<?php
/**
 * 归档扩展搜索：在新闻/公告归档搜索时，额外按作者显示名/登录名/昵称匹配。
 * 由主题模板通过查询变量 itstudio_archive_extend_search / itstudio_archive_keyword 触发。
 * 抽离自主题 functions.php。
 */

if (!defined('ABSPATH')) {
    exit;
}

function itstudio_archive_extended_search_enabled($query) {
    if (!($query instanceof WP_Query)) {
        return false;
    }

    if (!$query->get('itstudio_archive_extend_search')) {
        return false;
    }

    $keyword = trim((string) $query->get('itstudio_archive_keyword'));
    return $keyword !== '';
}

function itstudio_archive_extended_search_join($join, $query) {
    if (!itstudio_archive_extended_search_enabled($query)) {
        return $join;
    }

    global $wpdb;
    if (strpos($join, $wpdb->users) !== false) {
        return $join;
    }

    return $join . " LEFT JOIN {$wpdb->users} ON ({$wpdb->posts}.post_author = {$wpdb->users}.ID) ";
}
add_filter('posts_join', 'itstudio_archive_extended_search_join', 10, 2);

function itstudio_archive_extended_search_where($where, $query) {
    if (!itstudio_archive_extended_search_enabled($query)) {
        return $where;
    }

    global $wpdb;
    $keyword = trim((string) $query->get('itstudio_archive_keyword'));
    $like = '%' . $wpdb->esc_like($keyword) . '%';

    $search_sql = $wpdb->prepare(
        " AND (
            {$wpdb->posts}.post_title LIKE %s
            OR {$wpdb->posts}.post_excerpt LIKE %s
            OR {$wpdb->posts}.post_content LIKE %s
            OR {$wpdb->users}.display_name LIKE %s
            OR {$wpdb->users}.user_login LIKE %s
            OR {$wpdb->users}.user_nicename LIKE %s
        )",
        $like,
        $like,
        $like,
        $like,
        $like,
        $like
    );

    return $where . $search_sql;
}
add_filter('posts_where', 'itstudio_archive_extended_search_where', 10, 2);