<?php
/**
 * Horde Hooks configuration file.
 *
 * THE HOOKS PROVIDED IN THIS FILE ARE EXAMPLES ONLY.  DO NOT ENABLE THEM
 * BLINDLY IF YOU DO NOT KNOW WHAT YOU ARE DOING.  YOU HAVE TO CUSTOMIZE THEM
 * TO MATCH YOUR SPECIFIC NEEDS AND SYSTEM ENVIRONMENT.
 *
 * This file is where you define any hooks, for preferences or general Horde
 * use, that your installation uses. The functions in this file can vastly
 * change how your installation behaves, so make sure to test out any changes
 * here before doing them in a production environment.
 *
 * Hook function names are automatically determined. The format of the name
 * is:
 *
 * _<type of hook>_hook_<name of hook>.
 *
 * Types of hooks that are defined in this file are 'prefs' (hooks to set the
 * value of preferences), 'horde' (hooks for the Horde Framework scripts) and
 * 'app' (where app is any Horde application name, like 'imp') hooks that are
 * application specific.
 *
 * So, a hook to set the preference 'theme' would be named
 * "_prefs_hook_theme".
 *
 * NOTE 1: Having a hook function in this file does NOT mean that the hook
 * will automatically be used. YOU MUST enable the hook. For preferences, set
 * 'hook' => true in that preferences attributes; for other hooks, there will
 * be a configuration option in each application's conf.php file such as
 * $conf['hooks']['hookname'] which must be set to true.
 *
 * NOTE 2: Preferences hooks are ONLY executed on login. Preferences are
 * cached during a users session and, to avoid unnecessary overhead every time
 * a preference is accessed, the results of hooks are cached as well. This
 * leads to ...
 *
 * NOTE 3: Any preference that is NOT LOCKED, that is set by a hook, WILL BE
 * SAVED WITH THAT VALUE. This means several things:
 * 1) Users will get the results of the hook set for them in their
 *    preferences.
 * 2) By virtue of this, the next time they log in and load their
 *    preferences, the hook will NOT be called, because in their last session,
 *    we saved the results of the hook for them. However, if the preference is
 *    locked, the result of the hook will never be saved.
 *
 * $Horde: horde/config/hooks.php.dist,v 1.73.6.13 2006/05/23 02:13:42 selsky Exp $
 */

// Example theme hook function. This shows how you can access things like the
// currently logged in user, global variables, server config, etc. It isn't,
// however, something you probably want to actually use in production, by
// virtue of demonstrating all those. :)

// if (!function_exists('_prefs_hook_theme')) {
//     function _prefs_hook_theme($username = null)
//     {
//         if (Auth::getAuth() != 'chuck') {
//             return 'mozilla';
//         }
//
//         global $registry;
//         switch ($registry->getApp()) {
//         case 'imp':
//             return 'brown';
//
//         case 'turba':
//             return 'orange';
//
//         case 'kronolith':
//             return 'green';
//
//         default:
//             return '';
//         }
//     }
// }

// Example from_addr hook function. THIS FUNCTION ASSUMES THAT YOU ARE USING
// AN LDAP SERVER and that your /etc/ldap.conf or wherever it is correctly set
// to a valid host.
//
// You get passed NOTHING; you are responsible for bringing in to scope any
// information you need. You can "global" anything else you need. Return an
// address - either just the user@ side or a full address - and it will be
// used.
//
// If you want to use this code you will need to uncomment it below.

// if (!function_exists('_prefs_hook_from_addr')) {
//     function _prefs_hook_from_addr($name = null)
//     {
//         if (is_null($name)) {
//             $name = Auth::getAuth();
//         }
//         if (!empty($name)) {
//             $base_context = 'o=myorg';
//             $scope = 'sub';
//
//             // You will probably need to replace cd= with uid=; this
//             // syntax is for Netware 5.1 nldap.
//             $cmd  = '/usr/bin/ldapsearch -b ' . $base_context . ' -s ' . $scope . ' cn=';
//             $cmd .= escapeShellCmd(Auth::getAuth());
//             $cmd .= ' | /usr/bin/grep mail | /usr/bin/awk \'{print $2}\'';
//             $mails = `$cmd`;
//             $mail_array = explode("\n", $mails);
//
//             // Send back the first email found, not the whole list.
//             $mail = $mail_array['0'];
//
//             // If no email address is found, then the login name will
//             // be used.
//             return (empty($mail) ? '' : $mail);
//         }
//
//         return '';
//     }
// }

// Here is another way of doing the same thing.

// if (!function_exists('_prefs_hook_from_addr')) {
//     function _prefs_hook_from_addr($user = null)
//     {
//         $ldapServer = '172.31.0.236';
//         $ldapPort = '389';
//         $searchBase = 'o=myorg';
//
//         $ds = @ldap_connect($ldapServer, $ldapPort);
//
//         if (is_null($user)) {
//             $user = Auth::getAuth();
//         }
//
//         // You will probably need to replace cn= with uid=; this
//         // syntax is for Netware 5.1 nldap.
//         $searchResult = @ldap_search($ds, $searchBase, 'cn=' . $user);
//         $information = @ldap_get_entries($ds, $searchResult);
//         if ($information[0]['mail'][0] != '') {
//             $name = $information[0]['mail'][0];
//         } else {
//             $name = $information[0]['cn'][0];
//         }
//
//         ldap_close($ds);
//
//         return (empty($name) ? $user : $name);
//     }
// }

// Here is an example fullname hook function to set the fullname from the GECOS
// information in the passwd file.

// if (!function_exists('_prefs_hook_fullname')) {
//     function _prefs_hook_fullname($user = null)
//     {
//         if (is_null($user)) {
//             $user = Auth::getBareAuth();
//         }
//         $array = posix_getpwnam($user);
//         $gecos_array = explode(',', $array['gecos']);
//         return (empty($gecos_array) ? $user : $gecos_array[0]);
//     }
// }

// This is another example of how to get the user's full name, in this case
// from an ldap server. In this example we look if a Spanish name exists and
// return this or the standard 'cn' entry if not.

// if (!function_exists('_prefs_hook_fullname')) {
//     function _prefs_hook_fullname($user = null)
//     {
//         $ldapServer = 'ldap.example.com';
//         $ldapPort = '389';
//         $searchBase = 'ou=people,o=example.com';
//         $ldapcharset = 'utf-8';
//         $outputcharset = NLS::getCharset();
//
//         $ds = @ldap_connect($ldapServer, $ldapPort);
//
//         if (is_null($user)) {
//             $user = Auth::getAuth();
//         }
//         $searchResult = @ldap_search($ds, $searchBase, 'uid=' . $user);
//         $information = @ldap_get_entries($ds, $searchResult);
//         if ($information[0]['cn;lang-es'][0] != '') {
//             $name = $information[0]['cn;lang-es'][0];
//         } else {
//             $name = $information[0]['cn'][0];
//         }
//
//         ldap_close($ds);
//
//         $name = String::convertCharset($name, $ldapcharset, $outputcharset);
//         return (empty($name) ? $user : $name);
//     }
// }

// Here is an example signature hook function to set the signature from the
// system taglines file; the string "%TAG%" (if present in a user's signature)
// will be replaced by the content of the file "/usr/share/tagline" (generated
// by the "TaRT" utility).
//
// Notice how we global in the $prefs array to get the user's current
// signature.

// if (!function_exists('_prefs_hook_signature')) {
//     function _prefs_hook_signature($username = null)
//     {
//         $sig = $GLOBALS['prefs']->getValue('signature');
//         if (preg_match('/%TAG%/', $sig)) {
//             $tag = `cat /usr/share/tagline`;
//             $sig = preg_replace('|%TAG%|', $tag, $sig);
//         }
//         return $sig;
//     }
// }

// IE on Mac hangs when there are several icons to be loaded. At least on some
// systems. This hook disables the show_icons preference from Krononlith for
// these browsers.

// if (!function_exists('_prefs_hook_show_icons')) {
//     function _prefs_hook_show_icons()
//     {
//         global $browser;
//         if ($browser->getPlatform() == 'mac' &&
//             $browser->getBrowser() == 'msie') {
//             return false;
//         } else {
//             return true;
//         }
//     }
// }

// This hook is called when a user submits a signup request.  It allows
// a chance to alter or validate the data submitted by a user before any
// attempts are made to add them to the system.

// if (!function_exists('_horde_hook_signup_preprocess')) {
//     function _horde_hook_signup_preprocess($info) {
//         $info['user_name'] = String::lower($info['user_name']);
//         return $info;
//     }
// }

// This hook is called when a signup is queued for administrative approval.
// This example sends a notification message to the web server
// administrator's e-mail address.

// if (!function_exists('_horde_hook_signup_queued')) {
//     function _horde_hook_signup_queued_walkdata($fields, $data)
//     {
//         $msg = '';
//         foreach ($data as $field => $value) {
//             if ($field == 'password' || $field == 'url') {
//                 continue;
//             }
//
//             if (is_array($value)) {
//                 $msg .= _horde_hook_signup_queued_walkdata($fields, $value);
//             } else {
//                 $field = isset($fields[$field]['label']) ?
//                          $fields[$field]['label'] : $field;
//                 $msg .= "$field: $value\n";
//             }
//         }
//         return $msg;
//     }
//
//     function _horde_hook_signup_queued($userID, $data)
//     {
//         require_once 'Mail.php';
//         global $conf, $registry;
//
//         $headers = array(
//             'To'      => $_SERVER['SERVER_ADMIN'],
//             'From'    => $_SERVER['SERVER_ADMIN'],
//             'Subject' => 'New ' . $registry->get('name', 'horde') . ' Signup'
//         );
//
//         $extraFields = Horde::callHook('_horde_hook_signup_getextra');
//
//         $msg  = _("A new signup has been received and is awaiting your approval.");
//         $msg .= "\n\n";
//         $msg .= _horde_hook_signup_queued_walkdata($extraFields, $data);
//         $msg .= "\n";
//         $msg .= sprintf(_("You can approve this signup at %s"), Horde::applicationUrl('admin/user.php', true, -1));
//
//         $mailer = Mail::factory($conf['mailer']['type'], $conf['mailer']['params']);
//         return $mailer->send($_SERVER['SERVER_ADMIN'], $headers, $msg);
//     }
// }

// Here is an example _horde_hook_signup_getextra function. It returns any
// extra fields which need to be filled in when a non registered user wishes
// to sign up.
// The example here takes the hypothetical case where we would want to store
// extra information about a user into a turba sql address book. All this
// function does then is to include the attributes.php file from the turba
// config directory and return the $attributes array.
// Otherwise any structure that would return an array with the following
// syntax would be valid:
//   $somearray['somefieldname'] = array(...
//      label    - the text that the user will see attached to this field
//      type     - any allowed Horde_Form field type
//      params   - any allowed parameter to Horde_Form field types
//      required - boolean, true or false whether this field is mandatory
//      readonly - boolean, true or false whether this editable
//      desc     - any help text attached to the field
// NOTE: You DO NEED Turba to be correctly installed before you can use this
// example below.

// if (!function_exists('_horde_hook_signup_getextra')) {
//     function _horde_hook_signup_getextra()
//     {
//         global $registry;
//         require $registry->get('fileroot', 'turba') . '/config/attributes.php';
//         return $attributes;
//     }
// }

// Following on from the example in the above function, this is how a sample
// _horde_hook_signup_addextra function would look like.
// Here we connect to the database using the sql parameters configured in
// $conf and store the extra fields in turba_objects, using the $userId as the
// key for the object and values from the $extra array.
// You could create your own sql syntax or code to store this in whichever
// backend you require.
// NOTE: You DO NEED Turba to be correctly installed before you can use this
// example below. It also assumes that you are using an SQL backend.

// if (!function_exists('_horde_hook_signup_addextra')) {
//     function _horde_hook_signup_addextra($userID, $extra)
//     {
//         global $conf;
//
//         require_once 'DB.php';
//         $_db = &DB::connect($conf['sql'], true);
//
//         $fields = array();
//         $values = array();
//         foreach ($extra as $field => $value) {
//             $fields[] = 'object_' . String::lower($field);
//             $values[] = $_db->quote(String::convertCharset($value, NLS::getCharset(), $conf['sql']['charset']));
//         }
//         $fields[] = 'object_id';
//         $values[] = $_db->quote($userID);
//
//         $query  = 'INSERT INTO turba_objects ( owner_id, ' . implode(', ', $fields) . ')';
//         $query .= ' VALUES ( \'admin\', ' . implode(', ', $values) . ')';
//         $result = $_db->query($query);
//
//         return is_a($result, 'PEAR_Error') ? $result : true;
//     }
// }

// Here is an example _horde_hook_preauthenticate that make Horde respect the
// Unix convention of not allowing login when a file named /etc/nologin exist.
// This function get passed the username, credential and realm information but
// they are not used in this example.

// if (!function_exists('_horde_hook_preauthenticate')) {
//     function _horde_hook_preauthenticate($userID, $credential, $realm)
//     {
//         return !file_exists('/etc/nologin');
//     }
// }

// Here is an example of validating the user's right to login to Horde by
// consulting group membership in an LDAP directory.  That way, if your Horde
// installation is configured to authenticate against IMP which in turn
// authenticate via IMAP, it is still possible to limit access to Horde by
// group membership.  The following example had been made with an MS Active
// Directory in mind.  Note that if the LDAP directory is unavailable or some
// other error occur, authentication will fail.

// if (!function_exists('_horde_hook_postauthenticate')) {
//     function _horde_hook_postauthenticate($userID, $credential, $realm)
//     {
//         $ldapServer = 'ad.example.com';
//         $ldapPort = '389';
//         // Note that credential is sent plain-text in this case, so don't use
//         // privileged account here or setup SSL (by using port 636 above).
//         $binddn = 'cn=WithoutPrivilege,dc=ulaval-dev,dc=ca';
//         $bindpw = 'Remember this is sent in the clear unless SSL is used';
//         $searchBase = 'ou=People,dc=example,dc=com';
//         // Attribute to match $userID against in search
//         $userAttr = 'sAMAccountName';
//         // Group membership attribute, need to be all lowercase
//         $groupAttr = 'memberof';
//         // Attribute to check for right to use Horde
//         $groupdn = 'cn=HordeUser,ou=People,dc=example,dc=com';
//         $ret = true;
//
//         $ds = @ldap_connect($ldapServer, $ldapPort);
//
//         if (@ldap_bind($ds, $binddn, $bindpw)) {
//             $searchResult = @ldap_search($ds, $searchBase, $userAttr . '=' . $userID, array($groupAttr), 0, 1, 5);
//             if ($information = @ldap_get_entries($ds, $searchResult)) {
//                 // make pattern case-insensitive
//                 $pattern = '/' . $groupdn . '/i';
//                 foreach ($information[0][$groupAttr] as $group) {
//                     if (preg_match($pattern, $group)) {
//                         $ret = true;
//                         break;
//                     }
//                 }
//             }
//         }
//
//         ldap_close($ds);
//         return $ret;
//     }
// }

// Here is an example of creating credentials needed by the LDAP Auth driver
// for adding/deleting/updating users.

// if (!function_exists('_horde_hook_authldap')) {
//     function _horde_hook_authldap($userID, $credentials = null)
//     {
//         $entry['dn'] = 'uid=' . $userID . ',ou=People,dc=example.com';
//         if (isset($credentials) && isset($credentials['user_fullname'])) {
//             $entry['cn'] = $credentials['user_fullname'];
//         } else {
//             $entry['cn'] = $userID;
//         }
//         $entry['sn'] = $userID;
//         $entry['objectclass'][0] = 'top';
//         $entry['objectclass'][1] = 'person';
//         $entry['objectclass'][2] = 'qmailuser';
//         $entry['objectclass'][3] = 'CourierMailACcount';
//         $entry['mailhost'] = 'mail.example.com';
//         $entry['mailMessageStore'] = '/home/mail/' . $userID;
//         $entry['homeDirectory'] = '/home/mail/' . $userID;
//         $entry['mailbox'] = $entry['homeDirectory'] . '/Maildir';
//         $entry['uid'] = $userID;
//         $entry['accountStatus'] = 'active';
//         $entry['mailQuota'] = '104857600S';
//         $entry['mail'] = $userID;
//         $entry['uidNumber'] = 501;
//         $entry['gidNumber'] = 501;
//
//         // need to check for new users (password) and edited users (user_pass_2)
//         if (isset($credentials) && isset($credentials['password'])) {
//             $entry['userPassword'] =  '{MD5}' . base64_encode(mHash(MHASH_MD5, $credentials['password']));
//         } elseif (isset($credentials) && isset($credentials['user_pass_2'])) {
//             $entry['userPassword'] =  '{MD5}' . base64_encode(mHash(MHASH_MD5, $credentials['user_pass_2']));
//         }
//         $entry['deliveryMode'] = 'nolocal';
//         return $entry;
//     }
// }

// This function is called when a Horde_Share object is created. It takes a
// reference to the Horde_Share object that is being created as well as th
// name of the application for which the Horde_Share object is being created as
// parameters. The return value is ignored.

// if (!function_exists('_horde_hook_share_init')) {
//     function _horde_hook_share_init(&$share_object, $app)
//     {
//         if ($GLOBALS['conf']['kolab']['enabled']) {
//             require_once 'Horde/Kolab.php';
//             Kolab::synchroniseShares($share_object, $app);
//         }
//     }
// }

// The following three functions are examples of those that can be called when
// adding, modifying and removing shares, respectively. They are called with
// the share that is being added, modified or removed as their single
// parameter.  If a PEAR_Error object is returned the respective share
// operation will fail with the error result.

// if (!function_exists('_horde_hook_share_add')) {
//     function _horde_hook_share_add(&$share)
//     {
//         require_once 'Horde/Kolab.php';
//         return Kolab::updateShare($share);
//     }
// }

// if (!function_exists('_horde_hook_share_modify')) {
//     function _horde_hook_share_modify(&$share)
//     {
//         require_once 'Horde/Kolab.php';
//         return Kolab::updateShare($share);
//     }
// }
//
// if (!function_exists('_horde_hook_share_remove')) {
//     function _horde_hook_share_remove(&$share)
//     {
//         require_once 'Horde/Kolab.php';
//         return Kolab::removeShare($share);
//     }
// }

// This example is of a function that can be called when a share listing is
// requested. It takes a userid, a permissions level, an optional string
// containing a userid to restrict the owner of the shares returned, and the
// result of the corresponding Horde_Share::listShares() call as its
// parameters. As is the case in the previous three functions, if a PEAR_Error
// result is returned the Horde_Share::listShares() call that triggered this
// hook will fail with the returned result.

// if (!function_exists('_horde_hook_share_list')) {
//     function _horde_hook_share_list($userid, $perm, $owner, &$share_list)
//     {
//         global $registry;
//         //error_log('Number of ' . $GLOBALS['registry']->getApp() . ' shares' . ($owner ?
//         //    ' owned by ' . $owner : '') . ' available to ' . $userid . ' at perms level ' .
//         //    $perm . ': ' .  count($share_list));
//         return true;
//     }
// }

// Here is an example _username_hook_frombackend function. It appends the
// virtual domain to the user name.
//
// ex. $HTTP_HOST = 'mail.mydomain.com', $userID = 'myname' returns:
//   'myname@mydomain.com'

// if (!function_exists('_username_hook_frombackend')) {
//     function _username_hook_frombackend($userID)
//     {
//         $vdomain = getenv('HTTP_HOST');
//         $vdomain = preg_replace('|^mail\.|i', '', $vdomain);
//         $vdomain = String::lower($vdomain);
//
//         return $userID . '@' . $vdomain;
//     }
// }

// Here is an example _username_hook_tobackend function as a counterpart of the
// previous example. It strips the virtual domain from the user name.
//
// ex. $HTTP_HOST = 'mail.mydomain.com', $userID = 'myname' returns:
//   'myname@mydomain.com'

// if (!function_exists('_username_hook_tobackend')) {
//     function _username_hook_tobackend($userID)
//     {
//         $vdomain = getenv('HTTP_HOST');
//         $vdomain = preg_replace('|^mail\.|i', '', $vdomain);
//         $vdomain = '@' . String::lower($vdomain);
//
//         if (substr($userID, -strlen($vdomain)) == $vdomain) {
//             $userID = substr($userID, 0, -strlen($vdomain));
//         }
//
//         return $userID;
//     }
// }

// Here is an example _username_hook_frombackend function. It converts the user
// name to all lower case. This might be necessary if an authentication backend
// is case insensitive to take into account that Horde's preference system is
// case sensitive.
//
// ex. $userID = 'MyName' returns: 'myname'

// if (!function_exists('_username_hook_frombackend')) {
//     function _username_hook_frombackend($userID)
//     {
//         return String::lower($userID);
//     }
// }

// Here is an example _perms_hook_denied function.  It is called if a user
// tries to make an action that is under permission control and that he
// doesn't have sufficient permissions for.  It can be used to show the user a
// custom message including HTML code (you have to take care about HTML
// escaping on your own), or to interrupt the code flow and send the user to a
// different page for example.

// if (!function_exists('_perms_hook_denied')) {
//     function _perms_hook_denied($permission)
//     {
//         if (($pos = strpos($permission, ':')) === false) {
//             $app = $permission;
//         } else {
//             $app = substr($permission, 0, $pos);
//         }
//
//         return sprintf('Permission denied. Click <a href="http://www.example.com/upgrade.php?app=%s">HERE</a> to upgrade %s.',
//                        $app, $GLOBALS['registry']->get('name'));
//     }
// }

// This is an example of a group hook.  To use it you must set the group
// driver to hooks in conf.php.  Then you must create a IT_department group
// (because that is how we know what hook to call).  You can add users to the
// group as normal, and in addition this function will be called to
// dynamically include users in the group.  In this example we will look up
// whether or not this user is part of the IT department using an external
// database.

// if (!function_exists('_group_hook_IT_department')) {
//     function _group_hook_IT_department($userName)
//     {
//         global $conf;
//
//         $dept = 'IT';
//         include_once 'DB.php';
//         $_db = &DB::connect($conf['sql'], true);
//         $query = 'SELECT COUNT(*) FROM departments WHERE user_name = ? AND department = ?';
//         $values = array($userName, $dept);
//         $result = $_db->getOne($query, $values);
//         if (!is_a($result, 'PEAR_Error') && $result > 0) {
//             return true;
//         } else {
//             return false;
//         }
//     }
// }

// This is an example of a post-push hook; it is called right after an
// application is pushed successfully onto the app stack.

// if (!function_exists('_horde_hook_post_pushapp')) {
//     function _horde_hook_post_pushapp($app)
//     {
//         if (in_array($app, array('kronolith', 'turba', 'horde', 'ingo')) ||
//              strpos($_SERVER['PHP_SELF'], 'prefs.php') !== false) {
//             require_once $GLOBALS['registry']->get('fileroot', 'dimp') . '/lib/Notification/Listener/statusOverride.php';
//             $GLOBALS['notification'] = &Notification::singleton();
//             $GLOBALS['notification']->attach('status', null, 'Notification_Listener_dimp_statusOverride');
//         }
//     }
// }

// Here is an example _imp_hook_trailer function to set the trailer from the
// system taglines file; the string "@@TAG@@" (if present in a trailer) will be
// replaced by the content of the file "/usr/share/tagline" (generated by the
// "TaRT" utility).

// if (!function_exists('_imp_hook_trailer')) {
//     function _imp_hook_trailer($trailer)
//     {
//         if (preg_match('/@@TAG@@/', $trailer)) {
//             $tag = `cat /usr/share/tagline`;
//             $trailer = preg_replace('|@@TAG@@|', $tag, $trailer);
//         }
//         return $trailer;
//     }
// }

// Here is an another example _imp_hook_trailer function to set the trailer
// from the LDAP directory for each domain. This function replaces the current
// trailer with the data it gets from ispmanDomainSignature.

// if (!function_exists('_imp_hook_trailer')) {
//     function _imp_hook_trailer($trailer)
//     {
//         $vdomain = getenv('HTTP_HOST');
//         $vdomain = preg_replace('|^.*?\.|i', '', $vdomain);
//         $vdomain = String::lower($vdomain);
//         $ldapServer = 'localhost';
//         $ldapPort = '389';
//         $searchBase = 'ispmanDomain=' . $vdomain  . ",o=ispman";
//
//         $ds = @ldap_connect($ldapServer, $ldapPort);
//         $searchResult = @ldap_search($ds, $searchBase, 'uid=' . $vdomain);
//         $information = @ldap_get_entries($ds, $searchResult);
//         $trailer= $information[0]['ispmandomainsignature'][0];
//         ldap_close($ds);
//
//         return $trailer;
//     }
// }

// Here is an example _imp_hook_vinfo function. If $type == 'vdomain', this
// function returns the HTTP_HOST variable after removing the 'mail.'
// subdomain.
//
// If $type == 'username', this function returns a unique username composed of
// $_SESSION['imp']['user'] + vdomain.
//
// ex. $HTTP_HOST = 'mail.mydomain.com', $_SESSION['imp']['user'] = 'myname':
//   $vdomain  = 'mydomain.com'
//   $username = 'myname_mydomain_com'

// if (!function_exists('_imp_hook_vinfo')) {
//     function _imp_hook_vinfo($type = 'username')
//     {
//         $vdomain = getenv('HTTP_HOST');
//         $vdomain = preg_replace('|^mail\.|i', '', $vdomain);
//         $vdomain = String::lower($vdomain);
//
//         if ($type == 'username') {
//             return preg_replace('|\.|', '_', $_SESSION['imp']['user'] . '_' . $vdomain);
//         } elseif ($type == 'vdomain') {
//             return $vdomain;
//         } else {
//             return PEAR::raiseError('invalid type: ' . $type);
//         }
//     }
// }

// Here is an example of the _imp_hook_fetchmail_filter function to run
// SpamAssassin on email before it is written to the mailbox.
// Note: to use the spamassassin instead of spamd, change 'spamc' to
// 'spamassassin -P' and add any other important arguments, but realize spamc
// is MUCH faster than spamassassin.
// WARNING: Make sure to use the --noadd-from filter on spamd or spamassassin

// if (!function_exists('_imp_hook_fetchmail_filter')) {
//     function _imp_hook_fetchmail_filter($message)
//     {
//         // Where does SpamAssassin live, and what username should we use
//         // for preferences?
//         $cmd = '/usr/local/bin/spamc';
//         $username = Auth::getAuth();
//         // If you use the _sam_hook_username() hook, uncomment the next line
//         //$username = _sam_hook_username($username);
//         $username = escapeshellarg($username);
//
//         // Also, we remove the file ourselves; this hook may be called
//         // hundreds of times per run depending on how many messages we fetch
//         $file = Horde::getTempFile('horde', false);
//
//         // Call SpamAssassin; pipe the new message to our tempfile
//         $fp = popen("$cmd -u $username > $file", 'w');
//         fwrite($fp, $message);
//         pclose($fp);
//
//         // Read the new message from the temporary file
//         $message = file_get_contents($file);
//         unlink($file);
//         return $message;
//     }
// }

// Here is an example signature hook function to set the signature from the
// system taglines file; the string "%TAG%" (if present in a user's signature)
// will be replaced by the content of the file "/usr/share/tagline" (generated
// by the "TaRT" utility).

// if (!function_exists('_imp_hook_signature')) {
//     function _imp_hook_signature($sig)
//     {
//         if (preg_match('/%TAG%/', $sig)) {
//             $tag = `cat /usr/share/tagline`;
//             $sig = preg_replace('/%TAG%/', $tag, $sig);
//         }
//
//         return $sig;
//     }
// }

// This is an example hook function for the IMP redirection scheme. This
// function is called when the user opens a mailbox in IMP, and allows the
// client to be redirected based on the mailbox name. The return value of this
// function should be a valid page within a horde application which will be
// placed in a "Location" header to redirect the client.  The only parameter
// is the name of the mailbox which the user has opened.  If an empty string
// is returned the user is not redirected.

// if (!function_exists('_imp_hook_mbox_redirect')) {
//     function _imp_hook_mbox_redirect($mailbox)
//     {
//         require_once 'Horde/Kolab.php';
//
//         if (strpos($mailbox, "INBOX/Calendar") !== false
//             || preg_match("!^user/[^/]+/Calendar!", $mailbox)) {
//             return $GLOBALS['registry']->get('webroot', 'kronolith');
//         } elseif (strpos($mailbox, "INBOX/Tasks") !== false
//             || preg_match("!^user/[^/]+/Tasks!", $mailbox)) {
//             return $GLOBALS['registry']->get('webroot', 'nag');
//         } elseif (strpos($mailbox, "INBOX/Notes") !== false
//             || preg_match("!^user/[^/]+/Notes!", $mailbox)) {
//             return $GLOBALS['registry']->get('webroot', 'mnemo');
//         } elseif (strpos($mailbox, "INBOX/Contacts") !== false
//             || preg_match("!^user/[^/]+/Contacts!", $mailbox)) {
//             return $GLOBALS['registry']->get('webroot', 'turba');
//         }
//
//         return '';
//     }
// }

// This is an example hook function for the IMP mailbox icon scheme. This
// function is called when the folder list is created and a "standard" folder
// is to be displayed - it allows custom folder icons to be specified.
// ("Standard" means all folders except the INBOX, sent-mail folders and
// trash folders.)
// If a mailbox name doesn't appear in the below list, the default mailbox
// icon is displayed.

// if (!function_exists('_imp_hook_mbox_icons')) {
//     function _imp_hook_mbox_icons()
//     {
//         static $newmailboxes;
//
//         if (!empty($newmailboxes)) {
//             return $newmailboxes;
//         }
//
//         require_once 'Horde/Kolab.php';
//
//         $kc = new Kolab_Cyrus($GLOBALS['conf']['kolab']['server']);
//         $mailboxes = $kc->listMailBoxes();
//         $newmailboxes = array();
//
//         foreach ($mailboxes as $box) {
//             $box = preg_replace("/^{[^}]+}/", "", $box);
//             if (strpos($box, "INBOX/Calendar") !== false
//                 || preg_match("!^user/[^/]+/Calendar!", $box)) {
//                 $newmailboxes[$box] = Horde::img(
//                     $GLOBALS['registry']->get('icon', 'kronolith'),
//                     _("Calendar"),
//                     'width="16" height="16" style="vertical-align:middle"',
//                     ''
//                 );
//             } elseif (strpos($box, "INBOX/Tasks") !== false
//                 || preg_match("!^user/[^/]+/Tasks!", $box)) {
//                 $newmailboxes[$box] = Horde::img(
//                     $GLOBALS['registry']->get('icon', 'nag'),
//                     _("Tasks"),
//                     'width="16" height="16" style="vertical-align:middle"',
//                     ''
//                 );
//             } elseif (strpos($box, "INBOX/Notes") !== false
//                 || preg_match("!^user/[^/]+/Notes!", $box)) {
//                 $newmailboxes[$box] = Horde::img(
//                     $GLOBALS['registry']->get('icon', 'mnemo'),
//                     _("Notes"),
//                     'width="16" height="16" style="vertical-align:middle"',
//                     ''
//                 );
//             } elseif (strpos($box, "INBOX/Contacts") !== false
//                 || preg_match("!^user/[^/]+/Contacts!", $box)) {
//                 $newmailboxes[$box] = Horde::img(
//                     $GLOBALS['registry']->get('icon', 'turba'),
//                     _("Contacts"),
//                     'width="16" height="16" style="vertical-align:middle"',
//                     ''
//                 );
//             }
//         }
//
//         return $newmailboxes;
//     }
// }

// This is an example hook function for the IMP spam reporting bouce option.
// This function is called when the message is about to be bounced - it
// will return the email address to bounce to.  This is handy for spam
// reporting software (e.g. DSPAM) which has different e-mail aliases for
// spam reporting for each user.

// if (!function_exists('_imp_hook_spam_bounce')) {
//     function _imp_hook_spam_bounce($action)
//     {
//         $prefix = ($action == 'spam') ? 'spam-' : 'fp-';
//         return $prefix . Auth::getBareAuth() . '@example.com';
//     }
// }

// Here an example _sam_hook_username function to set the username that
// SpamAssassin sees to one different from the Horde username.

// if (!function_exists('_sam_hook_username')) {
//     function _sam_hook_username($horde_uid)
//     {
//         if (strstr($horde_uid, '@')) {
//             $parts = explode('@', $horde_uid);
//             return $parts[0];
//         } else {
//             return $horde_uid;
//         }
//     }
// }

// Here is an example _turba_hook_encode_password (and decode). encode is
// called when we store a value; decode when we display it.  Passwords should
// be MD5 encoded, but not displayed.
//
// IMPORTANT: The last parameter in these examples (&$object) is only
// passed by Turba 2.1 and later. If you are using Turba 2.0, then you
// must remove the &$object parameter.

// if (!function_exists('_turba_hook_encode_password')) {
//     function _turba_hook_encode_password($new_password, $old_password, &$contact)
//     {
//         if (is_null($new_password) || $new_password == '' ||
//             $new_password == '[Not Displayed]') {
//             return $old_password;
//         } else {
//             return md5($new_password);
//         }
//     }
//     function _turba_hook_decode_password($password, &$contact)
//     {
//         if (strstr($_SERVER['PHP_SELF'], 'editobject')) {
//             return null;
//         } else {
//             return '[Not Displayed]';
//         }
//     }
// }

// Here is an example _passwd_hook_username function to translate what the
// user enters, in the username box, into what the backend expects. If we want
// to add @example.com to the end of the username then enable the hook and use
// this function.

// if (!function_exists('_passwd_hook_username')) {
//     function _passwd_hook_username($userid)
//     {
//         return $userid . '@example.com';
//     }
// }

// Here is an example _passwd_hook_default_username function to set the
// username the passwd module sees when resetting passwords based on userid
// and realm.  The default is to take a username of user@domain.tld and change
// it to user.  If we want to leave it untouched, enable the hook and use this
// function.

// if (!function_exists('_passwd_hook_default_username')) {
//     function _passwd_hook_default_username($userid)
//     {
//         return $userid;
//     }
// }

// Here is an example _passwd_hook_userdn function that you can use to provide
// your ldap server with a userdn so that you do not have to perform anonymous
// binds. The function takes Auth::getAuth() as a parameter

// if (!function_exists('_passwd_hook_userdn')) {
//     function _passwd_hook_userdn($auth)
//     {
//         return 'uid=' . $auth . ',o=example.com';
//     }
// }

// This is an example of a hook to set custom tags to be included in a Giapeto
// page template. In this example a tag containing the current date is set to
// the $template object and which is then available in the page template as:
//     <tag:date />

// if (!function_exists('_giapeto_hook_settags')) {
//     function _giapeto_hook_settags(&$template)
//     {
//         $template->set('date', strftime('%a, %e %b %Y'));
//     }
// }

// This is an example of a group hook.  To use it you must set the group
// driver to hooks in conf.php.  Then you must create a IT_department group
// (because that is how we know what hook to call).  You can add users to the
// group as normal, and in addition this function will be called to
// dynamically include users in the group.  In this example we will look up
// whether or not this user is part of the IT department using an external
// database.

// Default Kolab hooks:
if (!empty($GLOBALS['conf']['kolab']['enabled'])) {
    require_once 'Horde/Kolab.php';
    if (!function_exists('_horde_hook_share_init')) {
        function _username_hook_frombackend($userID)
        {
            // Connect to the LDAP server.
            $ds = ldap_connect(
                $GLOBALS['conf']['kolab']['ldap']['server'],
                $GLOBALS['conf']['kolab']['ldap']['port']
            );
            if (!$ds) {
                return $userID;
            }
            ldap_set_option($ds, LDAP_OPT_PROTOCOL_VERSION, 3);
            // Bind anonymously.
            $result = @ldap_bind($ds);
            if (!$result) {
                return $userID;
            }
            // Find the user's DN.
            $result = ldap_search(
                $ds,
                $GLOBALS['conf']['kolab']['ldap']['basedn'],
                'uid=' . $userID
            );
            $entry = ldap_first_entry($ds, $result);
            if ($entry === false) {
                // The user already authenticated with his email address.
                return $userID;
            }
            $email = ldap_get_values($ds, $entry, 'mail');
            return $email[0];
        }
        function _horde_hook_share_init(&$share_object, $app)
        {
            Kolab::synchroniseShares($share_object, $app);
        }
        function _horde_hook_share_add(&$share)
        {
            return Kolab::updateShare($share);
        }
        function _horde_hook_share_modify(&$share)
        {
            return Kolab::updateShare($share);
        }
        function _horde_hook_share_remove(&$share)
        {
            return Kolab::removeShare($share);
        }
        function _imp_hook_mbox_redirect($mailbox)
        {
            switch (Kolab::getMailboxType($mailbox)) {
            case 'event':
                return $GLOBALS['registry']->get('webroot', 'kronolith');

            case 'task':
                return $GLOBALS['registry']->get('webroot', 'nag');

            case 'note':
                return $GLOBALS['registry']->get('webroot', 'mnemo');

            case 'contact':
                return $GLOBALS['registry']->get('webroot', 'turba');

            default:
                return '';
            }
        }
        function _imp_hook_mbox_icons()
        {
            static $icons;

            if (!empty($icons)) {
                return $icons;
            }

            $folders = Kolab::listFolders();

            $icons = array();

            foreach ($folders as $folder) {
                $name = preg_replace('/^{[^}]+}/', '', $folder[0]);

                switch ($folder[1]) {
                case 'event':
                    $icons[$name] = Horde::img(
                        $GLOBALS['registry']->get('icon', 'kronolith'),
                        _("Calendar"),
                        'width="16" height="16" style="vertical-align:middle"',
                        ''
                    );
                    break;

                case 'task':
                    $icons[$name] = Horde::img(
                        $GLOBALS['registry']->get('icon', 'nag'),
                        _("Tasks"),
                        'width="16" height="16" style="vertical-align:middle"',
                        ''
                    );
                    break;

                case 'note':
                    $icons[$name] = Horde::img(
                        $GLOBALS['registry']->get('icon', 'mnemo'),
                        _("Notes"),
                        'width="16" height="16" style="vertical-align:middle"',
                        ''
                    );
                    break;

                case 'contact':
                    $icons[$name] = Horde::img(
                        $GLOBALS['registry']->get('icon', 'turba'),
                        _("Contacts"),
                        'width="16" height="16" style="vertical-align:middle"',
                        ''
                    );
                    break;
                }
            }

            return $icons;
        }
    }
}