<?php
// $Id$

/**
 * @file
 * Enables users to comment on published content.
 *
 * When enabled, the Drupal comment module creates a discussion
 * board for each Drupal node. Users can post comments to discuss
 * a forum topic, weblog post, story, collaborative book page, etc.
 */

/**
 * Comment is awaiting approval.
 */
define('COMMENT_NOT_PUBLISHED', 0);

/**
 * Comment is published.
 */
define('COMMENT_PUBLISHED', 1);

/**
 * Comments are displayed in a flat list - collapsed.
 */
define('COMMENT_MODE_FLAT_COLLAPSED', 1);

/**
 * Comments are displayed in a flat list - expanded.
 */
define('COMMENT_MODE_FLAT_EXPANDED', 2);

/**
 * Comments are displayed as a threaded list - collapsed.
 */
define('COMMENT_MODE_THREADED_COLLAPSED', 3);

/**
 * Comments are displayed as a threaded list - expanded.
 */
define('COMMENT_MODE_THREADED_EXPANDED', 4);

/**
 * Anonymous posters cannot enter their contact information.
 */
define('COMMENT_ANONYMOUS_MAYNOT_CONTACT', 0);

/**
 * Anonymous posters may leave their contact information.
 */
define('COMMENT_ANONYMOUS_MAY_CONTACT', 1);

/**
 * Anonymous posters are required to leave their contact information.
 */
define('COMMENT_ANONYMOUS_MUST_CONTACT', 2);

/**
 * Comment form should be displayed on a separate page.
 */
define('COMMENT_FORM_SEPARATE_PAGE', 0);

/**
 * Comment form should be shown below post or list of comments.
 */
define('COMMENT_FORM_BELOW', 1);

/**
 * Comments for this node are disabled.
 */
define('COMMENT_NODE_DISABLED', 0);

/**
 * Comments for this node are locked.
 */
define('COMMENT_NODE_READ_ONLY', 1);

/**
 * Comments are enabled on this node.
 */
define('COMMENT_NODE_READ_WRITE', 2);

/**
 * Comment preview is optional.
 */
define('COMMENT_PREVIEW_OPTIONAL', 0);

/**
 * Comment preview is required.
 */
define('COMMENT_PREVIEW_REQUIRED', 1);

/**
 * Implementation of hook_help().
 */
function comment_help($path, $arg) {
  switch ($path) {
    case 'admin/help#comment':
      $output  = '<p>' . t('The comment module allows visitors to comment on your posts, creating ad hoc discussion boards. Any <a href="@content-type">content type</a> may have its <em>Default comment setting</em> set to <em>Read/Write</em> to allow comments, or <em>Disabled</em>, to prevent comments. Comment display settings and other controls may also be customized for each content type.', array('@content-type' => url('admin/build/types'))) . '</p>';
      $output .= '<p>' . t('Comment permissions are assigned to user roles, and are used to determine whether anonymous users (or other roles) are allowed to comment on posts. If anonymous users are allowed to comment, their individual contact information may be retained in cookies stored on their local computer for use in later comment submissions. When a comment has no replies, it may be (optionally) edited by its author. The comment module uses the same input formats and HTML tags available when creating other forms of content.') . '</p>';
      $output .= '<p>' . t('For more information, see the online handbook entry for <a href="@comment">Comment module</a>.', array('@comment' => 'http://drupal.org/handbook/modules/comment/')) . '</p>';

      return $output;

    case 'admin/content/comment':
      return '<p>' . t("Below is a list of the latest comments posted to your site. Click on a subject to see the comment, the author's name to edit the author's user information, 'edit' to modify the text, and 'delete' to remove their submission.") . '</p>';

    case 'admin/content/comment/approval':
      return '<p>' . t("Below is a list of the comments posted to your site that need approval. To approve a comment, click on 'edit' and then change its 'moderation status' to Approved. Click on a subject to see the comment, the author's name to edit the author's user information, 'edit' to modify the text, and 'delete' to remove their submission.") . '</p>';
  }
}

/**
 * Implementation of hook_theme().
 */
function comment_theme() {
  return array(
    'comment_block' => array(
      'arguments' => array(),
    ),
    'comment_admin_overview' => array(
      'arguments' => array('form' => NULL),
    ),
    'comment_preview' => array(
      'arguments' => array('comment' => NULL, 'node' => NULL, 'links' => array(), 'visible' => 1),
    ),
    'comment_view' => array(
      'arguments' => array('comment' => NULL, 'node' => NULL, 'links' => array(), 'visible' => 1),
    ),
    'comment' => array(
      'template' => 'comment',
      'arguments' => array('comment' => NULL, 'node' => NULL, 'links' => array()),
    ),
    'comment_folded' => array(
      'template' => 'comment-folded',
      'arguments' => array('comment' => NULL),
    ),
    'comment_flat_collapsed' => array(
      'arguments' => array('comment' => NULL, 'node' => NULL),
    ),
    'comment_flat_expanded' => array(
      'arguments' => array('comment' => NULL, 'node' => NULL),
    ),
    'comment_thread_collapsed' => array(
      'arguments' => array('comment' => NULL, 'node' => NULL),
    ),
    'comment_thread_expanded' => array(
      'arguments' => array('comment' => NULL, 'node' => NULL),
    ),
    'comment_post_forbidden' => array(
      'arguments' => array('nid' => NULL),
    ),
    'comment_wrapper' => array(
      'template' => 'comment-wrapper',
      'arguments' => array('content' => NULL, 'node' => NULL),
    ),
    'comment_submitted' => array(
      'arguments' => array('comment' => NULL),
    ),
  );
}

/**
 * Implementation of hook_menu().
 */
function comment_menu() {
  $items['admin/content/comment'] = array(
    'title' => 'Comments',
    'description' => 'List and edit site comments and the comment moderation queue.',
    'page callback' => 'comment_admin',
    'access arguments' => array('administer comments'),
  );
  // Tabs begin here.
  $items['admin/content/comment/new'] = array(
    'title' => 'Published comments',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items['admin/content/comment/approval'] = array(
    'title' => 'Approval queue',
    'page arguments' => array('approval'),
    'access arguments' => array('administer comments'),
    'type' => MENU_LOCAL_TASK,
  );
  $items['comment/delete'] = array(
    'title' => 'Delete comment',
    'page callback' => 'comment_delete',
    'access arguments' => array('administer comments'),
    'type' => MENU_CALLBACK,
  );
  $items['comment/edit'] = array(
    'title' => 'Edit comment',
    'page callback' => 'comment_edit',
    'access arguments' => array('post comments'),
    'type' => MENU_CALLBACK,
  );
  $items['comment/reply/%node'] = array(
    'title' => 'Reply to comment',
    'page callback' => 'comment_reply',
    'page arguments' => array(2),
    'access callback' => 'node_access',
    'access arguments' => array('view', 2),
    'type' => MENU_CALLBACK,
  );
  $items['comment/approve'] = array(
    'title' => 'Approve a comment',
    'page callback' => 'comment_approve',
    'page arguments' => array(2),
    'access arguments' => array('administer comments'),
    'type' => MENU_CALLBACK,
  );

  return $items;
}

/**
 * Implementation of hook_node_type().
 */
function comment_node_type($op, $info) {
  $settings = array(
    'comment',
    'comment_default_mode',
    'comment_default_per_page',
    'comment_anonymous',
    'comment_subject_field',
    'comment_preview',
    'comment_form_location',
  );

  switch ($op) {
    case 'delete':
      foreach ($settings as $setting) {
        variable_del($setting . '_' . $info->type);
      }
      break;
  }
}

/**
 * Implementation of hook_perm().
 */
function comment_perm() {
  return array(
    'administer comments' => array(
      'title' => t('Administer comments'),
      'description' => t('Manage and approve comments, and configure comment administration settings.'),
    ),
    'access comments' => array(
      'title' => t('Access comments'),
      'description' => t('View comments attached to content.'),
    ),
    'post comments' => array(
      'title' => t('Post comments'),
      'description' => t('Add comments to content (approval required).'),
    ),
    'post comments without approval' => array(
      'title' => t('Post comments without approval'),
      'description' => t('Add comments to content (no approval required).'),
    ),
  );
}

/**
 * Implementation of hook_block_list().
 */
function comment_block_list() {
  $blocks['recent']['info'] = t('Recent comments');

  return $blocks;
}

/**
 * Implementation of hook_block_configure().
 */
function comment_block_configure($delta = '') {
  $form['comment_block_count'] = array(
    '#type' => 'select',
    '#title' => t('Number of recent comments'),
    '#default_value' => variable_get('comment_block_count', 10),
    '#options' => drupal_map_assoc(array(2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30)),
    '#description' => t('Number of comments displayed in the <em>Recent comments</em> block.'),
  );

  return $form;
}

/**
 * Implementation of hook_block_save().
 */
function comment_block_save($delta = '', $edit = array()) {
  variable_set('comment_block_count', (int)$edit['comment_block_count']);
}

/**
 * Implementation of hook_block_view().
 *
 * Generates a block with the most recent comments.
 */
function comment_block_view($delta = '') {
  if (user_access('access comments')) {
    $block['subject'] = t('Recent comments');
    $block['content'] = theme('comment_block');

    return $block;
  }
}

/**
 * Find the most recent comments that are available to the current user.
 *
 * This is done in two steps:
 *   1. Query the {node_comment_statistics} table to find n number of nodes that
 *      have the most recent comments. This table is indexed on
 *      last_comment_timestamp, thus making it a fast query.
 *   2. Load the information from the comments table based on the nids found
 *      in step 1.
 *
 * @param integer $number
 *   (optional) The maximum number of comments to find.
 * @return
 *   An array of comment objects each containing a nid,
 *   subject, cid, and timestamp, or an empty array if there are no recent
 *   comments visible to the current user.
 */
function comment_get_recent($number = 10) {
  // Step 1: Select a $number of nodes which have new comments,
  //         and are visible to the current user.
  $nids = db_query_range("SELECT nc.nid FROM {node_comment_statistics} nc WHERE nc.comment_count > 0 ORDER BY nc.last_comment_timestamp DESC", 0, $number)->fetchCol();

  $comments = array();
  if (!empty($nids)) {
    // Step 2: From among the comments on the nodes selected in the first query,
    //         find the $number of most recent comments.
    // Using Query Builder here for the IN-Statement.
    $result = db_select('comment', 'c')
      ->fields('c', array('nid', 'subject', 'cid', 'timestamp') )
      ->innerJoin('node', 'n', 'n.nid = c.nid')
      ->condition('c.nid', $nids, 'IN')
      ->condition('c.status', COMMENT_PUBLISHED)
      ->condition('n.status', 1)
      ->orderBy('c.cid', 'DESC')
      ->range(0, $number)
      ->execute();
    foreach ($result as $comment) {
     $comments[] = $comment;
    }
  }

  return $comments;
}

/**
 * Calculate page number for first new comment.
 *
 * @param $num_comments
 *   Number of comments.
 * @param $new_replies
 *   Number of new replies.
 * @param $node
 *   The first new comment node.
 * @return
 *   "page=X" if the page number is greater than zero; empty string otherwise.
 */
function comment_new_page_count($num_comments, $new_replies, $node) {
  $comments_per_page = _comment_get_display_setting('comments_per_page', $node);
  $mode = _comment_get_display_setting('mode', $node);
  $pagenum = NULL;
  $flat = in_array($mode, array(COMMENT_MODE_FLAT_COLLAPSED, COMMENT_MODE_FLAT_EXPANDED));
  if ($num_comments <= $comments_per_page) {
    // Only one page of comments.
    $pageno = 0;
  }
  elseif ($flat) {
    // Flat comments.
    $count = $num_comments - $new_replies;
    $pageno =  $count / $comments_per_page;
  }
  else {
    // Threaded comments.
    // Find the first thread with a new comment.
    $result = db_query_range('(SELECT thread
      FROM {comment}
      WHERE nid = :nid
        AND status = 0
      ORDER BY timestamp DESC)
      ORDER BY SUBSTRING(thread, 1, (LENGTH(thread) - 1))', array(':nid' => $node->nid), 0, $new_replies)
      ->fetchField();
    $thread = substr($result, 0, -1);
    $count = db_query('SELECT COUNT(*) FROM {comment} WHERE nid = :nid AND status = 0 AND SUBSTRING(thread, 1, (LENGTH(thread) - 1)) < :thread', array(
      ':nid' => $node->nid,
      ':thread' => $thread))
      ->fetchField();
    $pageno =  $count / $comments_per_page;
  }

  if ($pageno >= 1) {
    $pagenum = "page=" . intval($pageno);
  }

  return $pagenum;
}

/**
 * Returns a formatted list of recent comments to be displayed in the comment block.
 *
 * @return
 *   The comment list HTML.
 * @ingroup themeable
 */
function theme_comment_block() {
  $items = array();
  $number = variable_get('comment_block_count', 10);
  foreach (comment_get_recent($number) as $comment) {
    $items[] = l($comment->subject, 'node/' . $comment->nid, array('fragment' => 'comment-' . $comment->cid)) . '<br />' . t('@time ago', array('@time' => format_interval(REQUEST_TIME - $comment->timestamp)));
  }

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

/**
 * An implementation of hook_nodeapi_view().
 */
function comment_nodeapi_view($node, $teaser, $page) {
  $links = array();

  if ($node->comment) {
    if ($teaser) {
      // Main page: display the number of comments that have been posted.
      if (user_access('access comments')) {
        if (!empty($node->comment_count)) {
          $links['comment_comments'] = array(
            'title' => format_plural($node->comment_count, '1 comment', '@count comments'),
            'href' => "node/$node->nid",
            'attributes' => array('title' => t('Jump to the first comment of this posting.')),
            'fragment' => 'comments'
          );

          $new = comment_num_new($node->nid);
          if ($new) {
            $links['comment_new_comments'] = array(
              'title' => format_plural($new, '1 new comment', '@count new comments'),
              'href' => "node/$node->nid",
              'query' => comment_new_page_count($node->comment_count, $new, $node),
              'attributes' => array('title' => t('Jump to the first new comment of this posting.')),
              'fragment' => 'new'
            );
          }
        }
        else {
          if ($node->comment == COMMENT_NODE_READ_WRITE) {
            if (user_access('post comments')) {
              $links['comment_add'] = array(
                'title' => t('Add new comment'),
                'href' => "comment/reply/$node->nid",
                'attributes' => array('title' => t('Add a new comment to this page.')),
                'fragment' => 'comment-form'
              );
            }
            else {
              $links['comment_forbidden']['title'] = theme('comment_post_forbidden', $node);
            }
          }
        }
      }
    }
    else {
      // Node page: add a "post comment" link if the user is allowed to post comments,
      // if this node is not read-only, and if the comment form isn't already shown.
      if ($node->comment == COMMENT_NODE_READ_WRITE) {
        if (user_access('post comments')) {
          if (variable_get('comment_form_location_' . $node->type, COMMENT_FORM_SEPARATE_PAGE) == COMMENT_FORM_SEPARATE_PAGE) {
            $links['comment_add'] = array(
              'title' => t('Add new comment'),
              'href' => "comment/reply/$node->nid",
              'attributes' => array('title' => t('Share your thoughts and opinions related to this posting.')),
              'fragment' => 'comment-form'
            );
          }
        }
        else {
          $links['comment_forbidden']['title'] = theme('comment_post_forbidden', $node);
        }
      }
    }
    
    if (isset($links['comment_forbidden'])) {
      $links['comment_forbidden']['html'] = TRUE;
    }

    $node->content['links']['comment'] = array(
      '#type' => 'node_links',
      '#value' => $links,
    );
  }
}

/**
 * Implementation of hook_form_alter().
 */
function comment_form_alter(&$form, $form_state, $form_id) {
  if ($form_id == 'node_type_form' && isset($form['identity']['type'])) {
    $form['comment'] = array(
      '#type' => 'fieldset',
      '#title' => t('Comment settings'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
    );
    $form['comment']['comment'] = array(
      '#type' => 'radios',
      '#title' => t('Default comment setting'),
      '#default_value' => variable_get('comment_' . $form['#node_type']->type, COMMENT_NODE_READ_WRITE),
      '#options' => array(t('Disabled'), t('Read only'), t('Read/Write')),
      '#description' => t('Users with the <em>administer comments</em> permission will be able to override this setting.'),
    );
    $form['comment']['comment_default_mode'] = array(
      '#type' => 'radios',
      '#title' => t('Default display mode'),
      '#default_value' => variable_get('comment_default_mode_' . $form['#node_type']->type, COMMENT_MODE_THREADED_EXPANDED),
      '#options' => _comment_get_modes(),
      '#description' => t('Expanded views display the body of the comment. Threaded views keep replies together.'),
    );
    $form['comment']['comment_default_per_page'] = array(
      '#type' => 'select',
      '#title' => t('Comments per page'),
      '#default_value' => variable_get('comment_default_per_page_' . $form['#node_type']->type, 50),
      '#options' => _comment_per_page(),
      '#description' => t('Additional comments will be displayed on separate pages.'),
    );
    $form['comment']['comment_anonymous'] = array(
      '#type' => 'radios',
      '#title' => t('Anonymous commenting'),
      '#default_value' => variable_get('comment_anonymous_' . $form['#node_type']->type, COMMENT_ANONYMOUS_MAYNOT_CONTACT),
      '#options' => array(
        COMMENT_ANONYMOUS_MAYNOT_CONTACT => t('Anonymous posters may not enter their contact information'),
        COMMENT_ANONYMOUS_MAY_CONTACT => t('Anonymous posters may leave their contact information'),
        COMMENT_ANONYMOUS_MUST_CONTACT => t('Anonymous posters must leave their contact information')),
      '#description' => t('This option is enabled when anonymous users have permission to post comments on the <a href="@url">permissions page</a>.', array('@url' => url('admin/user/permissions', array('fragment' => 'module-comment')))),
    );

    if (!user_access('post comments', drupal_anonymous_user())) {
      $form['comment']['comment_anonymous']['#disabled'] = TRUE;
    }

    $form['comment']['comment_subject_field'] = array(
      '#type' => 'radios',
      '#title' => t('Comment subject field'),
      '#default_value' => variable_get('comment_subject_field_' . $form['#node_type']->type, 1),
      '#options' => array(t('Disabled'), t('Enabled')),
      '#description' => t('Can users provide a unique subject for their comments?'),
    );
    $form['comment']['comment_preview'] = array(
      '#type' => 'radios',
      '#title' => t('Preview comment'),
      '#default_value' => variable_get('comment_preview_' . $form['#node_type']->type, COMMENT_PREVIEW_REQUIRED),
      '#options' => array(t('Optional'), t('Required')),
      '#description' => t("Forces a user to look at their comment by clicking on a 'Preview' button before they can actually add the comment"),
    );
    $form['comment']['comment_form_location'] = array(
      '#type' => 'radios',
      '#title' => t('Location of comment submission form'),
      '#default_value' => variable_get('comment_form_location_' . $form['#node_type']->type, COMMENT_FORM_SEPARATE_PAGE),
      '#options' => array(t('Display on separate page'), t('Display below post or comments')),
    );
  }
  elseif (!empty($form['#node_edit_form'])) {
    $node = $form['#node'];
    $form['comment_settings'] = array(
      '#type' => 'fieldset',
      '#access' => user_access('administer comments'),
      '#title' => t('Comment settings'),
      '#collapsible' => TRUE,
      '#collapsed' => TRUE,
      '#weight' => 30,
    );
    $form['comment_settings']['comment'] = array(
      '#type' => 'radios',
      '#parents' => array('comment'),
      '#default_value' => $node->comment,
      '#options' => array(t('Disabled'), t('Read only'), t('Read/Write')),
    );
  }
}

/**
 * Implementation of hook_nodeapi_load().
 */
function comment_nodeapi_load($nodes, $types) {
  $comments_enabled = array();

  // Check if comments are enabled for each node. If comments are disabled,
  // assign values without hitting the database.
  foreach ($nodes as $node) {
    // Store whether comments are enabled for this node.
    if ($node->comment != COMMENT_NODE_DISABLED) {
      $comments_enabled[] = $node->nid;
    }
    else {
      $node->last_comment_timestamp = $node->created;
      $node->last_comment_name = '';
      $node->comment_count = 0;
    }
  }

  // For nodes with comments enabled, fetch information from the database.
  if (!empty($comments_enabled)) {
    $result = db_query('SELECT nid, last_comment_timestamp, last_comment_name, comment_count FROM {node_comment_statistics} WHERE nid IN(' . db_placeholders($comments_enabled) . ')', $comments_enabled);
    foreach ($result as $record) {
      $nodes[$record->nid]->last_comment_timestamp = $record->last_comment_timestamp;
      $nodes[$record->nid]->last_comment_name = $record->last_comment_name;
      $nodes[$record->nid]->comment_count = $record->comment_count;
    }
  }
}

/**
 * Implementation of hook_nodeapi_prepare().
 */
function comment_nodeapi_prepare($node) {
  if (!isset($node->comment)) {
    $node->comment = variable_get("comment_$node->type", COMMENT_NODE_READ_WRITE);
  }
}

/**
 * Implementation of hook_nodeapi_insert().
 */
function comment_nodeapi_insert($node) {
  db_insert('node_comment_statistics')
    ->fields(array(
      'nid' => $node->nid,
      'last_comment_timestamp' => $node->changed,
      'last_comment_name' => NULL,
      'last_comment_uid' => $node->uid,
      'comment_count' => 0 ))
    ->execute();
}

/**
 * Implementation of hook_nodeapi_delete().
 */
function comment_nodeapi_delete($node) {
  db_delete('comment')
    ->condition('nid', $node->nid)
    ->execute();
  db_delete('node_comment_statistics')
    ->condition('nid', $node->nid)
    ->execute();
}

/**
 * Implementation of hook_nodeapi_update_index().
 */
function comment_nodeapi_update_index($node) {
  $text = '';
  $comments = db_query('SELECT subject, comment, format FROM {comment} WHERE nid = :nid AND status = :status', array(':nid' => $node->nid, ':status' => COMMENT_PUBLISHED));
  foreach ($comments as $comment) {
    $text .= '<h2>' . check_plain($comment->subject) . '</h2>' . check_markup($comment->comment, $comment->format, FALSE);
  }
  return $text;
}

/**
 * Implementation of hook_nodeapi_search_result().
 */
function comment_nodeapi_search_result($node) {
  $comments = db_query('SELECT comment_count FROM {node_comment_statistics} WHERE nid = :nid', array('nid' => $node->nid))->fetchField();
  return format_plural($comments, '1 comment', '@count comments');
}

/**
 * Implementation of hook_nodeapi_rss_item().
 */
function comment_nodeapi_rss_item($node) {
  if ($node->comment != COMMENT_NODE_DISABLED) {
    return array(array('key' => 'comments', 'value' => url('node/' . $node->nid, array('fragment' => 'comments', 'absolute' => TRUE))));
  }
  else {
    return array();
  }
}

/**
 * Implementation of hook_user_delete().
 */
function comment_user_delete(&$edit, &$user, $category = NULL) {
  db_update('comment')
    ->fields(array('uid' => 0))
    ->condition('uid', $user->uid)
    ->execute();
  db_update('node_comment_statistics')
    ->fields(array('last_comment_uid' => 0))
    ->condition('last_comment_uid', $user->uid)
    ->execute();
}

/**
 * This is *not* a hook_access() implementation. This function is called
 * to determine whether the current user has access to a particular comment.
 *
 * Authenticated users can edit their comments as long they have not been
 * replied to. This prevents people from changing or revising their
 * statements based on the replies to their posts.
 *
 * @param $op
 *   The operation that is to be performed on the comment. Only 'edit' is recognized now.
 * @param $comment
 *   The comment object.
 * @return
 *   TRUE if the current user has acces to the comment, FALSE otherwise.
 */
function comment_access($op, $comment) {
  global $user;

  if ($op == 'edit') {
    return ($user->uid && $user->uid == $comment->uid && comment_num_replies($comment->cid) == 0) || user_access('administer comments');
  }
}

/**
 * A simple helper function.
 *
 * @return
 *   The 0th and the 1st path components joined by a slash.
 */
function comment_node_url() {
  return arg(0) . '/' . arg(1);
}

/**
 * Accepts a submission of new or changed comment content.
 *
 * @param $edit
 *   A comment array.
 *
 * @return
 *   If the comment is successfully saved the comment ID is returned. If the comment
 *   is not saved, FALSE is returned.
 */
function comment_save($edit) {
  global $user;
  if (user_access('post comments') && (user_access('administer comments') || node_comment_mode($edit['nid']) == COMMENT_NODE_READ_WRITE)) {
    if (!form_get_errors()) {
      $edit += array(
        'mail' => '',
        'homepage' => '',
        'name' => '',
        'status' => user_access('post comments without approval') ? COMMENT_PUBLISHED : COMMENT_NOT_PUBLISHED,
      );
      if ($edit['cid']) {
        // Update the comment in the database.
        db_update('comment')
          ->fields(array(
            'status' => $edit['status'],
            'timestamp' => $edit['timestamp'],
            'subject' => $edit['subject'],
            'comment' => $edit['comment'],
            'format' => $edit['comment_format'],
            'uid' => $edit['uid'],
            'name' => $edit['name'],
            'mail' => $edit['mail'],
            'homepage' => $edit['homepage']
          ))
          ->condition('cid', $edit['cid'])
          ->execute();
        // Allow modules to respond to the updating of a comment.
        comment_invoke_comment($edit, 'update');
        // Add an entry to the watchdog log.
        watchdog('content', 'Comment: updated %subject.', array('%subject' => $edit['subject']), WATCHDOG_NOTICE, l(t('view'), 'node/' . $edit['nid'], array('fragment' => 'comment-' . $edit['cid'])));
      }
      else {
        // Add the comment to database. This next section builds the thread field.
        // Also see the documentation for comment_render().
        if ($edit['pid'] == 0) {
          // This is a comment with no parent comment (depth 0): we start
          // by retrieving the maximum thread level.
          $max = db_query('SELECT MAX(thread) FROM {comment} WHERE nid = :nid', array(':nid' => $edit['nid']))->fetchField();
          // Strip the "/" from the end of the thread.
          $max = rtrim($max, '/');
          // Finally, build the thread field for this new comment.
          $thread = int2vancode(vancode2int($max) + 1) . '/';
        }
        else {
          // This is a comment with a parent comment, so increase
          // the part of the thread value at the proper depth.

          // Get the parent comment:
          $parent = comment_load($edit['pid']);
          // Strip the "/" from the end of the parent thread.
          $parent->thread = (string) rtrim((string) $parent->thread, '/');
          // Get the max value in *this* thread.
          $max = db_query("SELECT MAX(thread) FROM {comment} WHERE thread LIKE :thread AND nid = :nid", array(
            ':thread' => $parent->thread .'.%',
            ':nid' => $edit['nid']))
            ->fetchField();

          if ($max == '') {
            // First child of this parent.
            $thread = $parent->thread . '.' . int2vancode(0) . '/';
          }
          else {
            // Strip the "/" at the end of the thread.
            $max = rtrim($max, '/');
            // Get the value at the correct depth.
            $parts = explode('.', $max);
            $parent_depth = count(explode('.', $parent->thread));
            $last = $parts[$parent_depth];
            // Finally, build the thread field for this new comment.
            $thread = $parent->thread . '.' . int2vancode(vancode2int($last) + 1) . '/';
          }
        }

        if (empty($edit['timestamp'])) {
          $edit['timestamp'] = REQUEST_TIME;
        }

        if ($edit['uid'] === $user->uid && isset($user->name)) { // '===' Need to modify anonymous users as well.
          $edit['name'] = $user->name;
        }

        $edit['cid'] = db_insert('comment')
          ->fields(array(
           'nid' => $edit['nid'],
            'pid' => empty($edit['pid']) ? 0 : $edit['pid'],
            'uid' => $edit['uid'],
            'subject' => $edit['subject'],
            'comment' => $edit['comment'],
            'format' => $edit['comment_format'],
            'hostname' => ip_address(),
            'timestamp' => $edit['timestamp'],
            'status' => $edit['status'],
            'thread' => $thread,
            'name' => $edit['name'],
            'mail' => $edit['mail'],
            'homepage' => $edit['homepage']
          ))
          ->execute();
        // Tell the other modules a new comment has been submitted.
        comment_invoke_comment($edit, 'insert');
        // Add an entry to the watchdog log.
        watchdog('content', 'Comment: added %subject.', array('%subject' => $edit['subject']), WATCHDOG_NOTICE, l(t('view'), 'node/' . $edit['nid'], array('fragment' => 'comment-' . $edit['cid'])));
      }
      _comment_update_node_statistics($edit['nid']);
      // Clear the cache so an anonymous user can see his comment being added.
      cache_clear_all();

      // Explain the approval queue if necessary, and then
      // redirect the user to the node he's commenting on.
      if ($edit['status'] == COMMENT_NOT_PUBLISHED) {
        if (!user_access('administer comments')) {
          drupal_set_message(t('Your comment has been queued for moderation by site administrators and will be published after approval.'));
        }
      }
      else {
        drupal_set_message(t('Your comment has been posted.'));
        comment_invoke_comment($edit, 'publish');
      }

      return $edit['cid'];
    }
    else {
      return FALSE;
    }
  }
  else {
    watchdog('content', 'Comment: unauthorized comment submitted or comment submitted to a closed post %subject.', array('%subject' => $edit['subject']), WATCHDOG_WARNING);
    drupal_set_message(t('Comment: unauthorized comment submitted or comment submitted to a closed post %subject.', array('%subject' => $edit['subject'])), 'error');

    return FALSE;
  }
}

// An implementation of hook_link().
function comment_link($type, $object, $teaser) {
  if ($type == 'comment') {
    $links = comment_links($object, FALSE);
    return $links;
  }
}

/**
 * Build command links for a comment (e.g.\ edit, reply, delete) with respect to the current user's access permissions.
 *
 * @param $comment
 *   The comment to which the links will be related.
 * @param $return
 *   Not used.
 * @return
 *   An associative array containing the links.
 */
function comment_links($comment, $return = 1) {
  global $user;
  $links = array();

  // If viewing just this comment, link back to the node.
  if ($return) {
    $links['comment_parent'] = array(
      'title' => t('parent'),
      'href' => comment_node_url(),
      'fragment' => "comment-$comment->cid"
    );
  }

  if (node_comment_mode($comment->nid) == COMMENT_NODE_READ_WRITE) {
    if (user_access('administer comments') && user_access('post comments')) {
      $links['comment_delete'] = array(
        'title' => t('delete'),
        'href' => "comment/delete/$comment->cid"
      );
      $links['comment_edit'] = array(
        'title' => t('edit'),
        'href' => "comment/edit/$comment->cid"
      );
      $links['comment_reply'] = array(
        'title' => t('reply'),
        'href' => "comment/reply/$comment->nid/$comment->cid"
      );
      if ($comment->status == COMMENT_NOT_PUBLISHED) {
        $links['comment_approve'] = array(
          'title' => t('approve'),
          'href' => "comment/approve/$comment->cid"
        );
      }
    }
    elseif (user_access('post comments')) {
      if (comment_access('edit', $comment)) {
        $links['comment_edit'] = array(
          'title' => t('edit'),
          'href' => "comment/edit/$comment->cid"
        );
      }
      $links['comment_reply'] = array(
        'title' => t('reply'),
        'href' => "comment/reply/$comment->nid/$comment->cid"
      );
    }
    else {
      $node = node_load($comment->nid);
      $links['comment_forbidden']['title'] = theme('comment_post_forbidden', $node);
    }
  }

  return $links;
}

/**
 * Renders comment(s).
 *
 * @param $node
 *   The node which comment(s) needs rendering.
 * @param $cid
 *   Optional, if given, only one comment is rendered.
 *
 * To display threaded comments in the correct order we keep a 'thread' field
 * and order by that value. This field keeps this data in
 * a way which is easy to update and convenient to use.
 *
 * A "thread" value starts at "1". If we add a child (A) to this comment,
 * we assign it a "thread" = "1.1". A child of (A) will have "1.1.1". Next
 * brother of (A) will get "1.2". Next brother of the parent of (A) will get
 * "2" and so on.
 *
 * First of all note that the thread field stores the depth of the comment:
 * depth 0 will be "X", depth 1 "X.X", depth 2 "X.X.X", etc.
 *
 * Now to get the ordering right, consider this example:
 *
 * 1
 * 1.1
 * 1.1.1
 * 1.2
 * 2
 *
 * If we "ORDER BY thread ASC" we get the above result, and this is the
 * natural order sorted by time. However, if we "ORDER BY thread DESC"
 * we get:
 *
 * 2
 * 1.2
 * 1.1.1
 * 1.1
 * 1
 *
 * Clearly, this is not a natural way to see a thread, and users will get
 * confused. The natural order to show a thread by time desc would be:
 *
 * 2
 * 1
 * 1.2
 * 1.1
 * 1.1.1
 *
 * which is what we already did before the standard pager patch. To achieve
 * this we simply add a "/" at the end of each "thread" value. This way, the
 * thread fields will look like this:
 *
 * 1/
 * 1.1/
 * 1.1.1/
 * 1.2/
 * 2/
 *
 * we add "/" since this char is, in ASCII, higher than every number, so if
 * now we "ORDER BY thread DESC" we get the correct order. However this would
 * spoil the reverse ordering, "ORDER BY thread ASC" -- here, we do not need
 * to consider the trailing "/" so we use a substring only.
 */
function comment_render($node, $cid = 0) {
  global $user;
  $output = '';

  if (user_access('access comments')) {
    // Pre-process variables.
    $nid = $node->nid;
    if (empty($nid)) {
      $nid = 0;
    }

    $mode = _comment_get_display_setting('mode', $node);
    $comments_per_page = _comment_get_display_setting('comments_per_page', $node);

    if ($cid && is_numeric($cid)) {
      // Single comment view.
      $query = db_select('comment', 'c');
      $query->fields('c', array('cid', 'nid', 'pid', 'comment', 'subject', 'format', 'timestamp', 'name', 'mail', 'homepage', 'status') );
      $query->fields('u', array( 'uid', 'signature', 'picture', 'data', 'status') );
      $query->addField('u', 'name', 'registered_name');
      $query->innerJoin('users', 'u', 'c.uid = u.uid');
      $query->condition('c.cid', $cid);

      if (!user_access('administer comments')) {
        $query->condition('c.status', COMMENT_PUBLISHED);
      }

      $result = $query->execute();

      if ($comment = $result->fetchObject()) {
        $comment->name = $comment->uid ? $comment->registered_name : $comment->name;
        $links = module_invoke_all('link', 'comment', $comment, 1);
        drupal_alter('link', $links, $node);

        $output .= theme('comment_view', $comment, $node, $links);
      }
    }
    else {

      //TODO Convert to dynamic queries once the pager query is updated to the new DBTNG API.

      // Multiple comment view.
      $query_count = 'SELECT COUNT(*) FROM {comment} c WHERE c.nid = %d';
      $query = 'SELECT c.cid as cid, c.pid, c.nid, c.subject, c.comment, c.format, c.timestamp, c.name, c.mail, c.homepage, u.uid, u.name AS registered_name, u.signature, u.picture, u.data, c.thread, c.status FROM {comment} c INNER JOIN {users} u ON c.uid = u.uid WHERE c.nid = %d';

      $query_args = array($nid);
      if (!user_access('administer comments')) {
        $query .= ' AND c.status = %d';
        $query_count .= ' AND c.status = %d';
        $query_args[] = COMMENT_PUBLISHED;
      }
      if ($mode == COMMENT_MODE_FLAT_COLLAPSED || $mode == COMMENT_MODE_FLAT_EXPANDED) {
        $query .= ' ORDER BY c.cid';
      }
      else {
        // See comment above. Analysis reveals that this doesn't cost too
        // much. It scales much much better than having the whole comment
        // structure.
        $query .= ' ORDER BY SUBSTRING(c.thread, 1, (LENGTH(c.thread) - 1))';
      }

      $query = db_rewrite_sql($query, 'c', 'cid');
      $query_count = db_rewrite_sql($query_count, 'c', 'cid');

      $result = pager_query($query, $comments_per_page, 0, $query_count, $query_args);

      $divs = 0;
      $num_rows = FALSE;
      $comments = '';
      drupal_add_css(drupal_get_path('module', 'comment') . '/comment.css');
      foreach ($result as $comment) {
        $comment = drupal_unpack($comment);
        $comment->name = $comment->uid ? $comment->registered_name : $comment->name;
        $comment->depth = count(explode('.', $comment->thread)) - 1;

        if ($mode == COMMENT_MODE_THREADED_COLLAPSED || $mode == COMMENT_MODE_THREADED_EXPANDED) {
          if ($comment->depth > $divs) {
            $divs++;
            $comments .= '<div class="indented">';
          }
          else {
            while ($comment->depth < $divs) {
              $divs--;
              $comments .= '</div>';
            }
          }
        }

        if ($mode == COMMENT_MODE_FLAT_COLLAPSED) {
          $comments .= theme('comment_flat_collapsed', $comment, $node);
        }
        elseif ($mode == COMMENT_MODE_FLAT_EXPANDED) {
          $comments .= theme('comment_flat_expanded', $comment, $node);
        }
        elseif ($mode == COMMENT_MODE_THREADED_COLLAPSED) {
          $comments .= theme('comment_thread_collapsed', $comment, $node);
        }
        elseif ($mode == COMMENT_MODE_THREADED_EXPANDED) {
          $comments .= theme('comment_thread_expanded', $comment, $node);
        }
        $num_rows = TRUE;
      }
      while ($divs-- > 0) {
        $comments .= '</div>';
      }
      $output .= $comments;
      $output .= theme('pager', NULL, $comments_per_page, 0);
    }

    // If enabled, show new comment form if it's not already being displayed.
    $reply = arg(0) == 'comment' && arg(1) == 'reply';
    if (user_access('post comments') && node_comment_mode($nid) == COMMENT_NODE_READ_WRITE && (variable_get('comment_form_location_' . $node->type, COMMENT_FORM_SEPARATE_PAGE) == COMMENT_FORM_BELOW) && !$reply) {
      $output .= comment_form_box(array('nid' => $nid), t('Post new comment'));
    }
    $output = theme('comment_wrapper', $output, $node);
  }

  return $output;
}

/**
 * Comment operations. Offer different update operations depending on
 * which comment administration page is being viewed.
 *
 * @param $action
 *   The comment administration page.
 * @return
 *   An associative array containing the offered operations.
 */
function comment_operations($action = NULL) {
  if ($action == 'publish') {
    $operations = array(
      'publish' => array(t('Publish the selected comments'), db_update('comment')->fields(array( 'status' => COMMENT_PUBLISHED)) ),
      'delete' => array(t('Delete the selected comments'), '')
    );
  }
  elseif ($action == 'unpublish') {
    $operations = array(
      'unpublish' => array(t('Unpublish the selected comments'), db_update('comment')->fields(array( 'status' => COMMENT_NOT_PUBLISHED)) ),
      'delete' => array(t('Delete the selected comments'), '')
    );
  }
  else {
    $operations = array(
      'publish' => array(t('Publish the selected comments'), db_update('comment')->fields(array( 'status' => COMMENT_PUBLISHED)) ),
      'unpublish' => array(t('Unpublish the selected comments'), db_update('comment')->fields(array( 'status' => COMMENT_NOT_PUBLISHED)) ),
      'delete' => array(t('Delete the selected comments'), '')
    );
  }

  return $operations;
}

/**
 * Begin the misc functions: helpers, privates, history.
 */

/**
 * Load the entire comment by cid.
 *
 * @param $cid
 *   The identifying comment id.
 * @return
 *   The comment object.
 */
function comment_load($cid) {
  return db_query('SELECT * FROM {comment} WHERE cid = :cid', array(':cid' => $cid))->fetchObject();
}

/**
 * Get replies count for a comment.
 *
 * @param $pid
 *   The comment id.
 * @return
 *   The replies count.
 */
function comment_num_replies($pid) {
  static $cache;

  if (!isset($cache[$pid])) {
    $cache[$pid] = db_query('SELECT COUNT(cid) FROM {comment} WHERE pid = :pid AND status = :status', array(
      ':pid' => $pid,
      ':status' => COMMENT_PUBLISHED))
      ->fetchField();
  }

  return $cache[$pid];
}

/**
 * Get number of new comments for current user and specified node.
 *
 * @param $nid
 *   Node-id to count comments for.
 * @param $timestamp
 *   Time to count from (defaults to time of last user access
 *   to node).
 * @return The result or FALSE on error.
 */
function comment_num_new($nid, $timestamp = 0) {
  global $user;

  if ($user->uid) {
    // Retrieve the timestamp at which the current user last viewed this node.
    if (!$timestamp) {
      $timestamp = node_last_viewed($nid);
    }
    $timestamp = ($timestamp > NODE_NEW_LIMIT ? $timestamp : NODE_NEW_LIMIT);

    // Use the timestamp to retrieve the number of new comments.
    return db_query('SELECT COUNT(c.cid) FROM {node} n INNER JOIN {comment} c ON n.nid = c.nid WHERE n.nid = :nid AND timestamp > :timestamp AND c.status = :status', array(
      ':nid' => $nid,
      ':timestamp' => $timestamp,
      ':status' => COMMENT_PUBLISHED ))
      ->fetchField();
  }
  else {
    return FALSE;
  }

}

/**
 * Validate comment data.
 *
 * @param $edit
 *   An associative array containing the comment data.
 * @return
 *   The original $edit.
 */
function comment_validate($edit) {
  global $user;

  // Invoke other validation handlers.
  comment_invoke_comment($edit, 'validate');

  if (isset($edit['date'])) {
    if (strtotime($edit['date']) === FALSE) {
      form_set_error('date', t('You have to specify a valid date.'));
    }
  }
  if (isset($edit['author']) && !$account = user_load(array('name' => $edit['author']))) {
    form_set_error('author', t('You have to specify a valid author.'));
  }

  // Check validity of name, mail and homepage (if given).
  if (!$user->uid || isset($edit['is_anonymous'])) {
    $node = node_load($edit['nid']);
    if (variable_get('comment_anonymous_' . $node->type, COMMENT_ANONYMOUS_MAYNOT_CONTACT) > COMMENT_ANONYMOUS_MAYNOT_CONTACT) {
      if ($edit['name']) {
        $query = db_select('users', 'u');
        $query->addField('u', 'uid', 'uid');
        $taken = $query->where('LOWER(name) = :name', array(':name' => $edit['name']))
          ->countQuery()
          ->execute()
          ->fetchField();
        if ($taken != 0) {
          form_set_error('name', t('The name you used belongs to a registered user.'));
        }
      }
      elseif (variable_get('comment_anonymous_' . $node->type, COMMENT_ANONYMOUS_MAYNOT_CONTACT) == COMMENT_ANONYMOUS_MUST_CONTACT) {
        form_set_error('name', t('You have to leave your name.'));
      }

      if ($edit['mail']) {
        if (!valid_email_address($edit['mail'])) {
          form_set_error('mail', t('The e-mail address you specified is not valid.'));
        }
      }
      elseif (variable_get('comment_anonymous_' . $node->type, COMMENT_ANONYMOUS_MAYNOT_CONTACT) == COMMENT_ANONYMOUS_MUST_CONTACT) {
        form_set_error('mail', t('You have to leave an e-mail address.'));
      }

      if ($edit['homepage']) {
        if (!valid_url($edit['homepage'], TRUE)) {
          form_set_error('homepage', t('The URL of your homepage is not valid. Remember that it must be fully qualified, i.e. of the form <code>http://example.com/directory</code>.'));
        }
      }
    }
  }

  return $edit;
}

/**
 * Generate the basic commenting form, for appending to a node or display on a separate page.
 *
 * @param $title
 *   Not used.
 * @ingroup forms
 * @see comment_form_validate()
 * @see comment_form_submit()
 */
function comment_form(&$form_state, $edit, $title = NULL) {
  global $user;
  $op = isset($_POST['op']) ? $_POST['op'] : '';
  $node = node_load($edit['nid']);

  if (!$user->uid && variable_get('comment_anonymous_' . $node->type, COMMENT_ANONYMOUS_MAYNOT_CONTACT) != COMMENT_ANONYMOUS_MAYNOT_CONTACT) {
    drupal_add_js(drupal_get_path('module', 'comment') . '/comment.js');
  }
  $edit += array('name' => '', 'mail' => '', 'homepage' => '');

  if ($user->uid) {
    if (!empty($edit['cid']) && user_access('administer comments')) {
      if (!empty($edit['author'])) {
        $author = $edit['author'];
      }
      elseif (!empty($edit['name'])) {
        $author = $edit['name'];
      }
      else {
        $author = $edit['registered_name'];
      }

      if (!empty($edit['status'])) {
        $status = $edit['status'];
      }
      else {
        $status = 0;
      }

      if (!empty($edit['date'])) {
        $date = $edit['date'];
      }
      else {
        $date = format_date($edit['timestamp'], 'custom', 'Y-m-d H:i O');
      }

      $form['admin'] = array(
        '#type' => 'fieldset',
        '#title' => t('Administration'),
        '#collapsible' => TRUE,
        '#collapsed' => TRUE,
        '#weight' => -2,
      );

      if ($edit['registered_name'] != '') {
        // The comment is by a registered user.
        $form['admin']['author'] = array(
          '#type' => 'textfield',
          '#title' => t('Authored by'),
          '#size' => 30,
          '#maxlength' => 60,
          '#autocomplete_path' => 'user/autocomplete',
          '#default_value' => $author,
          '#weight' => -1,
        );
      }
      else {
        // The comment is by an anonymous user.
        $form['is_anonymous'] = array(
          '#type' => 'value',
          '#value' => TRUE,
        );
        $form['admin']['name'] = array(
          '#type' => 'textfield',
          '#title' => t('Authored by'),
          '#size' => 30,
          '#maxlength' => 60,
          '#default_value' => $author,
          '#weight' => -1,
        );
        $form['admin']['mail'] = array(
          '#type' => 'textfield',
          '#title' => t('E-mail'),
          '#maxlength' => 64,
          '#size' => 30,
          '#default_value' => $edit['mail'],
          '#description' => t('The content of this field is kept private and will not be shown publicly.'),
        );
        $form['admin']['homepage'] = array(
          '#type' => 'textfield',
          '#title' => t('Homepage'),
          '#maxlength' => 255,
          '#size' => 30,
          '#default_value' => $edit['homepage'],
        );
      }
      $form['admin']['date'] = array(
        '#type' => 'textfield',
        '#parents' => array('date'),
        '#title' => t('Authored on'),
        '#size' => 20,
        '#maxlength' => 25,
        '#default_value' => $date,
        '#weight' => -1,
      );
      $form['admin']['status'] = array(
        '#type' => 'radios',
        '#parents' => array('status'),
        '#title' => t('Status'),
        '#default_value' =>  $status,
        '#options' => array(t('Published'), t('Not published')),
        '#weight' => -1,
      );
    }
    else {
      $form['_author'] = array(
        '#type' => 'item',
        '#title' => t('Your name'),
        '#markup' => theme('username', $user),
      );
      $form['author'] = array(
        '#type' => 'value',
        '#value' => $user->name,
      );
    }
  }
  elseif (variable_get('comment_anonymous_' . $node->type, COMMENT_ANONYMOUS_MAYNOT_CONTACT) == COMMENT_ANONYMOUS_MAY_CONTACT) {
    $form['name'] = array(
      '#type' => 'textfield',
      '#title' => t('Your name'),
      '#maxlength' => 60,
      '#size' => 30,
      '#default_value' => $edit['name'] ? $edit['name'] : variable_get('anonymous', t('Anonymous')),
    );
    $form['mail'] = array(
      '#type' => 'textfield',
      '#title' => t('E-mail'),
      '#maxlength' => 64,
      '#size' => 30,
      '#default_value' => $edit['mail'], '#description' => t('The content of this field is kept private and will not be shown publicly.'),
    );
    $form['homepage'] = array(
      '#type' => 'textfield',
      '#title' => t('Homepage'),
      '#maxlength' => 255,
      '#size' => 30,
      '#default_value' => $edit['homepage'],
    );
  }
  elseif (variable_get('comment_anonymous_' . $node->type, COMMENT_ANONYMOUS_MAYNOT_CONTACT) == COMMENT_ANONYMOUS_MUST_CONTACT) {
    $form['name'] = array(
      '#type' => 'textfield',
      '#title' => t('Your name'),
      '#maxlength' => 60,
      '#size' => 30,
      '#default_value' => $edit['name'] ? $edit['name'] : variable_get('anonymous', t('Anonymous')),
      '#required' => TRUE,
    );
    $form['mail'] = array(
      '#type' => 'textfield',
      '#title' => t('E-mail'),
      '#maxlength' => 64,
      '#size' => 30,
      '#default_value' => $edit['mail'], '#description' => t('The content of this field is kept private and will not be shown publicly.'),
      '#required' => TRUE,
    );
    $form['homepage'] = array(
      '#type' => 'textfield',
      '#title' => t('Homepage'),
      '#maxlength' => 255,
      '#size' => 30,
      '#default_value' => $edit['homepage'],
    );
  }

  if (variable_get('comment_subject_field_' . $node->type, 1) == 1) {
    $form['subject'] = array(
      '#type' => 'textfield',
      '#title' => t('Subject'),
      '#maxlength' => 64,
      '#default_value' => !empty($edit['subject']) ? $edit['subject'] : '',
    );
  }

  if (!empty($edit['comment'])) {
    $default = $edit['comment'];
  }
  else {
    $default = '';
  }

  $form['comment'] = array(
    '#type' => 'textarea',
    '#title' => t('Comment'),
    '#rows' => 15,
    '#default_value' => $default,
    '#input_format' => isset($edit['format']) ? $edit['format'] : FILTER_FORMAT_DEFAULT,
    '#required' => TRUE,
  );

  $form['cid'] = array(
    '#type' => 'value',
    '#value' => !empty($edit['cid']) ? $edit['cid'] : NULL,
  );
  $form['pid'] = array(
    '#type' => 'value',
    '#value' => !empty($edit['pid']) ? $edit['pid'] : NULL,
  );
  $form['nid'] = array(
    '#type' => 'value',
    '#value' => $edit['nid'],
  );
  $form['uid'] = array(
    '#type' => 'value',
    '#value' => !empty($edit['uid']) ? $edit['uid'] : 0,
  );

  // Only show the save button if comment previews are optional or if we are
  // already previewing the submission. However, if there are form errors,
  // we hide the save button no matter what, so that optional form elements
  // (e.g., captchas) can be updated.
  if (!form_get_errors() && ((variable_get('comment_preview_' . $node->type, COMMENT_PREVIEW_REQUIRED) == COMMENT_PREVIEW_OPTIONAL) || ($op == t('Preview')) || ($op == t('Save')))) {
    $form['submit'] = array(
      '#type' => 'submit',
      '#value' => t('Save'),
      '#weight' => 19,
    );
  }
  $form['preview'] = array(
    '#type' => 'button',
    '#value' => t('Preview'),
    '#weight' => 20,
  );
  $form['#token'] = 'comment' . $edit['nid'] . (isset($edit['pid']) ? $edit['pid'] : '');

  if ($op == t('Preview')) {
    $form['#after_build'] = array('comment_form_add_preview');
  }

  if (empty($edit['cid']) && empty($edit['pid'])) {
    $form['#action'] = url('comment/reply/' . $edit['nid']);
  }

  return $form;
}

/**
 * Theme the comment form box.
 *
 * @param $edit
 *   The form structure.
 * @param $title
 *   The form title.
 */
function comment_form_box($edit, $title = NULL) {
  return theme('box', $title, drupal_get_form('comment_form', $edit, $title));
}

/**
 * Form builder; Generate and validate a comment preview form.
 *
 * @ingroup forms
 */
function comment_form_add_preview($form, &$form_state) {
  global $user;
  $edit = $form_state['values'];
  drupal_set_title(t('Preview comment'), PASS_THROUGH);
  $output = '';
  $node = node_load($edit['nid']);

  // Invoke full validation for the form, to protect against cross site
  // request forgeries (CSRF) and setting arbitrary values for fields such as
  // the input format. Preview the comment only when form validation does not
  // set any errors.
  drupal_validate_form($form['form_id']['#value'], $form, $form_state);
  if (!form_get_errors()) {
    _comment_form_submit($edit);
    $comment = (object)$edit;
    $comment->format = $comment->comment_format;

    // Attach the user and time information.
    if (!empty($edit['author'])) {
      $account = user_load(array('name' => $edit['author']));
    }
    elseif ($user->uid && !isset($edit['is_anonymous'])) {
      $account = $user;
    }

    if (!empty($account)) {
      $comment->uid = $account->uid;
      $comment->name = check_plain($account->name);
    }
    elseif (empty($comment->name)) {
      $comment->name = variable_get('anonymous', t('Anonymous'));
    }

    $comment->timestamp = !empty($edit['timestamp']) ? $edit['timestamp'] : REQUEST_TIME;
    $output .= theme('comment_view', $comment, $node);
  }

  $form['comment_preview'] = array(
    '#markup' => $output,
    '#weight' => -100,
    '#prefix' => '<div class="preview">',
    '#suffix' => '</div>',
  );

  $output = ''; // Isn't this line a duplication of the first $output above?

  if ($edit['pid']) {
    $comment = db_query('SELECT c.*, u.uid, u.name AS registered_name, u.signature, u.picture, u.data FROM {comment} c INNER JOIN {users} u ON c.uid = u.uid WHERE c.cid = :cid AND c.status = :status', array(
      ':cid' => $edit['pid'],
      ':status' => COMMENT_PUBLISHED ))
      ->fetchObject();
    $comment = drupal_unpack($comment);
    $comment->name = $comment->uid ? $comment->registered_name : $comment->name;
    $output .= theme('comment_view', $comment, $node);
  }
  else {
    $suffix = empty($form['#suffix']) ? '' : $form['#suffix'];
    $form['#suffix'] = $suffix . node_view($node);
    $edit['pid'] = 0;
  }

  $form['comment_preview_below'] = array(
    '#markup' => $output,
    '#weight' => 100,
  );

  return $form;
}

/**
 * Validate comment form submissions.
 */
function comment_form_validate($form, &$form_state) {
  global $user;
  if ($user->uid === 0) {
    foreach (array('name', 'homepage', 'mail') as $field) {
      // Set cookie for 365 days.
      if (isset($form_state['values'][$field])) {
        setcookie('comment_info_' . $field, $form_state['values'][$field], REQUEST_TIME + 31536000, '/');
      }
    }
  }
  comment_validate($form_state['values']);
}

/**
 * Prepare a comment for submission.
 *
 * @param $comment_values
 *   An associative array containing the comment data.
 */
function _comment_form_submit(&$comment_values) {
  $comment_values += array('subject' => '');
  if (!isset($comment_values['date'])) {
    $comment_values['date'] = 'now';
  }

  $comment_values['timestamp'] = strtotime($comment_values['date']);
  if (isset($comment_values['author'])) {
    $account = user_load(array('name' => $comment_values['author']));
    $comment_values['uid'] = $account->uid;
    $comment_values['name'] = $comment_values['author'];
  }

  // Validate the comment's subject. If not specified, extract from comment body.
  if (trim($comment_values['subject']) == '') {
    // The body may be in any format, so:
    // 1) Filter it into HTML
    // 2) Strip out all HTML tags
    // 3) Convert entities back to plain-text.
    // Note: format is checked by check_markup().
    $comment_values['subject'] = trim(truncate_utf8(decode_entities(strip_tags(check_markup($comment_values['comment'], $comment_values['comment_format']))), 29, TRUE));
    // Edge cases where the comment body is populated only by HTML tags will
    // require a default subject.
    if ($comment_values['subject'] == '') {
      $comment_values['subject'] = t('(No subject)');
    }
  }
}

/**
 * Process comment form submissions; prepare the comment, store it, and set a redirection target.
 */
function comment_form_submit($form, &$form_state) {
  _comment_form_submit($form_state['values']);
  if ($cid = comment_save($form_state['values'])) {
    $node = node_load($form_state['values']['nid']);
    $page = comment_new_page_count($node->comment_count, 1, $node);
    $form_state['redirect'] = array('node/' . $node->nid, $page, "comment-$cid");
    return;
  }
}

/**
 * Theme a single comment block.
 *
 * @param $comment
 *   The comment object.
 * @param $node
 *   The comment node.
 * @param $links
 *   An associative array containing control links.
 * @param $visible
 *   Switches between folded/unfolded view.
 * @ingroup themeable
 */
function theme_comment_view($comment, $node, $links = array(), $visible = TRUE) {
  static $first_new = TRUE;
  $comment->new = node_mark($comment->nid, $comment->timestamp);
  $output = '';

  if ($first_new && $comment->new != MARK_READ) {
    // Assign the anchor only for the first new comment. This avoids duplicate
    // id attributes on a page.
    $first_new = FALSE;
    $output .= "<a id=\"new\"></a>\n";
  }

  $output .= "<a id=\"comment-$comment->cid\"></a>\n";

  // Switch to folded/unfolded view of the comment.
  if ($visible) {
    $comment->comment = check_markup($comment->comment, $comment->format, '', FALSE);
    // Comment API hook.
    comment_invoke_comment($comment, 'view');
    $output .= theme('comment', $comment, $node, $links);
  }
  else {
    $output .= theme('comment_folded', $comment);
  }

  return $output;
}

/**
 * Process variables for comment.tpl.php.
 *
 * @see comment.tpl.php
 * @see theme_comment()
 */
function template_preprocess_comment(&$variables) {
  $comment = $variables['comment'];
  $node = $variables['node'];
  $variables['author']    = theme('username', $comment);
  $variables['content']   = $comment->comment;
  $variables['date']      = format_date($comment->timestamp);
  $variables['links']     = isset($variables['links']) ? theme('links', $variables['links']) : '';
  $variables['new']       = $comment->new ? t('new') : '';
  $variables['picture']   = theme_get_setting('toggle_comment_user_picture') ? theme('user_picture', $comment) : '';
  $variables['signature'] = $comment->signature;
  $variables['submitted'] = theme('comment_submitted', $comment);
  $variables['title']     = l($comment->subject, $_GET['q'], array('fragment' => "comment-$comment->cid"));
  $variables['template_files'][] = 'comment-' . $node->type;
  // Set status to a string representation of comment->status.
  if (isset($comment->preview)) {
    $variables['status']  = 'comment-preview';
  }
  else {
    $variables['status']  = ($comment->status == COMMENT_NOT_PUBLISHED) ? 'comment-unpublished' : 'comment-published';
  }
}

/**
 * Process variables for comment-folded.tpl.php.
 *
 * @see comment-folded.tpl.php
 * @see theme_comment_folded()
 */
function template_preprocess_comment_folded(&$variables) {
  $comment = $variables['comment'];
  $variables['author'] = theme('username', $comment);
  $variables['date']   = format_date($comment->timestamp);
  $variables['new']    = $comment->new ? t('new') : '';
  $variables['title']  = l($comment->subject, comment_node_url() . '/' . $comment->cid, array('fragment' => "comment-$comment->cid"));
}

/**
 * Theme comment flat collapsed view.
 *
 * @param $comment
 *   The comment to be themed.
 * @param $node
 *   The comment node.
 * @ingroup themeable
 */
function theme_comment_flat_collapsed($comment, $node) {
  return theme('comment_view', $comment, $node, '', 0);
}

/**
 * Theme comment flat expanded view.
 *
 * @param $comment
 *   The comment to be themed.
 * @param $node
 *   The comment node.
 * @ingroup themeable
 */
function theme_comment_flat_expanded($comment, $node) {
  return theme('comment_view', $comment, $node, module_invoke_all('link', 'comment', $comment, 0));
}

/**
 * Theme comment thread collapsed view.
 *
 * @param $comment
 *   The comment to be themed.
 * @param $node
 *   The comment node.
 * @ingroup themeable
 */
function theme_comment_thread_collapsed($comment, $node) {
  return theme('comment_view', $comment, $node, '', 0);
}

/**
 * Theme comment thread expanded view.
 *
 * @param $comment
 *   The comment to be themed.
 * @param $node
 *   The comment node.
 * @ingroup themeable
 */
function theme_comment_thread_expanded($comment, $node) {
  return theme('comment_view', $comment, $node, module_invoke_all('link', 'comment', $comment, 0));
}

/**
 * Theme a "you can't post comments" notice.
 *
 * @param $node
 *   The comment node.
 * @ingroup themeable
 */
function theme_comment_post_forbidden($node) {
  global $user;
  static $authenticated_post_comments;

  if (!$user->uid) {
    if (!isset($authenticated_post_comments)) {
      // We only output any link if we are certain, that users get permission
      // to post comments by logging in. We also locally cache this information.
      $authenticated_post_comments = array_key_exists(DRUPAL_AUTHENTICATED_RID, user_roles(TRUE, 'post comments') + user_roles(TRUE, 'post comments without approval'));
    }

    if ($authenticated_post_comments) {
      // We cannot use drupal_get_destination() because these links
      // sometimes appear on /node and taxonomy listing pages.
      if (variable_get('comment_form_location_' . $node->type, COMMENT_FORM_SEPARATE_PAGE) == COMMENT_FORM_SEPARATE_PAGE) {
        $destination = 'destination=' . drupal_urlencode("comment/reply/$node->nid#comment-form");
      }
      else {
        $destination = 'destination=' . drupal_urlencode("node/$node->nid#comment-form");
      }

      if (variable_get('user_register', 1)) {
        // Users can register themselves.
        return t('<a href="@login">Login</a> or <a href="@register">register</a> to post comments', array('@login' => url('user/login', array('query' => $destination)), '@register' => url('user/register', array('query' => $destination))));
      }
      else {
        // Only admins can add new users, no public registration.
        return t('<a href="@login">Login</a> to post comments', array('@login' => url('user/login', array('query' => $destination))));
      }
    }
  }
}

/**
 * Process variables for comment-wrapper.tpl.php.
 *
 * @see comment-wrapper.tpl.php
 * @see theme_comment_wrapper()
 */
function template_preprocess_comment_wrapper(&$variables) {
  // Provide contextual information.
  $variables['display_mode']  = _comment_get_display_setting('mode', $variables['node']);
  $variables['template_files'][] = 'comment-wrapper-' . $variables['node']->type;
}

/**
 * Theme a "Submitted by ..." notice.
 *
 * @param $comment
 *   The comment.
 * @ingroup themeable
 */
function theme_comment_submitted($comment) {
  return t('Submitted by !username on @datetime.',
    array(
      '!username' => theme('username', $comment),
      '@datetime' => format_date($comment->timestamp)
    ));
}

/**
 * Return an array of viewing modes for comment listings.
 *
 * We can't use a global variable array because the locale system
 * is not initialized yet when the comment module is loaded.
 */
function _comment_get_modes() {
  return array(
    COMMENT_MODE_FLAT_COLLAPSED => t('Flat list - collapsed'),
    COMMENT_MODE_FLAT_EXPANDED => t('Flat list - expanded'),
    COMMENT_MODE_THREADED_COLLAPSED => t('Threaded list - collapsed'),
    COMMENT_MODE_THREADED_EXPANDED => t('Threaded list - expanded')
  );
}

/**
 * Return an array of "comments per page" settings from which the user
 * can choose.
 */
function _comment_per_page() {
  return drupal_map_assoc(array(10, 30, 50, 70, 90, 150, 200, 250, 300));
}

/**
 * Return a current comment display setting
 *
 * @param $setting
 *   can be one of these: 'mode', 'sort', 'comments_per_page'
 * @param $node
 *   The comment node in question.
 */
function _comment_get_display_setting($setting, $node) {
  switch ($setting) {
    case 'mode':
      $value = variable_get('comment_default_mode_' . $node->type, COMMENT_MODE_THREADED_EXPANDED);
      break;

    case 'comments_per_page':
      $value = variable_get('comment_default_per_page_' . $node->type, 50);
  }

  return $value;
}

/**
 * Updates the comment statistics for a given node. This should be called any
 * time a comment is added, deleted, or updated.
 *
 * The following fields are contained in the node_comment_statistics table.
 * - last_comment_timestamp: the timestamp of the last comment for this node or the node create stamp if no comments exist for the node.
 * - last_comment_name: the name of the anonymous poster for the last comment
 * - last_comment_uid: the uid of the poster for the last comment for this node or the node authors uid if no comments exists for the node.
 * - comment_count: the total number of approved/published comments on this node.
 */
function _comment_update_node_statistics($nid) {
  $count = db_query('SELECT COUNT(cid) FROM {comment} WHERE nid = :nid AND status = :status', array(':nid' => $nid, ':status' => COMMENT_PUBLISHED))->fetchField();

  if ($count > 0) {
    // Comments exist.
    $last_reply = db_query_range('SELECT cid, name, timestamp, uid FROM {comment} WHERE nid = :nid AND status = :status ORDER BY cid DESC', array(':nid' => $nid, ':status' => COMMENT_PUBLISHED), 0, 1)->fetchObject();
    db_update('node_comment_statistics')
      ->fields( array(
        'comment_count' => $count,
        'last_comment_timestamp' => $last_reply->timestamp,
        'last_comment_name' => $last_reply->uid ? '' : $last_reply->name,
        'last_comment_uid' => $last_reply->uid ))
      ->condition('nid', $nid)
      ->execute();
  }
  else {
    // Comments do not exist.
    $node = db_query('SELECT uid, created FROM {node} WHERE nid = :nid', array(':nid' => $nid))->fetchObject();
    db_update('node_comment_statistics')
      ->fields( array(
        'comment_count' => 0,
        'last_comment_timestamp' => $node->created,
        'last_comment_name' => '',
        'last_comment_uid' => $node->uid ))
      ->condition('nid', $nid)
      ->execute();
  }
}

/**
 * Invoke a hook_comment() operation in all modules.
 *
 * @param &$comment
 *   A comment object.
 * @param $op
 *   A string containing the name of the comment operation.
 * @return
 *   The returned value of the invoked hooks.
 */
function comment_invoke_comment(&$comment, $op) {
  $return = array();
  foreach (module_implements('comment') as $module) {
    $function = $module . '_comment';
    $result = $function($comment, $op);
    if (isset($result) && is_array($result)) {
      $return = array_merge($return, $result);
    }
    elseif (isset($result)) {
      $return[] = $result;
    }
  }

  return $return;
}

/**
 * Generate vancode.
 *
 * Consists of a leading character indicating length, followed by N digits
 * with a numerical value in base 36. Vancodes can be sorted as strings
 * without messing up numerical order.
 *
 * It goes:
 * 00, 01, 02, ..., 0y, 0z,
 * 110, 111, ... , 1zy, 1zz,
 * 2100, 2101, ..., 2zzy, 2zzz,
 * 31000, 31001, ...
 */
function int2vancode($i = 0) {
  $num = base_convert((int)$i, 10, 36);
  $length = strlen($num);

  return chr($length + ord('0') - 1) . $num;
}

/**
 * Decode vancode back to an integer.
 */
function vancode2int($c = '00') {
  return base_convert(substr($c, 1), 36, 10);
}

/**
 * Implementation of hook_hook_info().
 */
function comment_hook_info() {
  return array(
    'comment' => array(
      'comment' => array(
        'insert' => array(
          'runs when' => t('After saving a new comment'),
        ),
        'update' => array(
          'runs when' => t('After saving an updated comment'),
        ),
        'delete' => array(
          'runs when' => t('After deleting a comment')
        ),
        'view' => array(
          'runs when' => t('When a comment is being viewed by an authenticated user')
        ),
      ),
    ),
  );
}

/**
 * Implementation of hook_action_info().
 */
function comment_action_info() {
  return array(
    'comment_unpublish_action' => array(
      'description' => t('Unpublish comment'),
      'type' => 'comment',
      'configurable' => FALSE,
      'hooks' => array(
        'comment' => array('insert', 'update'),
      )
    ),
    'comment_unpublish_by_keyword_action' => array(
      'description' => t('Unpublish comment containing keyword(s)'),
      'type' => 'comment',
      'configurable' => TRUE,
      'hooks' => array(
        'comment' => array('insert', 'update'),
      )
    )
  );
}

/**
 * Drupal action to unpublish a comment.
 *
 * @param $context
 *   Keyed array. Must contain the id of the comment if $comment is not passed.
 * @param $comment
 *   An optional comment object.
 */
function comment_unpublish_action($comment, $context = array()) {
  if (isset($comment->cid)) {
    $cid = $comment->cid;
    $subject = $comment->subject;
  }
  else {
    $cid = $context['cid'];
    $subject = db_query('SELECT subject FROM {comment} WHERE cid = :cid', array(':cid', $cid))->fetchField();
  }
  db_update('comment')
    ->fields(array('status' => COMMENT_NOT_PUBLISHED,))
    ->condition('cid', $cid)
    ->execute();
  watchdog('action', 'Unpublished comment %subject.', array('%subject' => $subject));
}

/**
 * Form builder; Prepare a form for blacklisted keywords.
 *
 * @ingroup forms
 */
function comment_unpublish_by_keyword_action_form($context) {
  $form['keywords'] = array(
    '#title' => t('Keywords'),
    '#type' => 'textarea',
    '#description' => t('The comment will be unpublished if it contains any of the character sequences above. Use a comma-separated list of character sequences. Example: funny, bungee jumping, "Company, Inc." . Character sequences are case-sensitive.'),
    '#default_value' => isset($context['keywords']) ? drupal_implode_tags($context['keywords']) : '',
  );

  return $form;
}

/**
 * Process comment_unpublish_by_keyword_action_form form submissions.
 */
function comment_unpublish_by_keyword_action_submit($form, $form_state) {
  return array('keywords' => drupal_explode_tags($form_state['values']['keywords']));
}

/**
 * Implementation of a configurable Drupal action.
 *
 * Unpublish a comment if it contains a certain string.
 *
 * @param $context
 *   An array providing more information about the context of the call to this action.
 *   Unused here, since this action currently only supports the insert and update ops of
 *   the comment hook, both of which provide a complete $comment object.
 * @param $comment
 *   A comment object.
 */
function comment_unpublish_by_keyword_action($comment, $context) {
  foreach ($context['keywords'] as $keyword) {
    if (strstr($comment->comment, $keyword) || strstr($comment->subject, $keyword)) {
      db_update('comment')
        ->fields(array('status' => COMMENT_NOT_PUBLISHED,))
        ->condition('cid', $comment->cid)
        ->execute();
      watchdog('action', 'Unpublished comment %subject.', array('%subject' => $comment->subject));
      break;
    }
  }
}

/**
 * Implementation of hook_ranking().
 */
function comment_ranking() {
  return array(
    'comments' => array(
      'title' => t('Number of comments'),
      'join' => 'LEFT JOIN {node_comment_statistics} node_comment_statistics ON node_comment_statistics.nid = i.sid',
      // Inverse law that maps the highest reply count on the site to 1 and 0 to 0.
      'score' => '2.0 - 2.0 / (1.0 + node_comment_statistics.comment_count * CAST(%f AS DECIMAL))',
      'arguments' => array(variable_get('node_cron_comments_scale', 0)),
    ),
  );
}