Comments within a federated share should be made visible to all federated parties

In the context of a (federated) share, we consider comments as a valuable means of communication and hence an essential part of the collaboration effort.

While we appreciate use cases where tags are being contained to the server where they are initially created and stored, we deem it appropriate to make comments within a federated share available to all parties having access to that share.

Steps to reproduce

1. For collaboration purposes, UserA federates a share (shareX) on serverA to UserB on ServerB ;
2. UserA creates comments in the shareX realm ;
3. UserB creates comments in the shareX realm.

Expected behaviour

Parties with access to shareX (i.e. both UserA and UserB) should see all comments in this share's realm.

Actual behaviour

UserA only sees his/her own shareX comments (stored on ServerA), UserB only sees his/her own shareX comments (stored on ServerB).

Server configuration

Nextcloud version: 10.0.1

Workflow proposal :

• Add a 'public/private' boolean field to table oc_comments (defaulting to private) ;

• When a share is federated, disclose a [public] checkbox next to the [Post] button in the UI, allowing (new) comments to be made public ;

• For performance and privacy reasons, comments which are tagged public are stored in or transferred to table oc_comments on the server hosting the share, private comments are stored on or transferred to the user's server;

• Reversal from public to private status and vice versa can only be executed by the comment owner [oc_comments.actor_id].

Start by tracing how federated shares create, store, and display comments on both servers, then inspect the oc_comments schema and the comment UI around the Post button. Done means parties with access to a federated share can see the intended comments, with public/private behavior and ownership rules clarified and covered by regression tests.