<?php
/**
 * StatusNet, the distributed open-source microblogging tool
 *
 * Login or register a local user based on a Facebook user
 *
 * PHP version 5
 *
 * LICENCE: This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @category  Plugin
 * @package   StatusNet
 * @author    Zach Copley <zach@status.net>
 * @copyright 2010 StatusNet, Inc.
 * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
 * @link      http://status.net/
 */

if (!defined('STATUSNET')) {
    exit(1);
}

class FacebookfinishloginAction extends Action
{
    private $facebook = null; // Facebook client
    private $fbuid    = null; // Facebook user ID
    private $fbuser   = null; // Facebook user object (JSON)

    function prepare($args) {
        parent::prepare($args);

        $this->facebook = new Facebook(
            array(
                'appId'  => common_config('facebook', 'appid'),
                'secret' => common_config('facebook', 'secret'),
                'cookie' => true,
            )
        );

        // Check for a Facebook user session

        $session = $this->facebook->getSession();
        $me      = null;

        if ($session) {
            try {
                $this->fbuid  = $this->facebook->getUser();
                $this->fbuser = $this->facebook->api('/me');
            } catch (FacebookApiException $e) {
                common_log(LOG_ERROR, $e, __FILE__);
            }
        }

        if (!empty($this->fbuser)) {
            // OKAY, all is well... proceed to register

            common_debug("Found a valid Facebook user.", __FILE__);
        } else {

            // This shouldn't happen in the regular course of things

            list($proxy, $ip) = common_client_ip();

            common_log(
                LOG_WARNING,
                    sprintf(
                        'Failed Facebook authentication attempt, proxy = %s, ip = %s.',
                         $proxy,
                         $ip
                    ),
                    __FILE__
            );

            $this->clientError(
                // TRANS: Client error displayed when trying to connect to Facebook while not logged in.
                _m('You must be logged into Facebook to register a local account using Facebook.')
            );
        }

        return true;
    }

    function handle($args)
    {
        parent::handle($args);

        if (common_is_real_login()) {

            // User is already logged in, are her accounts already linked?

            $flink = Foreign_link::getByForeignID($this->fbuid, FACEBOOK_SERVICE);

            if (!empty($flink)) {

                // User already has a linked Facebook account and shouldn't be here!

                common_debug(
                    sprintf(
                        'There\'s already a local user %d linked with Facebook user %s.',
                        $flink->user_id,
                        $this->fbuid
                    )
                );

                $this->clientError(
                    // TRANS: Client error displayed when trying to connect to a Facebook account that is already linked
                    // TRANS: in the same StatusNet site.
                    _m('There is already a local account linked with that Facebook account.')
                );

            } else {

                // Possibly reconnect an existing account

                $this->connectUser();
            }

        } else if ($_SERVER['REQUEST_METHOD'] == 'POST') {
            $this->handlePost();
        } else {
            $this->tryLogin();
        }
    }

    function handlePost()
    {
        $token = $this->trimmed('token');

        if (!$token || $token != common_session_token()) {
            $this->showForm(
                // TRANS: Client error displayed when the session token does not match or is not given.
                _m('There was a problem with your session token. Try again, please.')
            );
            return;
        }

        if ($this->arg('create')) {

            if (!$this->boolean('license')) {
                $this->showForm(
                    // TRANS: Form validation error displayed when user has not agreed to the license.
                    _m('You cannot register if you do not agree to the license.'),
                    $this->trimmed('newname')
                );
                return;
            }

            // We has a valid Facebook session and the Facebook user has
            // agreed to the SN license, so create a new user
            $this->createNewUser();

        } else if ($this->arg('connect')) {

            $this->connectNewUser();

        } else {

            $this->showForm(
                // TRANS: Form validation error displayed when an unhandled error occurs.
                _m('An unknown error has occured.'),
                $this->trimmed('newname')
            );
        }
    }

    function showPageNotice()
    {
        if ($this->error) {

            $this->element('div', array('class' => 'error'), $this->error);

        } else {

            $this->element(
                'div', 'instructions',
                sprintf(
                    // TRANS: Form instructions for connecting to Facebook.
                    // TRANS: %s is the site name.
                    _m('This is the first time you have logged into %s so we must connect your Facebook to a local account. You can either create a new local account, or connect with an existing local account.'),
                    common_config('site', 'name')
                )
            );
        }
    }

    function title()
    {
        // TRANS: Page title.
        return _m('Facebook Setup');
    }

    function showForm($error=null, $username=null)
    {
        $this->error = $error;
        $this->username = $username;

        $this->showPage();
    }

    function showPage()
    {
        parent::showPage();
    }

    /**
     * @todo FIXME: Much of this duplicates core code, which is very fragile.
     * Should probably be replaced with an extensible mini version of
     * the core registration form.
     */
    function showContent()
    {
        if (!empty($this->message_text)) {
            $this->element('p', null, $this->message);
            return;
        }

        $this->elementStart('form', array('method' => 'post',
                                          'id' => 'form_settings_facebook_connect',
                                          'class' => 'form_settings',
                                          'action' => common_local_url('facebookfinishlogin')));
        $this->elementStart('fieldset', array('id' => 'settings_facebook_connect_options'));
        // TRANS: Fieldset legend.
        $this->element('legend', null, _m('Connection options'));
        $this->elementStart('ul', 'form_data');
        $this->elementStart('li');
        $this->element('input', array('type' => 'checkbox',
                                      'id' => 'license',
                                      'class' => 'checkbox',
                                      'name' => 'license',
                                      'value' => 'true'));
        $this->elementStart('label', array('class' => 'checkbox', 'for' => 'license'));
        // TRANS: %s is the name of the license used by the user for their status updates.
        $message = _m('My text and files are available under %s ' .
                     'except this private data: password, ' .
                     'email address, IM address, and phone number.');
        $link = '<a href="' .
                htmlspecialchars(common_config('license', 'url')) .
                '">' .
                htmlspecialchars(common_config('license', 'title')) .
                '</a>';
        $this->raw(sprintf(htmlspecialchars($message), $link));
        $this->elementEnd('label');
        $this->elementEnd('li');
        $this->elementEnd('ul');

        $this->elementStart('fieldset');
        $this->hidden('token', common_session_token());
        $this->element('legend', null,
                       // TRANS: Fieldset legend.
                       _m('Create new account'));
        $this->element('p', null,
                       // TRANS: Form instructions.
                       _m('Create a new user with this nickname.'));
        $this->elementStart('ul', 'form_data');

        // Hook point for captcha etc
        Event::handle('StartRegistrationFormData', array($this));

        $this->elementStart('li');
        // TRANS: Field label.
        $this->input('newname', _m('New nickname'),
                     ($this->username) ? $this->username : '',
                     // TRANS: Field title.
                     _m('1-64 lowercase letters or numbers, no punctuation or spaces.'));
        $this->elementEnd('li');

        // Hook point for captcha etc
        Event::handle('EndRegistrationFormData', array($this));

        $this->elementEnd('ul');
        // TRANS: Submit button to create a new account.
        $this->submit('create', _m('BUTTON','Create'));
        $this->elementEnd('fieldset');

        $this->elementStart('fieldset');
        $this->element('legend', null,
                       // TRANS: Fieldset legend.
                       _m('Connect existing account'));
        $this->element('p', null,
                       // TRANS: Form instructions.
                       _m('If you already have an account, login with your username and password to connect it to your Facebook.'));
        $this->elementStart('ul', 'form_data');
        $this->elementStart('li');
        // TRANS: Field label.
        $this->input('nickname', _m('Existing nickname'));
        $this->elementEnd('li');
        $this->elementStart('li');
        // TRANS: Field label.
        $this->password('password', _m('Password'));
        $this->elementEnd('li');
        $this->elementEnd('ul');
        // TRANS: Submit button to connect a Facebook account to an existing StatusNet account.
        $this->submit('connect', _m('BUTTON','Connect'));
        $this->elementEnd('fieldset');

        $this->elementEnd('fieldset');
        $this->elementEnd('form');
    }

    function message($msg)
    {
        $this->message_text = $msg;
        $this->showPage();
    }

    function createNewUser()
    {
        if (!Event::handle('StartRegistrationTry', array($this))) {
            return;
        }

        if (common_config('site', 'closed')) {
            // TRANS: Client error trying to register with registrations not allowed.
            $this->clientError(_m('Registration not allowed.'));
            return;
        }

        $invite = null;

        if (common_config('site', 'inviteonly')) {
            $code = $_SESSION['invitecode'];
            if (empty($code)) {
                // TRANS: Client error trying to register with registrations 'invite only'.
                $this->clientError(_m('Registration not allowed.'));
                return;
            }

            $invite = Invitation::staticGet($code);

            if (empty($invite)) {
                // TRANS: Client error trying to register with an invalid invitation code.
                $this->clientError(_m('Not a valid invitation code.'));
                return;
            }
        }

        try {
            $nickname = Nickname::normalize($this->trimmed('newname'));
        } catch (NicknameException $e) {
            $this->showForm($e->getMessage());
            return;
        }

        if (!User::allowed_nickname($nickname)) {
            // TRANS: Form validation error displayed when picking a nickname that is not allowed.
            $this->showForm(_m('Nickname not allowed.'));
            return;
        }

        if (User::staticGet('nickname', $nickname)) {
            // TRANS: Form validation error displayed when picking a nickname that is already in use.
            $this->showForm(_m('Nickname already in use. Try another one.'));
            return;
        }

        $args = array(
            'nickname'        => $nickname,
            'fullname'        => $this->fbuser['first_name']
                . ' ' . $this->fbuser['last_name'],
            'homepage'        => $this->fbuser['website'],
            'bio'             => $this->fbuser['about'],
            'location'        => $this->fbuser['location']['name']
        );

        // It's possible that the email address is already in our
        // DB. It's a unique key, so we need to check
        if ($this->isNewEmail($this->fbuser['email'])) {
            $args['email']           = $this->fbuser['email'];
            $args['email_confirmed'] = true;
        }

        if (!empty($invite)) {
            $args['code'] = $invite->code;
        }

        $user   = User::register($args);
        $result = $this->flinkUser($user->id, $this->fbuid);

        if (!$result) {
            // TRANS: Server error displayed when connecting to Facebook fails.
            $this->serverError(_m('Error connecting user to Facebook.'));
            return;
        }

        // Add a Foreign_user record
        Facebookclient::addFacebookUser($this->fbuser);

        $this->setAvatar($user);

        common_set_user($user);
        common_real_login(true);

        common_log(
            LOG_INFO,
            sprintf(
                'Registered new user %s (%d) from Facebook user %s, (fbuid %d)',
                $user->nickname,
                $user->id,
                $this->fbuser['name'],
                $this->fbuid
            ),
            __FILE__
        );

        Event::handle('EndRegistrationTry', array($this));

        $this->goHome($user->nickname);
    }

    /*
     * Attempt to download the user's Facebook picture and create a
     * StatusNet avatar for the new user.
     */
    function setAvatar($user)
    {
        $picUrl = sprintf(
            'http://graph.facebook.com/%s/picture?type=large',
            $this->fbuid
        );

        // fetch the picture from Facebook
        $client = new HTTPClient();

        // fetch the actual picture
        $response = $client->get($picUrl);

        if ($response->isOk()) {

            $finalUrl = $client->getUrl();

            // Make sure the filename is unique becuase it's possible for a user
            // to deauthorize our app, and then come back in as a new user but
            // have the same Facebook picture (avatar URLs have a unique index
            // and their URLs are based on the filenames).
            $filename = 'facebook-' . common_good_rand(4) . '-'
                . substr(strrchr($finalUrl, '/'), 1);

            $ok = file_put_contents(
                Avatar::path($filename),
                $response->getBody()
            );

            if (!$ok) {
                common_log(
                    LOG_WARNING,
                    sprintf(
                        'Couldn\'t save Facebook avatar %s',
                        $tmp
                    ),
                    __FILE__
                );

            } else {

                // save it as an avatar
                $profile = $user->getProfile();

                if ($profile->setOriginal($filename)) {
                    common_log(
                        LOG_INFO,
                        sprintf(
                            'Saved avatar for %s (%d) from Facebook picture for '
                                . '%s (fbuid %d), filename = %s',
                             $user->nickname,
                             $user->id,
                             $this->fbuser['name'],
                             $this->fbuid,
                             $filename
                        ),
                        __FILE__
                    );
                }
            }
        }
    }

    function connectNewUser()
    {
        $nickname = $this->trimmed('nickname');
        $password = $this->trimmed('password');

        if (!common_check_user($nickname, $password)) {
            // TRANS: Form validation error displayed when username/password combination is incorrect.
            $this->showForm(_m('Invalid username or password.'));
            return;
        }

        $user = User::staticGet('nickname', $nickname);

        if (!empty($user)) {
            common_debug(
                sprintf(
                    'Found a legit user to connect to Facebook: %s (%d)',
                    $user->nickname,
                    $user->id
                ),
                __FILE__
            );
        }

        $this->tryLinkUser($user);

        common_set_user($user);
        common_real_login(true);

        $this->goHome($user->nickname);
    }

    function connectUser()
    {
        $user = common_current_user();
        $this->tryLinkUser($user);
        common_redirect(common_local_url('facebookfinishlogin'), 303);
    }

    function tryLinkUser($user)
    {
        $result = $this->flinkUser($user->id, $this->fbuid);

        if (empty($result)) {
            // TRANS: Server error displayed when connecting to Facebook fails.
            $this->serverError(_m('Error connecting user to Facebook.'));
            return;
        }

        common_debug(
            sprintf(
                'Connected Facebook user %s (fbuid %d) to local user %s (%d)',
                $this->fbuser['name'],
                $this->fbuid,
                $user->nickname,
                $user->id
            ),
            __FILE__
        );
    }

    function tryLogin()
    {
        common_debug(
            sprintf(
                'Trying login for Facebook user %s',
                $this->fbuid
            ),
            __FILE__
        );

        $flink = Foreign_link::getByForeignID($this->fbuid, FACEBOOK_SERVICE);

        if (!empty($flink)) {
            $user = $flink->getUser();

            if (!empty($user)) {

                common_log(
                    LOG_INFO,
                    sprintf(
                        'Logged in Facebook user %s as user %d (%s)',
                        $this->fbuid,
                        $user->nickname,
                        $user->id
                    ),
                    __FILE__
                );

                common_set_user($user);
                common_real_login(true);
                $this->goHome($user->nickname);
            }

        } else {

            common_debug(
                sprintf(
                    'No flink found for fbuid: %s - new user',
                    $this->fbuid
                ),
                __FILE__
            );

            $this->showForm(null, $this->bestNewNickname());
        }
    }

    function goHome($nickname)
    {
        $url = common_get_returnto();
        if ($url) {
            // We don't have to return to it again
            common_set_returnto(null);
        } else {
            $url = common_local_url('all',
                                    array('nickname' =>
                                          $nickname));
        }

        common_redirect($url, 303);
    }

    function flinkUser($user_id, $fbuid)
    {
        $flink = new Foreign_link();
        $flink->user_id = $user_id;
        $flink->foreign_id = $fbuid;
        $flink->service = FACEBOOK_SERVICE;

        // Pull the access token from the Facebook cookies
        $flink->credentials = $this->facebook->getAccessToken();

        $flink->created = common_sql_now();

        $flink_id = $flink->insert();

        return $flink_id;
    }

    function bestNewNickname()
    {
        if (!empty($this->fbuser['name'])) {
            $nickname = $this->nicknamize($this->fbuser['name']);
            if ($this->isNewNickname($nickname)) {
                return $nickname;
            }
        }

        // Try the full name

        $fullname = trim($this->fbuser['first_name'] .
            ' ' . $this->fbuser['last_name']);

        if (!empty($fullname)) {
            $fullname = $this->nicknamize($fullname);
            if ($this->isNewNickname($fullname)) {
                return $fullname;
            }
        }

        return null;
    }

     /**
      * Given a string, try to make it work as a nickname
      */
     function nicknamize($str)
     {
         $str = preg_replace('/\W/', '', $str);
         return strtolower($str);
     }

     /*
      * Is the desired nickname already taken?
      *
      * @return boolean result
      */
     function isNewNickname($str)
     {
        if (!Nickname::isValid($str)) {
            return false;
        }

        if (!User::allowed_nickname($str)) {
            return false;
        }

        if (User::staticGet('nickname', $str)) {
            return false;
        }

        return true;
    }

    /*
     * Do we already have a user record with this email?
     * (emails have to be unique but they can change)
     *
     * @param string $email the email address to check
     *
     * @return boolean result
     */
     function isNewEmail($email)
     {
         // we shouldn't have to validate the format
         $result = User::staticGet('email', $email);

         if (empty($result)) {
             common_debug("XXXXXXXXXXXXXXXXXX We've never seen this email before!!!");
             return true;
         }
         common_debug("XXXXXXXXXXXXXXXXXX dupe email address!!!!");

         return false;
     }
}