PHP转换几小时前

<?php

function mdate($time = NULL) {
    $text = '';
    $time = $time === NULL || $time > time() ? time() : intval($time);
    $t = time() - $time; //时间差 （秒）
    $y = date('Y', $time)-date('Y', time());//是否跨年
    switch($t){
     case $t == 0:
       $text = '刚刚';
       break;
     case $t < 60:
      $text = $t . '秒前'; // 一分钟内
      break;
     case $t < 60 * 60:
      $text = floor($t / 60) . '分钟前'; //一小时内
      break;
     case $t < 60 * 60 * 24:
      $text = floor($t / (60 * 60)) . '小时前'; // 一天内
      break;
     case $t < 60 * 60 * 24 * 3:
      $text = floor($time/(60*60*24)) ==1 ?'昨天 ' . date('H:i', $time) : '前天 ' . date('H:i', $time) ; //昨天和前天
      break;
     case $t < 60 * 60 * 24 * 30:
      $text = date('m月d日 H:i', $time); //一个月内
      break;
     case $t < 60 * 60 * 24 * 365&&$y==0:
      $text = date('m月d日', $time); //一年内
      break;
     default:
      $text = date('Y年m月d日', $time); //一年以前
      break;
    }
        
    echo $text;
}
$timestamp = strtotime("2022-07-15 15:46:50");
mdate($timestamp);```