drb/app/Service/Service.php

<?php

namespace App\Service;


use App\Jobs\OperationLog;
use App\Model\Depart;
use App\Model\Employee;
use Illuminate\Support\Facades\Redis;
use Illuminate\Support\Facades\Storage;

/**
 * 公用的公共服务
 * @package App\Models
 */
class Service
{

    public $log;
    public $total = 0;

    public function __construct()
    {

    }

    //分页共用
    public function limit($db, $columns, $request)
    {
        $per_page = $request['page_size'] ?? 100;
        $page = $request['page_index'] ?? 1;
        $return = $db->paginate($per_page, $columns, 'page', $page)->toArray();

        $data['total'] = $return['total'];
        $data['data'] = $return['data'];
        return $data;
    }

    //分页共用2
    public function limitData($db, $columns, $request)
    {
        $per_page = $request['page_size'] ?? 1000;
        $page = $request['page_index'] ?? 1;
        $return = $db->paginate($per_page, $columns, 'page', $page)->toArray();

        return $return['data'];
    }


    //抽象一个查询条件，省的每天写很多行
    protected function is_exist_db($data, $word, $words, $db, $formula = '=', $type = '')
    {
        if (isset($data[$word]) && ($data[$word] !== null && $data[$word] !== '' && $data[$word] !== [])) {
            switch ($type) {
                case 'time':
                    $data[$word] = ctype_digit($data[$word]) ? $data[$word] : strtotime($data[$word]);
                    if ($formula == '<'||$formula == '<=') $data[$word] += 86400;
                    $db = $db->where($words, $formula, $data[$word]);
                    break;
                case 'like':
                    $db = $db->where($words, $type, '%' . $data[$word] . '%');
                    break;
                case 'in':
                    if (is_array($data[$word])) {
                        $db = $db->wherein($words, $data[$word]);
                    } else {
                        $db = $db->wherein($words, explode(',', $data[$word]));
                    }

                    break;
                default:
                    $db = $db->where($words, $formula, $data[$word]);
                    break;
            }

            return $db;
        }
        return $db;
    }


    //判断是否为空
    protected function isEmpty($data, $word)
    {
        if (isset($data[$word]) && (!empty($data[$word]) || $data[$word] === '0'|| $data[$word] === 0)) return false;
        return true;
    }


    //递归处理数据成子父级关系
    public function makeTree($parentId, &$node)
    {
        $tree = [];
        foreach ($node as $key => $value) {
            if ($value['parent_id'] == $parentId) {
                $tree[$value['id']] = $value;
                unset($node[$key]);
                if (isset($tree[$value['id']]['children'])) {
                    $tree[$value['id']]['children'] = array_merge($tree[$value['id']]['children'], $this->makeTree($value['id'], $node));
                } else {
                    $tree[$value['id']]['children'] = $this->makeTree($value['id'], $node);
                }
            }
        }
        return $tree;
    }

    //进行递归处理数组的排序问题
    public function set_sort_circle($data){
        foreach ($data as $k=>$v){
//            var_dump($v);die;
            if(isset($v['children'])&&!empty($v['children'])){
                $data[$k]['children'] =  $this->set_sort_circle($v['children']);
            }
        }
        $data = array_merge($data);

        return $data;
    }


    //根据编码规则获取每一级的code
    public function get_rule_code($code, $rule)
    {
        $rules = [];
        $num = 0;
        foreach ($rule as $v) {
            $num += $v['num'];
            $code = substr($code, 0, $num);
            if (strlen($code) != $num) continue;
            $rules[] = $code;

        }

        return $rules;
    }



    function curlOpen($url, $config = array())
    {
        $arr = array('post' => false,'referer' => $url,'cookie' => '', 'useragent' => 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; customie8)', 'timeout' => 100, 'return' => true, 'proxy' => '', 'userpwd' => '', 'nobody' => false,'header'=>array(),'gzip'=>true,'ssl'=>true,'isupfile'=>false,'returnheader'=>false,'request'=>'post');
        $arr = array_merge($arr, $config);
        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, $arr['return']);
        curl_setopt($ch, CURLOPT_NOBODY, $arr['nobody']);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
        curl_setopt($ch, CURLOPT_USERAGENT, $arr['useragent']);
        curl_setopt($ch, CURLOPT_REFERER, $arr['referer']);
        curl_setopt($ch, CURLOPT_TIMEOUT, $arr['timeout']);


        curl_setopt($ch, CURLOPT_HEADER, $arr['returnheader']);//��ȡheader
        if($arr['gzip']) curl_setopt($ch, CURLOPT_ENCODING, 'gzip,deflate');
        if($arr['ssl'])
        {
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        }
        if(!empty($arr['cookie']))
        {
            curl_setopt($ch, CURLOPT_COOKIEJAR, $arr['cookie']);
            curl_setopt($ch, CURLOPT_COOKIEFILE, $arr['cookie']);
        }

        if(!empty($arr['proxy']))
        {
            //curl_setopt($ch, CURLOPT_PROXYTYPE, CURLPROXY_HTTP);
            curl_setopt ($ch, CURLOPT_PROXY, $arr['proxy']);
            if(!empty($arr['userpwd']))
            {
                curl_setopt($ch,CURLOPT_PROXYUSERPWD,$arr['userpwd']);
            }
        }

        //ip�Ƚ����⣬�ü�ֵ��ʾ
        if(!empty($arr['header']['ip']))
        {
            array_push($arr['header'],'X-FORWARDED-FOR:'.$arr['header']['ip'],'CLIENT-IP:'.$arr['header']['ip']);
            unset($arr['header']['ip']);
        }
        $arr['header'] = array_filter($arr['header']);

        if(!empty($arr['header']))
        {
            curl_setopt($ch, CURLOPT_HTTPHEADER, $arr['header']);
        }

        if($arr['request'] === 'put'){
            curl_setopt ($ch, CURLOPT_CUSTOMREQUEST, "PUT");
            curl_setopt($ch, CURLOPT_POSTFIELDS,$arr['post']);
        }elseif($arr['post'] != false)
        {
            curl_setopt($ch, CURLOPT_POST, true);
            if(is_array($arr['post']) && $arr['isupfile'] === false)
            {
                $post = http_build_query($arr['post']);
            }
            else
            {
                $post = $arr['post'];
            }
            curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
        }

        $result = curl_exec($ch);
        curl_close($ch);

        return $result;
    }

    function getAllIdsArr($data, $pid = 0, $prefix = '', &$result = []) {
        foreach ($data as $node) {
            if ($node['parent_id'] == $pid) {
                $id = $prefix . $node['id'];
                $result[] = $id;
                $this->getAllIdsArr($data, $node['id'], $id . ',', $result);
            }
        }
        return $result;
    }

    function getLongestStr($arr = [], $searchStr){
        if(empty($arr) || ! $searchStr) return '';
        if(! is_string($searchStr)) $searchStr = (string)$searchStr;

        $longest = '';
        foreach ($arr as $str) {
            if (strpos($str, $searchStr) !== false && strlen($str) > strlen($longest)) {
                $longest = $str;
            }
        }
        return $longest;
    }

    function getAllDescendants($data, $id) {
        $result = array(); // 存储结果的数组

        foreach ($data as $node) {
            if ($node['parent_id'] == $id) { // 如果当前节点的父 ID 等于指定 ID，则将该节点添加到结果中
                $result[] = $node['id'];
                // 递归查询该节点的所有子孙节点，并将结果合并到结果数组中
                $result = array_merge($result, $this->getAllDescendants($data, $node['id']));
            }
        }

        return $result;
    }

    //后台端 某些需要限制请求频率的接口
    //需要主动删除  Redis::del($key)
    public function limitingSendRequest($key,$value=0){
        $prefix = config('app.name') . ':';
        $key = $prefix . $key;
        if(! empty($value)) $value = 1;
        // 使用Redis Facade设置，当键名不存在时才设置成功
        if (Redis::setnx($key, $value)) return [true, ''];

        return [false,'操作频繁！'];
    }

    public function delLimitingSendRequest($key){
        $prefix = config('app.name') . ':';
        $key = $prefix . $key;
        Redis::del($key);
    }

    //后台端 某些需要限制请求频率的接口 有过期时间
    public function limitingSendRequestBackgExpire($key,$ttl = 5){
        $prefix = config('app.name') . ':';
        $key = $prefix . $key;

        if($ttl < 5) $ttl = 5;

        // 使用Redis Facade设置，当键名不存在时才设置成功
        if (Redis::setnx($key, 1)) {
            Redis::expire($key, $ttl); //多少秒后过期

            return [true, ''];
        }

        return [false,'操作频繁, 请在 ' . $ttl . '秒后重试'];
    }

    //前端传来的时间段 转换为时间戳
    //精确到秒
    function changeDateToTimeStampAboutRange($time_range, $is_end = true){
        if(empty($time_range[0]) || empty($time_range[1])) return [];

        // 创建一个 DateTime 对象并设置时区为 UTC
        $dateTime = new \DateTime($time_range[0], new \DateTimeZone('UTC'));
        $dateTime1 = new \DateTime($time_range[1], new \DateTimeZone('UTC'));

        // 将时区设置为 PRC
        $dateTime->setTimezone(new \DateTimeZone('Asia/Shanghai'));
        $dateTime1->setTimezone(new \DateTimeZone('Asia/Shanghai'));

        // 将日期时间格式化为特定格式
        $formattedDate = $dateTime->format('Y-m-d');
        $formattedDate1 = $dateTime1->format('Y-m-d');

        $str = " 23:59:59";
        if(! $is_end) $str = " 00:00:00";
        $return = [];
        $return[] = strtotime($formattedDate . " 00:00:00");
        $return[] = strtotime($formattedDate1 . $str);

        return $return;
    }

    //前端传来的时间段 转换为时间戳
    //精确到日
    function changeDateToNewDate($time_range){
        if(empty($time_range[0]) || empty($time_range[1])) return [];

        // 创建一个 DateTime 对象并设置时区为 UTC
        $dateTime = new \DateTime($time_range[0], new \DateTimeZone('UTC'));
        $dateTime1 = new \DateTime($time_range[1], new \DateTimeZone('UTC'));

        // 将时区设置为 PRC
        $dateTime->setTimezone(new \DateTimeZone('Asia/Shanghai'));
        $dateTime1->setTimezone(new \DateTimeZone('Asia/Shanghai'));

        // 将日期时间格式化为特定格式
        $formattedDate = $dateTime->format('Y-m-d');
        $formattedDate1 = $dateTime1->format('Y-m-d');

        $return = [];
        $return[] = strtotime($formattedDate);
        $return[] = strtotime($formattedDate1);

        return $return;
    }

    function changeDateToNewDate2($time){
        if(empty($time_range)) return [];

        // 创建一个 DateTime 对象并设置时区为 UTC
        $dateTime = new \DateTime($time_range, new \DateTimeZone('UTC'));

        // 将时区设置为 PRC
        $dateTime->setTimezone(new \DateTimeZone('Asia/Shanghai'));

        // 将日期时间格式化为特定格式
        $formattedDate = $dateTime->format('Y-m-d 00:00:00');
        $formattedDate1 = $dateTime->format('Y-m-d 23:59:59');

        $return = [];
        $return[] = strtotime($formattedDate);
        $return[] = strtotime($formattedDate1);

        return $return;
    }

    //前端传来的时间 转为时间戳
    //精确到分
    function changeDateToDateMin($time){
        if(empty($time)) return '';

        // 创建一个 DateTime 对象并设置时区为 UTC
        $dateTime = new \DateTime($time, new \DateTimeZone('UTC'));

        // 将时区设置为 PRC
        $dateTime->setTimezone(new \DateTimeZone('Asia/Shanghai'));

        // 将日期时间格式化为特定格式
        $formattedDate = $dateTime->format('Y-m-d H:i');

        return strtotime($formattedDate);
    }

    //前端传来的时间 转为时间戳
    //精确到日
    function changeDateToDate($time, $is_end = false){
        if(empty($time)) return '';

        // 创建一个 DateTime 对象并设置时区为 UTC
        $dateTime = new \DateTime($time, new \DateTimeZone('UTC'));

        // 将时区设置为 PRC
        $dateTime->setTimezone(new \DateTimeZone('Asia/Shanghai'));

        $str = "00:00:00";
        if($is_end) $str = "23:59:59";

        // 将日期时间格式化为特定格式
        $formattedDate = $dateTime->format('Y-m-d ' . $str);

        return strtotime($formattedDate);
    }

    /**
     * 检查数字是否合法，并可验证其正负性和小数位数
     *
     * @param mixed $number 要检查的值
     * @param int $decimals 允许的最大小数位数（默认 2）
     * @param string|null $sign 要求的符号：'positive', 'negative', 'zero', 'non-negative', 'non-positive' null 表示不限制
     * @param bool $strict 是否严格模式（不允许整数传字符串等）
     * @return array ['valid' => bool, 'error' => string|null, 'info' => array]
     */
    public function checkNumber($number, $decimals = 2, $sign = null, $strict = false)
    {
        $result = [
            'valid' => false,
            'error' => null,
            'info' => []
        ];

        // 1. 类型检查
        if ($strict) {
            if (!is_numeric($number) || is_bool($number)) {
                $result['error'] = '必须是数字类型';
                return $result;
            }
        } else {
            // 宽松模式：允许字符串数字
            if (!is_numeric($number)) {
                $result['error'] = '不是有效数字';
                return $result;
            }
        }

        $num = (float)$number; // 统一转为浮点数处理

        // 2. 正负号检查
        if ($sign !== null) {
            switch ($sign) {
                case 'positive':
                    if ($num <= 0) {
                        $result['error'] = '数字必须大于 0';
                        return $result;
                    }
                    break;
                case 'negative':
                    if ($num >= 0) {
                        $result['error'] = '数字必须小于 0';
                        return $result;
                    }
                    break;
                case 'zero':
                    if ($num != 0) {
                        $result['error'] = '数字必须等于 0';
                        return $result;
                    }
                    break;
                case 'non-negative': // 大于等于 0
                    if ($num < 0) {
                        $result['error'] = '数字必须大于或等于 0';
                        return $result;
                    }
                    break;
                case 'non-positive': // 小于等于 0
                    if ($num > 0) {
                        $result['error'] = '数字必须小于或等于 0';
                        return $result;
                    }
                    break;
                default:
                    $result['error'] = "不支持的符号类型: '{$sign}'";
                    return $result;
            }
        }

        // 3. 小数位数检查
        // 将数字转为标准格式，避免科学计数法
        $numStr = rtrim(rtrim(sprintf('%.10F', $num), '0'), '.'); // 去除末尾无意义的0
        if ($numStr === '' || $numStr === '-') {
            $numStr = '0';
        }

        // 检查是否有小数点
        if (strpos($numStr, '.') === false) {
            $decimalPlaces = 0;
        } else {
            $parts = explode('.', $numStr);
            $decimalPlaces = strlen($parts[1]);
        }

        if ($decimalPlaces > $decimals) {
            $result['error'] = "小数位数超过 {$decimals} 位（实际 {$decimalPlaces} 位）";
            return $result;
        }

        // 4. 附加信息
        $result['valid'] = true;
        $result['info'] = [
            'original' => $number,
            'value' => $num,
            'decimal_places' => $decimalPlaces,
            'sign' => $num > 0 ? 'positive' : ($num < 0 ? 'negative' : 'zero'),
        ];

        return $result;
    }

    public function getTopId($id, $data) {
        foreach ($data as $item) {
            if ($item['id'] == $id) {
                if ($item['parent_id'] == 0) {
                    // 找到最顶级的id
                    return $item['id'];
                } else {
                    // 继续递归查找父级
                    return $this->getTopId($item['parent_id'], $data);
                }
            }
        }

        // 如果没有找到匹配的id，则返回null或者其他你希望的默认值
        return 0;
    }

    // 递归查找所有父级id
    public function findParentIds($id, $data) {
        $parentIds = [];

        foreach ($data as $item) {
            if ($item['id'] == $id) {
                $parentId = $item['parent_id'];
                if ($parentId) {
                    $parentIds[] = $parentId;
                    $parentIds = array_merge($parentIds, $this->findParentIds($parentId, $data));
                }
                break;
            }
        }

        return $parentIds;
    }

    // 递归查找所有子级id
    public function findChildIds($id, $data) {
        $childIds = [];

        foreach ($data as $item) {
            if ($item['parent_id'] == $id) {
                $childId = $item['id'];
                $childIds[] = $childId;
                $childIds = array_merge($childIds, $this->findChildIds($childId, $data));
            }
        }

        return $childIds;
    }

    public function getDataFile($data){
        foreach ($data as $key => $value){
            if($key == 'depart_id' || $key == 'top_depart_id') unset($data[$key]);
        }

        return $data;
    }

    // 校验域名是否通畅可达
    // $domain baidu.com 不要带http这些协议头
    // gethostbyname() 函数可能会受到 PHP 配置中的 allow_url_fopen 和 disable_functions 选项的限制
    function isDomainAvailable($domain) {
        $ip = gethostbyname($domain);

        // 如果解析失败或者返回的 IP 地址与输入的域名相同，则说明域名无效
        if ($ip === $domain || filter_var($ip, FILTER_VALIDATE_IP) === false)  return false;

        return true;
    }

    public function delStorageFile($old, $new = [], $dir = "upload_files/"){
        foreach ($old as $value){
            if(! in_array($value, $new)){
                $filename_rep = "/api/uploadFiles/";
                $filename = str_replace($filename_rep, "", $value);
                $filePath = $dir . $filename;
                if (Storage::disk('public')->exists($filePath)) {
                    // 文件存在 进行删除操作
                    Storage::disk('public')->delete($filePath);
                }
            }
        }
    }

    public function showTimeAgo($time, $time_big){
        // 计算时间差（秒）
        $diffInSeconds = $time_big - $time;

        // 将时间差转换为更易处理的单位
        $diffInMinutes = floor($diffInSeconds / 60);
        $diffInHours = floor($diffInSeconds / 3600);
        $diffInDays = floor($diffInSeconds / (3600 * 24));

        // 根据时间差生成描述性文本
        if ($diffInSeconds < 60) {
            $timeAgo = '刚刚';
        } elseif ($diffInMinutes < 60) {
            $timeAgo = $diffInMinutes . '分钟前';
        } elseif ($diffInHours < 24) {
            $timeAgo = $diffInHours . '小时前';
        } elseif ($diffInDays < 2) {
            $timeAgo = '昨天';
        } elseif ($diffInDays < 7) {
            $timeAgo = $diffInDays . '天前';
        } elseif ($diffInDays < 15) {
            $timeAgo = '一周前';
        } elseif ($diffInDays < 30) {
            $timeAgo = '半个月内';
        } else {
            // 如果超过半个月，可以使用具体的日期格式
            $crtTimeDate = date('Y-m-d', $time);
            $timeAgo = '在 ' . $crtTimeDate;
        }

        return $timeAgo;
    }

    // 递归函数，用于在数据结构中查找值
    function findLabelsByValue($data, $valuesToFind, &$foundLabels) {
        foreach ($data as $item) {
            if (isset($item['value']) && in_array($item['value'], $valuesToFind)) {
                // 如果找到值，则添加其label到结果数组中
                $foundLabels[] = $item['label'];
                // 移除已找到的值，避免重复查找
                $key = array_search($item['value'], $valuesToFind);
                if ($key !== false) {
                    unset($valuesToFind[$key]);
                }
            }
            if (isset($item['children']) && !empty($item['children'])) {
                // 递归调用自身来查找子节点
                $this->findLabelsByValue($item['children'], $valuesToFind, $foundLabels);
            }
            // 如果所有值都已找到，则停止递归
            if (empty($valuesToFind)) {
                break;
            }
        }
    }

    public function changeAndReturnDate($date_int){
        $int = intval($date_int);
        $bool = (string)$int === $date_int;
        if(! $bool || $date_int < 0) return [false, '日期不正确'];

        $epoch = strtotime("1900-01-01 00:00:00");
        $days = $date_int - 1;
        $seconds = $days * 86400;
        return [true,strtotime(date('Y-m-d 00:00:00', $epoch + $seconds))];
    }

    function findTopLevelId($data, $id) {
        // 遍历数据，查找给定ID的节点
        foreach ($data as $item) {
            if ($item['id'] == $id) {
                // 如果找到了给定ID的节点，并且它的parent_id为null，则它就是最顶层节点
                if ($item['parent_id'] === 0) {
                    return $item['id'];
                } else {
                    // 否则，继续寻找其父节点的最顶层节点
                    return $this->findTopLevelId($data, $item['parent_id']);
                }
            }
        }

        // 如果没有找到给定ID的节点，返回null或抛出异常
        return 0;
    }

    function returnDays($time = [], $is_mirco_time = false){

        // 示例时间戳
        $timestamp1 = $time[0];
        $timestamp2 = $time[1];

        // 计算时间差
        $difference = abs($timestamp2 - $timestamp1);

        // 将时间差转换为天数
        $days = floor($difference / (60 * 60 * 24));
        if($is_mirco_time) $days = $days / 1000;

        return $days;
    }

    public function post_helper($url, $data, $header = [], $timeout = 30){
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch,  CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_ENCODING, '');
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
        curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);

        if(!is_null($data)) curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
        $r = curl_exec($ch);

        if ($r === false) {
            // 获取错误号
            $errorNumber = curl_errno($ch);
            // 获取错误信息
            $errorMessage = curl_error($ch);
            $message = "cURL Error #{$errorNumber}: {$errorMessage}";

            return [false, $message];
        }
        curl_close($ch);

        return [true, json_decode($r, true)];
    }

    function isOverThreeMonths($timestamp1, $timestamp2, $default_month = 3) {
        $date1 = new \DateTime();
        $date1->setTimestamp($timestamp1);

        $date2 = new \DateTime();
        $date2->setTimestamp($timestamp2);

        // 计算两个日期的间隔
        $interval = $date1->diff($date2);

        // 总月数 = 年差 * 12 + 月差
        $months = $interval->y * 12 + $interval->m;

        if ($months >= $default_month) {
            return [false, "时间区间须在" . $default_month . "个月内"];
        }elseif ($months == 3 && ($interval->d > 0 || $interval->h > 0 || $interval->i > 0 || $interval->s > 0)) {
            return [false, "时间区间须在" . $default_month . "个月内"];
        }

        return [true, ''];
    }

    public function countTotal($rows, $config = [])
    {
        if (empty($rows)) return [];

        $total = [];

        foreach ($config as $col) {
            $key = $col['key'] ?? null;
            if (!$key) continue;

            $decimals = $col['decimals'] ?? 2; // 默认保留 2 位

            // 1. 基础字段累加
            if (!empty($col['sum']) && $col['sum'] == 1) {
                $sum = '0';
                foreach ($rows as $row) {
                    $sum = bcadd($sum, (string)($row[$key] ?? 0), $decimals);
                }
                $total[$key] = $sum;
            }

            // 2. 公式字段
            if (!empty($col['sum']) && $col['sum'] == 2 && !empty($col['formula'])) {
                $total[$key] = $this->calcFormula($col['formula'], $total, $decimals);
            }
        }

        return $total;
    }


    /**
     * 解析并计算公式（基于 bcmath）
     * 例: profit / income * 100
     */
    public function calcFormula($formula, $values, $decimals = 2)
    {
        $tokens = preg_split('/\s+/', trim($formula));

        $stack = [];
        foreach ($tokens as $token) {
            if ($token === '') continue;

            if (isset($values[$token])) {
                $stack[] = $values[$token];
            } elseif (is_numeric($token)) {
                $stack[] = (string)$token;
            } else {
                $stack[] = $token;
            }
        }

        $expr = implode(' ', $stack);

        return $this->evaluateWithBCMath($expr, $decimals);
    }


    /**
     * 用 bcmath 安全执行表达式 (支持 + - * /)
     */
    public function evaluateWithBCMath($expr, $decimals = 2)
    {
        preg_match_all('/(\d+(?:\.\d+)?|[+\/*-])/', $expr, $matches);
        $tokens = $matches[0] ?? [];

        if (empty($tokens)) return 0;

        $output = [];
        $ops = [];

        foreach ($tokens as $token) {
            if (is_numeric($token)) {
                $output[] = (string)$token;
            } elseif (in_array($token, ['+', '-', '*', '/'])) {
                $ops[] = $token;
            }
        }

        $result = array_shift($output);
        foreach ($ops as $i => $op) {
            $next = $output[$i] ?? '0';

            switch ($op) {
                case '+':
                    $result = bcadd($result, $next, $decimals);
                    break;
                case '-':
                    $result = bcsub($result, $next, $decimals);
                    break;
                case '*':
                    $result = bcmul($result, $next, $decimals);
                    break;
                case '/':
                    if (bccomp($next, '0', $decimals) === 0) {
                        $result = '0'; // 避免除零
                    } else {
                        $result = bcdiv($result, $next, $decimals);
                    }
                    break;
            }
        }

        return $result;
    }
}