szkp-map-service/app/Support/VenueAdminCredentials.php

<?php

namespace App\Support;

use Overtrue\Pinyin\Pinyin;

/**
 * 场馆后台账号：用户名（拼音首字母缩写）与密码（首尾大写 + @）规则。
 */
final class VenueAdminCredentials
{
    /**
     * 由场馆名称得到拼音首字母缩写（小写、仅字母数字），用于用户名及密码变换的基底。
     */
    public static function acronymFromVenueName(string $name): string
    {
        $joined = Pinyin::abbr($name)->join('');
        $joined = strtolower($joined);
        $joined = preg_replace('/[^a-z0-9]/', '', $joined) ?? '';

        return $joined !== '' ? $joined : 'v';
    }

    /**
     * 由「缩写基底」生成密码：首字母大写、中间小写、末字母大写、末尾 @。
     * 例：zjgkjg → ZjgkjG@
     */
    public static function passwordFromAcronym(string $acronymLower): string
    {
        $slug = strtolower(preg_replace('/[^a-z0-9]/', '', $acronymLower) ?? '');
        if ($slug === '') {
            return 'Xx@';
        }

        $len = strlen($slug);
        if ($len === 1) {
            return strtoupper($slug[0]).'@';
        }

        $first = strtoupper($slug[0]);
        $last = strtoupper($slug[$len - 1]);
        $middle = strtolower(substr($slug, 1, $len - 2));

        return $first.$middle.$last.'@';
    }
}