<?php
/**
 * AKSRT User Notifications
 *
 * Notification CRUD, AJAX handlers, and event-driven notification creators.
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

if (!function_exists('aksrt_get_user_notifications')) :
/**
 * 获取用户提醒列表（即时提醒，不持久化）
 *
 * 当前通知源：
 * - 邮箱待验证
 * - 评论待审核
 *
 * @param int $user_id 用户 ID，默认当前用户
 * @return array<int, array{type:string,title:string,desc:string,url:string,count:int}>
 */
function aksrt_get_user_notifications(int $user_id = 0): array {
    $user_id = $user_id > 0 ? $user_id : get_current_user_id();
    if ($user_id <= 0) {
        return [];
    }

    $items = [];

    $email_verified = true;
    if (class_exists('\AKSRT\Auth\Service')) {
        $email_verified = \AKSRT\Auth\Service::user_is_email_verified($user_id);
    }

    if (!$email_verified && (!class_exists('\AKSRT\Settings\Settings') || \AKSRT\Settings\Settings::notification_enabled('verify_email'))) {
        $items[] = [
            'type'  => 'verify_email',
            'title' => __('邮箱待验证', 'aksrt'),
            'desc'  => __('请尽快完成邮箱验证，部分功能需要验证后才能使用。', 'aksrt'),
            'url'   => function_exists('aksrt_get_verify_email_url') ? aksrt_get_verify_email_url($user_id) : home_url('/'),
            'count' => 1,
        ];
    }

    $pending_comments = (int) get_comments([
        'user_id' => $user_id,
        'count'   => true,
        'status'  => 'hold',
    ]);

    if ($pending_comments > 0 && (!class_exists('\AKSRT\Settings\Settings') || \AKSRT\Settings\Settings::notification_enabled('pending_comments'))) {
        $items[] = [
            'type'  => 'pending_comments',
            'title' => __('评论待审核', 'aksrt'),
            'desc'  => sprintf(__('你有 %d 条评论正在等待审核。', 'aksrt'), $pending_comments),
            'url'   => aksrt_get_user_center_url('comments'),
            'count' => $pending_comments,
        ];
    }

    return $items;
}
endif;

if (!function_exists('aksrt_notification_type_label')) :
/** 通知类型中文标签 */
function aksrt_notification_type_label(string $type): string {
    $map = [
        'comment_reply'     => __('评论回复', 'aksrt'),
        'comment_approved'  => __('评论审核', 'aksrt'),
        'download_ready'    => __('下载就绪', 'aksrt'),
        'credits_added'     => __('积分增加', 'aksrt'),
        'credits_deducted'  => __('积分扣减', 'aksrt'),
        'verify_email'      => __('邮箱验证', 'aksrt'),
        'pending_comments'  => __('待审核评论', 'aksrt'),
        'notice'            => __('通知', 'aksrt'),
    ];
    return $map[$type] ?? $type;
}
endif;

if (!function_exists('aksrt_get_user_notification_count')) :
/** 获取用户提醒总数 */
function aksrt_get_user_notification_count(int $user_id = 0): int {
    $items = aksrt_get_user_notifications($user_id);
    $count = 0;
    foreach ($items as $item) {
        $count += max(0, (int) ($item['count'] ?? 0));
    }
    return $count;
}
endif;

if (!function_exists('aksrt_get_user_inbox_notifications')) :
/** 获取用户通知收件箱 */
function aksrt_get_user_inbox_notifications(int $user_id = 0): array {
    $user_id = $user_id > 0 ? $user_id : get_current_user_id();
    if ($user_id <= 0) return [];

    global $wpdb;
    $table = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('notification') : '';
    if ($table === '') {
        $items = get_user_meta($user_id, 'aksrt_notifications', true);
        return is_array($items) ? array_values($items) : [];
    }

    static $migrated = [];
    if (empty($migrated[$user_id])) {
        $legacy = get_user_meta($user_id, 'aksrt_notifications', true);
        if (is_array($legacy) && !empty($legacy)) {
            foreach ($legacy as $item) {
                aksrt_add_user_notification($user_id, [
                    'id'         => $item['id'] ?? '',
                    'type'       => $item['type'] ?? 'notice',
                    'title'      => $item['title'] ?? '',
                    'desc'       => $item['desc'] ?? '',
                    'url'        => $item['url'] ?? '',
                    'read'       => !empty($item['read']),
                    'created_at' => $item['created_at'] ?? current_time('mysql', true),
                ]);
            }
            delete_user_meta($user_id, 'aksrt_notifications');
        }
        $migrated[$user_id] = true;
    }

    $rows = $wpdb->get_results($wpdb->prepare(
        "SELECT id, type, title, description, target_url, is_read, created_at, read_at
         FROM {$table}
         WHERE user_id = %d
         ORDER BY created_at DESC, id DESC
         LIMIT 50",
        $user_id
    ), ARRAY_A);

    if (!is_array($rows)) return [];

    return array_map(static function ($row) {
        return [
            'id'         => (string) ($row['id'] ?? ''),
            'type'       => (string) ($row['type'] ?? 'notice'),
            'title'      => (string) ($row['title'] ?? ''),
            'desc'       => (string) ($row['description'] ?? ''),
            'url'        => (string) ($row['target_url'] ?? ''),
            'read'       => !empty($row['is_read']) ? 1 : 0,
            'created_at' => (string) ($row['created_at'] ?? ''),
            'read_at'    => (string) ($row['read_at'] ?? ''),
        ];
    }, $rows);
}
endif;

if (!function_exists('aksrt_schedule_notification_cleanup')) :
/** 注册通知清理定时任务 */
function aksrt_schedule_notification_cleanup(): void {
    if (!wp_next_scheduled('aksrt_notification_cleanup')) {
        $next = (new DateTimeImmutable('tomorrow 04:10', wp_timezone()))->getTimestamp();
        wp_schedule_event($next, 'daily', 'aksrt_notification_cleanup');
    }
}
endif;

if (!function_exists('aksrt_cleanup_notifications')) :
/**
 * 清理通知表：
 * - 已读通知保留 30 天
 * - 未读通知保留 180 天
 * - 每个用户最多保留最近 200 条通知
 */
function aksrt_cleanup_notifications(): void {
    global $wpdb;

    $table = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('notification') : '';
    if ($table === '') {
        return;
    }

    $settings = class_exists('\AKSRT\Settings\Settings') ? \AKSRT\Settings\Settings::get_notification_settings() : [
        'read_retention_days'   => 30,
        'unread_retention_days' => 180,
        'max_per_user'          => 200,
    ];

    $read_retention_days = max(1, (int) ($settings['read_retention_days'] ?? 30));
    $unread_retention_days = max(7, (int) ($settings['unread_retention_days'] ?? 180));
    $max_per_user = max(20, (int) ($settings['max_per_user'] ?? 200));

    $read_cutoff = (new DateTimeImmutable('-' . $read_retention_days . ' days', new DateTimeZone('UTC')))->format('Y-m-d H:i:s');
    $unread_cutoff = (new DateTimeImmutable('-' . $unread_retention_days . ' days', new DateTimeZone('UTC')))->format('Y-m-d H:i:s');

    $wpdb->query($wpdb->prepare(
        "DELETE FROM {$table} WHERE is_read = 1 AND created_at < %s",
        $read_cutoff
    ));

    $wpdb->query($wpdb->prepare(
        "DELETE FROM {$table} WHERE is_read = 0 AND created_at < %s",
        $unread_cutoff
    ));

    $user_ids = $wpdb->get_col("SELECT DISTINCT user_id FROM {$table}");
    if (empty($user_ids)) {
        return;
    }

    foreach ($user_ids as $user_id) {
        $user_id = (int) $user_id;
        if ($user_id <= 0) continue;

        $ids = $wpdb->get_col($wpdb->prepare(
            "SELECT id FROM {$table} WHERE user_id = %d ORDER BY created_at DESC, id DESC LIMIT %d, 1000",
            $user_id,
            $max_per_user
        ));

        if (empty($ids)) {
            continue;
        }

        $ids = array_map('absint', $ids);
        $ids = array_filter($ids, static function ($id) { return $id > 0; });
        if (empty($ids)) {
            continue;
        }

        $wpdb->query("DELETE FROM {$table} WHERE id IN (" . implode(',', $ids) . ")");
    }
}
endif;

add_action('wp', 'aksrt_schedule_notification_cleanup');
add_action('aksrt_notification_cleanup', 'aksrt_cleanup_notifications');

if (!function_exists('aksrt_write_user_inbox_notifications')) :
/** 写入用户通知收件箱 */
function aksrt_write_user_inbox_notifications(int $user_id, array $items): void {
    if ($user_id <= 0) return;
    global $wpdb;
    $table = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('notification') : '';
    if ($table === '') {
        update_user_meta($user_id, 'aksrt_notifications', array_values(array_slice($items, 0, 50)));
        return;
    }

    $wpdb->delete($table, ['user_id' => $user_id], ['%d']);
    $items = array_values(array_slice($items, 0, 50));
    foreach ($items as $item) {
        $wpdb->insert($table, [
            'user_id'     => $user_id,
            'type'        => sanitize_key((string) ($item['type'] ?? 'notice')),
            'title'       => sanitize_text_field((string) ($item['title'] ?? '')),
            'description' => sanitize_text_field((string) ($item['desc'] ?? '')),
            'target_url'  => esc_url_raw((string) ($item['url'] ?? '')),
            'is_read'     => !empty($item['read']) ? 1 : 0,
            'created_at'  => (string) ($item['created_at'] ?? current_time('mysql', true)),
            'read_at'     => !empty($item['read']) ? current_time('mysql', true) : null,
        ], ['%d', '%s', '%s', '%s', '%s', '%d', '%s', '%s']);
    }
}
endif;

if (!function_exists('aksrt_add_user_notification')) :
/** 添加一条用户通知 */
function aksrt_add_user_notification(int $user_id, array $payload): void {
    if ($user_id <= 0) return;
    $type = sanitize_key((string) ($payload['type'] ?? 'notice'));
    if (class_exists('\AKSRT\Settings\Settings') && !\AKSRT\Settings\Settings::notification_enabled($type)) {
        return;
    }

    global $wpdb;
    $table = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('notification') : '';
    $created_at = (string) ($payload['created_at'] ?? current_time('mysql', true));

    if ($table === '') {
        $items = aksrt_get_user_inbox_notifications($user_id);
        array_unshift($items, [
            'id'         => isset($payload['id']) && $payload['id'] !== '' ? sanitize_text_field((string) $payload['id']) : uniqid('notif_', true),
            'type'       => $type,
            'title'      => sanitize_text_field((string) ($payload['title'] ?? '')),
            'desc'       => sanitize_text_field((string) ($payload['desc'] ?? '')),
            'url'        => esc_url_raw((string) ($payload['url'] ?? '')),
            'read'       => !empty($payload['read']) ? 1 : 0,
            'created_at' => $created_at,
        ]);
        aksrt_write_user_inbox_notifications($user_id, $items);
        return;
    }

    $wpdb->insert($table, [
        'user_id'     => $user_id,
        'type'        => $type,
        'title'       => sanitize_text_field((string) ($payload['title'] ?? '')),
        'description' => sanitize_text_field((string) ($payload['desc'] ?? '')),
        'target_url'  => esc_url_raw((string) ($payload['url'] ?? '')),
        'is_read'     => !empty($payload['read']) ? 1 : 0,
        'created_at'  => $created_at,
        'read_at'     => !empty($payload['read']) ? current_time('mysql', true) : null,
    ], ['%d', '%s', '%s', '%s', '%s', '%d', '%s', '%s']);
}
endif;

if (!function_exists('aksrt_mark_user_notification_read')) :
/** 标记通知已读 */
function aksrt_mark_user_notification_read(int $user_id, string $notification_id = '', bool $mark_all = false): void {
    if ($user_id <= 0) return;
    global $wpdb;
    $table = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('notification') : '';
    if ($table === '') {
        $items = aksrt_get_user_inbox_notifications($user_id);
        foreach ($items as &$item) {
            if ($mark_all || (($item['id'] ?? '') === $notification_id)) {
                $item['read'] = 1;
            }
        }
        unset($item);
        aksrt_write_user_inbox_notifications($user_id, $items);
        return;
    }

    if ($mark_all) {
        $wpdb->update(
            $table,
            ['is_read' => 1, 'read_at' => current_time('mysql', true)],
            ['user_id' => $user_id, 'is_read' => 0],
            ['%d', '%s'],
            ['%d', '%d']
        );
        return;
    }

    $wpdb->update(
        $table,
        ['is_read' => 1, 'read_at' => current_time('mysql', true)],
        ['id' => absint($notification_id), 'user_id' => $user_id],
        ['%d', '%s'],
        ['%d', '%d']
    );
}
endif;

if (!function_exists('aksrt_delete_user_notification')) :
/** 删除一条用户通知 */
function aksrt_delete_user_notification(int $user_id, string $notification_id): void {
    if ($user_id <= 0 || $notification_id === '') return;
    global $wpdb;
    $table = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('notification') : '';
    if ($table === '') {
        $items = aksrt_get_user_inbox_notifications($user_id);
        $items = array_values(array_filter($items, static function ($item) use ($notification_id) {
            return (string) ($item['id'] ?? '') !== $notification_id;
        }));
        aksrt_write_user_inbox_notifications($user_id, $items);
        return;
    }
    $wpdb->delete($table, ['id' => absint($notification_id), 'user_id' => $user_id], ['%d', '%d']);
}
endif;

if (!function_exists('aksrt_delete_user_notifications')) :
/** 批量删除用户通知 */
function aksrt_delete_user_notifications(int $user_id, array $notification_ids): void {
    if ($user_id <= 0 || empty($notification_ids)) return;
    $ids = array_values(array_filter(array_map('absint', $notification_ids), static function ($id) { return $id > 0; }));
    if (empty($ids)) return;

    global $wpdb;
    $table = class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('notification') : '';
    if ($table === '') {
        $items = aksrt_get_user_inbox_notifications($user_id);
        $items = array_values(array_filter($items, static function ($item) use ($ids) {
            return !in_array(absint($item['id'] ?? 0), $ids, true);
        }));
        aksrt_write_user_inbox_notifications($user_id, $items);
        return;
    }

    $wpdb->query(
        "DELETE FROM {$table} WHERE user_id = " . (int) $user_id . " AND id IN (" . implode(',', $ids) . ")"
    );
}
endif;

if (!function_exists('aksrt_get_user_unread_notification_count')) :
/** 获取用户未读通知数 */
function aksrt_get_user_unread_notification_count(int $user_id = 0): int {
    $items = aksrt_get_user_inbox_notifications($user_id);
    $count = 0;
    foreach ($items as $item) {
        if (empty($item['read'])) $count++;
    }
    return $count;
}
endif;

if (!function_exists('aksrt_get_user_tab_badge_count')) :
/** user 底部 Tab 徽标计数：未读持久化通知 + 即时状态提醒 */
function aksrt_get_user_tab_badge_count(int $user_id = 0): int {
    $user_id = $user_id > 0 ? $user_id : get_current_user_id();
    if ($user_id <= 0) {
        return 0;
    }
    if (class_exists('\AKSRT\Settings\Settings') && !\AKSRT\Settings\Settings::notification_user_badge_enabled()) {
        return 0;
    }

    $count = aksrt_get_user_unread_notification_count($user_id);
    if (class_exists('\AKSRT\Settings\Settings') && \AKSRT\Settings\Settings::notification_badge_include_stateful()) {
        $count += aksrt_get_user_notification_count($user_id);
    }
    return $count;
}
endif;

if (!function_exists('aksrt_get_user_all_notifications')) :
/** 获取用户完整通知列表（持久化通知 + 即时提醒） */
function aksrt_get_user_all_notifications(int $user_id = 0): array {
    $user_id = $user_id > 0 ? $user_id : get_current_user_id();
    if ($user_id <= 0) return [];

    $inbox = aksrt_get_user_inbox_notifications($user_id);
    $alerts = aksrt_get_user_notifications($user_id);

    $normalized_alerts = [];
    foreach ($alerts as $alert) {
        $normalized_alerts[] = [
            'id'         => 'state_' . sanitize_key((string) ($alert['type'] ?? 'notice')),
            'type'       => sanitize_key((string) ($alert['type'] ?? 'notice')),
            'title'      => sanitize_text_field((string) ($alert['title'] ?? '')),
            'desc'       => sanitize_text_field((string) ($alert['desc'] ?? '')),
            'url'        => esc_url_raw((string) ($alert['url'] ?? '')),
            'read'       => 0,
            'created_at' => current_time('mysql', true),
            'count'      => max(0, (int) ($alert['count'] ?? 0)),
            'stateful'   => 1,
        ];
    }

    return array_merge($inbox, $normalized_alerts);
}
endif;

add_action('wp_ajax_aksrt_mark_notification_read', function () {
    if (!is_user_logged_in()) {
        wp_send_json_error(['message' => __('请先登录', 'aksrt')], 401);
    }

    $nonce = isset($_POST['nonce']) ? (string) $_POST['nonce'] : '';
    if (!wp_verify_nonce($nonce, 'aksrt_public_nonce')) {
        wp_send_json_error(['message' => __('安全验证失败', 'aksrt')], 403);
    }

    $notification_id = sanitize_text_field((string) ($_POST['notification_id'] ?? ''));
    $mark_all = !empty($_POST['mark_all']);
    aksrt_mark_user_notification_read(get_current_user_id(), $notification_id, $mark_all);
    wp_send_json_success([
        'unread' => aksrt_get_user_unread_notification_count(get_current_user_id()),
    ]);
});

add_action('wp_ajax_aksrt_delete_notification', function () {
    if (!is_user_logged_in()) {
        wp_send_json_error(['message' => __('请先登录', 'aksrt')], 401);
    }

    $nonce = isset($_POST['nonce']) ? (string) $_POST['nonce'] : '';
    if (!wp_verify_nonce($nonce, 'aksrt_public_nonce')) {
        wp_send_json_error(['message' => __('安全验证失败', 'aksrt')], 403);
    }

    $notification_id = sanitize_text_field((string) ($_POST['notification_id'] ?? ''));
    if ($notification_id === '') {
        wp_send_json_error(['message' => __('参数错误', 'aksrt')], 400);
    }

    aksrt_delete_user_notification(get_current_user_id(), $notification_id);
    wp_send_json_success([
        'unread' => aksrt_get_user_unread_notification_count(get_current_user_id()),
    ]);
});

add_action('wp_ajax_aksrt_delete_notifications', function () {
    if (!is_user_logged_in()) {
        wp_send_json_error(['message' => __('请先登录', 'aksrt')], 401);
    }

    $nonce = isset($_POST['nonce']) ? (string) $_POST['nonce'] : '';
    if (!wp_verify_nonce($nonce, 'aksrt_public_nonce')) {
        wp_send_json_error(['message' => __('安全验证失败', 'aksrt')], 403);
    }

    $ids = isset($_POST['notification_ids']) ? (array) $_POST['notification_ids'] : [];
    aksrt_delete_user_notifications(get_current_user_id(), $ids);
    wp_send_json_success([
        'unread' => aksrt_get_user_unread_notification_count(get_current_user_id()),
    ]);
});

add_action('wp_ajax_aksrt_check_new_notifications', function () {
    if (!is_user_logged_in()) {
        wp_send_json_error(['message' => __('请先登录', 'aksrt')], 401);
    }

    $nonce = isset($_POST['nonce']) ? (string) $_POST['nonce'] : '';
    if (!wp_verify_nonce($nonce, 'aksrt_public_nonce')) {
        wp_send_json_error(['message' => __('安全验证失败', 'aksrt')], 403);
    }

    $unread = aksrt_get_user_unread_notification_count(get_current_user_id());
    wp_send_json_success([
        'count' => $unread,
        'unread' => $unread,
    ]);
});
add_action('wp_insert_comment', function ($comment_id, $comment) {
    if (!$comment instanceof WP_Comment) return;
    if ((int) $comment->comment_parent <= 0) return;
    if ((int) $comment->comment_approved !== 1) return;
    if (get_comment_meta($comment_id, 'aksrt_reply_notified', true)) return;

    $parent = get_comment((int) $comment->comment_parent);
    if (!$parent instanceof WP_Comment) return;
    $target_user_id = (int) $parent->user_id;
    if ($target_user_id <= 0 || $target_user_id === (int) $comment->user_id) return;

    $post_id = (int) $comment->comment_post_ID;
    $url = get_comment_link($comment);
    aksrt_add_user_notification($target_user_id, [
        'type'  => 'comment_reply',
        'title' => __('评论收到回复', 'aksrt'),
        'desc'  => sprintf(__('“%s” 回复了你的评论。', 'aksrt'), get_comment_author($comment)),
        'url'   => $url ?: get_permalink($post_id),
    ]);
    update_comment_meta($comment_id, 'aksrt_reply_notified', 1);
}, 20, 2);

add_action('transition_comment_status', function ($new_status, $old_status, $comment) {
    if (!$comment instanceof WP_Comment) return;
    if ($new_status !== 'approve' || $old_status === 'approve') return;

    $comment_owner_id = (int) $comment->user_id;
    if ($comment_owner_id > 0 && !get_comment_meta($comment->comment_ID, 'aksrt_approved_notified', true)) {
        aksrt_add_user_notification($comment_owner_id, [
            'type'  => 'comment_approved',
            'title' => __('评论已通过审核', 'aksrt'),
            'desc'  => __('你的评论已通过审核，现已公开展示。', 'aksrt'),
            'url'   => get_comment_link($comment),
        ]);
        update_comment_meta($comment->comment_ID, 'aksrt_approved_notified', 1);
    }

    if ((int) $comment->comment_parent <= 0) return;
    if (get_comment_meta($comment->comment_ID, 'aksrt_reply_notified', true)) return;

    $parent = get_comment((int) $comment->comment_parent);
    if (!$parent instanceof WP_Comment) return;
    $target_user_id = (int) $parent->user_id;
    if ($target_user_id <= 0 || $target_user_id === (int) $comment->user_id) return;

    aksrt_add_user_notification($target_user_id, [
        'type'  => 'comment_reply',
        'title' => __('评论收到回复', 'aksrt'),
        'desc'  => sprintf(__('“%s” 回复了你的评论。', 'aksrt'), get_comment_author($comment)),
        'url'   => get_comment_link($comment),
    ]);
    update_comment_meta($comment->comment_ID, 'aksrt_reply_notified', 1);
}, 20, 3);

add_action('aksrt_credits_added', function ($user_id, $delta, $reason, $new_balance) {
    if ($user_id <= 0 || $delta <= 0) return;
    aksrt_add_user_notification((int) $user_id, [
        'type'  => 'credits_added',
        'title' => __('积分增加', 'aksrt'),
        'desc'  => sprintf(__('积分变动：+%1$d，当前余额 %2$d。', 'aksrt'), (int) $delta, (int) $new_balance),
        'url'   => aksrt_get_user_center_url('credits'),
    ]);
}, 10, 4);

add_action('aksrt_credits_deducted', function ($user_id, $cost, $reason, $new_balance) {
    if ($user_id <= 0 || $cost <= 0) return;
    aksrt_add_user_notification((int) $user_id, [
        'type'  => 'credits_deducted',
        'title' => __('积分扣减', 'aksrt'),
        'desc'  => sprintf(__('积分变动：-%1$d，当前余额 %2$d。', 'aksrt'), (int) $cost, (int) $new_balance),
        'url'   => aksrt_get_user_center_url('credits'),
    ]);
}, 10, 4);