thinkphp php 获取多久时间之前

/**
 * 获取多长时间之前
 * @param  $time [string]   时间戳
 */
function formatDate($time)
{
    if (!$time)
        return false;
    $fdate = '';
    $d = time() - intval($time);
    $ld = $time - mktime(0, 0, 0, 0, 0, date('Y')); //得出年
    $md = $time - mktime(0, 0, 0, date('m'), 0, date('Y')); //得出月
    $byd = $time - mktime(0, 0, 0, date('m'), date('d') - 2, date('Y')); //前天
    $yd = $time - mktime(0, 0, 0, date('m'), date('d') - 1, date('Y')); //昨天
    $dd = $time - mktime(0, 0, 0, date('m'), date('d'), date('Y')); //今天
    $td = $time - mktime(0, 0, 0, date('m'), date('d') + 1, date('Y')); //明天
    $atd = $time - mktime(0, 0, 0, date('m'), date('d') + 2, date('Y')); //后天
    if ($d == 0) {
        $fdate = '刚刚';
    } else {
        switch ($d) {
            case $d < $atd:
                $fdate = date('Y年m月d日', $time);
                break;
            case $d < $td:
                $fdate = '后天' . date('H:i', $time);
                break;
            case $d < 0:
                $fdate = '明天' . date('H:i', $time);
                break;
            case $d < 60:
                $fdate = $d . '秒前';
                break;
            case $d < 3600:
                $fdate = floor($d / 60) . '分钟前';
                break;
            case $d < $dd:
                $fdate = floor($d / 3600) . '小时前';
                break;
            case $d < $yd:
                $fdate = '昨天' . date('H:i', $time);
                break;
            case $d < $byd:
                $fdate = '前天' . date('H:i', $time);
                break;
            case $d < $md:
                $fdate = date('m月d日 H:i', $time);
                break;
            case $d < $ld:
                $fdate = date('m月d日', $time);
                break;
            default:
                $fdate = date('Y年m月d日', $time);
                break;
        }
    }
    return $fdate;
}