From 9fd1e0f87cefddbd0e8b3c9db0073d2bb0a38048 Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Wed, 22 Oct 2025 18:56:41 +0300
Subject: [PATCH] bridgev2/networkinterface: allow deleting children in chat
 delete event

---
 bridgev2/networkinterface.go |  5 ++++
 bridgev2/portal.go           | 49 ++++++++++++++++++++++++++++++++++++
 bridgev2/simplevent/chat.go  |  7 +++++-
 3 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/bridgev2/networkinterface.go b/bridgev2/networkinterface.go
index 9ca2dc43..da505435 100644
--- a/bridgev2/networkinterface.go
+++ b/bridgev2/networkinterface.go
@@ -1135,6 +1135,11 @@ type RemoteChatDelete interface {
 	RemoteDeleteOnlyForMe
 }
 
+type RemoteChatDeleteWithChildren interface {
+	RemoteChatDelete
+	DeleteChildren() bool
+}
+
 type RemoteEventThatMayCreatePortal interface {
 	RemoteEvent
 	ShouldCreatePortal() bool
diff --git a/bridgev2/portal.go b/bridgev2/portal.go
index 566847fb..0bd23b9e 100644
--- a/bridgev2/portal.go
+++ b/bridgev2/portal.go
@@ -284,6 +284,16 @@ func (br *Bridge) GetDMPortalsWith(ctx context.Context, otherUserID networkid.Us
 	return br.loadManyPortals(ctx, rows)
 }
 
+func (br *Bridge) GetChildPortals(ctx context.Context, parent networkid.PortalKey) ([]*Portal, error) {
+	br.cacheLock.Lock()
+	defer br.cacheLock.Unlock()
+	rows, err := br.DB.Portal.GetChildren(ctx, parent)
+	if err != nil {
+		return nil, err
+	}
+	return br.loadManyPortals(ctx, rows)
+}
+
 func (br *Bridge) GetDMPortal(ctx context.Context, receiver networkid.UserLoginID, otherUserID networkid.UserID) (*Portal, error) {
 	br.cacheLock.Lock()
 	defer br.cacheLock.Unlock()
@@ -3514,6 +3524,20 @@ func (portal *Portal) findOtherLogins(ctx context.Context, source *UserLogin) (o
 	return
 }
 
+type childDeleteProxy struct {
+	RemoteChatDeleteWithChildren
+	child networkid.PortalKey
+	done  func()
+}
+
+func (cdp *childDeleteProxy) AddLogContext(c zerolog.Context) zerolog.Context {
+	return cdp.RemoteChatDeleteWithChildren.AddLogContext(c).Str("subaction", "delete children")
+}
+func (cdp *childDeleteProxy) GetPortalKey() networkid.PortalKey              { return cdp.child }
+func (cdp *childDeleteProxy) ShouldCreatePortal() bool                       { return false }
+func (cdp *childDeleteProxy) PreHandle(ctx context.Context, portal *Portal)  {}
+func (cdp *childDeleteProxy) PostHandle(ctx context.Context, portal *Portal) { cdp.done() }
+
 func (portal *Portal) handleRemoteChatDelete(ctx context.Context, source *UserLogin, evt RemoteChatDelete) EventHandlingResult {
 	log := zerolog.Ctx(ctx)
 	if portal.Receiver == "" && evt.DeleteOnlyForMe() {
@@ -3549,6 +3573,31 @@ func (portal *Portal) handleRemoteChatDelete(ctx context.Context, source *UserLo
 			}
 		}
 	}
+	if childDeleter, ok := evt.(RemoteChatDeleteWithChildren); ok && childDeleter.DeleteChildren() && portal.RoomType == database.RoomTypeSpace {
+		children, err := portal.Bridge.GetChildPortals(ctx, portal.PortalKey)
+		if err != nil {
+			log.Err(err).Msg("Failed to fetch children to delete")
+			return EventHandlingResultFailed.WithError(err)
+		}
+		log.Debug().
+			Int("portal_count", len(children)).
+			Msg("Deleting child portals before remote chat delete")
+		var wg sync.WaitGroup
+		wg.Add(len(children))
+		for _, child := range children {
+			child.queueEvent(ctx, &portalRemoteEvent{
+				evt: &childDeleteProxy{
+					RemoteChatDeleteWithChildren: childDeleter,
+					child:                        child.PortalKey,
+					done:                         wg.Done,
+				},
+				source:  source,
+				evtType: RemoteEventChatDelete,
+			})
+		}
+		wg.Wait()
+		log.Debug().Msg("Finished deleting child portals")
+	}
 	err := portal.Delete(ctx)
 	if err != nil {
 		log.Err(err).Msg("Failed to delete portal from database")
diff --git a/bridgev2/simplevent/chat.go b/bridgev2/simplevent/chat.go
index c725141b..56e3a6b1 100644
--- a/bridgev2/simplevent/chat.go
+++ b/bridgev2/simplevent/chat.go
@@ -65,14 +65,19 @@ func (evt *ChatResync) GetChatInfo(ctx context.Context, portal *bridgev2.Portal)
 type ChatDelete struct {
 	EventMeta
 	OnlyForMe bool
+	Children  bool
 }
 
-var _ bridgev2.RemoteChatDelete = (*ChatDelete)(nil)
+var _ bridgev2.RemoteChatDeleteWithChildren = (*ChatDelete)(nil)
 
 func (evt *ChatDelete) DeleteOnlyForMe() bool {
 	return evt.OnlyForMe
 }
 
+func (evt *ChatDelete) DeleteChildren() bool {
+	return evt.Children
+}
+
 // ChatInfoChange is a simple implementation of [bridgev2.RemoteChatInfoChange].
 type ChatInfoChange struct {
 	EventMeta