // Already permanent — keep permanent.
            return;
        }
        $base = max($current_exp, time());
        update_user_meta($user_id, 'aksrt_vip_expires', $base + ($days * DAY_IN_SECONDS));
    }

    /**
     * Parse packages_raw lines: price|days|title
     *
     * @return array<int, array{price:float,days:int,title:string}>
     */
    public function parse_packages(string $raw): array {
        $lines = preg_split('/\r\n|\r|\n/', $raw) ?: [];
        $out = [];
        foreach ($lines as $line) {
            $line = trim((string) $line);
            if ($line === '') {
                continue;
            }
            $parts = array_map('trim', explode('|', $line));
            $price = isset($parts[0]) ? (float) $parts[0] : 0.0;
            $days = isset($parts[1]) ? (int) $parts[1] : 0;
            $title = isset($parts[2]) ? sanitize_text_field($parts[2]) : '';
            if ($price <= 0) {
                continue;
            }
            if ($title === '') {
                $title = $days > 0
                    ? sprintf(__('%d天会员', 'aksrt'), $days)
                    : __('永久会员', 'aksrt');
            }
            $out[] = [
                'price' => round($price, 2),
                'days'  => max(0, $days),
                'title' => $title,
            ];
        }
        return $out;
    }

    public function encode_package_id(int $level, int $index): int {
        return (max(1, min(2, $level)) * 1000) + max(1, $index);
    }

    /**
     * @return array{level:int,index:int}|null
     */
    public function decode_package_id(int $package_id): ?array {
        if ($package_id < 1001) {
            return null;
        }
        $level = intdiv($package_id, 1000);
        $index = $package_id % 1000;
        if ($level < 1 || $level > 2 || $index < 1) {
            return null;
        }
        return ['level' => $level, 'index' => $index];
    }

    /**
     * @return array<int, array{id:string,name:string}>
     */
    private function available_payment_methods(): array {
        $methods = [];
        if (!class_exists('AKSRT_Payment_Gateway')) {
            return [['id' => 'balance', 'name' => __('站内余额', 'aksrt')]];
        }
        $gw = AKSRT_Payment_Gateway::get_instance();
        foreach (['balance', 'alipay', 'wechatpay', 'paypal', 'stripe'] as $id) {
            $g = $gw->get_gateway($id);
            if (!$g) {
                continue;
            }
            if (method_exists($g, 'is_configured') && !$g->is_configured()) {
                continue;
            }
            $methods[] = [
                'id' => $id,
                'name' => method_exists($g, 'get_name') ? (string) $g->get_name() : $id,
            ];
        }
        if ($methods === []) {
            $methods[] = ['id' => 'balance', 'name' => __('站内余额', 'aksrt')];
        }
        return $methods;
    }

    private function format_cash_label(float $amount): string {
        $symbol = '￥';
        if (class_exists('AKSRT_Settings')) {
            $paid = AKSRT_Settings::get_paid_content_settings();
            $symbol = (string) ($paid['display']['currency_symbol'] ?? '￥');
        }
        $n = function_exists('aksrt_format_price') ? aksrt_format_price($amount) : (string) $amount;
        return $symbol . $n;
    }

    private function format_expires_label(int $expires, int $level): string {
        if ($level <= 0) {
            return __('未开通', 'aksrt');
        }
        if ($expires <= 0) {
            return __('永久有效', 'aksrt');
        }
        if ($expires < time()) {
            return __('已过期', 'aksrt');
        }
        return sprintf(
            /* translators: %s: date */
            __('到期时间：%s', 'aksrt'),
            wp_date('Y-m-d H:i', $expires)
        );
    }
}