<?php

$ldap_connection = @ldap_connect($config['auth_ldap_server'], $config['auth_ldap_port']);

if ($config['auth_ldap_starttls'] && ($config['auth_ldap_starttls'] == 'optional' || $config['auth_ldap_starttls'] == 'require')) {
    $tls = ldap_start_tls($ldap_connection);
    if ($config['auth_ldap_starttls'] == 'require' && $tls === false) {
        echo '<h2>Fatal error: LDAP TLS required but not successfully negotiated:'.ldap_error($ldap_connection).'</h2>';
        exit;
    }
}


function authenticate($username, $password)
{
    global $config, $ldap_connection;

    if ($username && $ldap_connection) {
        if ($config['auth_ldap_version']) {
            ldap_set_option($ldap_connection, LDAP_OPT_PROTOCOL_VERSION, $config['auth_ldap_version']);
        }

        if (ldap_bind($ldap_connection, $config['auth_ldap_prefix'].$username.$config['auth_ldap_suffix'], $password)) {
            if (!$config['auth_ldap_group']) {
                return 1;
            } else {
                $ldap_groups = get_group_list();
                foreach ($ldap_groups as $ldap_group) {
                    $ldap_comparison = ldap_compare(
                        $ldap_connection,
                        $ldap_group,
                        $config['auth_ldap_groupmemberattr'],
                        get_membername($username)
                    );
                    if ($ldap_comparison === true) {
                        return 1;
                    }
                }
            }
        } else {
            echo ldap_error($ldap_connection);
        }
    } else {
        // FIXME return a warning that LDAP couldn't connect?
    }

    return 0;
}


function reauthenticate($sess_id, $token)
{
    return 0;
}


function passwordscanchange($username = '')
{
    return 0;
}


function changepassword($username, $newpassword)
{
    // Not supported (for now)
}


function auth_usermanagement()
{
    return 0;
}


function adduser($username, $password, $level, $email = '', $realname = '', $can_modify_passwd = '1')
{
    // Not supported
    return 0;
}


function user_exists($username)
{
    global $config, $ldap_connection;

    $filter  = '('.$config['auth_ldap_prefix'].$username.')';
    $search  = ldap_search($ldap_connection, trim($config['auth_ldap_suffix'], ','), $filter);
    $entries = ldap_get_entries($ldap_connection, $search);
    if ($entries['count']) {
        return 1;
    }

    return 0;
}


function get_userlevel($username)
{
    global $config, $ldap_connection;

    $userlevel = 0;

    // Find all defined groups $username is in
    $filter  = '(&(|(cn='.join(')(cn=', array_keys($config['auth_ldap_groups'])).'))('.$config['auth_ldap_groupmemberattr'].'='.get_membername($username).'))';
    $search  = ldap_search($ldap_connection, $config['auth_ldap_groupbase'], $filter);
    $entries = ldap_get_entries($ldap_connection, $search);

    // Loop the list and find the highest level
    foreach ($entries as $entry) {
        $groupname = $entry['cn'][0];
        $userlevel = array();
        if ($config['auth_ldap_groups'][$groupname]['level'] > $userlevel) {
            $userlevel['level'] = $config['auth_ldap_groups'][$groupname]['level'];
        }
    }

    return $userlevel;
}


function get_userid($username)
{
    global $config, $ldap_connection;

    $filter  = '('.$config['auth_ldap_prefix'].$username.')';
    $search  = ldap_search($ldap_connection, trim($config['auth_ldap_suffix'], ','), $filter);
    $entries = ldap_get_entries($ldap_connection, $search);

    if ($entries['count']) {
        return $entries[0]['uidnumber'][0];
    }

    return -1;
}


function deluser($username)
{
    // Not supported
    return 0;
}


function get_userlist()
{
    global $config, $ldap_connection;
    $userlist = array();

    $filter = '('.$config['auth_ldap_prefix'].'*)';

    $search  = ldap_search($ldap_connection, trim($config['auth_ldap_suffix'], ','), $filter);
    $entries = ldap_get_entries($ldap_connection, $search);

    if ($entries['count']) {
        foreach ($entries as $entry) {
            $username    = $entry['uid'][0];
            $realname    = $entry['cn'][0];
            $user_id     = $entry['uidnumber'][0];
            $email       = $entry[$config['auth_ldap_emailattr']][0];
            $ldap_groups = get_group_list();
            foreach ($ldap_groups as $ldap_group) {
                $ldap_comparison = ldap_compare(
                    $ldap_connection,
                    $ldap_group,
                    $config['auth_ldap_groupmemberattr'],
                    get_membername($username)
                );
                if (!isset($config['auth_ldap_group']) || $ldap_comparison === true) {
                    $userlist[] = array(
                                   'username' => $username,
                                   'realname' => $realname,
                                   'user_id'  => $user_id,
                                   'email'    => $email,
                                  );
                }
            }
        }
    }
    return $userlist;
}


function can_update_users()
{
    // not supported so return 0
    return 0;
}


function get_user($user_id)
{
    foreach (get_userlist() as $users) {
        if ($users['user_id'] === $user_id) {
            return $users;
        }
    }
    return 0;
}


function update_user($user_id, $realname, $level, $can_modify_passwd, $email)
{
    // not supported
    return 0;
}


function get_membername($username)
{
    global $config, $ldap_connection;
    if ($config['auth_ldap_groupmembertype'] == 'fulldn') {
        $membername = $config['auth_ldap_prefix'].$username.$config['auth_ldap_suffix'];
    } elseif ($config['auth_ldap_groupmembertype'] == 'puredn') {
        $filter  = '('.$config['auth_ldap_attr']['uid'].'='.$username.')';
        $search  = ldap_search($ldap_connection, $config['auth_ldap_groupbase'], $filter);
        $entries = ldap_get_entries($ldap_connection, $search);
        $membername = $entries[0]['dn'];
    } else {
        $membername = $username;
    }

    return $membername;
}


function get_group_list()
{
    global $config;

    $ldap_groups   = array();
    $default_group = 'cn=groupname,ou=groups,dc=example,dc=com';
    if (isset($config['auth_ldap_group'])) {
        if ($config['auth_ldap_group'] !== $default_group) {
            $ldap_groups[] = $config['auth_ldap_group'];
        }
    }

    foreach ($config['auth_ldap_groups'] as $key => $value) {
        $dn            = "cn=$key,".$config['auth_ldap_groupbase'];
        $ldap_groups[] = $dn;
    }

    return $ldap_groups;
}