<?php
// $Id$

/**
 * @file
 *
 * This module provides comment follow-up e-mail notification for anonymous and registered users.
 */

define('AUTHOR_MAILTEXT',
'Hi !name,

You have received a comment on: "!node_title"

You can view the comment at the following url
!comment_url

You will receive emails like this for all replies to your posts. You can disable this by logging in and going to your account settings.

Webmaster of !site
!mission
!uri');

define('DEFAULT_MAILTEXT',
'Hi !name,

!commname has commented on: "!node_title"

The post is about
----
!node_teaser
----

You can view the comment at the following url
!comment_url

You can stop receiving emails when someone replies to this post,
by going to !link1

If you have auto-following enabled in your account, you will receive emails like this for all replies to a blog post you commented on. You can disable this by logging in and going to your account settings or unchecking the flag at the time you post the comment.

You can set up auto-following feature for all future posts
by creating your own user with a few clicks here !uri/user/register

Thanks for your feedback,

Webmaster of !site
!mission
!uri');

define('COMMENT_NOTIFY_DISABLED', 0);
define('COMMENT_NOTIFY_NODE', 1);
define('COMMENT_NOTIFY_COMMENT', 2);

/**
 * Provide an array of available options for notification on a comment.
 */
function _comment_notify_options() {
  $total_options = array(
    COMMENT_NOTIFY_NODE     => t('All comments'),
    COMMENT_NOTIFY_COMMENT  => t('Replies to my comment')
  );

  $available_options = array();
  $options = variable_get('comment_notify_available_alerts', array(COMMENT_NOTIFY_NODE, COMMENT_NOTIFY_COMMENT));
  foreach ($options as $key => $available) {
    if ($key == $available) {
      $available_options[$available] = $total_options[$available];
    }
  }

  return $available_options;
}

/**
 * Insert our checkbox, add a submit button, and populate fields.
 */
function comment_notify_form_alter(&$form, &$form_state, $form_id) {
  global $user;

  // Only do alter the form if it's a comment form and the user has the permission to subscribe
  if ($form_id != 'comment_form' || !user_access('subscribe to comments')) {
    return;
  }

  // Only add the checkbox if this is an enabled content type
  $node = node_load($form['nid']['#value']);
  $enabled_types = variable_get('comment_notify_node_types', array($node->type => TRUE));
  if (empty($enabled_types[$node->type])) {
    return;
  }

  $available_options = _comment_notify_options();

  drupal_add_css(drupal_get_path('module', 'comment_notify') .'/comment_notify.css');
  drupal_add_js(drupal_get_path('module', 'comment_notify') .'/comment_notify.js');

  // Add the checkbox for anonymous users and set the default based on admin settings.
  if ($user->uid == 0) {
    // If anonymous user's can't enter their e-mail don't tempt them with the checkbox.
    if (empty($form['mail'])) {
      return;
    }
    $preference = variable_get('comment_notify_default_anon_mailalert', COMMENT_NOTIFY_DISABLED);
  }
  else {
    $user_preference = db_result(db_query("SELECT comment_notify FROM {comment_notify_user_settings} WHERE uid = %d", $user->uid));
    $preference = strlen($user_preference) ? $user_preference : variable_get('comment_notify_default_registered_mailalert', COMMENT_NOTIFY_DISABLED);
  }

  // If you want to hide this on your site see http://drupal.org/node/322482
  $form['notify_settings'] = array(
    '#prefix' => '<div class="clear-block">',
    '#suffix' => '</div>',
  );

  $form['notify_settings']['notify'] = array(
    '#type' => 'checkbox',
    '#title' => t('Notify me when new comments are posted'),
    '#default_value' => $preference,
  );

  if (count($available_options) > 1) {
    $form['notify_settings']['notify_type'] = array(
      '#type' => 'radios',
      '#options' => $available_options,
      '#default_value' => $preference,
    );
  }
  else {
    $form['notify_settings']['notify_type'] = array(
      '#type' => 'hidden',
      '#default_value' => key($available_options),
    );
  }
  $form['notify_settings']['notify_type']['#default_value'] = $preference;

  // If this is an existing comment we set the default value based on their selection last time.
  if ($form['cid']['#value'] != '') {
    $notify = db_result(db_query("SELECT notify FROM {comment_notify} WHERE cid = %d", $form['cid']['#value']));
    $form['notify_settings']['notify']['#default_value'] = $notify;
    if (count($available_options) > 1) {
      $form['notify_settings']['notify_type']['#default_value'] = $notify;
    }
    else {
      $form['notify_settings']['notify_type']['#default_value'] = key($available_options);
    }
  }
}

/**
 * Implementation of hook_perm().
 */
function comment_notify_perm() {
  return array('administer comment notify', 'subscribe to comments');
}

/**
 * Implementation of hook_menu().
 */
function comment_notify_menu() {

  $items['admin/settings/comment_notify'] = array(
    'title' => 'Comment notify',
    'description' => 'Configure settings for e-mails about new comments.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('comment_notify_settings'),
    'access arguments' => array('administer comment notify'),
    'type' => MENU_NORMAL_ITEM,
  );
  $items['admin/settings/comment_notify/settings'] = array(
    'title' => 'Settings',
    'description' => 'Configure settings for e-mails about new comments.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('comment_notify_settings'),
    'access arguments' => array('administer comment notify'),
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );

  $items['admin/settings/comment_notify/unsubscribe'] = array(
    'title' => 'Unsubscribe',
    'description' => 'Unsubscribe an email from all notifications.',
    'weight' => 2,
    'page callback' => 'drupal_get_form',
    'page arguments' => array('comment_notify_unsubscribe'),
    'access arguments' => array('administer comment notify'),
    'type' => MENU_LOCAL_TASK,
  );
  $items['comment_notify/disable/%'] = array(
    'title' => 'Disable comment notification',
    'page callback' => 'comment_notify_disable_page',
    'page arguments' => array(2),
    'access arguments' => array('access content'),
    'type' => MENU_CALLBACK
  );

  return $items;
}

/**
 * Page callback to allow users to unsubscribe simply by visiting the page.
 */
function comment_notify_disable_page($hash) {
  db_query("UPDATE {comment_notify} SET notify = 0 WHERE notify_hash = '%s'", $hash);

  drupal_set_message(t('Your comment follow-up notification for this post was disabled. Thanks.'));
  return ' ';
}

/**
 * Implementation of hook_comment().
 */
function comment_notify_comment($comment, $op) {
  global $user;

  // In theory, the update or insert operations are duplicates with publish which
  // would lead to duplicate messages.  _comment_notify_mailalert() protects against that.
  switch ($op) {
    case 'validate':
       // We assume that if they are non-anonymous then they have a valid mail.
       // For anonymous users, though, we verify that they entered a mail and let comment.module validate it is real.
      if (!$user->uid && $comment['notify'] && empty($comment['mail'])) {
        form_set_error('mail', t('If you want to subscribe to comments you must supply a valid e-mail address.'));
      }
      break;
    case 'publish':
      // And send notifications - the real purpose of the module.
      _comment_notify_mailalert($comment);
      break;
    case 'update':
      // In case they have changed their status, save it in the database.
      $sql = 'UPDATE {comment_notify} SET notify = %d WHERE cid = %d';
      if ($comment['notify']) {
        db_query($sql, $comment['notify_type'], $comment['cid']);
      }
      else {
        db_query($sql, 0, $comment['cid']);
      }
      // And send notifications - the real purpose of the module.
      if ($comment['status'] == COMMENT_PUBLISHED) {
        _comment_notify_mailalert($comment);
      }
      break;
    case 'insert':
      // For new comments, we first build up a string to be used as the identifier for the alert
      $mail = empty($comment['mail']) ? $user->mail : $comment['mail'];
      $notify_hash = drupal_get_token($mail . $comment['cid']);

      if ($comment['notify']) {
        $notify = $comment['notify_type'];
        $current = db_result(db_query("SELECT count(1) from {comment_notify_user_settings} WHERE uid = %d", $user->uid));
        if ($current == 0 && $user->uid) {
          db_query("INSERT INTO {comment_notify_user_settings} (uid, comment_notify) VALUES (%d, %d)", $user->uid, $comment['notify_type']);
        }
      }
      else {
        $notify = $comment['notify'];
      }
      // And then save the data.
      db_query("INSERT INTO {comment_notify} (cid, notify, notify_hash) values (%d, %d, '%s')", $comment['cid'], $notify, $notify_hash);

      // And send notifications - the real purpose of the module.
      if ($comment['status'] == COMMENT_PUBLISHED) {
        _comment_notify_mailalert($comment);
      }
      break;
    case 'delete':
      db_query("DELETE FROM {comment_notify} WHERE cid = %d", $comment->cid);
      break;
  }
}

/**
 * Implementation of hook_user().
 */
function comment_notify_user($type, &$edit, &$user, $category = NULL) {
  switch ($type) {
    case 'form':
      if ($category == 'account' && user_access('subscribe to comments', $user)) {
        $form = array();
        $form['comment_notify_settings'] = array(
          '#type' => 'fieldset',
          '#title' => t('Comment follow-up notification settings'),
          '#weight' => 4,
          '#collapsible' => TRUE
        );

        $form['comment_notify_settings']['node_notify_mailalert'] = array(
          '#type' => 'checkbox',
          '#title' => t('Receive node follow-up notification e-mails'),
          '#default_value' => isset($edit['node_notify_mailalert']) ? $edit['node_notify_mailalert'] : variable_get('node_notify_default_mailalert', FALSE),
          '#description' => t('Check this box to receive an e-mail notification for follow-ups on your nodes (pages, forum topics, etc). You can not disable notifications for individual threads.')
        );

        $available_options[COMMENT_NOTIFY_DISABLED] = t('No notifications');
        $available_options += _comment_notify_options();
        $form['comment_notify_settings']['comment_notify_mailalert'] = array(
          '#type' => 'select',
          '#title' => t('Receive comment follow-up notification e-mails'),
          '#default_value' => isset($edit['comment_notify_mailalert']) ? $edit['comment_notify_mailalert'] : variable_get('comment_notify_default_registered_mailalert', COMMENT_NOTIFY_DISABLED),
          '#options' => $available_options,
          '#description' => t("Check this box to receive e-mail notification for follow-up comments to comments you posted. You can later disable this on a post-by-post basis... so if you leave this to YES, you can still disable follow-up notifications for comments you don't want follow-up mails anymore - i.e. for very popular posts.")
        );
        return $form;
      }
      break;

    case 'submit':
      // Save the values of node_notify_mailalert and comment_notify_mailalert
      // to {comment_notify_user_settings}.
      if (db_result(db_query('SELECT uid FROM {comment_notify_user_settings} WHERE uid = %d', $user->uid))) {
        db_query('UPDATE {comment_notify_user_settings} SET node_notify = %d, comment_notify = %d WHERE uid = %d', $edit['node_notify_mailalert'], $edit['comment_notify_mailalert'], $user->uid);
      }
      else {
        db_query('INSERT INTO {comment_notify_user_settings} (uid, node_notify, comment_notify) VALUES (%d, %d, %d)', $user->uid, $edit['node_notify_mailalert'], $edit['comment_notify_mailalert']);
      }

      // Unset them from $user so they don't also get saved into {users}.data.
      unset($edit['node_notify_mailalert']);
      unset($edit['comment_notify_mailalert']);
      break;

    case 'load':
      $user_settings = db_fetch_array(db_query('SELECT node_notify AS node_notify_mailalert, comment_notify AS comment_notify_mailalert FROM {comment_notify_user_settings} WHERE uid = %d', $user->uid));
      if (!empty($user_settings)) {
        foreach ($user_settings as $property => $value) {
          $user->$property = $value;
        }
      }
      break;

    case 'delete':
      db_query('DELETE FROM {comment_notify_user_settings} WHERE uid = %d', $user->uid);
      break;

      break;
  }
}

/**
 * Private function to send the notifications.
 *
 * @param $comment
 *   The comment array as found in hook_comment $op = publish.
 */
function _comment_notify_mailalert($comment) {
  $comment = (object) $comment;
  global $language;
  global $base_url;
  global $user;

  $nid = $comment->nid;
  $cid = $comment->cid;

  // Check to see if a notification has already been sent for this
  // comment so that edits to a comment don't trigger an additional
  // notification.
  if (db_result(db_query('SELECT cid from {comment_notify} WHERE cid = %d AND notified = %d', $cid, 1))) {
    return;
  }

  $initial_language = $language;

  if (function_exists('locale')) {
    $languages = locale_language_list();
    $languages = $languages['name'];
  }

  // Render up the node and comment.
  $node = node_load($nid);
  $node_teaser = node_view($node, TRUE, TRUE, FALSE);
  $node_body = node_view($node, FALSE, TRUE, FALSE);
  $comment_text = check_markup($comment->comment, $comment->format);

  if (!isset($comment->mail)) {
    $comment_account = user_load(array('name' => $comment->name));
    $comment_mail = $comment_account->mail;
  }
  else {
    $comment_mail = $comment->mail;
  }
  $sent_to = array();

  // Send to a subscribed author if they are not the current commenter
  $author = user_load(array('uid' => $node->uid));
  if (!empty($author->node_notify_mailalert) && $author->node_notify_mailalert == 1 && $user->uid != $author->uid) {
    // Get the author's language.
    $language = user_preferred_language($author);
    $message['subject'] = t('!site :: new comment for your post.', array('!site' => variable_get('site_name', 'drupal')));
    $message['body'] = t(
      variable_get('node_notify_default_mailtext', AUTHOR_MAILTEXT),
      array(
        '!commname' => $comment->name,
        '!commtext' => drupal_html_to_text($comment_text),
        '!commsubj' => $comment->subject,
        '!comment_url' => url('node/'. $nid, array('absolute' => TRUE, 'fragment' => 'comment-'. $cid)),
        '!node_title' =>  $node->title,
        '!node_teaser' => drupal_html_to_text($node_teaser),
        '!mission' => variable_get('site_mission', ''),
        '!node_body' =>  drupal_html_to_text($node_body),
        '!name' => $author->name,
        '!site' => variable_get('site_name', 'drupal'),
        '!uri' => $base_url,
        '!uri_brief' => preg_replace('!^https?://!', '', $base_url),
        '!date' => format_date(time()),
        '!login_uri' => url('user', array('absolute' => TRUE)),
        '!edit_uri' => url('user/'. $author->uid .'/edit', array('absolute' => TRUE))
      )
    );
    drupal_mail('comment_notify', 'comment_notify_mail', $author->mail, $language, $message);
    $sent_to[] = $author->mail;
  }

  // For "reply to my comments" notifications, figure out what thread this is.
  $thread = db_result(db_query("SELECT thread FROM {comments} WHERE cid = %d", $cid));

  //Get the list of commenters to notify
  $result = db_query("SELECT DISTINCT c.cid, c.uid, c.name, c.nid, c.mail AS cmail, u.mail AS umail, u.init AS uinit, c.uid, c.name, cn.notify, cn.notify_hash, c.thread
    FROM {comments} c INNER JOIN {comment_notify} cn on c.cid = cn.cid LEFT OUTER JOIN {users} u ON c.uid = u.uid
    WHERE nid = %d AND cn.notify > 0 AND c.status = 0 AND (u.status = 1 OR u.uid = 0)", $nid
  );
  // TODO? the original big query had stuff making sure the mail was populated and contained .+@.+ Perhaps check for that here and set notify = 0 if that is the case for this cid

  while ($alert = db_fetch_object($result)) {
    $umail = empty($alert->umail) ? $alert->uinit : $alert->umail;
    $mail = empty($alert->cmail) ? $umail : $alert->cmail;

    $relevant_thread = substr($thread, 0, drupal_strlen($alert->thread) -1);
    if ($alert->notify == COMMENT_NOTIFY_COMMENT && strcmp($relevant_thread . '/', $alert->thread) != 0) {
      continue;
    }
    if ($mail != $comment_mail && !in_array($mail, $sent_to) && $alert->uid != $comment->uid) {
      $message = array();
      if (!empty($alert->uid)) {
        $recipient_user = user_load(array('uid' => $alert->uid));
        $language = user_preferred_language($recipient_user);
      }
      else {
        $language = language_default();
      }

      $message['subject'] = t('!site :: new comment for your post.', array('!site' => variable_get('site_name', 'drupal')));
      $message['body'] = t(
        variable_get('comment_notify_default_mailtext', DEFAULT_MAILTEXT),
        array(
          '!commname' => $comment->name,
          '!commtext' => drupal_html_to_text($comment_text),
          '!commsubj' => $comment->subject,
          '!comment_url' => url('node/'. $nid, array('absolute' => TRUE, 'fragment' => 'comment-'. $cid)),
          '!node_title' =>  $node->title,
          '!node_teaser' => drupal_html_to_text($node_teaser),
          '!mission' => variable_get('site_mission', ''),
          '!node_body' =>  drupal_html_to_text($node_body),
          '!name' => $alert->name,
          '!site' => variable_get('site_name', 'drupal'),
          '!uri' => $base_url,
          '!uri_brief' => preg_replace('!^https?://!', '', $base_url),
          '!date' => format_date(time()),
          '!login_uri' => url('user', array('absolute' => TRUE)),
          '!edit_uri' => url('user/'. $alert->uid .'/edit', array('absolute' => TRUE)),
          '!link1' => url('comment_notify/disable/'. $alert->notify_hash, array('absolute' => TRUE))
        )
      );
      drupal_mail('comment_notify', 'comment_notify_mail', $mail, $language, $message);
      $sent_to[] = $mail;

      // Make the mail link to user's /edit, unless it's an anonymous user.
      if ($alert->uid != 0) {
        $user_mail = l($mail, 'user/'. $alert->uid .'/edit');
      }
      else {
        $user_mail = check_plain($mail);
      }

      // Add an entry to the watchdog log.
      watchdog(
        'comment_notify',
        'Notified: !user_mail',
        array('!user_mail' => $user_mail),
        WATCHDOG_NOTICE,
        l(t('source comment'), 'node/'. $nid, array(
          'fragment' => 'comment-'. $alert->cid,
        ))
      );

      // revert to previous (site default) locale
      $language = $initial_language;
    }
  }
  // Record that a notification was sent for this comment so that
  // notifications aren't sent again if the comment is later edited.
  db_query('UPDATE {comment_notify} SET notified = 1 WHERE cid = %d', $cid);
}

/**
 * Implementation of hook_mail().
 */
function comment_notify_mail($key, &$message, $params) {
  $message['subject'] = $params['subject'];
  $message['body'][] = $params['body'];
}

/**
 * Callback for an administrative form to unsubscribe users by e-mail address.
 */
function comment_notify_unsubscribe() {
  $form['comment_notify_unsubscribe'] = array();
  $form['comment_notify_unsubscribe']['email_to_unsubscribe'] = array(
    '#type' => 'textfield',
    '#title' => t('Email to unsubscribe'),
  );
  $form['comment_notify_unsubscribe']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Unsubscribe this e-mail'),
  );
  return $form;
}

/**
 * Based on admin submit, do the actual unsubscribe from notifications.
 */
function comment_notify_unsubscribe_submit($form, &$form_state) {
  $email = trim($form_state['values']['email_to_unsubscribe']);
  // If they have a uid, use that, otherwise update comments directly
  $result = db_result(db_query_range("SELECT uid FROM {users} WHERE mail = '%s'", $email, 0, 1));
  if ($result > 0) {
    $comments = db_result(db_query("SELECT COUNT(1) FROM {comments} c INNER JOIN {comment_notify} cn ON c.cid = cn.cid WHERE c.uid = %d AND cn.notify > 0", $result));
    db_query("UPDATE {comment_notify} SET notify = 0 WHERE cid IN (SELECT cid FROM  {comments} WHERE uid = %d)", $result);
  }
  else {
    $comments = db_result(db_query("SELECT COUNT(1) FROM {comments} c INNER JOIN {comment_notify} cn ON c.cid = cn.cid WHERE c.mail = '%s' AND cn.notify > 0", $email));
    db_query("UPDATE {comment_notify} SET notify = 0 WHERE cid IN (SELECT cid FROM {comments} WHERE mail = '%s')", $email);
  }
  // Update the admin about the state of this comment notification subscription.
  if ($comments == 0) {
    drupal_set_message(t("There were no active comment notifications for that email."));
  }
  else {
    drupal_set_message(format_plural($comments, "Email unsubscribed from 1 comment notification.",
      "Email unsubscribed from @count comment notifications."));
  }
}

/*
 * Page callback for administrative settings form.
 */
function comment_notify_settings() {
  $form['comment_notify_settings'] = array();

  // Only perform comment_notify for certain node types (default, all)
  $enabled_types = variable_get('comment_notify_node_types', FALSE);
  $anonymous_problems = '';
  foreach (node_get_types('names') as $type => $name) {
    $checkboxes[$type] = check_plain($name);
    $default[] = $type;

    // If they don't have the ability to leave contact info, then we make a report
    if (isset($enabled_types[$type]) && $enabled_types[$type] && variable_get('comment_anonymous_'. $type, COMMENT_ANONYMOUS_MAYNOT_CONTACT) == COMMENT_ANONYMOUS_MAYNOT_CONTACT) {
      $account = user_load(array('uid' => 0));
      if (user_access('subscribe to comments', $account)) {
        $anonymous_problems[] = l(t('@content-type', array('@content-type' => $name)), 'admin/content/node-type/'. $type);
      }
    }
  }

  if (!empty($anonymous_problems)) {
    drupal_set_message(t('Anonymous commenters have the permission to subscribe to comments but cannot leave their contact infromation on the following content types: !types.  You should either disable subscriptions on those types here, revoke the permission for anonymous users, or enable anonymous users to leave their contact information in the comment settings.', array('!types' => implode(', ', $anonymous_problems))));
  }

  $form['comment_notify_settings']['comment_notify_node_types'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Content types to enable for comment notification'),
    '#default_value' => variable_get('comment_notify_node_types', $default),
    '#options' => $checkboxes,
    '#description' => t('Comments on content types enabled here will have the option of comment notification.'),
  );

  $form['comment_notify_settings']['comment_notify_available_alerts'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Available subscription modes'),
    '#return_value' => 1,
    '#default_value' => variable_get('comment_notify_available_alerts', array(COMMENT_NOTIFY_NODE, COMMENT_NOTIFY_COMMENT)),
    '#description' => t('Choose which notification subscription styles are available for users'),
    '#options' => array(
      COMMENT_NOTIFY_NODE     => t('All comments'),
      COMMENT_NOTIFY_COMMENT  => t('Replies to my comment')
    )
  );

  $available_options[COMMENT_NOTIFY_DISABLED] = t('No notifications');
  $available_options += _comment_notify_options();
  $form['comment_notify_settings']['comment_notify_default_anon_mailalert'] = array(
    '#type' => 'select',
    '#title' => t('Default state for the notification selection box for anonymous users'),
    '#return_value' => 1,
    '#default_value' => variable_get('comment_notify_default_anon_mailalert', COMMENT_NOTIFY_NODE),
    '#options' => $available_options,
  );

  $form['comment_notify_settings']['comment_notify_default_registered_mailalert'] = array(
    '#type' => 'select',
    '#title' => t('Default state for the notification selection box for registered users'),
    '#return_value' => 1,
    '#default_value' => variable_get('comment_notify_default_registered_mailalert', COMMENT_NOTIFY_NODE),
    '#description' => t('This flag presets the flag for the follow-up notification on the form that anon users will see when posting a comment'),
    '#options' => $available_options,
  );

  $form['comment_notify_settings']['node_notify_default_mailalert'] = array(
    '#type' => 'checkbox',
    '#title' => t('Subscribe users to their node follow-up notification emails by default'),
    '#default_value' => variable_get('node_notify_default_mailalert', FALSE),
    '#description' => t('If this is checked, new users will receive e-mail notifications for follow-ups on their nodes by default until they individually disable the feature.'),
  );


  $form['comment_notify_settings']['comment_notify_default_mailtext'] = array(
    '#type' => 'textarea',
    '#title' => t('Default mail text for sending out notifications to commenters'),
    '#description' => t(
      'You can use the following variables to be replaced:
      <ul>
      <li>!commname = the username who posted the comment
      <li>!commtext = the text of the posted comment
      <li>!commsubj = the subject of the posted comment
      <li>!comment_url = the full url of the post and comment - note: if you have paging enabled, this does not work correct - set your max comments per page so that all fit on one page or reverse order them
      <li>!node_title = the title of the node that was commented on
      <li>!node_teaser = the teaser of the node that was commented on
      <li>!node_body = the body of the node that was commented on
      <li>!mission = site_mission text
      <li>!name = username receiving the alert
      <li>!site = your site
      <li>!uri = base_url of site
      <li>!uri_brief = base_url of site w/o http
      <li>!date = the current time
      <li>!login_uri  uri to login the user
      <li>!edit_uri = uri to edit user profile
      <li>!link1 the QUICKLINK to disable future follow-up notifications for the user
      </ul>'
    ),
    '#default_value' => variable_get('comment_notify_default_mailtext', t(DEFAULT_MAILTEXT)),
    '#return_value' => 1,
    '#cols' => 80,
    '#rows' => 15
  );

  $form['comment_notify_settings']['node_notify_default_mailtext'] = array(
    '#type' => 'textarea',
    '#title' => t('Default mail text for sending out the notifications to node authors'),
    '#description' => t(
      'You can use the following variables to be replaced:
      <ul>
      <li>!commname = the username who posted the comment
      <li>!commtext = the text of the posted comment
      <li>!commsubj = the subject of the posted comment
      <li>!comment_url = the full url of the post and comment - note: if you have paging enabled, this does not work correct - set your max comments per page so that all fit on one page or reverse order them
      <li>!node_title = the title of the node that was commented on
      <li>!node_teaser = the teaser of the node that was commented on
      <li>!node_body = the body of the node that was commented on
      <li>!mission = site_mission text
      <li>!name = username receiving the alert
      <li>!site = your site
      <li>!uri = base_url of site
      <li>!uri_brief = base_url of site w/o http
      <li>!date = the current time
      <li>!login_uri  uri to login the user
      <li>!edit_uri = uri to edit user profile
      </ul>'
    ),
    '#default_value' => variable_get('node_notify_default_mailtext', t(AUTHOR_MAILTEXT)),
     '#return_value' => 1,
     '#cols' => 80,
     '#rows' => 15
  );

  $form['#validate'] = array('comment_notify_settings_validate');

  return system_settings_form($form);
}

function comment_notify_settings_validate($form, &$form_state) {
  $sum_enabled = 0;
  foreach ($form_state['values']['comment_notify_available_alerts'] as $enabled) {
    $sum_enabled += $enabled;
  }
  if (!$sum_enabled) {
    form_set_error('comment_notify_available_alerts', 'You must enable at least one subscription mode.');
  }
}