<?php

use dokuwiki\Extension\AuthPlugin;
use dokuwiki\plugin\pureldap\classes\ADClient;
use dokuwiki\plugin\pureldap\classes\Client;

/**
 * DokuWiki Plugin pureldap (Auth Component)
 *
 * @license GPL 2 http://www.gnu.org/licenses/gpl-2.0.html
 * @author  Andreas Gohr <andi@splitbrain.org>
 */
class auth_plugin_pureldap extends AuthPlugin
{
    /** @var Client */
    public $client;

    /**
     * Constructor.
     */
    public function __construct()
    {
        global $conf;
        parent::__construct(); // for compatibility

        // prepare the base client
        $this->loadConfig();
        $this->conf['admin_password'] = conf_decodeString($this->conf['admin_password']);
        $this->conf['defaultgroup'] = $conf['defaultgroup'];

        $this->client = new ADClient($this->conf); // FIXME decide class on config

        // set capabilities
        $this->cando['getUsers'] = true;
        $this->cando['getGroups'] = true;
        $this->cando['logout'] = !$this->client->getConf('sso');
        if ($this->client->getConf('encryption') !== 'none') {
            // with encryption passwords can be changed
            // for resetting passwords a privileged user is needed
            $this->cando['modPass'] = true;
        }


        $this->success = true;
    }

    /** @inheritDoc */
    public function checkPass($user, $pass)
    {
        global $INPUT;

        // when SSO is enabled, the login is autotriggered and we simply trust the environment
        if (
            $this->client->getConf('sso') &&
            $INPUT->server->str('REMOTE_USER') !== '' &&
            $INPUT->server->str('REMOTE_USER') == $user
        ) {
            return true;
        }

        // try to bind with the user credentials, client will stay authenticated as user
        $this->client = new ADClient($this->conf); // FIXME decide class on config
        try {
            $this->client->authenticate($user, $pass);
            return true;
        } catch (\Exception $e) {
            $this->parseErrorCodesToMessages($e);
            return false;
        }
    }

    /** @inheritDoc */
    public function getUserData($user, $requireGroups = true)
    {
        $info = $this->client->getCachedUser($user, $requireGroups);
        return $info ?: false;
    }

    /**
     * @inheritDoc
     */
    public function retrieveUsers($start = 0, $limit = 0, $filter = null)
    {
        return array_slice(
            $this->client->getFilteredUsers(
                $filter,
                Client::FILTER_CONTAINS
            ),
            $start,
            $limit
        );
    }

    /** @inheritDoc */
    public function retrieveGroups($start = 0, $limit = 0)
    {
        return array_slice($this->client->getCachedGroups(), $start, $limit);
    }

    /** @inheritDoc */
    public function isCaseSensitive()
    {
        return false;
    }

    /** @inheritDoc */
    public function cleanUser($user)
    {
        return $this->client->cleanUser($user);
    }

    /** @inheritDoc */
    public function cleanGroup($group)
    {
        return $group;
    }

    /** @inheritDoc */
    public function useSessionCache($user)
    {
        return true;
    }

    /**
     * Support password changing
     * @inheritDoc
     */
    public function modifyUser($user, $changes)
    {
        if (empty($changes['pass'])) {
            $this->client->error('Only password changes are supported', __FILE__, __LINE__);
            return false;
        }

        global $INPUT;
        return $this->client->setPassword($user, $changes['pass'], $INPUT->str('oldpass', null, true));
    }

    /**
     * Parse error codes from LDAP exceptions and output them as user-friendly messages.
     *
     * This is currently tailored for Active Directory bind errors.
     *
     * @param Exception $e
     * @return void
     */
    public function parseErrorCodesToMessages(\Exception $e)
    {
        // See https://ldapwiki.com/wiki/Wiki.jsp?page=Common%20Active%20Directory%20Bind%20Errors
        $bind_errors = [
            '52f' => 'ERROR_ACCOUNT_RESTRICTION',
            '530' => 'ERROR_INVALID_LOGON_HOURS',
            '531' => 'ERROR_INVALID_WORKSTATION',
            '532' => 'ERROR_PASSWORD_EXPIRED',
            '533' => 'ERROR_ACCOUNT_DISABLED',
            '701' => 'ERROR_ACCOUNT_EXPIRED',
            '773' => 'ERROR_PASSWORD_MUST_CHANGE',
        ];

        if (
            $e instanceof \FreeDSx\Ldap\Exception\BindException &&
            $e->getCode() === 49 &&
            preg_match('/ data ([0-9a-f]{3})/', $e->getMessage(), $matches)
        ) {
            $code = $matches[1];
            if (isset($bind_errors[$code])) {
                $message = $this->getLang($bind_errors[$code]) ?: $bind_errors[$code];

                // on password expired or must change, add reset hint
                if ($this->canDo('modPass') && ($code == 532 || $code == 773)) {
                    $link = '<a href="' . wl('start', ['do' => 'resendpwd']) . '" class="pureldap-reset-link">' .
                        $this->getLang('pass_reset') . '</a>';
                    $message .= ' ' . $link;
                }

                msg($message, -1);
            }
        }
    }
}