<?php
/**
 * Laconica, the distributed open-source microblogging tool
 *
 * Class for doing OAuth authentication against Twitter
 *
 * 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  TwitterauthorizationAction
 * @package   Laconica
 * @author    Zach Copely <zach@controlyourself.ca>
 * @copyright 2009 Control Yourself, Inc.
 * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
 * @link      http://laconi.ca/
 */

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

class TwitterauthorizationAction extends Action
{

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

        $this->oauth_token = $this->arg('oauth_token');

        return true;
    }

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

        if (!common_logged_in()) {
            $this->clientError(_('Not logged in.'), 403);
        }

        $user = common_current_user();
        $flink = Foreign_link::getByUserID($user->id, TWITTER_SERVICE);

        // If there's already a foreign link record, it means we already
        // have an access token, and this is unecessary. So go back.

        if (isset($flink)) {
            common_redirect(common_local_url('twittersettings'));
        }

        // $this->oauth_token is only populated once Twitter authorizes our
        // request token. If it's empty we're at the beginning of the auth
        // process

        if (empty($this->oauth_token)) {

            // Get a new request token and authorize it

            $client = new TwitterOAuthClient();
            $req_tok = $client->getRequestToken();

            // Sock the request token away in the session temporarily

            $_SESSION['twitter_request_token'] = $req_tok->key;
            $_SESSION['twitter_request_token_secret'] = $req_tok->key;

            $auth_link = $client->getAuthorizeLink($req_tok);
            common_redirect($auth_link);

        } else {

            // Check to make sure Twitter sent us the same request token we sent

            if ($_SESSION['twitter_request_token'] != $this->oauth_token) {
                $this->serverError(_('Couldn\'t link your Twitter account.'));
            }

            $client = new TwitterOAuthClient($_SESSION['twitter_request_token'],
                $_SESSION['twitter_request_token_secret']);

            // Exchange the request token for an access token

            $atok = $client->getAccessToken();

            // Save the access token and Twitter user info

            $client = new TwitterOAuthClient($atok->key, $atok->secret);

            $twitter_user = $client->verify_credentials();

            $user = common_current_user();

            $flink = new Foreign_link();

            $flink->user_id     = $user->id;
            $flink->foreign_id  = $twitter_user->id;
            $flink->service     = TWITTER_SERVICE;
            $flink->token       = $atok->key;
            $flink->credentials = $atok->secret;
            $flink->created     = common_sql_now();

            $flink->set_flags(true, false, false, false);

            $flink_id = $flink->insert();

            if (empty($flink_id)) {
                common_log_db_error($flink, 'INSERT', __FILE__);
                $this->serverError(_('Couldn\'t link your Twitter account.'));
            }

            save_twitter_user($twitter_user->id, $twitter_user->screen_name);

            // clean up the the mess we made in the session

            unset($_SESSION['twitter_request_token']);
            unset($_SESSION['twitter_request_token_secret']);

            common_redirect(common_local_url('twittersettings'));
        }
    }

}