streams/Code/Module/Follow.php

<?php

namespace Code\Module;

use App;
use Code\Web\Controller;
use Code\Lib\Libsync;
use Code\Lib\ActivityStreams;
use Code\Lib\Activity;
use Code\Lib\Connect;
use Code\Lib\Channel;
use Code\Daemon\Run;

class Follow extends Controller
{

    public function init()
    {
        if (ActivityStreams::is_as_request() && argc() >= 2) {
            $abook_id = intval(argv(1));
            if (!$abook_id) {
                return;
            }

            $r = q(
                "select * from abook left join xchan on abook_xchan = xchan_hash where abook_id = %d",
                intval($abook_id)
            );
            if (!$r) {
                return;
            }

            $chan = Channel::from_id($r[0]['abook_channel']);

            if (!$chan) {
                http_status_exit(404, 'Not found');
            }

            $actor = Activity::actorEncode($chan, false);
            if (!$actor) {
                http_status_exit(404, 'Not found');
            }

            // Pleroma requires a unique follow id for every follow and follow response
            // instead of our method of re-using the abook_id. This causes issues if they unfollow
            // and re-follow so md5 their follow id and slap it on the end, so they don't simply discard our
            // subsequent accept/reject actions.

            $orig_follow = get_abconfig($chan['channel_id'], $r[0]['xchan_hash'], 'activitypub', 'their_follow_id');
            $orig_follow_type = get_abconfig($chan['channel_id'], $r[0]['xchan_hash'], 'activitypub', 'their_follow_type');

            as_return_and_die([
                'id' => z_root() . '/follow/' . $r[0]['abook_id'] . (($orig_follow) ? '/' . md5($orig_follow) : EMPTY_STR),
                'type' => (($orig_follow_type) ?: 'Follow'),
                'actor' => $actor,
                'object' => $r[0]['xchan_url']
            ], $chan);
        }


        $uid = local_channel();

        if (!$uid) {
            return;
        }

        $url = notags(trim($_REQUEST['url']));
        if (str_starts_with($url, '@')) {
            $url = substr($url, 1);
        }
        $parsed = parse_url($url);
        if ($parsed['scheme'] && $parsed['host']) {
            $parsed['host'] = punify($parsed['host']);
            $url = unparse_url($parsed);
        }
        else {
            $arr = explode('@', $url);
            if ($arr[1]) {
                $arr[1] = punify($arr[1]);
                $url = implode('@', $arr);
            }
        }


        $return_url = $_SESSION['return_url'];
        $interactive = (($_REQUEST['interactive']) ? intval($_REQUEST['interactive']) : 1);
        $channel = App::get_channel();

        if ((str_starts_with($url, 'http')) || str_starts_with($url, 'bear:') || str_starts_with($url, 'x-zot:')) {
            $n = Activity::fetch($url);
            if ($n && isset($n['type']) && !ActivityStreams::is_an_actor($n['type'])) {
                // set client flag to convert objects to implied activities
                $a = new ActivityStreams($n, null, true);
                if (
                    $a->type === 'Announce' && is_array($a->obj)
                    && array_key_exists('object', $a->obj) && array_key_exists('actor', $a->obj)
                ) {
                    // This is a relayed/forwarded Activity (as opposed to a shared/boosted object)
                    // Reparse the encapsulated Activity and use that instead
                    logger('relayed activity', LOGGER_DEBUG);
                    $a = new ActivityStreams($a->obj, null, true);
                }

                if ($a->is_valid()) {
                    if (is_array($a->actor) && array_key_exists('id', $a->actor)) {
                        Activity::actor_store($a->actor['id'], $a->actor);
                    }

                    // ActivityPub sourced items are cacheable
                    $item = Activity::decode_note($a, true);

                    if ($item) {
                        Activity::store($channel, get_observer_hash(), $a, $item);

                        $r = q(
                            "select * from item where mid = '%s' and uid = %d",
                            dbesc($item['mid']),
                            intval($uid)
                        );
                        if ($r) {
                            if ($interactive) {
                                goaway(z_root() . '/display/?mid=' . gen_link_id($item['mid']));
                            } else {
                                $result['success'] = true;
                                json_return_and_die($result);
                            }
                        }
                    }
                }
            }
        }

        $result = Connect::connect($channel, $url);

        if (!$result['success']) {
            if ($result['message']) {
                notice($result['message']);
            }
            if ($interactive) {
                goaway($return_url);
            } else {
                json_return_and_die($result);
            }
        }

        info(t('Connection added.') . EOL);
        Channel::abook_sync($channel, $result['abook']);

        $can_view_stream = their_perms_contains($channel['channel_id'], $clone['abook_xchan'], 'view_stream');

        // If we can view their stream, pull in some posts

        if (($can_view_stream) || ($result['abook']['xchan_network'] === 'rss')) {
            Run::Summon(['Onepoll', $result['abook']['abook_id']]);
        }

        if ($interactive) {
            goaway(z_root() . '/connedit/' . $result['abook']['abook_id'] . '?follow=1');
        } else {
            json_return_and_die(['success' => true]);
        }
    }

    public function get()
    {
        if (!local_channel()) {
            return login();
        }
        return '';
    }
}