From: Felix Ableitner <me@nutomic.com>
Date: Sat, 31 Jul 2021 14:57:37 +0000 (+0200)
Subject: Rewrite apub comment (de)serialization using structs (ref #1657)
X-Git-Url: http://these/git/%7B%60%24%7BwebArchiveUrl%7D/%22%7B%7D/%22https:/nerdica.net/static/README.zh.hant.md?a=commitdiff_plain;h=43ad99bbe8701f5a25620ac60e65f3615a270a18;p=lemmy.git

Rewrite apub comment (de)serialization using structs (ref #1657)
---

diff --git a/crates/api_crud/src/comment/create.rs b/crates/api_crud/src/comment/create.rs
index 7923b083..4418c14e 100644
--- a/crates/api_crud/src/comment/create.rs
+++ b/crates/api_crud/src/comment/create.rs
@@ -8,7 +8,12 @@ use lemmy_api_common::{
   get_post,
   send_local_notifs,
 };
-use lemmy_apub::{generate_apub_endpoint, ApubLikeableType, ApubObjectType, EndpointType};
+use lemmy_apub::{
+  activities::comment::create::CreateComment as CreateApubComment,
+  generate_apub_endpoint,
+  ApubLikeableType,
+  EndpointType,
+};
 use lemmy_db_queries::{source::comment::Comment_, Crud, Likeable};
 use lemmy_db_schema::source::comment::*;
 use lemmy_db_views::comment_view::CommentView;
@@ -83,9 +88,7 @@ impl PerformCrud for CreateComment {
       .await?
       .map_err(|_| ApiError::err("couldnt_create_comment"))?;
 
-    updated_comment
-      .send_create(&local_user_view.person, context)
-      .await?;
+    CreateApubComment::send(&updated_comment, &local_user_view.person, context).await?;
 
     // Scan the comment for user mentions, add those rows
     let post_id = post.id;
diff --git a/crates/api_crud/src/comment/update.rs b/crates/api_crud/src/comment/update.rs
index dbdb1a6d..4bd35884 100644
--- a/crates/api_crud/src/comment/update.rs
+++ b/crates/api_crud/src/comment/update.rs
@@ -7,7 +7,7 @@ use lemmy_api_common::{
   get_local_user_view_from_jwt,
   send_local_notifs,
 };
-use lemmy_apub::ApubObjectType;
+use lemmy_apub::activities::comment::update::UpdateComment;
 use lemmy_db_queries::{source::comment::Comment_, DeleteableOrRemoveable};
 use lemmy_db_schema::source::comment::*;
 use lemmy_db_views::comment_view::CommentView;
@@ -59,9 +59,7 @@ impl PerformCrud for EditComment {
     .map_err(|_| ApiError::err("couldnt_update_comment"))?;
 
     // Send the apub update
-    updated_comment
-      .send_update(&local_user_view.person, context)
-      .await?;
+    UpdateComment::send(&updated_comment, &local_user_view.person, context).await?;
 
     // Do the mentions / recipients
     let updated_comment_content = updated_comment.content.to_owned();
diff --git a/crates/apub/src/activities/comment/create.rs b/crates/apub/src/activities/comment/create.rs
index 0e947219..6c79dec4 100644
--- a/crates/apub/src/activities/comment/create.rs
+++ b/crates/apub/src/activities/comment/create.rs
@@ -1,22 +1,27 @@
 use crate::{
   activities::{
-    comment::{get_notif_recipients, send_websocket_message},
+    comment::{collect_non_local_mentions, get_notif_recipients, send_websocket_message},
+    community::announce::AnnouncableActivities,
     extract_community,
+    generate_activity_id,
     verify_activity,
     verify_person_in_community,
   },
-  objects::FromApub,
+  activity_queue::send_to_community_new,
+  extensions::context::lemmy_context,
+  objects::{comment::Note, FromApub, ToApub},
   ActorType,
-  NoteExt,
 };
-use activitystreams::{activity::kind::CreateType, base::BaseExt};
+use activitystreams::{activity::kind::CreateType, link::Mention};
+use lemmy_api_common::blocking;
 use lemmy_apub_lib::{
   values::PublicUrl,
-  verify_domains_match_opt,
+  verify_domains_match,
   ActivityCommonFields,
   ActivityHandler,
 };
-use lemmy_db_schema::source::comment::Comment;
+use lemmy_db_queries::Crud;
+use lemmy_db_schema::source::{comment::Comment, community::Community, person::Person, post::Post};
 use lemmy_utils::LemmyError;
 use lemmy_websocket::{LemmyContext, UserOperationCrud};
 use url::Url;
@@ -25,14 +30,51 @@ use url::Url;
 #[serde(rename_all = "camelCase")]
 pub struct CreateComment {
   to: PublicUrl,
-  object: NoteExt,
+  object: Note,
   cc: Vec<Url>,
+  tag: Vec<Mention>,
   #[serde(rename = "type")]
   kind: CreateType,
   #[serde(flatten)]
   common: ActivityCommonFields,
 }
 
+impl CreateComment {
+  pub async fn send(
+    comment: &Comment,
+    actor: &Person,
+    context: &LemmyContext,
+  ) -> Result<(), LemmyError> {
+    // TODO: would be helpful to add a comment method to retrieve community directly
+    let post_id = comment.post_id;
+    let post = blocking(context.pool(), move |conn| Post::read(conn, post_id)).await??;
+    let community_id = post.community_id;
+    let community = blocking(context.pool(), move |conn| {
+      Community::read(conn, community_id)
+    })
+    .await??;
+    let id = generate_activity_id(CreateType::Create)?;
+    let maa = collect_non_local_mentions(comment, &community, context).await?;
+
+    let create = CreateComment {
+      to: PublicUrl::Public,
+      object: comment.to_apub(context.pool()).await?,
+      cc: maa.ccs,
+      tag: maa.tags,
+      kind: Default::default(),
+      common: ActivityCommonFields {
+        context: lemmy_context(),
+        id: id.clone(),
+        actor: actor.actor_id(),
+        unparsed: Default::default(),
+      },
+    };
+
+    let activity = AnnouncableActivities::CreateComment(create);
+    send_to_community_new(activity, &id, actor, &community, maa.inboxes, context).await
+  }
+}
+
 #[async_trait::async_trait(?Send)]
 impl ActivityHandler for CreateComment {
   async fn verify(
@@ -50,9 +92,10 @@ impl ActivityHandler for CreateComment {
       request_counter,
     )
     .await?;
-    verify_domains_match_opt(&self.common.actor, self.object.id_unchecked())?;
+    verify_domains_match(&self.common.actor, &self.object.id)?;
     // TODO: should add a check that the correct community is in cc (probably needs changes to
     //       comment deserialization)
+    self.object.verify(context, request_counter).await?;
     Ok(())
   }
 
diff --git a/crates/apub/src/activities/comment/mod.rs b/crates/apub/src/activities/comment/mod.rs
index 292d57bf..1bf94ed6 100644
--- a/crates/apub/src/activities/comment/mod.rs
+++ b/crates/apub/src/activities/comment/mod.rs
@@ -1,14 +1,27 @@
-use crate::fetcher::person::get_or_fetch_and_upsert_person;
-use lemmy_api_common::{blocking, comment::CommentResponse, send_local_notifs};
-use lemmy_db_queries::Crud;
+use crate::{fetcher::person::get_or_fetch_and_upsert_person, ActorType};
+use activitystreams::{
+  base::BaseExt,
+  link::{LinkExt, Mention},
+};
+use anyhow::anyhow;
+use itertools::Itertools;
+use lemmy_api_common::{blocking, comment::CommentResponse, send_local_notifs, WebFingerResponse};
+use lemmy_db_queries::{Crud, DbPool};
 use lemmy_db_schema::{
-  source::{comment::Comment, post::Post},
+  source::{comment::Comment, community::Community, person::Person, post::Post},
   CommentId,
   LocalUserId,
 };
 use lemmy_db_views::comment_view::CommentView;
-use lemmy_utils::{utils::scrape_text_for_mentions, LemmyError};
+use lemmy_utils::{
+  request::{retry, RecvError},
+  settings::structs::Settings,
+  utils::{scrape_text_for_mentions, MentionData},
+  LemmyError,
+};
 use lemmy_websocket::{messages::SendComment, LemmyContext};
+use log::debug;
+use reqwest::Client;
 use url::Url;
 
 pub mod create;
@@ -63,3 +76,104 @@ pub(crate) async fn send_websocket_message<
 
   Ok(())
 }
+
+pub struct MentionsAndAddresses {
+  pub ccs: Vec<Url>,
+  pub inboxes: Vec<Url>,
+  pub tags: Vec<Mention>,
+}
+
+/// This takes a comment, and builds a list of to_addresses, inboxes,
+/// and mention tags, so they know where to be sent to.
+/// Addresses are the persons / addresses that go in the cc field.
+pub async fn collect_non_local_mentions(
+  comment: &Comment,
+  community: &Community,
+  context: &LemmyContext,
+) -> Result<MentionsAndAddresses, LemmyError> {
+  let parent_creator = get_comment_parent_creator(context.pool(), comment).await?;
+  let mut addressed_ccs = vec![community.actor_id(), parent_creator.actor_id()];
+  // Note: dont include community inbox here, as we send to it separately with `send_to_community()`
+  let mut inboxes = vec![parent_creator.get_shared_inbox_or_inbox_url()];
+
+  // Add the mention tag
+  let mut tags = Vec::new();
+
+  // Get the person IDs for any mentions
+  let mentions = scrape_text_for_mentions(&comment.content)
+    .into_iter()
+    // Filter only the non-local ones
+    .filter(|m| !m.is_local())
+    .collect::<Vec<MentionData>>();
+
+  for mention in &mentions {
+    // TODO should it be fetching it every time?
+    if let Ok(actor_id) = fetch_webfinger_url(mention, context.client()).await {
+      debug!("mention actor_id: {}", actor_id);
+      addressed_ccs.push(actor_id.to_owned().to_string().parse()?);
+
+      let mention_person = get_or_fetch_and_upsert_person(&actor_id, context, &mut 0).await?;
+      inboxes.push(mention_person.get_shared_inbox_or_inbox_url());
+
+      let mut mention_tag = Mention::new();
+      mention_tag.set_href(actor_id).set_name(mention.full_name());
+      tags.push(mention_tag);
+    }
+  }
+
+  let inboxes = inboxes.into_iter().unique().collect();
+
+  Ok(MentionsAndAddresses {
+    ccs: addressed_ccs,
+    inboxes,
+    tags,
+  })
+}
+
+/// Returns the apub ID of the person this comment is responding to. Meaning, in case this is a
+/// top-level comment, the creator of the post, otherwise the creator of the parent comment.
+async fn get_comment_parent_creator(
+  pool: &DbPool,
+  comment: &Comment,
+) -> Result<Person, LemmyError> {
+  let parent_creator_id = if let Some(parent_comment_id) = comment.parent_id {
+    let parent_comment =
+      blocking(pool, move |conn| Comment::read(conn, parent_comment_id)).await??;
+    parent_comment.creator_id
+  } else {
+    let parent_post_id = comment.post_id;
+    let parent_post = blocking(pool, move |conn| Post::read(conn, parent_post_id)).await??;
+    parent_post.creator_id
+  };
+  Ok(blocking(pool, move |conn| Person::read(conn, parent_creator_id)).await??)
+}
+
+/// Turns a person id like `@name@example.com` into an apub ID, like `https://example.com/user/name`,
+/// using webfinger.
+async fn fetch_webfinger_url(mention: &MentionData, client: &Client) -> Result<Url, LemmyError> {
+  let fetch_url = format!(
+    "{}://{}/.well-known/webfinger?resource=acct:{}@{}",
+    Settings::get().get_protocol_string(),
+    mention.domain,
+    mention.name,
+    mention.domain
+  );
+  debug!("Fetching webfinger url: {}", &fetch_url);
+
+  let response = retry(|| client.get(&fetch_url).send()).await?;
+
+  let res: WebFingerResponse = response
+    .json()
+    .await
+    .map_err(|e| RecvError(e.to_string()))?;
+
+  let link = res
+    .links
+    .iter()
+    .find(|l| l.type_.eq(&Some("application/activity+json".to_string())))
+    .ok_or_else(|| anyhow!("No application/activity+json link found."))?;
+  link
+    .href
+    .to_owned()
+    .ok_or_else(|| anyhow!("No href found.").into())
+}
diff --git a/crates/apub/src/activities/comment/remove.rs b/crates/apub/src/activities/comment/remove.rs
deleted file mode 100644
index 5702f9fa..00000000
--- a/crates/apub/src/activities/comment/remove.rs
+++ /dev/null
@@ -1,64 +0,0 @@
-use crate::{
-  activities::{comment::send_websocket_message, verify_mod_action},
-  check_is_apub_id_valid,
-  fetcher::objects::get_or_fetch_and_insert_comment,
-};
-use activitystreams::activity::kind::RemoveType;
-use lemmy_api_common::blocking;
-use lemmy_apub_lib::{
-  values::PublicUrl,
-  verify_domains_match,
-  ActivityCommonFields,
-  ActivityHandlerNew,
-};
-use lemmy_db_queries::source::comment::Comment_;
-use lemmy_db_schema::source::comment::Comment;
-use lemmy_utils::LemmyError;
-use lemmy_websocket::{LemmyContext, UserOperationCrud};
-use url::Url;
-
-#[derive(Clone, Debug, serde::Deserialize, serde::Serialize)]
-#[serde(rename_all = "camelCase")]
-pub struct RemoveComment {
-  to: PublicUrl,
-  pub(in crate::activities::comment) object: Url,
-  cc: [Url; 1],
-  #[serde(rename = "type")]
-  kind: RemoveType,
-  #[serde(flatten)]
-  common: ActivityCommonFields,
-}
-
-#[async_trait::async_trait(?Send)]
-impl ActivityHandlerNew for RemoveComment {
-  async fn verify(&self, context: &LemmyContext, _: &mut i32) -> Result<(), LemmyError> {
-    verify_domains_match(&self.common.actor, self.common.id_unchecked())?;
-    check_is_apub_id_valid(&self.common.actor, false)?;
-    verify_mod_action(&self.common.actor, self.cc[0].clone(), context).await
-  }
-
-  async fn receive(
-    &self,
-    context: &LemmyContext,
-    request_counter: &mut i32,
-  ) -> Result<(), LemmyError> {
-    let comment = get_or_fetch_and_insert_comment(&self.object, context, request_counter).await?;
-
-    let removed_comment = blocking(context.pool(), move |conn| {
-      Comment::update_removed(conn, comment.id, true)
-    })
-    .await??;
-
-    send_websocket_message(
-      removed_comment.id,
-      vec![],
-      UserOperationCrud::EditComment,
-      context,
-    )
-    .await
-  }
-
-  fn common(&self) -> &ActivityCommonFields {
-    &self.common
-  }
-}
diff --git a/crates/apub/src/activities/comment/undo_remove.rs b/crates/apub/src/activities/comment/undo_remove.rs
deleted file mode 100644
index 07aa6711..00000000
--- a/crates/apub/src/activities/comment/undo_remove.rs
+++ /dev/null
@@ -1,73 +0,0 @@
-use crate::{
-  activities::{
-    comment::{remove::RemoveComment, send_websocket_message},
-    verify_mod_action,
-  },
-  check_is_apub_id_valid,
-  fetcher::objects::get_or_fetch_and_insert_comment,
-};
-use activitystreams::activity::kind::UndoType;
-use lemmy_api_common::blocking;
-use lemmy_apub_lib::{
-  values::PublicUrl,
-  verify_domains_match,
-  ActivityCommonFields,
-  ActivityHandlerNew,
-};
-use lemmy_db_queries::source::comment::Comment_;
-use lemmy_db_schema::source::comment::Comment;
-use lemmy_utils::LemmyError;
-use lemmy_websocket::{LemmyContext, UserOperationCrud};
-use url::Url;
-
-#[derive(Clone, Debug, serde::Deserialize, serde::Serialize)]
-#[serde(rename_all = "camelCase")]
-pub struct UndoRemoveComment {
-  to: PublicUrl,
-  object: RemoveComment,
-  cc: [Url; 1],
-  #[serde(rename = "type")]
-  kind: UndoType,
-  #[serde(flatten)]
-  common: ActivityCommonFields,
-}
-
-#[async_trait::async_trait(?Send)]
-impl ActivityHandlerNew for UndoRemoveComment {
-  async fn verify(
-    &self,
-    context: &LemmyContext,
-    request_counter: &mut i32,
-  ) -> Result<(), LemmyError> {
-    verify_domains_match(&self.common.actor, self.common.id_unchecked())?;
-    check_is_apub_id_valid(&self.common.actor, false)?;
-    verify_mod_action(&self.common.actor, self.cc[0].clone(), context).await?;
-    self.object.verify(context, request_counter).await
-  }
-
-  async fn receive(
-    &self,
-    context: &LemmyContext,
-    request_counter: &mut i32,
-  ) -> Result<(), LemmyError> {
-    let comment =
-      get_or_fetch_and_insert_comment(&self.object.object, context, request_counter).await?;
-
-    let removed_comment = blocking(context.pool(), move |conn| {
-      Comment::update_removed(conn, comment.id, false)
-    })
-    .await??;
-
-    send_websocket_message(
-      removed_comment.id,
-      vec![],
-      UserOperationCrud::EditComment,
-      context,
-    )
-    .await
-  }
-
-  fn common(&self) -> &ActivityCommonFields {
-    &self.common
-  }
-}
diff --git a/crates/apub/src/activities/comment/update.rs b/crates/apub/src/activities/comment/update.rs
index c0d01481..8dd44b80 100644
--- a/crates/apub/src/activities/comment/update.rs
+++ b/crates/apub/src/activities/comment/update.rs
@@ -1,22 +1,27 @@
 use crate::{
   activities::{
-    comment::{get_notif_recipients, send_websocket_message},
+    comment::{collect_non_local_mentions, get_notif_recipients, send_websocket_message},
+    community::announce::AnnouncableActivities,
     extract_community,
+    generate_activity_id,
     verify_activity,
     verify_person_in_community,
   },
-  objects::FromApub,
+  activity_queue::send_to_community_new,
+  extensions::context::lemmy_context,
+  objects::{comment::Note, FromApub, ToApub},
   ActorType,
-  NoteExt,
 };
-use activitystreams::{activity::kind::UpdateType, base::BaseExt};
+use activitystreams::{activity::kind::UpdateType, link::Mention};
+use lemmy_api_common::blocking;
 use lemmy_apub_lib::{
   values::PublicUrl,
-  verify_domains_match_opt,
+  verify_domains_match,
   ActivityCommonFields,
   ActivityHandler,
 };
-use lemmy_db_schema::source::comment::Comment;
+use lemmy_db_queries::Crud;
+use lemmy_db_schema::source::{comment::Comment, community::Community, person::Person, post::Post};
 use lemmy_utils::LemmyError;
 use lemmy_websocket::{LemmyContext, UserOperationCrud};
 use url::Url;
@@ -25,14 +30,51 @@ use url::Url;
 #[serde(rename_all = "camelCase")]
 pub struct UpdateComment {
   to: PublicUrl,
-  object: NoteExt,
+  object: Note,
   cc: Vec<Url>,
+  tag: Vec<Mention>,
   #[serde(rename = "type")]
   kind: UpdateType,
   #[serde(flatten)]
   common: ActivityCommonFields,
 }
 
+impl UpdateComment {
+  pub async fn send(
+    comment: &Comment,
+    actor: &Person,
+    context: &LemmyContext,
+  ) -> Result<(), LemmyError> {
+    // TODO: would be helpful to add a comment method to retrieve community directly
+    let post_id = comment.post_id;
+    let post = blocking(context.pool(), move |conn| Post::read(conn, post_id)).await??;
+    let community_id = post.community_id;
+    let community = blocking(context.pool(), move |conn| {
+      Community::read(conn, community_id)
+    })
+    .await??;
+    let id = generate_activity_id(UpdateType::Update)?;
+    let maa = collect_non_local_mentions(comment, &community, context).await?;
+
+    let update = UpdateComment {
+      to: PublicUrl::Public,
+      object: comment.to_apub(context.pool()).await?,
+      cc: maa.ccs,
+      tag: maa.tags,
+      kind: Default::default(),
+      common: ActivityCommonFields {
+        context: lemmy_context(),
+        id: id.clone(),
+        actor: actor.actor_id(),
+        unparsed: Default::default(),
+      },
+    };
+
+    let activity = AnnouncableActivities::UpdateComment(update);
+    send_to_community_new(activity, &id, actor, &community, maa.inboxes, context).await
+  }
+}
+
 #[async_trait::async_trait(?Send)]
 impl ActivityHandler for UpdateComment {
   async fn verify(
@@ -50,7 +92,8 @@ impl ActivityHandler for UpdateComment {
       request_counter,
     )
     .await?;
-    verify_domains_match_opt(&self.common.actor, self.object.id_unchecked())?;
+    verify_domains_match(&self.common.actor, &self.object.id)?;
+    self.object.verify(context, request_counter).await?;
     Ok(())
   }
 
diff --git a/crates/apub/src/activities/mod.rs b/crates/apub/src/activities/mod.rs
index af133167..d8eaa0e7 100644
--- a/crates/apub/src/activities/mod.rs
+++ b/crates/apub/src/activities/mod.rs
@@ -61,7 +61,7 @@ pub(crate) async fn extract_community(
 
 /// Fetches the person and community to verify their type, then checks if person is banned from site
 /// or community.
-async fn verify_person_in_community(
+pub(crate) async fn verify_person_in_community(
   person_id: &Url,
   community_id: &Url,
   context: &LemmyContext,
diff --git a/crates/apub/src/activities/send/comment.rs b/crates/apub/src/activities/send/comment.rs
index 47fc2a3e..619d59b1 100644
--- a/crates/apub/src/activities/send/comment.rs
+++ b/crates/apub/src/activities/send/comment.rs
@@ -1,112 +1,45 @@
 use crate::{
   activities::generate_activity_id,
-  activity_queue::{send_comment_mentions, send_to_community},
+  activity_queue::send_to_community,
   extensions::context::lemmy_context,
-  fetcher::person::get_or_fetch_and_upsert_person,
-  objects::ToApub,
   ActorType,
   ApubLikeableType,
   ApubObjectType,
 };
 use activitystreams::{
   activity::{
-    kind::{CreateType, DeleteType, DislikeType, LikeType, RemoveType, UndoType, UpdateType},
-    Create,
+    kind::{DeleteType, DislikeType, LikeType, RemoveType, UndoType},
     Delete,
     Dislike,
     Like,
     Remove,
     Undo,
-    Update,
   },
-  base::AnyBase,
-  link::Mention,
   prelude::*,
   public,
 };
-use anyhow::anyhow;
-use itertools::Itertools;
-use lemmy_api_common::{blocking, WebFingerResponse};
-use lemmy_db_queries::{Crud, DbPool};
+use lemmy_api_common::blocking;
+use lemmy_db_queries::Crud;
 use lemmy_db_schema::source::{comment::Comment, community::Community, person::Person, post::Post};
-use lemmy_utils::{
-  request::{retry, RecvError},
-  settings::structs::Settings,
-  utils::{scrape_text_for_mentions, MentionData},
-  LemmyError,
-};
+use lemmy_utils::LemmyError;
 use lemmy_websocket::LemmyContext;
-use log::debug;
-use reqwest::Client;
-use serde_json::Error;
-use url::Url;
 
 #[async_trait::async_trait(?Send)]
 impl ApubObjectType for Comment {
-  /// Send out information about a newly created comment, to the followers of the community and
-  /// mentioned persons.
-  async fn send_create(&self, creator: &Person, context: &LemmyContext) -> Result<(), LemmyError> {
-    let note = self.to_apub(context.pool()).await?;
-
-    let post_id = self.post_id;
-    let post = blocking(context.pool(), move |conn| Post::read(conn, post_id)).await??;
-
-    let community_id = post.community_id;
-    let community = blocking(context.pool(), move |conn| {
-      Community::read(conn, community_id)
-    })
-    .await??;
-
-    let maa = collect_non_local_mentions(self, &community, context).await?;
-
-    let mut create = Create::new(
-      creator.actor_id.to_owned().into_inner(),
-      note.into_any_base()?,
-    );
-    create
-      .set_many_contexts(lemmy_context())
-      .set_id(generate_activity_id(CreateType::Create)?)
-      .set_to(public())
-      .set_many_ccs(maa.ccs.to_owned())
-      // Set the mention tags
-      .set_many_tags(maa.get_tags()?);
-
-    send_to_community(create.clone(), creator, &community, None, context).await?;
-    send_comment_mentions(creator, maa.inboxes, create, context).await?;
-    Ok(())
+  async fn send_create(
+    &self,
+    _creator: &Person,
+    _context: &LemmyContext,
+  ) -> Result<(), LemmyError> {
+    unimplemented!()
   }
 
-  /// Send out information about an edited post, to the followers of the community and mentioned
-  /// persons.
-  async fn send_update(&self, creator: &Person, context: &LemmyContext) -> Result<(), LemmyError> {
-    let note = self.to_apub(context.pool()).await?;
-
-    let post_id = self.post_id;
-    let post = blocking(context.pool(), move |conn| Post::read(conn, post_id)).await??;
-
-    let community_id = post.community_id;
-    let community = blocking(context.pool(), move |conn| {
-      Community::read(conn, community_id)
-    })
-    .await??;
-
-    let maa = collect_non_local_mentions(self, &community, context).await?;
-
-    let mut update = Update::new(
-      creator.actor_id.to_owned().into_inner(),
-      note.into_any_base()?,
-    );
-    update
-      .set_many_contexts(lemmy_context())
-      .set_id(generate_activity_id(UpdateType::Update)?)
-      .set_to(public())
-      .set_many_ccs(maa.ccs.to_owned())
-      // Set the mention tags
-      .set_many_tags(maa.get_tags()?);
-
-    send_to_community(update.clone(), creator, &community, None, context).await?;
-    send_comment_mentions(creator, maa.inboxes, update, context).await?;
-    Ok(())
+  async fn send_update(
+    &self,
+    _creator: &Person,
+    _context: &LemmyContext,
+  ) -> Result<(), LemmyError> {
+    unimplemented!()
   }
 
   async fn send_delete(&self, creator: &Person, context: &LemmyContext) -> Result<(), LemmyError> {
@@ -327,114 +260,3 @@ impl ApubLikeableType for Comment {
     Ok(())
   }
 }
-
-struct MentionsAndAddresses {
-  ccs: Vec<Url>,
-  inboxes: Vec<Url>,
-  tags: Vec<Mention>,
-}
-
-impl MentionsAndAddresses {
-  fn get_tags(&self) -> Result<Vec<AnyBase>, Error> {
-    self
-      .tags
-      .iter()
-      .map(|t| t.to_owned().into_any_base())
-      .collect::<Result<Vec<AnyBase>, Error>>()
-  }
-}
-
-/// This takes a comment, and builds a list of to_addresses, inboxes,
-/// and mention tags, so they know where to be sent to.
-/// Addresses are the persons / addresses that go in the cc field.
-async fn collect_non_local_mentions(
-  comment: &Comment,
-  community: &Community,
-  context: &LemmyContext,
-) -> Result<MentionsAndAddresses, LemmyError> {
-  let parent_creator = get_comment_parent_creator(context.pool(), comment).await?;
-  let mut addressed_ccs = vec![community.actor_id(), parent_creator.actor_id()];
-  // Note: dont include community inbox here, as we send to it separately with `send_to_community()`
-  let mut inboxes = vec![parent_creator.get_shared_inbox_or_inbox_url()];
-
-  // Add the mention tag
-  let mut tags = Vec::new();
-
-  // Get the person IDs for any mentions
-  let mentions = scrape_text_for_mentions(&comment.content)
-    .into_iter()
-    // Filter only the non-local ones
-    .filter(|m| !m.is_local())
-    .collect::<Vec<MentionData>>();
-
-  for mention in &mentions {
-    // TODO should it be fetching it every time?
-    if let Ok(actor_id) = fetch_webfinger_url(mention, context.client()).await {
-      debug!("mention actor_id: {}", actor_id);
-      addressed_ccs.push(actor_id.to_owned().to_string().parse()?);
-
-      let mention_person = get_or_fetch_and_upsert_person(&actor_id, context, &mut 0).await?;
-      inboxes.push(mention_person.get_shared_inbox_or_inbox_url());
-
-      let mut mention_tag = Mention::new();
-      mention_tag.set_href(actor_id).set_name(mention.full_name());
-      tags.push(mention_tag);
-    }
-  }
-
-  let inboxes = inboxes.into_iter().unique().collect();
-
-  Ok(MentionsAndAddresses {
-    ccs: addressed_ccs,
-    inboxes,
-    tags,
-  })
-}
-
-/// Returns the apub ID of the person this comment is responding to. Meaning, in case this is a
-/// top-level comment, the creator of the post, otherwise the creator of the parent comment.
-async fn get_comment_parent_creator(
-  pool: &DbPool,
-  comment: &Comment,
-) -> Result<Person, LemmyError> {
-  let parent_creator_id = if let Some(parent_comment_id) = comment.parent_id {
-    let parent_comment =
-      blocking(pool, move |conn| Comment::read(conn, parent_comment_id)).await??;
-    parent_comment.creator_id
-  } else {
-    let parent_post_id = comment.post_id;
-    let parent_post = blocking(pool, move |conn| Post::read(conn, parent_post_id)).await??;
-    parent_post.creator_id
-  };
-  Ok(blocking(pool, move |conn| Person::read(conn, parent_creator_id)).await??)
-}
-
-/// Turns a person id like `@name@example.com` into an apub ID, like `https://example.com/user/name`,
-/// using webfinger.
-async fn fetch_webfinger_url(mention: &MentionData, client: &Client) -> Result<Url, LemmyError> {
-  let fetch_url = format!(
-    "{}://{}/.well-known/webfinger?resource=acct:{}@{}",
-    Settings::get().get_protocol_string(),
-    mention.domain,
-    mention.name,
-    mention.domain
-  );
-  debug!("Fetching webfinger url: {}", &fetch_url);
-
-  let response = retry(|| client.get(&fetch_url).send()).await?;
-
-  let res: WebFingerResponse = response
-    .json()
-    .await
-    .map_err(|e| RecvError(e.to_string()))?;
-
-  let link = res
-    .links
-    .iter()
-    .find(|l| l.type_.eq(&Some("application/activity+json".to_string())))
-    .ok_or_else(|| anyhow!("No application/activity+json link found."))?;
-  link
-    .href
-    .to_owned()
-    .ok_or_else(|| anyhow!("No href found.").into())
-}
diff --git a/crates/apub/src/activity_queue.rs b/crates/apub/src/activity_queue.rs
index f4f8ce90..3f8a019f 100644
--- a/crates/apub/src/activity_queue.rs
+++ b/crates/apub/src/activity_queue.rs
@@ -138,40 +138,6 @@ where
   Ok(())
 }
 
-/// Sends notification to any persons mentioned in a comment
-///
-/// * `creator` person who created the comment
-/// * `mentions` list of inboxes of persons which are mentioned in the comment
-/// * `activity` either a `Create/Note` or `Update/Note`
-pub(crate) async fn send_comment_mentions<T, Kind>(
-  creator: &Person,
-  mentions: Vec<Url>,
-  activity: T,
-  context: &LemmyContext,
-) -> Result<(), LemmyError>
-where
-  T: AsObject<Kind> + Extends<Kind> + Debug + BaseExt<Kind>,
-  Kind: Serialize,
-  <T as Extends<Kind>>::Error: From<serde_json::Error> + Send + Sync + 'static,
-{
-  debug!(
-    "Sending mentions activity {:?} to {:?}",
-    &activity.id_unchecked(),
-    &mentions
-  );
-  let mentions = mentions
-    .iter()
-    .filter(|inbox| check_is_apub_id_valid(inbox, false).is_ok())
-    .map(|i| i.to_owned())
-    .collect();
-  send_activity_internal(
-    context, activity, creator, mentions, false, // Don't create a new DB row
-    false,
-  )
-  .await?;
-  Ok(())
-}
-
 pub(crate) async fn send_to_community_new(
   activity: AnnouncableActivities,
   activity_id: &Url,
diff --git a/crates/apub/src/fetcher/objects.rs b/crates/apub/src/fetcher/objects.rs
index fd94f649..a06b99d6 100644
--- a/crates/apub/src/fetcher/objects.rs
+++ b/crates/apub/src/fetcher/objects.rs
@@ -1,7 +1,6 @@
 use crate::{
   fetcher::fetch::fetch_remote_object,
-  objects::{post::Page, FromApub},
-  NoteExt,
+  objects::{comment::Note, post::Page, FromApub},
   PostOrComment,
 };
 use anyhow::anyhow;
@@ -73,7 +72,7 @@ pub async fn get_or_fetch_and_insert_comment(
         comment_ap_id
       );
       let comment =
-        fetch_remote_object::<NoteExt>(context.client(), comment_ap_id, recursion_counter).await?;
+        fetch_remote_object::<Note>(context.client(), comment_ap_id, recursion_counter).await?;
       let comment = Comment::from_apub(
         &comment,
         context,
diff --git a/crates/apub/src/fetcher/search.rs b/crates/apub/src/fetcher/search.rs
index 69076c15..647d057a 100644
--- a/crates/apub/src/fetcher/search.rs
+++ b/crates/apub/src/fetcher/search.rs
@@ -6,9 +6,8 @@ use crate::{
     is_deleted,
   },
   find_object_by_id,
-  objects::{post::Page, FromApub},
+  objects::{comment::Note, post::Page, FromApub},
   GroupExt,
-  NoteExt,
   Object,
   PersonExt,
 };
@@ -46,7 +45,7 @@ enum SearchAcceptedObjects {
   Person(Box<PersonExt>),
   Group(Box<GroupExt>),
   Page(Box<Page>),
-  Comment(Box<NoteExt>),
+  Comment(Box<Note>),
 }
 
 /// Attempt to parse the query as URL, and fetch an ActivityPub object from it.
diff --git a/crates/apub/src/objects/comment.rs b/crates/apub/src/objects/comment.rs
index 8501ea2a..c97ea994 100644
--- a/crates/apub/src/objects/comment.rs
+++ b/crates/apub/src/objects/comment.rs
@@ -1,29 +1,24 @@
 use crate::{
+  activities::verify_person_in_community,
   extensions::context::lemmy_context,
   fetcher::objects::{get_or_fetch_and_insert_comment, get_or_fetch_and_insert_post},
-  get_community_from_to_or_cc,
-  objects::{
-    check_object_domain,
-    check_object_for_community_or_site_ban,
-    create_tombstone,
-    get_object_from_apub,
-    get_or_fetch_and_upsert_person,
-    get_source_markdown_value,
-    set_content_and_source,
-    FromApub,
-    FromApubToForm,
-    ToApub,
-  },
-  NoteExt,
+  objects::{create_tombstone, get_or_fetch_and_upsert_person, FromApub, Source, ToApub},
+  ActorType,
 };
 use activitystreams::{
-  object::{kind::NoteType, ApObject, Note, Tombstone},
-  prelude::*,
-  public,
+  base::AnyBase,
+  object::{kind::NoteType, Tombstone},
+  primitives::OneOrMany,
+  unparsed::Unparsed,
 };
 use anyhow::{anyhow, Context};
+use chrono::{DateTime, FixedOffset};
 use lemmy_api_common::blocking;
-use lemmy_db_queries::{Crud, DbPool};
+use lemmy_apub_lib::{
+  values::{MediaTypeHtml, MediaTypeMarkdown, PublicUrl},
+  verify_domains_match,
+};
+use lemmy_db_queries::{ApubObject, Crud, DbPool};
 use lemmy_db_schema::{
   source::{
     comment::{Comment, CommentForm},
@@ -39,24 +34,103 @@ use lemmy_utils::{
   LemmyError,
 };
 use lemmy_websocket::LemmyContext;
+use serde::{Deserialize, Serialize};
 use url::Url;
 
+#[derive(Clone, Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Note {
+  #[serde(rename = "@context")]
+  context: OneOrMany<AnyBase>,
+  r#type: NoteType,
+  pub(crate) id: Url,
+  pub(crate) attributed_to: Url,
+  /// Indicates that the object is publicly readable. Unlike [`Post.to`], this one doesn't contain
+  /// the community ID, as it would be incompatible with Pleroma (and we can get the community from
+  /// the post in [`in_reply_to`]).
+  to: PublicUrl,
+  content: String,
+  media_type: MediaTypeHtml,
+  source: Source,
+  in_reply_to: Vec<Url>,
+  published: DateTime<FixedOffset>,
+  updated: Option<DateTime<FixedOffset>>,
+  #[serde(flatten)]
+  unparsed: Unparsed,
+}
+
+impl Note {
+  async fn get_parents(
+    &self,
+    context: &LemmyContext,
+    request_counter: &mut i32,
+  ) -> Result<(Post, Option<CommentId>), LemmyError> {
+    // This post, or the parent comment might not yet exist on this server yet, fetch them.
+    let post_id = self.in_reply_to.get(0).context(location_info!())?;
+    let post = Box::pin(get_or_fetch_and_insert_post(
+      post_id,
+      context,
+      request_counter,
+    ))
+    .await?;
+
+    // The 2nd item, if it exists, is the parent comment apub_id
+    // Nested comments will automatically get fetched recursively
+    let parent_id: Option<CommentId> = match self.in_reply_to.get(1) {
+      Some(parent_comment_uri) => {
+        let parent_comment = Box::pin(get_or_fetch_and_insert_comment(
+          parent_comment_uri,
+          context,
+          request_counter,
+        ))
+        .await?;
+
+        Some(parent_comment.id)
+      }
+      None => None,
+    };
+
+    Ok((post, parent_id))
+  }
+
+  pub(crate) async fn verify(
+    &self,
+    context: &LemmyContext,
+    request_counter: &mut i32,
+  ) -> Result<(), LemmyError> {
+    let (post, _parent_comment_id) = self.get_parents(context, request_counter).await?;
+    let community_id = post.community_id;
+    let community = blocking(context.pool(), move |conn| {
+      Community::read(conn, community_id)
+    })
+    .await??;
+
+    if post.locked {
+      return Err(anyhow!("Post is locked").into());
+    }
+    verify_domains_match(&self.attributed_to, &self.id)?;
+    verify_person_in_community(
+      &self.attributed_to,
+      &community.actor_id(),
+      context,
+      request_counter,
+    )
+    .await?;
+    Ok(())
+  }
+}
+
 #[async_trait::async_trait(?Send)]
 impl ToApub for Comment {
-  type ApubType = NoteExt;
-
-  async fn to_apub(&self, pool: &DbPool) -> Result<NoteExt, LemmyError> {
-    let mut comment = ApObject::new(Note::new());
+  type ApubType = Note;
 
+  async fn to_apub(&self, pool: &DbPool) -> Result<Note, LemmyError> {
     let creator_id = self.creator_id;
     let creator = blocking(pool, move |conn| Person::read(conn, creator_id)).await??;
 
     let post_id = self.post_id;
     let post = blocking(pool, move |conn| Post::read(conn, post_id)).await??;
 
-    let community_id = post.community_id;
-    let community = blocking(pool, move |conn| Community::read(conn, community_id)).await??;
-
     // Add a vector containing some important info to the "in_reply_to" field
     // [post_ap_id, Option(parent_comment_ap_id)]
     let mut in_reply_to_vec = vec![post.ap_id.into_inner()];
@@ -67,23 +141,25 @@ impl ToApub for Comment {
       in_reply_to_vec.push(parent_comment.ap_id.into_inner());
     }
 
-    comment
-      // Not needed when the Post is embedded in a collection (like for community outbox)
-      .set_many_contexts(lemmy_context())
-      .set_id(self.ap_id.to_owned().into_inner())
-      .set_published(convert_datetime(self.published))
-      // NOTE: included community id for compatibility with lemmy v0.9.9
-      .set_many_tos(vec![community.actor_id.into_inner(), public()])
-      .set_many_in_reply_tos(in_reply_to_vec)
-      .set_attributed_to(creator.actor_id.into_inner());
-
-    set_content_and_source(&mut comment, &self.content)?;
-
-    if let Some(u) = self.updated {
-      comment.set_updated(convert_datetime(u));
-    }
+    let note = Note {
+      context: lemmy_context(),
+      r#type: NoteType::Note,
+      id: self.ap_id.to_owned().into_inner(),
+      attributed_to: creator.actor_id.into_inner(),
+      to: PublicUrl::Public,
+      content: self.content.clone(),
+      media_type: MediaTypeHtml::Html,
+      source: Source {
+        content: self.content.clone(),
+        media_type: MediaTypeMarkdown::Markdown,
+      },
+      in_reply_to: in_reply_to_vec,
+      published: convert_datetime(self.published),
+      updated: self.updated.map(convert_datetime),
+      unparsed: Default::default(),
+    };
 
-    Ok(comment)
+    Ok(note)
   }
 
   fn to_tombstone(&self) -> Result<Tombstone, LemmyError> {
@@ -98,108 +174,38 @@ impl ToApub for Comment {
 
 #[async_trait::async_trait(?Send)]
 impl FromApub for Comment {
-  type ApubType = NoteExt;
+  type ApubType = Note;
 
   /// Converts a `Note` to `Comment`.
   ///
   /// If the parent community, post and comment(s) are not known locally, these are also fetched.
   async fn from_apub(
-    note: &NoteExt,
+    note: &Note,
     context: &LemmyContext,
-    expected_domain: Url,
-    request_counter: &mut i32,
-    mod_action_allowed: bool,
-  ) -> Result<Comment, LemmyError> {
-    let comment: Comment = get_object_from_apub(
-      note,
-      context,
-      expected_domain,
-      request_counter,
-      mod_action_allowed,
-    )
-    .await?;
-
-    let post_id = comment.post_id;
-    let post = blocking(context.pool(), move |conn| Post::read(conn, post_id)).await??;
-    check_object_for_community_or_site_ban(note, post.community_id, context, request_counter)
-      .await?;
-    Ok(comment)
-  }
-}
-
-#[async_trait::async_trait(?Send)]
-impl FromApubToForm<NoteExt> for CommentForm {
-  async fn from_apub(
-    note: &NoteExt,
-    context: &LemmyContext,
-    expected_domain: Url,
+    _expected_domain: Url,
     request_counter: &mut i32,
     _mod_action_allowed: bool,
-  ) -> Result<CommentForm, LemmyError> {
-    let community = get_community_from_to_or_cc(note, context, request_counter).await?;
-    let ap_id = Some(check_object_domain(note, expected_domain, community.local)?);
-    let creator_actor_id = &note
-      .attributed_to()
-      .context(location_info!())?
-      .as_single_xsd_any_uri()
-      .context(location_info!())?;
-
+  ) -> Result<Comment, LemmyError> {
     let creator =
-      get_or_fetch_and_upsert_person(creator_actor_id, context, request_counter).await?;
-
-    let mut in_reply_tos = note
-      .in_reply_to()
-      .as_ref()
-      .context(location_info!())?
-      .as_many()
-      .context(location_info!())?
-      .iter()
-      .map(|i| i.as_xsd_any_uri().context(""));
-    let post_ap_id = in_reply_tos.next().context(location_info!())??;
+      get_or_fetch_and_upsert_person(&note.attributed_to, context, request_counter).await?;
+    let (post, parent_comment_id) = note.get_parents(context, request_counter).await?;
 
-    // This post, or the parent comment might not yet exist on this server yet, fetch them.
-    let post = Box::pin(get_or_fetch_and_insert_post(
-      post_ap_id,
-      context,
-      request_counter,
-    ))
-    .await?;
-    if post.locked {
-      return Err(anyhow!("Post is locked").into());
-    }
-
-    // The 2nd item, if it exists, is the parent comment apub_id
-    // For deeply nested comments, FromApub automatically gets called recursively
-    let parent_id: Option<CommentId> = match in_reply_tos.next() {
-      Some(parent_comment_uri) => {
-        let parent_comment_ap_id = &parent_comment_uri?;
-        let parent_comment = Box::pin(get_or_fetch_and_insert_comment(
-          parent_comment_ap_id,
-          context,
-          request_counter,
-        ))
-        .await?;
+    let content = &note.source.content;
+    let content_slurs_removed = remove_slurs(content);
 
-        Some(parent_comment.id)
-      }
-      None => None,
-    };
-
-    let content = get_source_markdown_value(note)?.context(location_info!())?;
-    let content_slurs_removed = remove_slurs(&content);
-
-    Ok(CommentForm {
+    let form = CommentForm {
       creator_id: creator.id,
       post_id: post.id,
-      parent_id,
+      parent_id: parent_comment_id,
       content: content_slurs_removed,
       removed: None,
       read: None,
-      published: note.published().map(|u| u.to_owned().naive_local()),
-      updated: note.updated().map(|u| u.to_owned().naive_local()),
+      published: Some(note.published.naive_local()),
+      updated: note.updated.map(|u| u.to_owned().naive_local()),
       deleted: None,
-      ap_id,
+      ap_id: Some(note.id.clone().into()),
       local: Some(false),
-    })
+    };
+    Ok(blocking(context.pool(), move |conn| Comment::upsert(conn, &form)).await??)
   }
 }
diff --git a/crates/apub/src/objects/mod.rs b/crates/apub/src/objects/mod.rs
index 7191a4a1..c4f57c51 100644
--- a/crates/apub/src/objects/mod.rs
+++ b/crates/apub/src/objects/mod.rs
@@ -1,8 +1,4 @@
-use crate::{
-  check_community_or_site_ban,
-  check_is_apub_id_valid,
-  fetcher::person::get_or_fetch_and_upsert_person,
-};
+use crate::{check_is_apub_id_valid, fetcher::person::get_or_fetch_and_upsert_person};
 use activitystreams::{
   base::{AsBase, BaseExt, ExtendsExt},
   markers::Base,
@@ -14,7 +10,7 @@ use chrono::NaiveDateTime;
 use lemmy_api_common::blocking;
 use lemmy_apub_lib::values::MediaTypeMarkdown;
 use lemmy_db_queries::{ApubObject, Crud, DbPool};
-use lemmy_db_schema::{CommunityId, DbUrl};
+use lemmy_db_schema::DbUrl;
 use lemmy_utils::{
   location_info,
   settings::structs::Settings,
@@ -219,21 +215,3 @@ where
     Ok(to)
   }
 }
-
-pub(in crate::objects) async fn check_object_for_community_or_site_ban<T, Kind>(
-  object: &T,
-  community_id: CommunityId,
-  context: &LemmyContext,
-  request_counter: &mut i32,
-) -> Result<(), LemmyError>
-where
-  T: ObjectExt<Kind>,
-{
-  let person_id = object
-    .attributed_to()
-    .context(location_info!())?
-    .as_single_xsd_any_uri()
-    .context(location_info!())?;
-  let person = get_or_fetch_and_upsert_person(person_id, context, request_counter).await?;
-  check_community_or_site_ban(&person, community_id, context.pool()).await
-}
diff --git a/crates/apub/src/objects/post.rs b/crates/apub/src/objects/post.rs
index a7a6cfe9..1f2172d1 100644
--- a/crates/apub/src/objects/post.rs
+++ b/crates/apub/src/objects/post.rs
@@ -1,8 +1,9 @@
 use crate::{
-  activities::extract_community,
+  activities::{extract_community, verify_person_in_community},
   extensions::context::lemmy_context,
   fetcher::person::get_or_fetch_and_upsert_person,
   objects::{create_tombstone, FromApub, Source, ToApub},
+  ActorType,
 };
 use activitystreams::{
   base::AnyBase,
@@ -35,9 +36,10 @@ use lemmy_utils::{
   LemmyError,
 };
 use lemmy_websocket::LemmyContext;
+use serde::{Deserialize, Serialize};
 use url::Url;
 
-#[derive(Clone, Debug, serde::Deserialize, serde::Serialize)]
+#[derive(Clone, Debug, Deserialize, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct Page {
   #[serde(rename = "@context")]
@@ -57,8 +59,6 @@ pub struct Page {
   pub(crate) stickied: Option<bool>,
   published: DateTime<FixedOffset>,
   updated: Option<DateTime<FixedOffset>>,
-
-  // unparsed fields
   #[serde(flatten)]
   unparsed: Unparsed,
 }
@@ -92,11 +92,20 @@ impl Page {
 
   pub(crate) async fn verify(
     &self,
-    _context: &LemmyContext,
-    _request_counter: &mut i32,
+    context: &LemmyContext,
+    request_counter: &mut i32,
   ) -> Result<(), LemmyError> {
+    let community = extract_community(&self.to, context, request_counter).await?;
+
     check_slurs(&self.name)?;
     verify_domains_match(&self.attributed_to, &self.id)?;
+    verify_person_in_community(
+      &self.attributed_to,
+      &community.actor_id(),
+      context,
+      request_counter,
+    )
+    .await?;
     Ok(())
   }
 }