Allows invites to be sent to offline remotes (#28176)

* Allows invites to be sent to offline remotes

Invites sent to remotes marked as offline will be stored as pending,
and when the remote comes back online, it will process the invites as
part of the synchronization process.

* Update condition name for excluding confirmed invites

server/platform/services/sharedchannel/sync_send.go

@@ -150,6 +150,61 @@ func (scs *Service) NotifyUserStatusChanged(status *model.Status) {
 	}
 }
 
+func (scs *Service) SendPendingInvitesForRemote(rc *model.RemoteCluster) {
+	if rcs := scs.server.GetRemoteClusterService(); rcs == nil {
+		return
+	}
+
+	scs.server.Log().Log(mlog.LvlSharedChannelServiceDebug, "Processing pending invites for remote after reconnection",
+		mlog.String("remote", rc.DisplayName),
+		mlog.String("remoteId", rc.RemoteId),
+	)
+
+	opts := model.SharedChannelRemoteFilterOpts{
+		RemoteId:         rc.RemoteId,
+		ExcludeConfirmed: true,
+	}
+	scrs, err := scs.server.GetStore().SharedChannel().GetRemotes(0, 999999, opts)
+	if err != nil {
+		scs.server.Log().Log(mlog.LvlSharedChannelServiceError, "Failed to fetch shared channel remotes for pending invites",
+			mlog.String("remote", rc.DisplayName),
+			mlog.String("remoteId", rc.RemoteId),
+			mlog.Err(err),
+		)
+		return
+	}
+
+	for _, scr := range scrs {
+		channel, err := scs.server.GetStore().Channel().Get(scr.ChannelId, true)
+		if err != nil {
+			scs.server.Log().Log(mlog.LvlSharedChannelServiceError, "Failed to fetch channel for pending invite",
+				mlog.String("remote_id", scr.RemoteId),
+				mlog.String("channel_id", scr.ChannelId),
+				mlog.String("sharedchannelremote_id", scr.Id),
+				mlog.Err(err),
+			)
+			continue
+		}
+
+		if err := scs.SendChannelInvite(channel, scr.CreatorId, rc); err != nil {
+			scs.server.Log().Log(mlog.LvlSharedChannelServiceError, "Failed to send pending invite",
+				mlog.String("remote_id", scr.RemoteId),
+				mlog.String("channel_id", scr.ChannelId),
+				mlog.String("sharedchannelremote_id", scr.Id),
+				mlog.Err(err),
+			)
+			continue
+		}
+
+		scs.server.Log().Log(mlog.LvlSharedChannelServiceDebug, "Pending invite sent",
+			mlog.String("remote", rc.DisplayName),
+			mlog.String("remoteId", rc.RemoteId),
+			mlog.String("channel_id", scr.ChannelId),
+			mlog.String("sharedchannelremote_id", scr.Id),
+		)
+	}
+}
+
 // ForceSyncForRemote causes all channels shared with the remote to be synchronized.
 func (scs *Service) ForceSyncForRemote(rc *model.RemoteCluster) {
 	if rcs := scs.server.GetRemoteClusterService(); rcs == nil {
@@ -327,9 +382,10 @@ func (scs *Service) processTask(task syncTask) error {
 			remotesMap[r.RemoteId] = r
 		}
 
-		// add all remotes that have the autoinvited option.
+		// add all confirmed remotes that have the autoinvited option.
 		filter = model.RemoteClusterQueryFilter{
 			RequireOptions: model.BitflagOptionAutoInvited,
+			OnlyConfirmed:  true,
 		}
 		remotesAutoInvited, err := scs.server.GetStore().RemoteCluster().GetAll(0, 999999, filter)
 		if err != nil {