<?php
/**
 * Authentication Plugin for authphpbb3.
 *
 * @license  GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author   Eole <eole.dev@outlook.com>
 */

if (!defined('DOKU_INC')) {
    die();
}

/**
 * phpBB 3.x Authentication class.
 */
class auth_plugin_authphpbb3 extends DokuWiki_Auth_Plugin {
    // @var object  phpBB database connection.
    protected $_phpbb_db_link = null;
    // @var array   phpBB configuration (cached).
    protected $_phpbb_conf = array(
        // @var string  phpBB root path.
        'root_path'     => '',
        // @var string  phpBB URL.
        'url'           => '',
        // @var string  php extension.
        'phpEx'         => '',
        // @var string  phpBB database's driver to use.
        'dbms'          => '',
        // @var string  phpBB database's host.
        'dbhost'        => '',
        // @var string  phpBB database's port.
        'dbport'        => '',
        // @var string  phpBB database's name.
        'dbname'        => '',
        // @var string  phpBB database's user.
        'dbuser'        => '',
        // @var string  phpBB database's password.
        'dbpasswd'      => '',
        // @var string  phpBB database's table prefix.
        'table_prefix'  => '',
        // @var string  phpBB cookie's name.
        'cookie_name'   => ''
    );
    // @var int     phpBB user ID.
    protected $_phpbb_user_id = 0;
    // @var int     phpBB user session ID.
    protected $_phpbb_user_session_id = '';
    // @var int     phpBB user type (0 = normal, 1 = inactive, 2 = bot, 3 = founder).
    protected $_phpbb_user_type = 0;
    // @var string  phpBB user name.
    protected $_phpbb_username = '';
    // @var string  phpBB user mail.
    protected $_phpbb_user_email = '';
    // @var array   phpBB user's groups.
    protected $_phpbb_groups = array();
    // @var long    phpBB user session time.
    protected $_phpbb_sessiontime = 0;
    // @var cache   DokuWiki cache object.
    protected $_cache = null;
    // @var int     Cache duration.
    protected $_cache_duration = 0;
    // @var int     Cache extension file name.
    protected $_cache_ext_name = '.phpbb3cache';
    // @var int     Cache unit constant (in seconds).
    CONST CACHE_DURATION_UNIT = 86400; /* 60 * 60 * 24 = 1 day */

    /**
     * Constructor.
     */
    public function __construct() {
        if (method_exists(get_parent_class($this), '__construct')) {
            parent::__construct();
        }
        // Set capabilities accordingly.
        $this->cando['addUser']     = false;    // Can Users be created?
        $this->cando['delUser']     = false;    // Can Users be deleted?
        $this->cando['modLogin']    = false;    // Can login names be changed?
        $this->cando['modPass']     = false;    // Can passwords be changed?
        $this->cando['modName']     = false;    // Can real names be changed?
        $this->cando['modMail']     = false;    // Can emails be changed?
        $this->cando['modGroups']   = false;    // Can groups be changed?
        $this->cando['getUsers']    = true;     // Can a (filtered) list of users be retrieved?
        $this->cando['getUserCount']= true;     // Can the number of users be retrieved?
        $this->cando['getGroups']   = true;     // Can a list of available groups be retrieved?
        $this->cando['external']    = true;     // Does the module do external auth checking?
        $this->cando['logout']      = true;     // Can the user logout again?
        // Check database connection requirement.
        if (!class_exists('PDO')) {
            $this->dbglog('PDO extension for PHP not found.');
            $this->success = false;
        } else {
            // Load plugin configuration.
            $this->success = $this->load_configuration();
        }
        if (!$this->success) {
            msg($this->getLang('config_error'), -1);
        }
    }

    /**
     * Destructor.
     */
    public function __destruct() {
        $this->phpbb_disconnect();
        $this->_cache = null;
        if (method_exists(get_parent_class($this), '__destruct')) {
            parent::__destruct();
        }
    }

    /**
     * Writes debug informations.
     *
     * @param    string  $msg    Message to write.
     */
    public function dbglog($msg) {
        $class_name = @get_class($this);

        if ($class_name !== false) {
            $msg = $class_name . ': ' . $msg;
        }
        dbglog($msg); 
    }

    /**
     * Sanitizes a given username.
     *
     * @param    string  $username   Username to clean.
     * @return   string              Clean username.
     */
    public function clean_username($username) {
        $username = preg_replace('#(?:[\x00-\x1F\x7F]+|(?:\xC2[\x80-\x9F])+)#', '', $username);
        $username = preg_replace('# {2,}#', ' ', $username);
        $username = trim($username);
        return strtolower($username);
    }

    /**
     * Gets phpBB URL.
     *
     * @return   string|false    phpBB URL if success, false otherwise.
     */
    public function get_phpbb_url() {
        if (!empty($this->_phpbb_conf['url'])) {
            return $this->_phpbb_conf['url'];
        }
        if ($this->use_phpbb_cache()) {
            $result = unserialize($this->_cache->retrieveCache(false));
            if (is_array($result) && array_key_exists('url', $result)) {
                $this->_phpbb_conf['url'] = $result['url'];
            }
        }
        if (!empty($this->_phpbb_conf['url'])) {
            return $this->_phpbb_conf['url'];
        }
        if (!$this->phpbb_connect()) {
            return false;
        }
        $query = "SELECT config_name, config_value
                  FROM {$this->_phpbb_conf['table_prefix']}config
                  WHERE config_name IN ('server_protocol', 'server_name', 'script_path', 'server_port')";
        $result = $this->_phpbb_sql_link->prepare($query);
        if ($result === false) {
            $this->dbglog('error while preparing query for phpBB URL');
            return false;
        }
        if ($result->execute() === false) {
            $this->dbglog('error while executing query for phpBB URL');
            return false;
        }
        $server_protocol = '';
        $server_name = '';
        $script_path = '';
        $server_port = '';
        while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
            switch ($row['config_name']) {
                case 'server_protocol':
                    $server_protocol = strtolower(trim($row['config_value']));
                    break;
                case 'server_name':
                    $server_name = rtrim(trim($row['config_value']), '/');
                    break;
                case 'script_path':
                    $script_path = trim($row['config_value']);
                    break;
                case 'server_port':
                    $server_port = intval($row['config_value']);
                    break;
                default:
                    break;
            }
        }
        if (empty($server_port)) {
            $server_port = '80';
            if ($server_protocol === 'https://') {
                $server_port = '443';
            }
        }
        $server_name = rtrim($server_protocol . $server_name . ':' . $server_port . $script_path, '/');
        $this->_phpbb_conf['url'] = $server_name;
        $result->closeCursor();
        $result = null;
        return $this->_phpbb_conf['url'];
    }

    /**
     * Authenticates the user. Called on every page loaded.
     *
     * @param    string  $user   Case sensitive user name.
     * @param    string  $pass   Plain text password for the user.
     * @param    boolean $sticky Remember login?
     * @return   boolean         True for match, false for everything else.
     */
    public function trustExternal($user, $pass, $sticky = false) {
        global $USERINFO;
        $b = false;

        $this->_phpbb_username = '';
        $this->_phpbb_user_email = '';
        $this->_phpbb_user_session_id = '';
        if (empty($user)) {
            $b = $this->do_login_cookie();
        }
        if (!$b ||
            empty($this->_phpbb_username) ||
            empty($this->_phpbb_user_email)) {
            return false;
        }
        $USERINFO['name'] = utf8_encode($this->_phpbb_username);
        $USERINFO['mail'] = $this->_phpbb_user_email;
        $USERINFO['grps'] = $this->_phpbb_groups;
        $_SERVER['REMOTE_USER'] = $USERINFO['name'];
        $_SESSION[DOKU_COOKIE]['auth']['user'] = $USERINFO['name'];
        $_SESSION[DOKU_COOKIE]['auth']['info'] = $USERINFO;
        return true;
    }

    /**
     * Fetchs user details from phpBB.
     *
     * @param   string          $user           Case sensitive username.
     * @param   boolean         $requireGroups  Whether or not the returned data must include groups.
     * @return  array/boolean                   False for error conditions and an array for success.
     *                                          array['name']           string  User's name.
     *                                          array['username']       string  User's name.
     *                                          array['mail']           string  User's email address.
     *                                          array['phpbb_user_id']  string  User's ID.
     *                                          array['phpbb_profile']  string  User's link to profile.
     *                                          array['grps']           array   Group names the user belongs to.
     */
    public function getUserData($user, $requireGroups = true) {
        if (empty($user)) {
            return false;
        }
        $this->_cache_duration = intval($this->getConf('phpbb_cache'));
        $depends = array('age' => self::CACHE_DURATION_UNIT * $this->_cache_duration);
        $cache = new cache('authphpbb3_getUserData_' . $user, $this->_cache_ext_name);
        $user_data = false;

        if (($this->_cache_duration > 0) && $cache->useCache($depends)) {
            $user_data = unserialize($cache->retrieveCache(false));
        } else {
            $cache->removeCache();
            if (!$this->phpbb_connect()) {
                return false;
            }
            $query = "SELECT user_id, username, username_clean, user_email, user_type
                      FROM {$this->_phpbb_conf['table_prefix']}users
                      WHERE username_clean = ?";
            $result = $this->_phpbb_sql_link->prepare($query);
            if ($result === false) {
                $this->dbglog('error while preparing query for user data');
                return false;
            }
            if (!$result->execute(array($this->clean_username($user)))) {
                $this->dbglog('error while executing query for user data');
                return false;
            }
            $row = $result->fetch(PDO::FETCH_ASSOC);
            $this->_phpbb_user_type = (int)$row['user_type'];
            $this->_phpbb_user_id = (int)$row['user_id'];
            $this->_phpbb_username = $row['username'];
            $this->_phpbb_user_email = $row['user_email'];
            $result->closeCursor();
            $result = null;
            $this->get_phpbb_user_groups();
            $this->get_phpbb_url();
            $user_data = array(
                'name'          => $this->_phpbb_username,
                'username'      => $this->_phpbb_username,
                'mail'          => $this->_phpbb_user_email,
                'phpbb_user_id' => $this->_phpbb_user_id,
                'phpbb_profile' => $this->_phpbb_conf['url'] . '/memberlist.php?mode=viewprofile&u=' .
                                   $this->_phpbb_user_id,
                'grps'          => $this->_phpbb_groups
            );
            $cache->storeCache(serialize($user_data));
        }
        $cache = null;
        return $user_data;
    }

    /**
    * Bulk retrieval of users' data (does not use cache system).
    *
    * @param    int             $start  Index of first user to be returned.
    * @param    int             $limit  Maximum number of users to be returned.
    * @param    array           $filter Array of field/pattern pairs.
    * @return   array/boolean           List of arrays returned by getUserData function.
    */
    public function retrieveUsers($start = 0, $limit = 0, $filter = array()) {
        if (!$this->phpbb_connect()) {
            return false;
        }
        $start = intval($start);
        if ($start < 0) {
            $start = 0;
        }
        $limit = intval($limit);
        if ($limit <= 0) {
            // Arbitrary limit.
            $limit = 10000;
        }
        if (is_null($filter)) {
            $filter = array();
        }
        if (isset($filter['grps'])) {
            $filter['group'] = $filter['grps'];
        }
        foreach (array('user', 'name', 'mail') as $key) {
            $tmp = '%';
            if (isset($filter[$key])) {
                $tmp = str_replace('%', '', $filter[$key]);
                if (!is_string($tmp)) {
                    $tmp = '';
                }
                if (empty($tmp)) {
                    $tmp = '%';
                } else {
                    $tmp = '%' . $tmp . '%';
                }
            }
            $filter[$key] = $tmp;
        }
        $filter['start'] = (int)$start;
        $filter['end'] = (int)($start + $limit);
        $filter['limit'] = (int)$limit;
        // Gets users.
        $query = "SELECT user_id, username, username_clean, user_email
                  FROM {$this->_phpbb_conf['table_prefix']}users
                  WHERE (username like :name OR username like :user OR
                        username_clean like :nameclean OR username_clean like :userclean) AND
                        user_email like :mail
                  LIMIT :limit OFFSET :start";
        $result = $this->_phpbb_sql_link->prepare($query);
        if ($result === false) {
            $this->dbglog('error while preparing query for users data');
            return false;
        }
        $result->bindValue(':name', $filter['name'], PDO::PARAM_STR);
        $result->bindValue(':user', $filter['user'], PDO::PARAM_STR);
        $result->bindValue(':nameclean', $filter['name'], PDO::PARAM_STR);
        $result->bindValue(':userclean', $filter['user'], PDO::PARAM_STR);
        $result->bindValue(':mail', $filter['mail'], PDO::PARAM_STR);
        $result->bindValue(':limit', (int)$filter['limit'], PDO::PARAM_INT);
        $result->bindValue(':start', (int)$filter['start'], PDO::PARAM_INT);
        if (!$result->execute()) {
            $this->dbglog('error while executing query for users data');
            return false;
        }
        $users = array();
        // Gets users' groups.
        while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
            $user_data = array(
                'name'          => $row['username'],
                'username'      => $row['username_clean'],
                'mail'          => $row['user_email'],
                'phpbb_user_id' => $row['user_id'],
                'phpbb_profile' => $this->_phpbb_conf['url'] . '/memberlist.php?mode=viewprofile&u=' .
                                   $row['user_id'],
                'grps'          => array()
            );
            $query = "SELECT *
                      FROM {$this->_phpbb_conf['table_prefix']}groups g, 
                           {$this->_phpbb_conf['table_prefix']}users u,
                           {$this->_phpbb_conf['table_prefix']}user_group ug
                      WHERE u.user_id = ug.user_id AND g.group_id = ug.group_id AND u.user_id = ?";
            $resgrp = $this->_phpbb_sql_link->prepare($query);
            if (($resgrp === false) || !$resgrp->execute(array($row['user_id']))) {
                $this->dbglog('error while executing query for ' . $row['user_id'] . ' groups');
                // If no group filter, we still add the user to the list.
                if (!isset($filter['group'])) {
                    $users[$user_data['username']] = $user_data;
                }
                $resgrp->closeCursor();
                $resgrp = null;
                continue;
            }
            $ingroup = false;
            while ($rowgrp = $resgrp->fetch(PDO::FETCH_ASSOC)) {
                $user_data['grps'][] = $rowgrp['group_name'];
                if (!$ingroup &&
                    isset($filter['group']) &&
                    (strpos($rowgrp['group_name'], $filter['group']) !== false)) {
                    $ingroup = true;
                }
            }
            // Apply group's filter.
            if (!isset($filter['group']) || (isset($filter['group']) && $ingroup)) {
                $users[$user_data['username']] = $user_data;
            }
            $resgrp->closeCursor();
            $resgrp = null;
        }
        $result->closeCursor();
        $result = null;
        return $users;
    }

    /**
    * Bulk retrieval of groups (does not use cache system).
    *
    * @param    int             $start  Index of first group to be returned.
    * @param    int             $limit  Maximum number of groups to be returned.
    * @return   array/boolean           List of groups.
    */
    public function retrieveGroups($start = 0, $limit = 0) {
        if (!$this->phpbb_connect()) {
            return false;
        }
        $start = intval($start);
        if ($start < 0) {
            $start = 0;
        }
        $limit = intval($limit);
        if ($limit <= 0) {
            // Arbitrary limit.
            $limit = 10000;
        }
        $query = "SELECT *
                  FROM {$this->_phpbb_conf['table_prefix']}groups
                  LIMIT :limit OFFSET :start";
        $result = $this->_phpbb_sql_link->prepare($query);
        if ($result === false) {
            $this->dbglog('error while preparing query for groups data');
            return false;
        }
        $result->bindValue(':limit', (int)$limit, PDO::PARAM_INT);
        $result->bindValue(':start', (int)$start, PDO::PARAM_INT);
        if (!$result->execute()) {
            $this->dbglog('error while executing query for groups data');
            return false;
        }
        $groups = array();
        while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
            if (isset($row['group_name']) && !empty($row['group_name'])) {
                $groups[$row['group_name']] = $row;
            }
        }
        $result->closeCursor();
        $result = null;
        ksort($groups);
        return $groups;
    }
    
    /**
     * Returns the number of users which meet $filter criteria (does not use cache system).
     *
     * @param   array   $filter Array of field/pattern pairs, empty array for no filter.
     * @return  int             Number of users matching criteria.
     */
    public function getUserCount($filter = array()) {
        $users = $this->retrieveUsers(0, 0, $filter);

        if ($users === false) {
            return 0;
        }
        return count($users);
    }

    /**
     * Logs off the user.
     */
    public function logOff() {
        if (method_exists(get_parent_class($this), 'logOff')) {
            parent::logOff();
        }
        if (empty($this->_phpbb_user_session_id)) {
            $this->get_phpbb_cookie_name();
            if (empty($this->_phpbb_conf['cookie_name'])) {
                return ;
            }
            $phpbb_cookie_sid_name = $this->_phpbb_conf['cookie_name'] . '_sid';
            if (array_key_exists($phpbb_cookie_sid_name, $_COOKIE)) {
                $this->_phpbb_user_session_id = $_COOKIE[$phpbb_cookie_sid_name];
            }
        }
        if (!empty($this->_phpbb_user_session_id) &&
            ($this->get_phpbb_url() !== false) &&
            $this->_phpbb_user_id) {
            //global $ID;

            $url = $this->_phpbb_conf['url'] . '/ucp.php?mode=logout&sid=' . $this->_phpbb_user_session_id;
            // phpBB doesn't natively support the logout redirection yet.
            //$url .= '&redirect=' . urlencode(wl($ID, '', true));
            send_redirect($url);
        }
    }

    /**
     * Loads the plugin's configuration.
     *
     * @return   boolean   True on success, false otherwise.
     */
    private function load_configuration() {
        if ($this->use_phpbb_cache()) {
            $this->_phpbb_conf = unserialize($this->_cache->retrieveCache(false));
        } else {
            $this->_cache->removeCache();
            $this->_phpbb_conf['root_path'] = DOKU_INC . rtrim(trim($this->getConf('phpbb_root_path')), '/') . '/';
            $this->_phpbb_conf['phpEx'] = substr(strrchr(__FILE__, '.'), 1);
            if (!@file_exists($this->_phpbb_conf['root_path'] . 'config.' . $this->_phpbb_conf['phpEx'])) {
                $this->dbglog('phpBB installation not found');
                return false;
            }
            include($this->_phpbb_conf['root_path'] . 'config.' . $this->_phpbb_conf['phpEx']);
            $this->_phpbb_conf['dbms'] = $dbms;
            $this->_phpbb_conf['dbhost'] = empty($dbhost) ? '127.0.0.1' : $dbhost;
            $this->_phpbb_conf['dbport'] = $dbport;
            $this->_phpbb_conf['dbname'] = $dbname;
            $this->_phpbb_conf['dbuser'] = $dbuser;
            $this->_phpbb_conf['dbpasswd'] = $dbpasswd;
            $this->_phpbb_conf['table_prefix'] = $table_prefix;
            foreach (array('dbms', 'dbhost', 'dbname', 'dbuser') as $member) {
                if (empty($this->_phpbb_conf[$member])) {
                    $this->dbglog("phpBB config variable {$member} not set");
                    return false;
                }
            }
            if ($this->get_phpbb_url() === false) {
                $this->dbglog('cannot get phpBB URL');
                return false;
            }
            if (!$this->get_phpbb_cookie_name()) {
                $this->dbglog('cannot get phpBB cookie name');
                return false;
            }
            $this->_cache->storeCache(serialize($this->_phpbb_conf));
        }
        return (!empty($this->_phpbb_conf['url']) &&
                !empty($this->_phpbb_conf['cookie_name']));
    }

    /**
     * Gets the phpBB configuration cache.
     *
     * @return object    Cache of the phpBB configuration.
     */
    private function get_phpbb_cache() {
        if ($this->_cache === null) {
            $this->_cache = new cache('authphpbb3', $this->_cache_ext_name);
        }
        return $this->_cache;
    }

    /**
     * Can use the phpBB configuration cache.
     *
     * @return object    Cache of the phpBB configuration.
     */
    private function use_phpbb_cache() {
        $depends = array();

        $this->get_phpbb_cache();
        $this->_cache_duration = intval($this->getConf('phpbb_cache'));
        if ($this->_cache_duration > 0) {
            $depends['age'] = self::CACHE_DURATION_UNIT * $this->_cache_duration;
        } else {
            $depends['purge'] = true;
        }
        return $this->_cache->useCache($depends);
    }

    /**
     * Connects to phpBB database.
     *
     * @return   boolean True on success, false otherwise.
     */
    private function phpbb_connect() {
        if (!$this->_phpbb_db_link) {
            $host = strtolower(end(explode('\\', $this->_phpbb_conf['dbms'])));
            $port = '';
            $dsn = '';

            if (!empty($this->_phpbb_conf['dbport'])) {
                $port = ';port=' . intval($this->_phpbb_conf['dbport']);
            }
            $dsn = ':host=' . $this->_phpbb_conf['dbhost'] . $port .
                   ';dbname=' . $this->_phpbb_conf['dbname'];
            try {
                switch ($host) {
                    case 'mysql':
                    case 'mysqli':
                        $dsn = 'mysql' . $dsn . ';charset=utf8';
                        $this->_phpbb_sql_link = new PDO(
                            $dsn,
                            $this->_phpbb_conf['dbuser'],
                            $this->_phpbb_conf['dbpasswd']);
                        break;
                    case 'postgres':
                        $dsn = 'pgsql' . $dsn .
                               ';user=' . $this->_phpbb_conf['dbuser'] . 
                               ';password=' . $this->_phpbb_conf['dbpasswd'];
                        $this->_phpbb_sql_link = new PDO($dsn);
                        $this->_phpbb_sql_link->exec("SET NAMES 'UTF8'");
                        break;
                    case 'oracle':
                        $dsn = 'oci' . $dsn . ';charset=utf8';
                        $this->_phpbb_sql_link = new PDO(
                            $dsn,
                            $this->_phpbb_conf['dbuser'],
                            $this->_phpbb_conf['dbpasswd']);
                        break;
                    case 'sqlite':
                    case 'sqlite3':
                        if ($host === 'sqlite') {
                            // SQLite 2 prefix.
                            $host = 'sqlite2';
                        } else {
                            // SQLite 3 prefix.
                            $host = 'sqlite';
                        }
                        $dsn = $host . ':' . $this->_phpbb_conf['root_path'] . $this->_phpbb_conf['dbhost'];
                        $this->_phpbb_sql_link = new PDO($dsn);
                        break;
                    default:
                        msg($this->getLang('database_support'), -1);
                        return false;
                }
            } catch (PDOException $e) {
                $this->dbglog('cannot connect to database server (' . $e->getMessage() .')');
                msg($this->getLang('database_error'), -1);
                $this->_phpbb_db_link = null;
                return false;
            }
        }
        return true;
    }

    /**
     * Disconnects from phpBB database.
     */
    private function phpbb_disconnect() {
        if ($this->_phpbb_db_link !== null) {
            $this->_phpbb_db_link = null;
        }
    }

    /**
     * Gets phpBB cookie's name.
     *
     * @return   boolean True for success, false otherwise.
     */
    private function get_phpbb_cookie_name() {
        if (!empty($this->_phpbb_conf['cookie_name'])) {
            return true;
        }
        if ($this->use_phpbb_cache()) {
            $result = unserialize($this->_cache->retrieveCache(false));
            if (is_array($result) && array_key_exists('cookie_name', $result)) {
                $this->_phpbb_conf['cookie_name'] = $result['cookie_name'];
            }
        }
        if (!empty($this->_phpbb_conf['cookie_name'])) {
            return true;
        }
        if (!$this->phpbb_connect()) {
            return false;
        }
        // Query for cookie_name.
        $query = "SELECT config_name, config_value
                  FROM {$this->_phpbb_conf['table_prefix']}config
                  WHERE config_name = 'cookie_name'";
        $result = $this->_phpbb_sql_link->prepare($query);
        if ($result === false) {
            $this->dbglog('error while preparing query for cookie.');
            return false;
        }
        if (!$result->execute()) {
            $this->dbglog('error while executing query for cookie.');
            return false;
        }
        $row = $result->fetch(PDO::FETCH_ASSOC);
        $this->_phpbb_conf['cookie_name'] = $row['config_value'];
        $result->closeCursor();
        $result = null;
        return true;
    }

    /**
     * Gets phpBB user's groups.
     *
     * @return   boolean True for success, false otherwise.
     */
    private function get_phpbb_user_groups() {
        $this->_phpbb_groups = array();
        $this->_phpbb_user_id = filter_var($this->_phpbb_user_id, FILTER_VALIDATE_INT);
        if (!$this->_phpbb_user_id) {
            return false;
        }
        if (!$this->phpbb_connect()) {
            return false;
        }
        $query = "SELECT *
                  FROM {$this->_phpbb_conf['table_prefix']}groups g,
                       {$this->_phpbb_conf['table_prefix']}users u,
                       {$this->_phpbb_conf['table_prefix']}user_group ug
                  WHERE u.user_id = ug.user_id AND g.group_id = ug.group_id AND u.user_id = ?";
        $result = $this->_phpbb_sql_link->prepare($query);
        if ($result === false) {
            $this->dbglog('error while preparing query for user\'s groups');
            return false;
        }
        if (!$result->execute(array($this->_phpbb_user_id))) {
            $this->dbglog('error while executing query for user\'s groups');
            return false;
        }
        while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
            $this->_phpbb_groups[] = $row['group_name'];
        }
        // If the user is a founder.
        if ($this->_phpbb_user_type === 3) {
            $this->_phpbb_groups[] = 'admin';
        }
        $result->closeCursor();
        $result = null;
        return true;
    }

    /**
     * Authenticate the user using cookie. Called on every page load.
     *
     * @return   boolean True for success, false otherwise.
     */
    private function do_login_cookie() {
        if (!$this->phpbb_connect()) {
            return false;
        }
        if (!$this->get_phpbb_cookie_name()) {
            return false;
        }
        $phpbb_cookie_user_sid = $this->_phpbb_conf['cookie_name'] . '_sid';
        $phpbb_cookie_user_id = $this->_phpbb_conf['cookie_name'] . '_u';
        $this->_phpbb_user_session_id =
            array_key_exists($phpbb_cookie_user_sid, $_COOKIE) ? $_COOKIE[$phpbb_cookie_user_sid] : null;
        $phpbb_cookie_user_id =
            array_key_exists($phpbb_cookie_user_id, $_COOKIE) ? intval($_COOKIE[$phpbb_cookie_user_id]) : null;
        if (empty($this->_phpbb_user_session_id) || !ctype_xdigit($this->_phpbb_user_session_id)) {
            $this->dbglog('invalid SID in user\'s cookie ' .
                '(SID=' . $phpbb_cookie_user_sid . ', Value=' . $this->_phpbb_user_session_id . ')');
            return false;
        }
        // Get session data from database.
        $query = "SELECT session_id, session_user_id
                  FROM {$this->_phpbb_conf['table_prefix']}sessions
                  WHERE session_id = ?";
        $result = $this->_phpbb_sql_link->prepare($query);
        if ($result === false) {
            $this->dbglog('error while preparing query for session');
            return false;
        }
        if (!$result->execute(array($this->_phpbb_user_session_id))) {
            $this->dbglog('error while executing query for session');
            return false;
        }
        $row = $result->fetch(PDO::FETCH_ASSOC);
        if ($phpbb_cookie_user_id !== (int)$row['session_user_id']) {
            $this->dbglog('invalid SID/User ID pair');
            $result->closeCursor();
            $result = null;
            return false;
        }
        $this->_phpbb_user_id = (int)$row['session_user_id'];
        $this->_phpbb_sessiontime = $row['session_time'];
        $result->closeCursor();
        $result = null;
        // Update session time.
        $current_time = time();
        if ($current_time > $this->_phpbb_sessiontime) {
            $query = "UPDATE {$this->_phpbb_conf['table_prefix']}sessions
                      SET session_time = ?
                      WHERE session_id = ?";
            $result = $this->_phpbb_sql_link->prepare($query);
            if ($result === false) {
                $this->dbglog('error while preparing query for session update');
                return false;
            }
            if (!$result->execute(array($current_time, $this->_phpbb_user_session_id))) {
                $this->dbglog('error while executing query for session update');
            }
            $result = null;
        }
        // Check for guest session.
        if ($this->_phpbb_user_id === 1) {
            return false;
        }
        // Get username from database.
        $query = "SELECT user_id, username, user_email, user_type
                  FROM {$this->_phpbb_conf['table_prefix']}users
                  WHERE user_id = ?";
        $result = $this->_phpbb_sql_link->prepare($query);
        if ($result === false) {
            $this->dbglog('error while preparing query for username');
            return false;
        }
        if (!$result->execute(array($this->_phpbb_user_id))) {
            $this->dbglog('error while executing query for username');
            return false;
        }
        $row = $result->fetch(PDO::FETCH_ASSOC);
        $this->_phpbb_user_type = (int)$row['user_type'];
        $this->_phpbb_username = $row['username'];
        $this->_phpbb_user_email = $row['user_email'];
        $result->closeCursor();
        $result = null;
        // Get user groups from database.
        $this->get_phpbb_user_groups();
        return true;
    }
}