pixelfed/app/Util/ActivityPub/Helpers.php

<?php

namespace App\Util\ActivityPub;

use DB, Cache, Purify, Storage, Request, Validator;
use App\{
    Activity,
    Follower,
    Instance,
    Like,
    Media,
    Notification,
    Profile,
    Status
};
use Zttp\Zttp;
use Carbon\Carbon;
use GuzzleHttp\Client;
use Illuminate\Http\File;
use Illuminate\Validation\Rule;
use App\Jobs\AvatarPipeline\CreateAvatar;
use App\Jobs\RemoteFollowPipeline\RemoteFollowImportRecent;
use App\Jobs\ImageOptimizePipeline\{ImageOptimize,ImageThumbnail};
use App\Jobs\StatusPipeline\NewStatusPipeline;
use App\Jobs\StatusPipeline\StatusReplyPipeline;
use App\Jobs\StatusPipeline\StatusTagsPipeline;
use App\Util\ActivityPub\HttpSignature;
use Illuminate\Support\Str;
use App\Services\ActivityPubFetchService;
use App\Services\ActivityPubDeliveryService;
use App\Services\CustomEmojiService;
use App\Services\InstanceService;
use App\Services\MediaPathService;
use App\Services\MediaStorageService;
use App\Services\NetworkTimelineService;
use App\Jobs\MediaPipeline\MediaStoragePipeline;
use App\Jobs\AvatarPipeline\RemoteAvatarFetch;
use App\Util\Media\License;
use App\Models\Poll;
use Illuminate\Contracts\Cache\LockTimeoutException;
use App\Jobs\ProfilePipeline\IncrementPostCount;
use App\Jobs\ProfilePipeline\DecrementPostCount;
use App\Services\DomainService;
use App\Services\UserFilterService;

class Helpers {

    public static function validateObject($data)
    {
        $verbs = ['Create', 'Announce', 'Like', 'Follow', 'Delete', 'Accept', 'Reject', 'Undo', 'Tombstone'];

        $valid = Validator::make($data, [
            'type' => [
                'required',
                'string',
                Rule::in($verbs)
            ],
            'id' => 'required|string',
            'actor' => 'required|string|url',
            'object' => 'required',
            'object.type' => 'required_if:type,Create',
            'object.attributedTo' => 'required_if:type,Create|url',
            'published' => 'required_if:type,Create|date'
        ])->passes();

        return $valid;
    }

    public static function verifyAttachments($data)
    {
        if(!isset($data['object']) || empty($data['object'])) {
            $data = ['object'=>$data];
        }

        $activity = $data['object'];

        $mimeTypes = explode(',', config_cache('pixelfed.media_types'));
        $mediaTypes = in_array('video/mp4', $mimeTypes) ? ['Document', 'Image', 'Video'] : ['Document', 'Image'];

        // Peertube
        // $mediaTypes = in_array('video/mp4', $mimeTypes) ? ['Document', 'Image', 'Video', 'Link'] : ['Document', 'Image'];

        if(!isset($activity['attachment']) || empty($activity['attachment'])) {
            return false;
        }

        // peertube
        // $attachment = is_array($activity['url']) ?
        //  collect($activity['url'])
        //  ->filter(function($media) {
        //      return $media['type'] == 'Link' && $media['mediaType'] == 'video/mp4';
        //  })
        //  ->take(1)
        //  ->values()
        //  ->toArray()[0] : $activity['attachment'];

        $attachment = $activity['attachment'];

        $valid = Validator::make($attachment, [
            '*.type' => [
                'required',
                'string',
                Rule::in($mediaTypes)
            ],
            '*.url' => 'required|url',
            '*.mediaType'  => [
                'required',
                'string',
                Rule::in($mimeTypes)
            ],
            '*.name' => 'sometimes|nullable|string',
            '*.blurhash' => 'sometimes|nullable|string|min:6|max:164',
            '*.width' => 'sometimes|nullable|integer|min:1|max:5000',
            '*.height' => 'sometimes|nullable|integer|min:1|max:5000',
        ])->passes();

        return $valid;
    }

    public static function normalizeAudience($data, $localOnly = true)
    {
        if(!isset($data['to'])) {
            return;
        }

        $audience = [];
        $audience['to'] = [];
        $audience['cc'] = [];
        $scope = 'private';

        if(is_array($data['to']) && !empty($data['to'])) {
            foreach ($data['to'] as $to) {
                if($to == 'https://www.w3.org/ns/activitystreams#Public') {
                    $scope = 'public';
                    continue;
                }
                $url = $localOnly ? self::validateLocalUrl($to) : self::validateUrl($to);
                if($url != false) {
                    array_push($audience['to'], $url);
                }
            }
        }

        if(is_array($data['cc']) && !empty($data['cc'])) {
            foreach ($data['cc'] as $cc) {
                if($cc == 'https://www.w3.org/ns/activitystreams#Public') {
                    $scope = 'unlisted';
                    continue;
                }
                $url = $localOnly ? self::validateLocalUrl($cc) : self::validateUrl($cc);
                if($url != false) {
                    array_push($audience['cc'], $url);
                }
            }
        }
        $audience['scope'] = $scope;
        return $audience;
    }

    public static function userInAudience($profile, $data)
    {
        $audience = self::normalizeAudience($data);
        $url = $profile->permalink();
        return in_array($url, $audience['to']) || in_array($url, $audience['cc']);
    }

    public static function validateUrl($url)
    {
        if(is_array($url)) {
            $url = $url[0];
        }

        $hash = hash('sha256', $url);
        $key = "helpers:url:valid:sha256-{$hash}";

        $valid = Cache::remember($key, 900, function() use($url) {
            $localhosts = [
                '127.0.0.1', 'localhost', '::1'
            ];

            if(strtolower(mb_substr($url, 0, 8)) !== 'https://') {
                return false;
            }

            if(substr_count($url, '://') !== 1) {
                return false;
            }

            if(mb_substr($url, 0, 8) !== 'https://') {
                $url = 'https://' . substr($url, 8);
            }

            $valid = filter_var($url, FILTER_VALIDATE_URL);

            if(!$valid) {
                return false;
            }

            $host = parse_url($valid, PHP_URL_HOST);

            if(in_array($host, $localhosts)) {
                return false;
            }

            if(config('security.url.verify_dns')) {
                if(DomainService::hasValidDns($host) === false) {
                    return false;
                }
            }

            if(app()->environment() === 'production') {
                $bannedInstances = InstanceService::getBannedDomains();
                if(in_array($host, $bannedInstances)) {
                    return false;
                }
            }

            return $url;
        });

        return $valid;
    }

    public static function validateLocalUrl($url)
    {
        $url = self::validateUrl($url);
        if($url == true) {
            $domain = config('pixelfed.domain.app');
            $host = parse_url($url, PHP_URL_HOST);
            $url = strtolower($domain) === strtolower($host) ? $url : false;
            return $url;
        }
        return false;
    }

    public static function zttpUserAgent()
    {
        $version = config('pixelfed.version');
        $url = config('app.url');
        return [
            'Accept'     => 'application/activity+json',
            'User-Agent' => "(Pixelfed/{$version}; +{$url})",
        ];
    }

    public static function fetchFromUrl($url = false)
    {
        if(self::validateUrl($url) == false) {
            return;
        }

        $hash = hash('sha256', $url);
        $key = "helpers:url:fetcher:sha256-{$hash}";
        $ttl = now()->addMinutes(15);

        return Cache::remember($key, $ttl, function() use($url) {
            $res = ActivityPubFetchService::get($url);
            if(!$res || empty($res)) {
                return false;
            }
            $res = json_decode($res, true, 8);
            if(json_last_error() == JSON_ERROR_NONE) {
                return $res;
            } else {
                return false;
            }
        });
    }

    public static function fetchProfileFromUrl($url)
    {
        return self::fetchFromUrl($url);
    }

    public static function pluckval($val)
    {
        if(is_string($val)) {
            return $val;
        }

        if(is_array($val)) {
            return !empty($val) ? head($val) : null;
        }

        return null;
    }

    public static function statusFirstOrFetch($url, $replyTo = false)
    {
        $url = self::validateUrl($url);
        if($url == false) {
            return;
        }

        $host = parse_url($url, PHP_URL_HOST);
        $local = config('pixelfed.domain.app') == $host ? true : false;

        if($local) {
            $id = (int) last(explode('/', $url));
            return Status::whereNotIn('scope', ['draft','archived'])->findOrFail($id);
        }

        $cached = Status::whereNotIn('scope', ['draft','archived'])
            ->whereUri($url)
            ->orWhere('object_url', $url)
            ->first();

        if($cached) {
            return $cached;
        }

        $res = self::fetchFromUrl($url);

        if(!$res || empty($res) || isset($res['error']) || !isset($res['@context']) || !isset($res['published']) ) {
            return;
        }

        if(isset($res['object'])) {
            $activity = $res;
        } else {
            $activity = ['object' => $res];
        }

        $scope = 'private';

        $cw = isset($res['sensitive']) ? (bool) $res['sensitive'] : false;

        if(isset($res['to']) == true) {
            if(is_array($res['to']) && in_array('https://www.w3.org/ns/activitystreams#Public', $res['to'])) {
                $scope = 'public';
            }
            if(is_string($res['to']) && 'https://www.w3.org/ns/activitystreams#Public' == $res['to']) {
                $scope = 'public';
            }
        }

        if(isset($res['cc']) == true) {
            if(is_array($res['cc']) && in_array('https://www.w3.org/ns/activitystreams#Public', $res['cc'])) {
                $scope = 'unlisted';
            }
            if(is_string($res['cc']) && 'https://www.w3.org/ns/activitystreams#Public' == $res['cc']) {
                $scope = 'unlisted';
            }
        }

        if(config('costar.enabled') == true) {
            $blockedKeywords = config('costar.keyword.block');
            if($blockedKeywords !== null) {
                $keywords = config('costar.keyword.block');
                foreach($keywords as $kw) {
                    if(Str::contains($res['content'], $kw) == true) {
                        return;
                    }
                }
            }

            $unlisted = config('costar.domain.unlisted');
            if(in_array(parse_url($url, PHP_URL_HOST), $unlisted) == true) {
                $unlisted = true;
                $scope = 'unlisted';
            } else {
                $unlisted = false;
            }

            $cwDomains = config('costar.domain.cw');
            if(in_array(parse_url($url, PHP_URL_HOST), $cwDomains) == true) {
                $cw = true;
            }
        }

        $id = isset($res['id']) ? self::pluckval($res['id']) : self::pluckval($url);
        $idDomain = parse_url($id, PHP_URL_HOST);
        $urlDomain = parse_url($url, PHP_URL_HOST);

        if(!self::validateUrl($id)) {
            return;
        }

        if(!isset($activity['object']['attributedTo'])) {
            return;
        }

        $attributedTo = is_string($activity['object']['attributedTo']) ?
            $activity['object']['attributedTo'] :
            (is_array($activity['object']['attributedTo']) ?
                collect($activity['object']['attributedTo'])
                    ->filter(function($o) {
                        return $o && isset($o['type']) && $o['type'] == 'Person';
                    })
                    ->pluck('id')
                    ->first() : null
            );

        if($attributedTo) {
            $actorDomain = parse_url($attributedTo, PHP_URL_HOST);
            if(!self::validateUrl($attributedTo) ||
                $idDomain !== $actorDomain ||
                $actorDomain !== $urlDomain
            )
            {
                return;
            }
        }

        if($idDomain !== $urlDomain) {
            return;
        }

        $profile = self::profileFirstOrNew($attributedTo);

        if(!$profile) {
            return;
        }

        if(isset($activity['object']['inReplyTo']) && !empty($activity['object']['inReplyTo']) || $replyTo == true) {
            $reply_to = self::statusFirstOrFetch(self::pluckval($activity['object']['inReplyTo']), false);
            if($reply_to) {
                $blocks = UserFilterService::blocks($reply_to->profile_id);
                if(in_array($profile->id, $blocks)) {
                    return;
                }
            }
            $reply_to = optional($reply_to)->id;
        } else {
            $reply_to = null;
        }
        $ts = self::pluckval($res['published']);

        if($scope == 'public' && in_array($urlDomain, InstanceService::getUnlistedDomains())) {
            $scope = 'unlisted';
        }

        if(in_array($urlDomain, InstanceService::getNsfwDomains())) {
            $cw = true;
        }

        if($res['type'] === 'Question') {
            $status = self::storePoll(
                $profile,
                $res,
                $url,
                $ts,
                $reply_to,
                $cw,
                $scope,
                $id
            );
            return $status;
        } else {
            $status = self::storeStatus($url, $profile, $res);
        }

        return $status;
    }

    public static function storeStatus($url, $profile, $activity)
    {
        $id = isset($activity['id']) ? self::pluckval($activity['id']) : self::pluckval($activity['url']);
        $url = isset($activity['url']) && is_string($activity['url']) ? self::pluckval($activity['url']) : self::pluckval($id);
        $idDomain = parse_url($id, PHP_URL_HOST);
        $urlDomain = parse_url($url, PHP_URL_HOST);
        if(!self::validateUrl($id) || !self::validateUrl($url)) {
            return;
        }

        $reply_to = self::getReplyTo($activity);

        $ts = self::pluckval($activity['published']);
        $scope = self::getScope($activity, $url);
        $cw = self::getSensitive($activity, $url);
        $pid = is_object($profile) ? $profile->id : (is_array($profile) ? $profile['id'] : null);
        $isUnlisted = is_object($profile) ? $profile->unlisted : (is_array($profile) ? $profile['unlisted'] : false);
        $commentsDisabled = isset($activity['commentsEnabled']) ? !boolval($activity['commentsEnabled']) : false;

        if(!$pid) {
            return;
        }

        if($scope == 'public') {
            if($isUnlisted == true) {
                $scope = 'unlisted';
            }
        }

        $status = Status::updateOrCreate(
            [
                'uri' => $url
            ], [
                'profile_id' => $pid,
                'url' => $url,
                'object_url' => $id,
                'caption' => isset($activity['content']) ? Purify::clean(strip_tags($activity['content'])) : null,
                'rendered' => isset($activity['content']) ? Purify::clean($activity['content']) : null,
                'created_at' => Carbon::parse($ts)->tz('UTC'),
                'in_reply_to_id' => $reply_to,
                'local' => false,
                'is_nsfw' => $cw,
                'scope' => $scope,
                'visibility' => $scope,
                'cw_summary' => ($cw == true && isset($activity['summary']) ?
                    Purify::clean(strip_tags($activity['summary'])) : null),
                'comments_disabled' => $commentsDisabled
            ]
        );

        if($reply_to == null) {
            self::importNoteAttachment($activity, $status);
        } else {
            if(isset($activity['attachment']) && !empty($activity['attachment'])) {
                self::importNoteAttachment($activity, $status);
            }
            StatusReplyPipeline::dispatch($status);
        }

        if(isset($activity['tag']) && is_array($activity['tag']) && !empty($activity['tag'])) {
            StatusTagsPipeline::dispatch($activity, $status);
        }

        if( config('instance.timeline.network.cached') &&
            $status->in_reply_to_id === null &&
            $status->reblog_of_id === null &&
            in_array($status->type, ['photo', 'photo:album', 'video', 'video:album', 'photo:video:album']) &&
            $status->created_at->gt(now()->subHours(config('instance.timeline.network.max_hours_old'))) &&
            (config('instance.hide_nsfw_on_public_feeds') == true ? $status->is_nsfw == false : true)
        ) {
            $filteredDomains = collect(InstanceService::getBannedDomains())
                ->merge(InstanceService::getUnlistedDomains())
                ->unique()
                ->values()
                ->toArray();
            if(!in_array($urlDomain, $filteredDomains)) {
                if(!$isUnlisted) {
                    NetworkTimelineService::add($status->id);
                }
            }
        }

        IncrementPostCount::dispatch($pid)->onQueue('low');

        return $status;
    }

    public static function getSensitive($activity, $url)
    {
        $id = isset($activity['id']) ? self::pluckval($activity['id']) : self::pluckval($url);
        $url = isset($activity['url']) ? self::pluckval($activity['url']) : $id;
        $urlDomain = parse_url($url, PHP_URL_HOST);

        $cw = isset($activity['sensitive']) ? (bool) $activity['sensitive'] : false;

        if(in_array($urlDomain, InstanceService::getNsfwDomains())) {
            $cw = true;
        }

        return $cw;
    }

    public static function getReplyTo($activity)
    {
        $reply_to = null;
        $inReplyTo = isset($activity['inReplyTo']) && !empty($activity['inReplyTo']) ?
            self::pluckval($activity['inReplyTo']) :
            false;

        if($inReplyTo) {
            $reply_to = self::statusFirstOrFetch($inReplyTo);
            if($reply_to) {
                $reply_to = optional($reply_to)->id;
            }
        } else {
            $reply_to = null;
        }

        return $reply_to;
    }

    public static function getScope($activity, $url)
    {
        $id = isset($activity['id']) ? self::pluckval($activity['id']) : self::pluckval($url);
        $url = isset($activity['url']) ? self::pluckval($activity['url']) : self::pluckval($id);
        $urlDomain = parse_url(self::pluckval($url), PHP_URL_HOST);
        $scope = 'private';

        if(isset($activity['to']) == true) {
            if(is_array($activity['to']) && in_array('https://www.w3.org/ns/activitystreams#Public', $activity['to'])) {
                $scope = 'public';
            }
            if(is_string($activity['to']) && 'https://www.w3.org/ns/activitystreams#Public' == $activity['to']) {
                $scope = 'public';
            }
        }

        if(isset($activity['cc']) == true) {
            if(is_array($activity['cc']) && in_array('https://www.w3.org/ns/activitystreams#Public', $activity['cc'])) {
                $scope = 'unlisted';
            }
            if(is_string($activity['cc']) && 'https://www.w3.org/ns/activitystreams#Public' == $activity['cc']) {
                $scope = 'unlisted';
            }
        }

        if($scope == 'public' && in_array($urlDomain, InstanceService::getUnlistedDomains())) {
            $scope = 'unlisted';
        }

        return $scope;
    }

    private static function storePoll($profile, $res, $url, $ts, $reply_to, $cw, $scope, $id)
    {
        if(!isset($res['endTime']) || !isset($res['oneOf']) || !is_array($res['oneOf']) || count($res['oneOf']) > 4) {
            return;
        }

        $options = collect($res['oneOf'])->map(function($option) {
            return $option['name'];
        })->toArray();

        $cachedTallies = collect($res['oneOf'])->map(function($option) {
            return $option['replies']['totalItems'] ?? 0;
        })->toArray();

        $status = new Status;
        $status->profile_id = $profile->id;
        $status->url = isset($res['url']) ? $res['url'] : $url;
        $status->uri = isset($res['url']) ? $res['url'] : $url;
        $status->object_url = $id;
        $status->caption = strip_tags($res['content']);
        $status->rendered = Purify::clean($res['content']);
        $status->created_at = Carbon::parse($ts)->tz('UTC');
        $status->in_reply_to_id = null;
        $status->local = false;
        $status->is_nsfw = $cw;
        $status->scope = 'draft';
        $status->visibility = 'draft';
        $status->cw_summary = $cw == true && isset($res['summary']) ?
            Purify::clean(strip_tags($res['summary'])) : null;
        $status->save();

        $poll = new Poll;
        $poll->status_id = $status->id;
        $poll->profile_id = $status->profile_id;
        $poll->poll_options = $options;
        $poll->cached_tallies = $cachedTallies;
        $poll->votes_count = array_sum($cachedTallies);
        $poll->expires_at = now()->parse($res['endTime']);
        $poll->last_fetched_at = now();
        $poll->save();

        $status->type = 'poll';
        $status->scope = $scope;
        $status->visibility = $scope;
        $status->save();

        return $status;
    }

    public static function statusFetch($url)
    {
        return self::statusFirstOrFetch($url);
    }

    public static function importNoteAttachment($data, Status $status)
    {
        if(self::verifyAttachments($data) == false) {
            // \Log::info('importNoteAttachment::failedVerification.', [$data['id']]);
            $status->viewType();
            return;
        }
        $attachments = isset($data['object']) ? $data['object']['attachment'] : $data['attachment'];
        // peertube
        // if(!$attachments) {
        //  $obj = isset($data['object']) ? $data['object'] : $data;
        //  $attachments = is_array($obj['url']) ? $obj['url'] : null;
        // }
        $user = $status->profile;
        $storagePath = MediaPathService::get($user, 2);
        $allowed = explode(',', config_cache('pixelfed.media_types'));

        foreach($attachments as $key => $media) {
            $type = $media['mediaType'];
            $url = $media['url'];
            $valid = self::validateUrl($url);
            if(in_array($type, $allowed) == false || $valid == false) {
                continue;
            }
            $blurhash = isset($media['blurhash']) ? $media['blurhash'] : null;
            $license = isset($media['license']) ? License::nameToId($media['license']) : null;
            $caption = isset($media['name']) ? Purify::clean($media['name']) : null;
            $width = isset($media['width']) ? $media['width'] : false;
            $height = isset($media['height']) ? $media['height'] : false;

            $media = new Media();
            $media->blurhash = $blurhash;
            $media->remote_media = true;
            $media->status_id = $status->id;
            $media->profile_id = $status->profile_id;
            $media->user_id = null;
            $media->media_path = $url;
            $media->remote_url = $url;
            $media->caption = $caption;
            $media->order = $key + 1;
            if($width) {
                $media->width = $width;
            }
            if($height) {
                $media->height = $height;
            }
            if($license) {
                $media->license = $license;
            }
            $media->mime = $type;
            $media->version = 3;
            $media->save();

            if(config_cache('pixelfed.cloud_storage') == true) {
                MediaStoragePipeline::dispatch($media);
            }
        }

        $status->viewType();
        return;
    }

    public static function profileFirstOrNew($url)
    {
        $url = self::validateUrl($url);
        if($url == false) {
            return;
        }

        $host = parse_url($url, PHP_URL_HOST);
        $local = config('pixelfed.domain.app') == $host ? true : false;

        if($local == true) {
            $id = last(explode('/', $url));
            return Profile::whereNull('status')
                ->whereNull('domain')
                ->whereUsername($id)
                ->firstOrFail();
        }

        if($profile = Profile::whereRemoteUrl($url)->first()) {
            if($profile->last_fetched_at && $profile->last_fetched_at->lt(now()->subHours(24))) {
                return self::profileUpdateOrCreate($url);
            }
            return $profile;
        }

        return self::profileUpdateOrCreate($url);
    }

    public static function profileUpdateOrCreate($url)
    {
        $res = self::fetchProfileFromUrl($url);
        if(!$res || isset($res['id']) == false) {
            return;
        }
        $domain = parse_url($res['id'], PHP_URL_HOST);
        if(!isset($res['preferredUsername']) && !isset($res['nickname'])) {
            return;
        }
        $username = (string) Purify::clean($res['preferredUsername'] ?? $res['nickname']);
        if(empty($username)) {
            return;
        }
        $remoteUsername = $username;
        $webfinger = "@{$username}@{$domain}";

        if(!self::validateUrl($res['inbox'])) {
            return;
        }
        if(!self::validateUrl($res['id'])) {
            return;
        }

        $instance = Instance::updateOrCreate([
            'domain' => $domain
        ]);
        if($instance->wasRecentlyCreated == true) {
            \App\Jobs\InstancePipeline\FetchNodeinfoPipeline::dispatch($instance)->onQueue('low');
        }

        $profile = Profile::updateOrCreate(
            [
                'domain' => strtolower($domain),
                'username' => Purify::clean($webfinger),
            ],
            [
                'webfinger' => Purify::clean($webfinger),
                'key_id' => $res['publicKey']['id'],
                'remote_url' => $res['id'],
                'name' => isset($res['name']) ? Purify::clean($res['name']) : 'user',
                'bio' => isset($res['summary']) ? Purify::clean($res['summary']) : null,
                'sharedInbox' => isset($res['endpoints']) && isset($res['endpoints']['sharedInbox']) ? $res['endpoints']['sharedInbox'] : null,
                'inbox_url' => $res['inbox'],
                'outbox_url' => isset($res['outbox']) ? $res['outbox'] : null,
                'public_key' => $res['publicKey']['publicKeyPem'],
                'indexable' => isset($res['indexable']) && is_bool($res['indexable']) ? $res['indexable'] : false,
            ]
        );

        if( $profile->last_fetched_at == null ||
            $profile->last_fetched_at->lt(now()->subMonths(3))
        ) {
            RemoteAvatarFetch::dispatch($profile);
        }
        $profile->last_fetched_at = now();
        $profile->save();
        return $profile;
    }

    public static function profileFetch($url)
    {
        return self::profileFirstOrNew($url);
    }

    public static function sendSignedObject($profile, $url, $body)
    {
        ActivityPubDeliveryService::queue()
            ->from($profile)
            ->to($url)
            ->payload($body)
            ->send();
    }
}