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::{verify_urls_match, ActivityCommonFields, ActivityHandler, PublicUrl};
  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, context, request_counter).await?;
  68       let object_creator =
  69         get_post_or_comment_actor_id(&self.object, context, request_counter).await?;
  70       verify_urls_match(&self.common.actor, &object_creator)?;
  71     }
  72     Ok(())
  73   }
  74
  75   async fn receive(
  76     &self,
  77     context: &LemmyContext,
  78     request_counter: &mut i32,
  79   ) -> Result<(), LemmyError> {
  80     let object_community =
  81       get_or_fetch_and_upsert_community(&self.object, context, request_counter).await;
  82     // deleting a community
  83     if let Ok(community) = object_community {
  84       if community.local {
  85         // repeat these checks just to be sure
  86         verify_person_in_community(&self.common().actor, &self.cc, context, request_counter)
  87           .await?;
  88         verify_mod_action(&self.common.actor, self.object.clone(), context).await?;
  89         let mod_ =
  90           get_or_fetch_and_upsert_person(&self.common.actor, context, request_counter).await?;
  91         community.send_delete(mod_, context).await?;
  92       }
  93       let deleted_community = blocking(context.pool(), move |conn| {
  94         Community::update_deleted(conn, community.id, true)
  95       })
  96       .await??;
  97
  98       send_community_message(
  99         deleted_community.id,
 100         UserOperationCrud::DeleteCommunity,
 101         context,
 102       )
 103       .await
 104     }
 105     // deleting a post or comment
 106     else {
 107       match get_or_fetch_and_insert_post_or_comment(&self.object, context, request_counter).await? {
 108         PostOrComment::Post(post) => {
 109           let deleted_post = blocking(context.pool(), move |conn| {
 110             Post::update_deleted(conn, post.id, true)
 111           })
 112           .await??;
 113           send_post_message(deleted_post.id, UserOperationCrud::EditPost, context).await
 114         }
 115         PostOrComment::Comment(comment) => {
 116           let deleted_comment = blocking(context.pool(), move |conn| {
 117             Comment::update_deleted(conn, comment.id, true)
 118           })
 119           .await??;
 120           send_comment_message(
 121             deleted_comment.id,
 122             vec![],
 123             UserOperationCrud::EditComment,
 124             context,
 125           )
 126           .await
 127         }
 128       }
 129     }
 130   }
 131
 132   fn common(&self) -> &ActivityCommonFields {
 133     &self.common
 134   }
 135 }
 136
 137 async fn get_post_or_comment_actor_id(
 138   object: &Url,
 139   context: &LemmyContext,
 140   request_counter: &mut i32,
 141 ) -> Result<Url, LemmyError> {
 142   let actor_id =
 143     match get_or_fetch_and_insert_post_or_comment(object, context, request_counter).await? {
 144       PostOrComment::Post(post) => {
 145         let creator_id = post.creator_id;
 146         blocking(context.pool(), move |conn| Person::read(conn, creator_id))
 147           .await??
 148           .actor_id()
 149       }
 150       PostOrComment::Comment(comment) => {
 151         let creator_id = comment.creator_id;
 152         blocking(context.pool(), move |conn| Person::read(conn, creator_id))
 153           .await??
 154           .actor_id()
 155       }
 156     };
 157   Ok(actor_id)
 158 }