<?php
// $Id: lists.module,v 1.14 2010-10-23 00:02:55 drumm Exp $

/**
 * @file
 *   Drupal.org mailing list subscription helper.
 *   
 *   How to configure mailman mailing lists with this module (there is no admin
 *   interface for this at this time):
 *
 *   1) Configure mailman lists as necessary.  It should be configured so that
 *   only messages from the drupal website mailing address are allowed to post
 *   to the mailing list.  (Posting to specific forums will generate an email
 *   sent from the drupal.org website to mailman, which will then be sent to
 *   everyone subscribed to the mailman list.)
 *
 *   2) Update function _lists_get_mailman_lists() with list configuration.  The
 *   individual list password should be stored directly in the database as a
 *   variable to avoid distributing it to everyone via source code or
 *   settings.php).
 *
 *   The following lists are already added:  'Drupal newsletter',  'Security
 *   announcements', and 'Maintainer news'.  You need to configure 'mail',
 *   'pass', and 'url' for each.  'mail' is the email address that mail needs to
 *   be sent to when posting to the mailing list.  'pass' is the admin password
 *   for this mailing list (this is sent to the server in the URL itself!).
 *   'url' is the HTTP url to the administrative interface for the given mailing
 *   list.
 *
 *   The 'Maintainer news' is a special newsletter that users can not manually
 *   subscribe/unsubscribe.  Instead, they will be automatically
 *   subscribed/unsubscribed based on whether or not they have CVS commit access.
 *
 *   3) Create a Forum container named "Newsletters", then create forums for each
 *   mailman-powered newsletter within this new container.  For the current lists,
 *   this means adding the following lists:
 *     • Security newsletter
 *     • Drupal newsletter
 *     • Maintainer newsletter
 *
 *   4) Update function _lists_get_forum_tids(), adding a correlation between the
 *   tid of each forum and the list's key in _lists_get_mailman_lists().
 *
 *   5) If this doesn't seem to work, file an issue and then email
 *   jeremy@tag1consulting.com to tell him to review it.
 */

/**
 * Implementation of hook_menu().
 */
function lists_menu() {
  $items['lists'] = array(
    'title' => 'Mailing lists',
    'access arguments' => array('access content'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('lists_subscribe_form'),
    'type' => MENU_SUGGESTED_ITEM
  );
  return $items;
}

// == Mailing list functionality ===============================================

/**
 * Internal helper function to return a list of mailing lists.
 */
function _lists_get_lists() {
  $lists = array(
    'support'       => array(
      'name'        => 'Support',
      'description' => 'A list for support questions.',
      'mailto'      => 'support-request@drupal.org',
    ),
    'development'   => array(
      'name'        => 'Development',
      'description' => 'A list for Drupal developers.',
      'mailto'      => 'development-request@drupal.org',
    ),
    'themes'        => array(
      'name'        => 'Themes',
      'description' => 'A list for Drupal theme developers/designers.',
      'mailto'      => 'themes-request@drupal.org',
    ),
    'translations'  => array(
      'name'        => 'Translations',
      'description' => 'A list for Drupal UI translators.',
      'mailto'      => 'translations-request@drupal.org',
    ),
    'consulting'    => array(
      'name'        => 'Consulting',
      'description' => 'A mailing list for Drupal consultants and Drupal service/hosting providers.',
      'mailto'      => 'consulting-request@drupal.org',
    ),
    'drupal-cvs'    => array(
      'name'        => 'CVS commits',
      'description' => 'A list with all CVS commit messages.',
      'mailto'      => 'drupal-cvs-request@drupal.org',
    ),
    'cvs-applications' => array(
      'name'        => 'CVS applications',
      'description' => 'A list of all applications for an account in the Drupal contributions CVS repository.',
      'mailto'      => 'cvs-applications-request@drupal.org',
      'private'     => TRUE,
    ),
    'webmasters'    => array(
      'name'        => 'Webmasters',
      'description' => 'A list for drupal.org webmasters (e.g. settings and content on the drupal.org website, user management, removing spam, etc.).',
      'mailto'      => 'webmasters-request@drupal.org',
      'private'     => TRUE,
    ),
    'infrastructure' => array(
      'name'         => 'Infrastructure',
      'description'  => 'A list for drupal.org infrastructure maintainers (e.g. drupal.org hardware and server configuration, the CVS repository, mailing lists, etc).',
      'mailto'       => 'infrastructure-request@drupal.org',
      'private'      => TRUE,
    ),
    'drupal-con'    => array(
      'name'        => 'DrupalCON',
      'description' => 'A list for the organization of Drupal conferences and events.',
      'mailto'      => 'drupal-con-request@drupal.org',
      'private'     => TRUE,
    ),
  );
  return $lists;
}

/**
 * Mailing list form builder function.
 *
 * @see lists_subscribe_form_validate()
 * @see lists_subscribe_form_submit()
 */
function lists_subscribe_form() {
  global $user;
  $lists = _lists_get_lists();

  foreach ($lists as $list => $info) {
    $links = array();
    if (isset($info['private']) && $info['private']) {
      $links[] = "<a href=\"http://lists.drupal.org/mailman/private/$list/\">view archive</a> (members only)";
    }
    else {
      $links[] = "<a href=\"http://lists.drupal.org/pipermail/$list/\">view archive</a>";
    }

    $output .= '<h2>'. $info['name'] ."</h2>\n";
    if (!$info['disabled']) {
      $links[] = "<a href=\"http://lists.drupal.org/listinfo/$list\">mailman page</a>";
    }
    else {
      $output .= "<em>This list has been disabled.</em>\n";
    }

    $output .= '<p>'. $info['description'] ."</p>\n";
    $output .= '<p>'. implode(' . ', $links) ."</p>\n";
  }
  $output .= '<h2>Subscribe</h2>';

  $form['intro'] = array(
    '#type' => 'markup',
    '#value' => $output,
  );

  $form['mail'] = array(
    '#type'          => 'textfield',
    '#title'         => t('E-mail address'),
    '#default_value' => ($user->uid ? $user->mail : ''),
    '#size'          => 50,
    '#maxlength'     => 255,
    '#required'      => TRUE,
  );
  $form['item'] = array(
    '#type' => 'item',
    '#title' => t('Mailing lists'),
    '#default_value' => '',
  );
  foreach ($lists as $list => $info) {
    if (!$info['disabled']) {
      $form[$list] = array(
        '#type' => 'checkbox',
        '#title' => $list,
      );
    }
  }
  $form['subscribe'] = array(
    '#type' => 'submit',
    '#value' => t('Subscribe'),
  );

  return $form;
}

/**
 * Validate form submission.
 *
 * @see lists_subscribe_form()
 */
function lists_subscribe_form_validate($form, &$form_state) {
  if (!valid_email_address($form_state['values']['mail'])) {
    form_set_error('mail', t('Please enter a valid e-mail address.'));
  }
}

/**
 * Submission handler for the subscription form.
 *
 * @see lists_subscribe_form()
 */
function lists_subscribe_form_submit($form, &$form_state) {
  $sent = FALSE;
  $mail = $form_state['values']['mail'];
  if ($mail) {
    foreach (_lists_get_lists() as $list => $info) {
      if ($form_state['values'][$list]) {
        $sent = TRUE;
        $headers = "From: $mail\nReturn-path: $mail\nError-to: $mail";
        $result[] = mail($info['mailto'], "subscribe address=$mail", 'subscribe to mailing list', $headers);
      }
    }
  }

  if (!$sent) {
    drupal_set_message(t('You did not fill in the form properly.'), 'error');
  }
  else {
    drupal_set_message(t('You will receive confirmation emails for your subscriptions. Please read them carefully and follow the directions.'));
  }
}

// == Newsletters ==============================================================

/**
 * Static definition of all mailman managed Drupal mailing lists.
 */
function _lists_get_mailman_lists() {
  // passwords need to be set in variable table in order to be able to
  // administer these lists.
  $lists = array(
    'drupal'        => array(
      'name'        => 'Drupal newsletter',
      'description' => 'A sometimes-monthly mailing about all things Drupal.',
      'allow_sub'   => TRUE,
      'mail'        => variable_get('lists_drupal_mail', ''),
      'pass'        => variable_get('lists_drupal_pass', ''),
      'url'         => variable_get('lists_drupal_url', ''),
    ),
    'security'      => array(
      'name'        => 'Security announcements',
      'description' => 'A low volume mailing list where all security issues affecting Drupal and Drupal contributed modules are publically announced.',
      'allow_sub'   => TRUE,
      'mail'        => variable_get('lists_security_mail', ''),
      'pass'        => variable_get('lists_security_pass', ''),
      'url'         => variable_get('lists_security_url', ''),
    ),
    'maintainer'    => array(
      'name'        => 'Maintainer news',
      'description' => 'This list is automatically enabled for users with a CVS account and can not be manually subscribed or unsubscribed.',
      'allow_sub'   => FALSE,
      'maintainer_auto' => TRUE,
      'mail'        => variable_get('lists_maintainer_mail', ''),
      'pass'        => variable_get('lists_maintainer_pass', ''),
      'url'         => variable_get('lists_maintainer_url', ''),
    ),
  );
  return $lists;
}

/**
 * List of all forums that are mailman mailing lists.
 */
function _lists_get_forum_tids() {
  return variable_get('lists_forum_tids', array());
}

/**
 * Implementation of hook_perm().
 */
function lists_perm() {
  return array('post to newsletter');
}

/**
 * Implementation of hook_user().
 *
 * We need to hack this in, since user module does try to have a tight control
 * of management of these menu items, so we need to get it created through
 * this hook and then altered by hook_menu_alter(). Drupal 7 should do better.
 */
function lists_user($op, &$edit, &$account, $category = NULL) {
  switch ($op) {
    case 'categories':
      return array(array('name' => 'newsletter', 'title' => t('My newsletters'), 'weight' => 10));
  }
}

/**
 * Implementation of hook_menu_alter().
 *
 * See why we need this hack in lists_user().
 */
function lists_menu_alter(&$callbacks) {
  $callbacks['user/%user_category/edit/newsletter']['page callback'] = 'drupal_get_form';
  $callbacks['user/%user_category/edit/newsletter']['page arguments'] = array('lists_mailman_user_form', 1);
}

/**
 * Per-use mailman subscription form.
 *
 * @ingroup forms
 * @see lists_mailman_user_form_submit()
 */
function lists_mailman_user_form(&$form_state, $account = FALSE) {
  $form = array();

  $form['newsletter'] = array(
    '#type' => 'fieldset',
    '#title' => t('Newsletter subscriptions'),
    '#description' => t('Select the newsletter(s) which you want to subcribe or unsubcribe.'),
    '#collapsible' => FALSE,
  );

  $lists = _lists_get_mailman_lists();
  foreach ($lists as $list => $info) {
    $default_value = _lists_mailman_user_subscribed($info, $account);
    $form['newsletter'][$list] = array(
      '#type' => 'checkbox',
      '#title' => $info['name'],
      '#description' => $info['description'],
      '#disabled' => !$info['allow_sub'],
      '#default_value' => $default_value,
    );
  }
  $form['uid'] = array(
    '#type' => 'hidden',
    '#value' => $account->uid,
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
  );
  return $form;
}

/**
 * Subscribe/unsubscribe from mailman mailing lists.
 */
function lists_mailman_user_form_submit($form, &$form_state) {
  $account = user_load(array('uid' => $form_state['values']['uid']));
  $lists = _lists_get_mailman_lists();
  foreach ($lists as $list => $data) {
    $old = (int)$form['newsletter'][$list]['#default_value'];
    $new = (int)$form_state['values'][$list];
    // Special handling for the maintainer newsletter.
    if ($data['maintainer_auto']) {
      $status = db_result(db_query('SELECT status FROM {cvs_accounts} WHERE uid = %d', $account->uid));
      // If CVS account is approved, be sure user is subscribed to the
      // maintainer newsletter.
      if ($status == CVS_APPROVED) {
        if (!$old) {
          _lists_mailman_subscribe($data, $account);
        }
      }
      // If CVS is not approved, be sure user is not subscribed to the
      // maintainer newsletter.
      else {
        if ($old) {
          _lists_mailman_unsubscribe($data, $account);
        }
      }
    }
    elseif ($data['allow_sub'] && ($old != $new)) {
      if ($new) {
        _lists_mailman_subscribe($data, $account);
      }
      else {
        _lists_mailman_unsubscribe($data, $account);
      }
    }
  }
}

/**
 * Implementation of hook_form_alter().
 */
function lists_form_alter(&$form, $form_state, $form_id) {
  // Add/remove users from maintainer newsletter when their CVS access is
  // updated.
  if ($form_id == 'cvs_user_edit_form') {
    $form['#submit'][] = 'lists_cvs_user_edit_submit';
  }
  else if ($form_id == 'forum_node_form') {
    $node = $form['#node'];
    $lists_forum_tids = array_keys(_lists_get_forum_tids());
    if (!user_access('post to newsletter')) {
      // See if user is trying to post to a forum for which they do not have
      // permission.  If so, redirect them back to the forum in question and
      // notify them they lack permission.
      if (is_array($node->taxonomy)) {
        foreach ($node->taxonomy as $tid => $data) {
          if (in_array($tid, $lists_forum_tids)) {
            drupal_set_message(t('You do not have permission to post to this forum.'));
            drupal_goto("forum/$tid");
          }
        }
      }
      // See if user has permission to post to mailing lists (generating emails
      // to potentially large numbers of users).  If not, remove these forums
      // as a selectable forum option.
      if (is_array($form['taxonomy'])) {
        foreach ($form['taxonomy'] as $vid => $taxonomy) {
          if (is_array($taxonomy) && is_array($taxonomy['#options'])) {
            foreach ($taxonomy['#options'] as $key => $option) {
              if (is_object($option) && isset($option->option)) {
                foreach ($option->option as $tid => $name) {
                  if (in_array($tid, $lists_forum_tids)) {
                    unset($form['taxonomy'][$vid]['#options'][$key]->option[$tid]);
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

/**
 * Submit newsletter forum to mailman for mass mailing.
 */
function lists_nodeapi(&$node, $op, $teaser, $page) {
  global $user;

  if ($node->status && ($op == 'insert' || $op == 'update') && user_access('post to newsletter')) {
    // We are going to return if $node->type is not one of the node
    // types assigned to the forum vocabulary.  If forum_nav_vocabulary
    // is undefined or the vocabulary does not exist, it clearly cannot
    // be assigned to $node->type, so return to avoid E_ALL warnings.
    $vid = variable_get('forum_nav_vocabulary', '');
    $vocabulary = taxonomy_vocabulary_load($vid);
    if (empty($vocabulary)) {
      return;
    }

    // Operate only on node types assigned for the forum vocabulary.
    if (!in_array($node->type, $vocabulary->nodes)) {
      return;
    }

    // Only generate mail for configured forum types.
    $generate_mail = FALSE;
    $lists_forum_tids = array_keys(_lists_get_forum_tids());
    if (is_array($node->taxonomy)) {
      foreach ($node->taxonomy as $key => $tid) {
        if (in_array($tid, $lists_forum_tids)) {
          $generate_mail = TRUE;
          $forum_tid = $tid;
          break;
        }
      }
    }

    // User has permission to generate emails, so send the node to mailman.
    if ($generate_mail) {
      // There's no reason I can see for sending a mailing multiple times, but
      // since we're tracking whether or not something is sent anyway...
      $sent = db_result(db_query('SELECT nid FROM {lists_mailman} WHERE nid = %d', $node->nid));
      if (!$sent) {
        $lists = _lists_get_mailman_lists();
        $lists_forum_tids = _lists_get_forum_tids();
        $list = $lists[$lists_forum_tids[$forum_tid]];
        $language = language_default();
        $params = array('node' => $node);
        drupal_mail('lists', 'mailman_newsletter', $list['mail'], $language, $params);
        db_query('INSERT INTO {lists_mailman} (nid, uid, timestamp) VALUES(%d, %d, %d)', $node->nid, $user->uid, time());
        drupal_set_message(t('Mail sent to !email.', array('!email' => $list['mail'])));
      }
      // Force comments to be disabled for these posts.  David doesn't like this.
      // This is an ugly kludge.
      db_query('UPDATE {node} SET comment = %d WHERE nid = %d', COMMENT_NODE_DISABLED, $node->nid);
    }
  }
}

/**
 * Implementation of hook_mail().
 */
function lists_mail($key, &$message, $params) {
  if ($key == 'mailman_newsletter') {
    // Just copy over the subject and body as provided.
    $message['subject'] = $params['node']->title;
    $message['body'] = drupal_html_to_text($params['node']->body);
  }
}

/**
 * Update maintainer newsletter mailman status when cvs status is updated.
 */
function lists_cvs_user_edit_submit($form, &$form_state) {
  if (isset($form_state['values']['cvs_status'])) {
    $account = user_load(array('uid' => $form_state['values']['cvs_uid']));
    $lists = _lists_get_mailman_lists();
    $list = $lists['maintainer'];
    switch ($form_state['values']['cvs_status']) {
      case CVS_APPROVED:
        _lists_mailman_subscribe($list, $account);
        break;
      case CVS_DISABLED:
      default:
        _lists_mailman_unsubscribe($list, $account);
        break;
    }
  }
}

/**
 * Helper function to check if the provided email address is susbcribed.
 * 
 * Some code borrowed from the mailman_api module.
 */
function _lists_mailman_user_subscribed($list, $account) {
  $query = array(
    'findmember'     => $account->mail,
    'findmember_btn' => 'Search...'
  );
  $url = url($list['url'] .'/members', array('query' => $query));
  $result = lists_mailman_query($url, $list);
  // replace '@' with '--at--' to match the mailman internal representation so
  // we don't match our own search query which would always result in a match.
  return (bool) strpos(strtolower($result->data), str_replace('@', '--at--', $account->mail));
}

/**
 * Helper function to subscribe a user to a mailman mailing list.
 * 
 * Some code borrowed from the mailmain_api module.
 */
function _lists_mailman_subscribe($list, $account) {
  $query = array(
    'subscribe_or_invite' => variable_get('lists_mailman_invite', 0),
    'send_welcome_msg_to_this_batch' => variable_get('lists_mailman_notify', 0),
    'notification_to_list_owner' => variable_get('lists_mailman_notify_admin', 0),
    'subscribees_upload' => $account->mail,
  );
  $url = url($list['url'] .'/members/add', array('query' => $query));
  $result = lists_mailman_query($url, $list);
  if ($result !== FALSE) {
    watchdog('lists', t('User %email subscribed to !list mailman list.', array('%email' => $account->mail, '!list' => $list['name'])));
    drupal_set_message(t('%email subscribed to %list.', array('%email' => $account->mail, '%list' => $list['name'])));
  }
  else {
    drupal_set_message(t('Failed to subscribe %email to %list. Please try again later.', array('%email' => $account->mail, '%list' => $list['name'])));
  }
}

/**
 * Helper function to subscribe a user to a mailman mailing list.
 * 
 * Some code borrowed from the mailmain_api module.
 */
function _lists_mailman_unsubscribe($list, $account) {
  $query = array(
    'send_unsub_ack_to_this_batch' => variable_get('lists_mailman_notify', 0),
    'send_unsub_notifications_to_list_owner' => variable_get('lists_mailman_notify_admin', 0),
    'unsubscribees_upload' => $account->mail,
  );
  $url = url($list['url'] .'/members/remove', array('query' => $query));
  $result = lists_mailman_query($url, $list);
  if ($result !== FALSE) {
    watchdog('lists', t('User %email unsubscribed from !list mailman list.', array('%email' => $account->mail, '!list' => $list['name'])));
    drupal_set_message(t('%email unsubscribed from %list.', array('%email' => $account->mail, '%list' => $list['name'])));
  }
  else {
    drupal_set_message(t('Failed to unsubscribe %email from %list.  Please try again later.', array('%email' => $account->mail, '%list' => $list['name'])));
  }
}

/**
 * Connect to admin interface for mailman mailing list and run a request.
 *
 * Break out adminpw so we don't log it on errors to minimize the
 * exposure of this value.
 * 
 * Some code borrowed from the mailmain_api module.
 */
function lists_mailman_query($url, $list) {
  $result = drupal_http_request($url .'&adminpw='. urlencode($list['pass']));
  
  // Provide debug information if connection to mailman fails.
  if (!is_object($result) || !isset($result->code) || $result->code != '200') {
    watchdog('lists', t('Mailman HTTP request error (!code) for !list: %error<br />url=%url', array('!code' => (int)$result->code, '!list' => $list['name'], '%error' => $result->error, '%url' => $url)));
    return FALSE;
  }
  
  // Provide debug information if connection to mailman succeeds but the list is invalid.
  elseif (is_object($result) && strpos($result->data, '>No such list')) {
    watchdog('lists', t('Mailman list !list does not exist.<br />url=%url', array('!list' => $list['name'], '%url' => $url)));
    return FALSE;
  }
  
  // All all right, so return full page reply.
  return $result;
}