2 activities::community::announce::AnnounceActivity,
4 fetch::fetch_remote_object,
6 person::get_or_fetch_and_upsert_person,
12 use activitystreams::{
14 collection::{CollectionExt, OrderedCollection},
17 use diesel::result::Error::NotFound;
18 use lemmy_api_common::blocking;
19 use lemmy_apub_lib::ActivityHandler;
20 use lemmy_db_queries::{source::community::Community_, ApubObject, Joinable};
21 use lemmy_db_schema::source::community::{Community, CommunityModerator, CommunityModeratorForm};
22 use lemmy_db_views_actor::community_moderator_view::CommunityModeratorView;
23 use lemmy_utils::{location_info, LemmyError};
24 use lemmy_websocket::LemmyContext;
28 /// Get a community from its apub ID.
30 /// If it exists locally and `!should_refetch_actor()`, it is returned directly from the database.
31 /// Otherwise it is fetched from the remote instance, stored and returned.
32 pub async fn get_or_fetch_and_upsert_community(
34 context: &LemmyContext,
35 recursion_counter: &mut i32,
36 ) -> Result<Community, LemmyError> {
37 let apub_id_owned = apub_id.to_owned();
38 let community = blocking(context.pool(), move |conn| {
39 Community::read_from_apub_id(conn, &apub_id_owned.into())
44 Ok(c) if !c.local && should_refetch_actor(c.last_refreshed_at) => {
45 debug!("Fetching and updating from remote community: {}", apub_id);
46 fetch_remote_community(apub_id, context, Some(c), recursion_counter).await
50 debug!("Fetching and creating remote community: {}", apub_id);
51 fetch_remote_community(apub_id, context, None, recursion_counter).await
53 Err(e) => Err(e.into()),
57 /// Request a community by apub ID from a remote instance, including moderators. If `old_community`,
58 /// is set, this is an update for a community which is already known locally. If not, we don't know
59 /// the community yet and also pull the outbox, to get some initial posts.
60 async fn fetch_remote_community(
62 context: &LemmyContext,
63 old_community: Option<Community>,
64 request_counter: &mut i32,
65 ) -> Result<Community, LemmyError> {
66 let group = fetch_remote_object::<GroupExt>(context.client(), apub_id, request_counter).await;
68 if let Some(c) = old_community.to_owned() {
69 if is_deleted(&group) {
70 blocking(context.pool(), move |conn| {
71 Community::update_deleted(conn, c.id, true)
74 } else if group.is_err() {
75 // If fetching failed, return the existing data.
82 Community::from_apub(&group, context, apub_id.to_owned(), request_counter, false).await?;
84 update_community_mods(&group, &community, context, request_counter).await?;
86 // only fetch outbox for new communities, otherwise this can create an infinite loop
87 if old_community.is_none() {
88 let outbox = group.inner.outbox()?.context(location_info!())?;
89 fetch_community_outbox(context, outbox, request_counter).await?
95 async fn update_community_mods(
97 community: &Community,
98 context: &LemmyContext,
99 request_counter: &mut i32,
100 ) -> Result<(), LemmyError> {
101 let new_moderators = fetch_community_mods(context, group, request_counter).await?;
102 let community_id = community.id;
103 let current_moderators = blocking(context.pool(), move |conn| {
104 CommunityModeratorView::for_community(conn, community_id)
107 // Remove old mods from database which arent in the moderators collection anymore
108 for mod_user in ¤t_moderators {
109 if !new_moderators.contains(&mod_user.moderator.actor_id.clone().into()) {
110 let community_moderator_form = CommunityModeratorForm {
111 community_id: mod_user.community.id,
112 person_id: mod_user.moderator.id,
114 blocking(context.pool(), move |conn| {
115 CommunityModerator::leave(conn, &community_moderator_form)
121 // Add new mods to database which have been added to moderators collection
122 for mod_uri in new_moderators {
123 let mod_user = get_or_fetch_and_upsert_person(&mod_uri, context, request_counter).await?;
125 if !current_moderators
128 .map(|c| c.moderator.actor_id.clone())
129 .any(|x| x == mod_user.actor_id)
131 let community_moderator_form = CommunityModeratorForm {
132 community_id: community.id,
133 person_id: mod_user.id,
135 blocking(context.pool(), move |conn| {
136 CommunityModerator::join(conn, &community_moderator_form)
145 async fn fetch_community_outbox(
146 context: &LemmyContext,
148 recursion_counter: &mut i32,
149 ) -> Result<(), LemmyError> {
151 fetch_remote_object::<OrderedCollection>(context.client(), outbox, recursion_counter).await?;
152 let outbox_activities = outbox.items().context(location_info!())?.clone();
153 let mut outbox_activities = outbox_activities.many().context(location_info!())?;
154 if outbox_activities.len() > 20 {
155 outbox_activities = outbox_activities[0..20].to_vec();
158 for announce in outbox_activities {
159 // TODO: instead of converting like this, we should create a struct CommunityOutbox with
160 // AnnounceActivity as inner type, but that gives me stackoverflow
161 let ser = serde_json::to_string(&announce)?;
162 let announce: AnnounceActivity = serde_json::from_str(&ser)?;
163 announce.receive(context, recursion_counter).await?;
169 pub(crate) async fn fetch_community_mods(
170 context: &LemmyContext,
172 recursion_counter: &mut i32,
173 ) -> Result<Vec<Url>, LemmyError> {
174 if let Some(mods_url) = &group.ext_one.moderators {
176 fetch_remote_object::<OrderedCollection>(context.client(), mods_url, recursion_counter)
180 .map(|i| i.as_many())
182 .context(location_info!())?
184 .filter_map(|i| i.as_xsd_any_uri())
185 .map(|u| u.to_owned())