<?php
/**
 * GNU social - a federating social network
 *
 * Plugin that handles ActivityPub
 *
 * 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   GNUsocial
 * @author    Daniel Supernault <danielsupernault@gmail.com>
 * @author    Diogo Cordeiro <diogo@fc.up.pt>
 * @copyright 2014 Free Software Foundation http://fsf.org
 * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
 * @link      https://www.gnu.org/software/social/
 */

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

class ActivityPubPlugin extends Plugin
{

    public function onRouterInitialized(URLMapper $m)
    {
        ActivityPubURLMapperOverwrite::overwrite_variable($m, ':nickname',
                                    ['action' => 'showstream'],
                                    ['nickname' => Nickname::DISPLAY_FMT],
                                    'apactorprofile');
        
        $m->connect(':nickname/liked.json',
                    ['action'    => 'apActorLikedCollection'],
                    ['nickname'  => Nickname::DISPLAY_FMT]);
        
        $m->connect(':nickname/followers.json',
                    ['action'    => 'apActorFollowers'],
                    ['nickname'  => Nickname::DISPLAY_FMT]);
        
        $m->connect(':nickname/following.json',
                    ['action'    => 'apActorFollowing'],
                    ['nickname'  => Nickname::DISPLAY_FMT]);
    }

    public function onPluginVersion(array &$versions)
    {
        $versions[] = [ 'name' => 'ActivityPub',
                        'version' => GNUSOCIAL_VERSION,
                        'author' => 'Daniel Supernault, Diogo Cordeiro',
                        'homepage' => 'https://www.gnu.org/software/social/',
                        'rawdescription' =>
                        // Todo: Translation
                        'Adds ActivityPub Support'];
        return true;
    }
}

/**
 * Overwrites variables in URL-mapping
 *
 */
class ActivityPubURLMapperOverwrite extends URLMapper
{
    static function overwrite_variable($m, $path, $args, $paramPatterns, $newaction)
    {
        $mimes = [
            'application/activity+json', 
            'application/ld+json',
            'application/ld+json; profile="https://www.w3.org/ns/activitystreams"'
        ];

        if (in_array ($_SERVER["HTTP_ACCEPT"], $mimes) == false) {
            return true;
        }
        
        $m->connect($path, array('action' => $newaction), $paramPatterns);
        $regex = self::makeRegex($path, $paramPatterns);
        foreach ($m->variables as $n => $v) {
            if ($v[1] == $regex) {
                $m->variables[$n][0]['action'] = $newaction;
            }
        }
    }
}

class ActivityPubReturn
{
    static function answer ($res)
    {
        header('Content-Type: application/activity+json');
        echo json_encode($res, JSON_UNESCAPED_SLASHES | (isset($_GET["pretty"]) ? JSON_PRETTY_PRINT : null));
        exit;
    }
    static function error ($m, $code=500)
    {
        http_response_code ($code);
        header('Content-Type: application/activity+json');
        $res[] = Activitypub_error::errorMessageToObject($m);
        echo json_encode($res, JSON_UNESCAPED_SLASHES);
        exit;
    }
}