<?php
/**
 * Implement hook_filter_info().
 */
function wowhead_filter_info() {
  $filters['filter_wowhead'] = array(
    'title' => t('Wowhead item filter'),
    'description' => "Converts wowhead links to item links with tooltips",
    'process callback' => '_wowhead_filter_process',
  );
  return $filters;
}

function _wowhead_filter_process($text, $format) {
  // Find all links.
  if (preg_match_all('/(http:\/\/(www\.)?wowhead\.com\/item=(\d+))/',$text, $links, PREG_SET_ORDER)) {
    foreach ($links as $match) {
      if ($new_link = _wowhead_link_item($match[0], $match[3])) {
        $text = str_replace($match[0], $new_link, $text);
      }
    }
  }
  return $text;
}

function _wowhead_link_item($url, $id) {
  // Find the name.
  if (!$item = cache_get("wowhead_$id")->data)
  {
    $xml = new SimpleXMLElement($url . "&xml", NULL, TRUE);
    $item = array("name" => sprintf("%s", $xml->item->name), "url" => $url, "quality" => sprintf("%d", $xml->item->quality["id"]));
    cache_set("wowhead_$id", $item);
  }
  return sprintf('<a class="q%d" href="%s">[%s]</a>', $item["quality"], $item["url"], $item["name"]);
}