crates/apub/src/activities/deletion/delete.rs

   1 use crate::{
   2   activities::{
   3     comment::send_websocket_message as send_comment_message,
   4     community::send_websocket_message as send_community_message,
   5     post::send_websocket_message as send_post_message,
   6     verify_activity,
   7     verify_mod_action,
   8     verify_person_in_community,
   9   },
  10   fetcher::{
  11     community::get_or_fetch_and_upsert_community,
  12     objects::get_or_fetch_and_insert_post_or_comment,
  13     person::get_or_fetch_and_upsert_person,
  14   },
  15   ActorType,
  16   CommunityType,
  17   PostOrComment,
  18 };
  19 use activitystreams::activity::kind::DeleteType;
  20 use lemmy_api_common::blocking;
  21 use lemmy_apub_lib::{values::PublicUrl, verify_urls_match, ActivityCommonFields, ActivityHandler};
  22 use lemmy_db_queries::{
  23   source::{comment::Comment_, community::Community_, post::Post_},
  24   Crud,
  25 };
  26 use lemmy_db_schema::source::{comment::Comment, community::Community, person::Person, post::Post};
  27 use lemmy_utils::LemmyError;
  28 use lemmy_websocket::{LemmyContext, UserOperationCrud};
  29 use url::Url;
  30
  31 /// This is very confusing, because there are four distinct cases to handle:
  32 /// - user deletes their post
  33 /// - user deletes their comment
  34 /// - remote community mod deletes local community
  35 /// - remote community deletes itself (triggered by a mod)
  36 ///
  37 /// TODO: we should probably change how community deletions work to simplify this. Probably by
  38 /// wrapping it in an announce just like other activities, instead of having the community send it.
  39 #[derive(Clone, Debug, serde::Deserialize, serde::Serialize)]
  40 #[serde(rename_all = "camelCase")]
  41 pub struct DeletePostCommentOrCommunity {
  42   to: PublicUrl,
  43   pub(in crate::activities::deletion) object: Url,
  44   cc: [Url; 1],
  45   #[serde(rename = "type")]
  46   kind: DeleteType,
  47   #[serde(flatten)]
  48   common: ActivityCommonFields,
  49 }
  50
  51 #[async_trait::async_trait(?Send)]
  52 impl ActivityHandler for DeletePostCommentOrCommunity {
  53   async fn verify(
  54     &self,
  55     context: &LemmyContext,
  56     request_counter: &mut i32,
  57   ) -> Result<(), LemmyError> {
  58     verify_activity(self.common())?;
  59     let object_community =
  60       get_or_fetch_and_upsert_community(&self.object, context, request_counter).await;
  61     // deleting a community (set counter 0 to only fetch from local db)
  62     if object_community.is_ok() {
  63       verify_mod_action(&self.common.actor, self.object.clone(), context).await?;
  64     }
  65     // deleting a post or comment
  66     else {
  67       verify_person_in_community(&self.common().actor, &self.cc[0], context, request_counter)
  68         .await?;
  69       let object_creator =
  70         get_post_or_comment_actor_id(&self.object, context, request_counter).await?;
  71       verify_urls_match(&self.common.actor, &object_creator)?;
  72     }
  73     Ok(())
  74   }
  75
  76   async fn receive(
  77     &self,
  78     context: &LemmyContext,
  79     request_counter: &mut i32,
  80   ) -> Result<(), LemmyError> {
  81     let object_community =
  82       get_or_fetch_and_upsert_community(&self.object, context, request_counter).await;
  83     // deleting a community
  84     if let Ok(community) = object_community {
  85       if community.local {
  86         // repeat these checks just to be sure
  87         verify_person_in_community(&self.common().actor, &self.cc[0], context, request_counter)
  88           .await?;
  89         verify_mod_action(&self.common.actor, self.object.clone(), context).await?;
  90         let mod_ =
  91           get_or_fetch_and_upsert_person(&self.common.actor, context, request_counter).await?;
  92         community.send_delete(mod_, context).await?;
  93       }
  94       let deleted_community = blocking(context.pool(), move |conn| {
  95         Community::update_deleted(conn, community.id, true)
  96       })
  97       .await??;
  98
  99       send_community_message(
 100         deleted_community.id,
 101         UserOperationCrud::DeleteCommunity,
 102         context,
 103       )
 104       .await
 105     }
 106     // deleting a post or comment
 107     else {
 108       match get_or_fetch_and_insert_post_or_comment(&self.object, context, request_counter).await? {
 109         PostOrComment::Post(post) => {
 110           let deleted_post = blocking(context.pool(), move |conn| {
 111             Post::update_deleted(conn, post.id, true)
 112           })
 113           .await??;
 114           send_post_message(deleted_post.id, UserOperationCrud::EditPost, context).await
 115         }
 116         PostOrComment::Comment(comment) => {
 117           let deleted_comment = blocking(context.pool(), move |conn| {
 118             Comment::update_deleted(conn, comment.id, true)
 119           })
 120           .await??;
 121           send_comment_message(
 122             deleted_comment.id,
 123             vec![],
 124             UserOperationCrud::EditComment,
 125             context,
 126           )
 127           .await
 128         }
 129       }
 130     }
 131   }
 132
 133   fn common(&self) -> &ActivityCommonFields {
 134     &self.common
 135   }
 136 }
 137
 138 async fn get_post_or_comment_actor_id(
 139   object: &Url,
 140   context: &LemmyContext,
 141   request_counter: &mut i32,
 142 ) -> Result<Url, LemmyError> {
 143   let actor_id =
 144     match get_or_fetch_and_insert_post_or_comment(object, context, request_counter).await? {
 145       PostOrComment::Post(post) => {
 146         let creator_id = post.creator_id;
 147         blocking(context.pool(), move |conn| Person::read(conn, creator_id))
 148           .await??
 149           .actor_id()
 150       }
 151       PostOrComment::Comment(comment) => {
 152         let creator_id = comment.creator_id;
 153         blocking(context.pool(), move |conn| Person::read(conn, creator_id))
 154           .await??
 155           .actor_id()
 156       }
 157     };
 158   Ok(actor_id)
 159 }