feat(blahd): impl non-self member removal

blah-types/src/msg.rs

@@ -387,9 +387,14 @@ bitflags::bitflags! {
     pub struct MemberPermission: i32 {
         const POST_CHAT = 1 << 0;
         const ADD_MEMBER = 1 << 1;
+        // TODO: Group admin permissions together.
         const DELETE_ROOM = 1 << 2;
         const LIST_MEMBERS = 1 << 3;
 
+        // TODO: Should we have multiple levels of removal permission, so that admins
+        // may not remove all other admins?
+        const REMOVE_MEMBER = 1 << 4;
+
         const MAX_SELF_ADD = Self::POST_CHAT.bits();
         const MAX_PEER_CHAT = Self::POST_CHAT.bits() | Self::DELETE_ROOM.bits() | Self::LIST_MEMBERS.bits();
 

blahd/src/database.rs

@@ -220,6 +220,26 @@ pub trait TransactionOps {
         .and_then(|row| Ok((row.get(0)?, row.get(1)?, row.get(2)?)))
     }
 
+    fn get_room_member_by_id_key(
+        &self,
+        rid: Id,
+        id_key: &PubKey,
+    ) -> Result<(i64, MemberPermission, Id)> {
+        prepare_cached_and_bind!(
+            self.conn(),
+            r"
+            SELECT `uid`, `room_member`.`permission`, `last_seen_cid`
+            FROM `room_member`
+            JOIN `user` USING (`uid`)
+            WHERE (`rid`, `id_key`) = (:rid, :id_key)
+            "
+        )
+        .raw_query()
+        .next()?
+        .ok_or(ApiError::MemberNotFound)
+        .and_then(|row| Ok((row.get(0)?, row.get(1)?, row.get(2)?)))
+    }
+
     fn get_room_having(&self, rid: Id, filter: RoomAttrs) -> Result<(RoomAttrs, Option<String>)> {
         prepare_cached_and_bind!(
             self.conn(),
@@ -527,7 +547,7 @@ pub trait TransactionOps {
         Ok(())
     }
 
-    fn remove_room_member(&self, rid: Id, uid: i64) -> Result<bool> {
+    fn remove_room_member(&self, rid: Id, uid: i64) -> Result<()> {
         // TODO: Check if it is the last member?
         let updated = prepare_cached_and_bind!(
             self.conn(),
@@ -537,7 +557,10 @@ pub trait TransactionOps {
             "
         )
         .raw_execute()?;
-        Ok(updated == 1)
+        if updated != 1 {
+            return Err(ApiError::UserNotFound);
+        }
+        Ok(())
     }
 
     fn add_room_chat_msg(&self, rid: Id, uid: i64, cid: Id, chat: &SignedChatMsg) -> Result<()> {

blahd/src/lib.rs

@@ -539,17 +539,23 @@ async fn delete_room_member(
     );
     let tgt_user = op.signee.payload.user;
     api_ensure!(id_key == tgt_user, "user id mismatch with URI");
-    api_ensure!(
-        op.signee.user.id_key == tgt_user,
-        ApiError::NotImplemented("only self-removal is implemented yet"),
-    );
+    let is_self_removal = op.signee.user.id_key == tgt_user;
 
     st.db.with_write(|txn| {
-        let (uid, ..) = txn.get_room_member(rid, &op.signee.user)?;
+        let (uid, perm, _) = txn.get_room_member(rid, &op.signee.user)?;
+        api_ensure!(
+            is_self_removal || perm.contains(MemberPermission::REMOVE_MEMBER),
+            ApiError::PermissionDenied("the user does not have permission to remove members")
+        );
         let (attrs, _) = txn.get_room_having(rid, RoomAttrs::empty())?;
         // Sanity check.
         assert!(!attrs.contains(RoomAttrs::PEER_CHAT));
-        txn.remove_room_member(rid, uid)?;
+        let tgt_uid = if is_self_removal {
+            uid
+        } else {
+            txn.get_room_member_by_id_key(rid, &tgt_user)?.0
+        };
+        txn.remove_room_member(rid, tgt_uid)?;
         Ok(NoContent)
     })
 }

blahd/src/middleware.rs

@@ -66,6 +66,7 @@ pub enum ApiError {
     UserNotFound = (StatusCode::NOT_FOUND, "the user does not exist"),
     RoomNotFound = (StatusCode::NOT_FOUND, "the room does not exist or the user is not a room member"),
     PeerUserNotFound = (StatusCode::NOT_FOUND, "peer user does not exist or disallows peer chat"),
+    MemberNotFound = (StatusCode::NOT_FOUND, "the operand user is not a room member"),
     Conflict(&'static str) = (StatusCode::CONFLICT),
     Exists(&'static str) = (StatusCode::CONFLICT),
     FetchIdDescription(Box<str>) = (StatusCode::UNPROCESSABLE_ENTITY),

blahd/tests/webapi.rs

@@ -320,17 +320,26 @@ impl Server {
     }
 
     fn leave_room(&self, rid: Id, user: &User) -> impl Future<Output = Result<()>> + use<'_> {
-        let user_id = user.pubkeys.id_key.clone();
+        self.remove_member(rid, user, user)
+    }
+
+    fn remove_member(
+        &self,
+        rid: Id,
+        act_user: &User,
+        tgt_user: &User,
+    ) -> impl Future<Output = Result<()>> + use<'_> {
+        let tgt_user_id = tgt_user.pubkeys.id_key.clone();
         let req = self.sign(
-            user,
+            act_user,
             RemoveMemberPayload {
                 room: rid,
-                user: user_id.clone(),
+                user: tgt_user_id.clone(),
             },
         );
         self.request::<_, NoContent>(
             Method::DELETE,
-            &format!("/room/{rid}/member/{user_id}"),
+            &format!("/room/{rid}/member/{tgt_user_id}"),
             None,
             Some(req),
         )
@@ -1627,3 +1636,48 @@ async fn room_member(server: Server) {
     };
     assert_eq!(got, expect);
 }
+
+#[rstest]
+#[tokio::test]
+async fn room_management(server: Server) {
+    let rid = server
+        .create_room(&ALICE, RoomAttrs::PUBLIC_JOINABLE, "public")
+        .await
+        .unwrap();
+    server
+        .join_room(rid, &BOB, MemberPermission::MAX_SELF_ADD)
+        .await
+        .unwrap();
+    // Now bob can access the room.
+    server
+        .get::<RoomMetadata>(&format!("/room/{rid}"), Some(&auth(&BOB)))
+        .await
+        .unwrap();
+
+    // No permission.
+    server
+        .remove_member(rid, &BOB, &ALICE)
+        .await
+        .expect_api_err(StatusCode::FORBIDDEN, "permission_denied");
+
+    // Invalid act user.
+    server
+        .remove_member(rid, &CAROL, &BOB)
+        .await
+        .expect_api_err(StatusCode::NOT_FOUND, "room_not_found");
+
+    // Invalid operand user.
+    server
+        .remove_member(rid, &ALICE, &CAROL)
+        .await
+        .expect_api_err(StatusCode::NOT_FOUND, "member_not_found");
+
+    // OK, removed.
+    server.remove_member(rid, &ALICE, &BOB).await.unwrap();
+
+    // Bob cannot access the room now.
+    server
+        .get::<RoomMetadata>(&format!("/room/{rid}"), Some(&auth(&BOB)))
+        .await
+        .expect_api_err(StatusCode::NOT_FOUND, "room_not_found");
+}