<?php

namespace app\util;
class StringUtil
{
    /**
     * 随机生成字符串
     * @param int $length
     * @return string
     */
    public static function generateRandomString(int $length): string
    {
        $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
        $randomString = '';

        for ($i = 0; $i < $length; $i++) {
            $randomString .= $characters[rand(0, strlen($characters) - 1)];
        }

        return $randomString;
    }
    /**
     * 生成订单号
     * @return string
     */
    public static function makeOrderNumber():string
    {
        return date_create()->format('ymdHisu');
    }

    /**
     * 生成商户端协议号
     * @return string
     */
    public static function makeAgreementId()
    {
        return md5(date_create()->format('ymdHisu'));
    }

    /**
     * 手机号加星
     * @param $phone
     * @return array|string|string[]|null
     */
    public static function maskPhone($phone) {
        return preg_replace("/(\d{3})\d{4}(\d{4})/", "$1****$2", $phone);
    }
}