<?php
function nassau_dice_filter($o) {
        $preg = '/\[dice=(?<num>\d*)[kd](?<dice>\d+)\]((?<res>[^\[]*)\[\/dice\])?/i';

        $o->Msg = preg_replace_callback($preg, 'nassau_dice_parse', $o->Msg);
}
function nassau_dice_parse($m) {
  if (false == empty($m['res'])) return $m[0];

  $dice = $m['dice'];
  $num = $m['num'] ? $m['num'] : 1;

  $sum = array ();
  foreach (range(1, $num) as $_) $sum[] = rand(1, $dice);
  $sum = implode(', ', $sum) . ' » ' . array_sum($sum);

  return sprintf('[dice=%dd%d]%s[/dice]', $num, $dice, $sum);
}

function nassau_dice_format(&$data) {
  $msg = $data['message'];
  $rep = preg_replace('/\[dice=(\d*[kd]\d+)\]([^\[]+)\[\/dice\]/i',
        '<span style="background:#0080FF;color:white;padding:1px 4px;border-radius:6px;">Rolled [$1]: $2</span>',
        $msg);

  $data['message'] = $rep;
}

UnbRegisterHook('post.beforeadd', 'nassau_dice_filter');
UnbRegisterHook('post.beforechange', 'nassau_dice_filter');
UnbRegisterHook('post.postparse', 'nassau_dice_format');