<?php

function clever_comment_block() {
  $items = array();
  $node_types = array();
  $comments_per_page = array();

  $comments_pages = array();

  $cache = cache_get('clever_comments_block');
  if(isset($cache) && $cache->expire > time()) {
    $comments_pages = $cache->data;
  }
  
  foreach (comment_get_recent() as $comment) {
    $page = 0;

    if(isset($comments_pages[$comment->cid])) {
      $page = $comments_pages[$comment->cid];
    } else {
      // Get the node type for this comment - we cache them
      // to save a few DB calls
      $nid = $comment->nid;
      if(!isset($node_types[$nid])) {
        $node_types[$nid] = db_result(db_query("SELECT type FROM {node} WHERE nid=%d", $nid));
      }
      $node_type = $node_types[$nid];
      if(!isset($node_type)) {
        $node_type = 'unknown';
      }
      // Now get the number of comments per page for this node type
      // again, we cache them to save a few variable_get() calls
      if(!isset($comments_per_page[$node_type])) {
        $comments_per_page[$node_type] = variable_get('comment_default_per_page_' . $node_type, 10);
      }
      $cpp = $comments_per_page[$node_type];

      // Get the sort mode...
      $sort_mode = variable_get('comment_default_mode_'. $node_type, COMMENT_MODE_THREADED_EXPANDED);
      // ...and the display mode
      $display_order = variable_get('comment_default_order_'. $node_type, COMMENT_ORDER_NEWEST_FIRST);

      // This section stolen from comment_render() in comment.module
      $order = '';
      if ($display_order == COMMENT_ORDER_NEWEST_FIRST) {
        if ($sort_mode == COMMENT_MODE_FLAT_COLLAPSED || $sort_mode == COMMENT_MODE_FLAT_EXPANDED) {
          $order .= ' ORDER BY cid DESC';
        } else {
          $order .= ' ORDER BY thread DESC';
        }
      } else if ($display_order == COMMENT_ORDER_OLDEST_FIRST) {
        if ($sort_mode == COMMENT_MODE_FLAT_COLLAPSED || $sort_mode == COMMENT_MODE_FLAT_EXPANDED) {
          $order .= ' ORDER BY cid';
        } else {
          $order .= ' ORDER BY SUBSTRING(thread, 1, (LENGTH(thread) - 1))';
        }
      }

      $sql = sprintf("SELECT cid FROM {comments} WHERE nid=%d AND cid<=%d$order", $comment->nid, $comment->cid);

      $result = db_query("SELECT cid FROM {comments} WHERE nid=%d AND cid<=%d$order", $comment->nid, $comment->cid);
      $count = 0;
      while($row = db_fetch_object($result)) {
        if($row->cid == $comment->cid) {
          break;
        }
        $count++;
      }


      //$count = db_result(db_query("SELECT count(1) FROM {comments} WHERE nid=%d AND cid<%d", $comment->nid, $comment->cid));

      $page = floor($count / $cpp);
      // And save it into the cache
      $comments_pages[$comment->cid] = $page;
    } // end of if cid was a cache hit...else...

    // Work out a query string
    $query = ($page > 0) ? 'page=' . $page : '';
 
    $items[] = l($comment->subject, 'node/'. $comment->nid, array('fragment' => 'comment-'. $comment->cid, 'query' => $query)) .'<br />'. t('@time ago', array('@time' => format_interval(time() - $comment->timestamp)));
  }

  // Now save whatever we just got into the cache...
  // Watch argument ordering!! It changes in Drupal 5->6!!
  // Expire the data in 24 hours
  if(DRUPAL_CORE_COMPATIBILITY == '6.x') {
    cache_set('clever_comments_block', $comments_pages, 'cache', time() + 86400);
  } else {
    cache_set('clever_comments_block', 'cache', $comments_pages, time() + 86400);
  }

  if ($items) {
    return theme('item_list', $items);
  }
}

echo clever_comment_block();

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