lemmy/crates/apub/src/activities/create_or_update/post.rs

use crate::{
  activities::{
    check_community_deleted_or_removed,
    community::send_activity_in_community,
    generate_activity_id,
    verify_is_public,
    verify_mod_action,
    verify_person_in_community,
  },
  activity_lists::AnnouncableActivities,
  objects::{community::ApubCommunity, person::ApubPerson, post::ApubPost},
  protocol::{
    activities::{create_or_update::page::CreateOrUpdatePage, CreateOrUpdateType},
    InCommunity,
  },
  ActorType,
  SendActivity,
};
use activitypub_federation::{
  core::object_id::ObjectId,
  data::Data,
  traits::{ActivityHandler, ApubObject},
  utils::{verify_domains_match, verify_urls_match},
};
use activitystreams_kinds::public;
use lemmy_api_common::{
  context::LemmyContext,
  post::{CreatePost, EditPost, FeaturePost, LockPost, PostResponse},
  utils::get_local_user_view_from_jwt,
  websocket::{send::send_post_ws_message, UserOperationCrud},
};
use lemmy_db_schema::{
  newtypes::PersonId,
  source::{
    community::Community,
    person::Person,
    post::{Post, PostLike, PostLikeForm},
  },
  traits::{Crud, Likeable},
};
use lemmy_utils::error::LemmyError;
use url::Url;

#[async_trait::async_trait(?Send)]
impl SendActivity for CreatePost {
  type Response = PostResponse;

  async fn send_activity(
    _request: &Self,
    response: &Self::Response,
    context: &LemmyContext,
  ) -> Result<(), LemmyError> {
    CreateOrUpdatePage::send(
      &response.post_view.post,
      response.post_view.creator.id,
      CreateOrUpdateType::Create,
      context,
    )
    .await
  }
}

#[async_trait::async_trait(?Send)]
impl SendActivity for EditPost {
  type Response = PostResponse;

  async fn send_activity(
    _request: &Self,
    response: &Self::Response,
    context: &LemmyContext,
  ) -> Result<(), LemmyError> {
    CreateOrUpdatePage::send(
      &response.post_view.post,
      response.post_view.creator.id,
      CreateOrUpdateType::Update,
      context,
    )
    .await
  }
}

#[async_trait::async_trait(?Send)]
impl SendActivity for LockPost {
  type Response = PostResponse;

  async fn send_activity(
    request: &Self,
    response: &Self::Response,
    context: &LemmyContext,
  ) -> Result<(), LemmyError> {
    let local_user_view =
      get_local_user_view_from_jwt(&request.auth, context.pool(), context.secret()).await?;
    CreateOrUpdatePage::send(
      &response.post_view.post,
      local_user_view.person.id,
      CreateOrUpdateType::Update,
      context,
    )
    .await
  }
}

#[async_trait::async_trait(?Send)]
impl SendActivity for FeaturePost {
  type Response = PostResponse;

  async fn send_activity(
    request: &Self,
    response: &Self::Response,
    context: &LemmyContext,
  ) -> Result<(), LemmyError> {
    let local_user_view =
      get_local_user_view_from_jwt(&request.auth, context.pool(), context.secret()).await?;
    CreateOrUpdatePage::send(
      &response.post_view.post,
      local_user_view.person.id,
      CreateOrUpdateType::Update,
      context,
    )
    .await
  }
}

impl CreateOrUpdatePage {
  pub(crate) async fn new(
    post: ApubPost,
    actor: &ApubPerson,
    community: &ApubCommunity,
    kind: CreateOrUpdateType,
    context: &LemmyContext,
  ) -> Result<CreateOrUpdatePage, LemmyError> {
    let id = generate_activity_id(
      kind.clone(),
      &context.settings().get_protocol_and_hostname(),
    )?;
    Ok(CreateOrUpdatePage {
      actor: ObjectId::new(actor.actor_id()),
      to: vec![public()],
      object: post.into_apub(context).await?,
      cc: vec![community.actor_id()],
      kind,
      id: id.clone(),
      audience: Some(ObjectId::new(community.actor_id())),
    })
  }

  #[tracing::instrument(skip_all)]
  async fn send(
    post: &Post,
    person_id: PersonId,
    kind: CreateOrUpdateType,
    context: &LemmyContext,
  ) -> Result<(), LemmyError> {
    let post = ApubPost(post.clone());
    let community_id = post.community_id;
    let person: ApubPerson = Person::read(context.pool(), person_id).await?.into();
    let community: ApubCommunity = Community::read(context.pool(), community_id).await?.into();

    let create_or_update =
      CreateOrUpdatePage::new(post, &person, &community, kind, context).await?;
    let is_mod_action = create_or_update.object.is_mod_action(context).await?;
    let activity = AnnouncableActivities::CreateOrUpdatePost(create_or_update);
    send_activity_in_community(
      activity,
      &person,
      &community,
      vec![],
      is_mod_action,
      context,
    )
    .await?;
    Ok(())
  }
}

#[async_trait::async_trait(?Send)]
impl ActivityHandler for CreateOrUpdatePage {
  type DataType = LemmyContext;
  type Error = LemmyError;

  fn id(&self) -> &Url {
    &self.id
  }

  fn actor(&self) -> &Url {
    self.actor.inner()
  }

  #[tracing::instrument(skip_all)]
  async fn verify(
    &self,
    context: &Data<LemmyContext>,
    request_counter: &mut i32,
  ) -> Result<(), LemmyError> {
    verify_is_public(&self.to, &self.cc)?;
    let community = self.community(context, request_counter).await?;
    verify_person_in_community(&self.actor, &community, context, request_counter).await?;
    check_community_deleted_or_removed(&community)?;

    match self.kind {
      CreateOrUpdateType::Create => {
        verify_domains_match(self.actor.inner(), self.object.id.inner())?;
        verify_urls_match(self.actor.inner(), self.object.creator()?.inner())?;
        // Check that the post isnt locked or stickied, as that isnt possible for newly created posts.
        // However, when fetching a remote post we generate a new create activity with the current
        // locked/stickied value, so this check may fail. So only check if its a local community,
        // because then we will definitely receive all create and update activities separately.
        let is_featured_or_locked =
          self.object.stickied == Some(true) || self.object.comments_enabled == Some(false);
        if community.local && is_featured_or_locked {
          return Err(LemmyError::from_message(
            "New post cannot be stickied or locked",
          ));
        }
      }
      CreateOrUpdateType::Update => {
        let is_mod_action = self.object.is_mod_action(context).await?;
        if is_mod_action {
          verify_mod_action(
            &self.actor,
            self.object.id.inner(),
            community.id,
            context,
            request_counter,
          )
          .await?;
        } else {
          verify_domains_match(self.actor.inner(), self.object.id.inner())?;
          verify_urls_match(self.actor.inner(), self.object.creator()?.inner())?;
        }
      }
    }
    ApubPost::verify(&self.object, self.actor.inner(), context, request_counter).await?;
    Ok(())
  }

  #[tracing::instrument(skip_all)]
  async fn receive(
    self,
    context: &Data<LemmyContext>,
    request_counter: &mut i32,
  ) -> Result<(), LemmyError> {
    let post = ApubPost::from_apub(self.object, context, request_counter).await?;

    // author likes their own post by default
    let like_form = PostLikeForm {
      post_id: post.id,
      person_id: post.creator_id,
      score: 1,
    };
    PostLike::like(context.pool(), &like_form).await?;

    let notif_type = match self.kind {
      CreateOrUpdateType::Create => UserOperationCrud::CreatePost,
      CreateOrUpdateType::Update => UserOperationCrud::EditPost,
    };
    send_post_ws_message(post.id, notif_type, None, None, context).await?;
    Ok(())
  }
}