<?php
/**
 * AKSRT Content Visibility
 *
 * Central access policy for shortcode-gated content and paid-content runtime.
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Content_Visibility {

    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 {
        // 短代码注册统一在 AKSRT_Shortcodes（registry）；本类只提供渲染实现。
        add_action('wp_ajax_aksrt_check_visibility', [$this, 'ajax_check_visibility']);
        add_action('wp_ajax_nopriv_aksrt_check_visibility', [$this, 'ajax_check_visibility']);
    }

    /**
     * @param int|WP_Post|null $post
     * @return array<string, mixed>
     */
    public static function get_post_access_state($post = null, int $user_id = 0): array {
        $resource_post = get_post($post);
        $uid = $user_id > 0 ? $user_id : get_current_user_id();
        $pay_meta = function_exists('aksrt_get_pay_meta')
            ? aksrt_get_pay_meta($resource_post)
            : AKSRT_Domain_Model::default_pay_meta();
        $pay_type = AKSRT_Domain_Model::normalize_pay_type((string) ($pay_meta['pay_type'] ?? AKSRT_Domain_Model::PAY_TYPE_NO));
        $price = (float) ($pay_meta['price'] ?? 0);
        $paid_settings = class_exists('AKSRT_Settings')
            ? AKSRT_Settings::get_paid_content_settings()
            : [
                'download_login' => true,
                'download_credit' => true,
                'download_captcha' => false,
            ];

        $state = [
            'post_id' => $resource_post instanceof WP_Post ? (int) $resource_post->ID : 0,
            'pay_type' => $pay_type,
            'price' => $price,
            'need_login' => false,
            'need_purchase' => false,
            'need_vip' => false,
            'require_captcha' => false,
            'has_paid_access' => false,
            'can_view' => true,
            'can_download' => true,
            'download_cost' => 0,
        ];

        if (!($resource_post instanceof WP_Post)) {
            $state['can_view'] = false;
            $state['can_download'] = false;
            return $state;
        }

        if ($pay_type === AKSRT_Domain_Model::PAY_TYPE_NO) {
            return $state;
        }

        $has_free_access = $price <= 0 && $pay_type !== AKSRT_Domain_Model::PAY_TYPE_VIP;
        $has_paid_order = false;

        if ($uid > 0 && class_exists('AKSRT_Order')) {
            $has_paid_order = AKSRT_Order::get_instance()->has_paid_access(
                $uid,
                AKSRT_Domain_Model::ORDER_PRODUCT_RESOURCE,
                (int) $resource_post->ID
            );
        }

        $has_vip_access = false;
        if ($uid > 0) {
            if (function_exists('aksrt_is_vip_exempt') && aksrt_is_vip_exempt($uid)) {
                $has_vip_access = true;
            } elseif (function_exists('aksrt_is_vip') && $pay_type === AKSRT_Domain_Model::PAY_TYPE_VIP) {
                $has_vip_access = aksrt_is_vip($uid);
            }
        }

        if ($pay_type === AKSRT_Domain_Model::PAY_TYPE_DOWNLOAD) {
            $download_cost = function_exists('aksrt_resource_download_cost')
                ? (int) aksrt_resource_download_cost($resource_post)
                : (int) ceil($price);

            $state['download_cost'] = max(0, $download_cost);
            $state['need_login'] = !empty($paid_settings['download_login']) || !empty($pay_meta['require_login']);
            $state['require_captcha'] = !empty($paid_settings['download_captcha']) || !empty($pay_meta['require_captcha']);
            $state['need_purchase'] = !$has_vip_access && $state['download_cost'] > 0;
            $state['has_paid_access'] = $has_vip_access || $has_paid_order || !$state['need_purchase'];
            $state['can_view'] = true;
            $state['can_download'] = !$state['need_login'] || $uid > 0;

            return $state;
        }

        if ($pay_type === AKSRT_Domain_Model::PAY_TYPE_VIP) {
            $state['need_vip'] = true;
            $state['has_paid_access'] = $has_vip_access;
            $state['can_view'] = $has_vip_access;
            $state['can_download'] = false;

            return $state;
        }

        $state['need_login'] = !empty($pay_meta['require_login']);
        $state['need_purchase'] = !$has_free_access;
        $state['has_paid_access'] = $has_free_access || $has_paid_order || $has_vip_access;
        $state['can_view'] = $state['has_paid_access'] && (!$state['need_login'] || $uid > 0);
        $state['can_download'] = false;

        return $state;
    }

    public static function can_view_paid_content($post = null, int $user_id = 0): bool {
        $state = self::get_post_access_state($post, $user_id);
        return !empty($state['can_view']);
    }

    /**
     * @param int|WP_Post|null $post
     * @return true|WP_Error
     */
    public static function can_download_resource($post = null, int $user_id = 0) {
        $resource_post = get_post($post);
        if (!($resource_post instanceof WP_Post) || !function_exists('aksrt_is_resource_post') || !aksrt_is_resource_post($resource_post)) {
            return new WP_Error('aksrt_not_resource', __('该内容不是可下载资源。', 'aksrt'));
        }

        $state = self::get_post_access_state($resource_post, $user_id);
        $uid = $user_id > 0 ? $user_id : get_current_user_id();

        if (($state['pay_type'] ?? '') !== AKSRT_Domain_Model::PAY_TYPE_DOWNLOAD) {
            return new WP_Error('aksrt_not_downloadable', __('该内容不是可下载资源。', 'aksrt'));
        }

        if (!empty($state['need_login']) && $uid <= 0) {
            return new WP_Error('aksrt_need_login', __('请先登录后再下载。', 'aksrt'), [
                'status' => 401,
                'login_url' => wp_login_url(get_permalink($resource_post)),
            ]);
        }

        $cost = (int) ($state['download_cost'] ?? 0);
        $paid_settings = class_exists('AKSRT_Settings')
            ? AKSRT_Settings::get_paid_content_settings()
            : ['download_credit' => true];

        if (!empty($paid_settings['download_credit']) && $cost > 0) {
            $balance = class_exists('AKSRT_Credits') ? AKSRT_Credits::balance($uid) : 0;
            if ($balance < $cost) {
                return new WP_Error('aksrt_credits_insufficient', __('积分不足，无法下载。', 'aksrt'), [
                    'status' => 402,
                    'balance' => $balance,
                    'cost' => $cost,
                ]);
            }
        }

        return true;
    }

    public function render_hide_shortcode(array $atts, string $content = ''): string {
        $atts = shortcode_atts([
            'mode'    => 'comment',
            'message' => '',
            'pid'     => get_the_ID(),
        ], $atts, 'aksrt_hide');

        $mode = sanitize_key((string) $atts['mode']);
        $pid  = (int) $atts['pid'];
        $message = (string) $atts['message'];

        if ($pid <= 0) {
            return '';
        }

        if ($this->is_unlocked($mode, $pid)) {
            return '<div class="aksrt-hidden-content aksrt-hidden-content--unlocked">' . do_shortcode($content) . '</div>';
        }

        if ($message === '') {
            switch ($mode) {
                case 'comment':
                    $message = __('评论后查看隐藏内容', 'aksrt');
                    break;
                case 'login':
                    $message = __('登录后查看隐藏内容', 'aksrt');
                    break;
                case 'password':
                    $message = __('输入密码后查看隐藏内容', 'aksrt');
                    break;
                default:
                    $message = __('此内容已隐藏', 'aksrt');
            }
        }

        $wrapper_class = 'aksrt-hidden-content aksrt-hidden-content--locked aksrt-hidden-content--' . esc_attr($mode);
        $html = '<div class="' . $wrapper_class . '" data-aksrt-visibility-mode="' . esc_attr($mode) . '" data-aksrt-visibility-pid="' . esc_attr((string) $pid) . '">';
        $html .= '<div class="aksrt-hidden-content__message">';
        $html .= '<i class="fas fa-lock" aria-hidden="true"></i> ';
        $html .= '<span>' . esc_html($message) . '</span>';
        $html .= '</div>';

        if ($mode === 'password') {
            $html .= '<div class="aksrt-hidden-content__form">';
            $html .= '<input type="password" class="aksrt-hidden-content__password-input" placeholder="' . esc_attr__('请输入密码', 'aksrt') . '">';
            $html .= '<button type="button" class="aksrt-hidden-content__submit-btn btn-primary btn-sm">' . esc_html__('验证', 'aksrt') . '</button>';
            $html .= '</div>';
        }

        $html .= '</div>';

        return $html;
    }

    private function is_unlocked(string $mode, int $pid): bool {
        switch ($mode) {
            case 'comment':
                if (!is_user_logged_in()) {
                    return false;
                }

                return get_comments([
                    'post_id' => $pid,
                    'user_id' => get_current_user_id(),
                    'count' => true,
                    'status' => 'approve',
                ]) > 0;

            case 'login':
                return is_user_logged_in();

            case 'password':
                return !empty($_COOKIE['aksrt_hide_pwd_' . $pid]);

            default:
                return false;
        }
    }

    public function ajax_check_visibility(): void {
        check_ajax_referer('aksrt_visibility', '_nonce');

        $mode = sanitize_key((string) ($_POST['mode'] ?? ''));
        $pid  = (int) ($_POST['pid'] ?? 0);

        if ($pid <= 0 || !in_array($mode, ['comment', 'login', 'password'], true)) {
            wp_send_json_error(['message' => __('参数无效', 'aksrt')]);
        }

        if ($mode === 'password') {
            $password = sanitize_text_field((string) ($_POST['password'] ?? ''));
            $post_password = get_post_password($pid);
            if ($post_password === '' || $password !== $post_password) {
                wp_send_json_error(['message' => __('密码错误', 'aksrt')]);
            }

            setcookie('aksrt_hide_pwd_' . $pid, '1', time() + HOUR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN, is_ssl(), true);
            wp_send_json_success(['message' => __('验证成功', 'aksrt')]);
        }

        if ($this->is_unlocked($mode, $pid)) {
            wp_send_json_success(['message' => __('已解锁', 'aksrt')]);
        }

        wp_send_json_error(['message' => __('未满足条件', 'aksrt')]);
    }
}