From 38172e0aaea2dc6c4f0055cef027a229c34d1466 Mon Sep 17 00:00:00 2001
From: Haw Loeung <haw.loeung@canonical.com>
Date: Mon, 9 Sep 2024 18:18:41 +1000
Subject: [PATCH] Add support for DM header updates, as topics

---
 bridge/mattermost/mattermost.go | 70 ++++++++++++++++++++++++++-------
 mm-go-irckit/userbridge.go      | 19 +++++++--
 2 files changed, 71 insertions(+), 18 deletions(-)

diff --git a/bridge/mattermost/mattermost.go b/bridge/mattermost/mattermost.go
index a0496644..eb671c82 100644
--- a/bridge/mattermost/mattermost.go
+++ b/bridge/mattermost/mattermost.go
@@ -176,6 +176,8 @@ func (m *Mattermost) handleWsMessage(quitChan chan struct{}) {
 			case model.WebsocketEventChannelRestored:
 				// check if we have the users/channels in our cache. If not update
 				m.checkWsActionMessage(message.Raw, updateChannelsThrottle)
+			case model.WebsocketEventChannelUpdated:
+				m.handleWsActionPost(message.Raw)
 			case model.WebsocketEventUserUpdated:
 				m.handleWsActionUserUpdated(message.Raw)
 			case model.WebsocketEventStatusChange:
@@ -844,6 +846,10 @@ var validIRCNickRegExp = regexp.MustCompile("^[a-zA-Z0-9_]*$")
 
 //nolint:funlen,gocognit,gocyclo,cyclop,forcetypeassert
 func (m *Mattermost) handleWsActionPost(rmsg *model.WebSocketEvent) {
+	if rmsg.GetData()["post"] == nil {
+		return
+	}
+
 	var data model.Post
 	if err := json.NewDecoder(strings.NewReader(rmsg.GetData()["post"].(string))).Decode(&data); err != nil {
 		return
@@ -908,19 +914,62 @@ func (m *Mattermost) handleWsActionPost(rmsg *model.WebSocketEvent) {
 		return
 	}
 
+	channelType := ""
+	if t, ok := props["channel_type"].(string); ok {
+		channelType = t
+	}
+
+	dmchannel, _ := rmsg.GetData()["channel_name"].(string)
+
 	if data.Type == model.PostTypeHeaderChange {
-		if topic, ok := extraProps["new_header"].(string); ok {
+		if _, ok := extraProps["new_header"].(string); !ok {
+			return
+		}
+		topic := extraProps["new_header"].(string)
+
+		// DirectMessage
+		if channelType == "D" {
 			event := &bridge.Event{
-				Type: "channel_topic",
-				Data: &bridge.ChannelTopicEvent{
-					Text:      topic,
-					ChannelID: data.ChannelId,
-					UserID:    data.UserId,
-				},
+				Type: "direct_message",
 			}
+
+			d := &bridge.DirectMessageEvent{
+				Text:      "\x01ACTION updated topic to: " + topic + " \x01",
+				ChannelID: data.ChannelId,
+				MessageID: data.Id,
+				Event:     "dm_topic",
+			}
+
+			userUpdated := extraProps["username"].(string)
+			if userUpdated == m.GetMe().Nick {
+				d.Sender = ghost
+				d.Receiver = m.getDMUser(dmchannel)
+			} else {
+				d.Sender = m.getDMUser(dmchannel)
+				d.Receiver = ghost
+			}
+
+			if d.Sender == nil || d.Receiver == nil {
+				logger.Errorf("dm: couldn't resolve sender or receiver: %#v", rmsg)
+				return
+			}
+
+			event.Data = d
+
 			m.eventChan <- event
+			return
 		}
 
+		event := &bridge.Event{
+			Type: "channel_topic",
+			Data: &bridge.ChannelTopicEvent{
+				Text:      topic,
+				ChannelID: data.ChannelId,
+				UserID:    data.UserId,
+			},
+		}
+
+		m.eventChan <- event
 		return
 	}
 
@@ -933,13 +982,6 @@ func (m *Mattermost) handleWsActionPost(rmsg *model.WebSocketEvent) {
 	// msgs := strings.Split(data.Message, "\n")
 	msgs := []string{data.Message}
 
-	channelType := ""
-	if t, ok := props["channel_type"].(string); ok {
-		channelType = t
-	}
-
-	dmchannel, _ := rmsg.GetData()["channel_name"].(string)
-
 	// add an edited/deleted string when messages are edited/deleted
 	if len(msgs) > 0 && (rmsg.EventType() == model.WebsocketEventPostEdited ||
 		rmsg.EventType() == model.WebsocketEventPostDeleted) {
diff --git a/mm-go-irckit/userbridge.go b/mm-go-irckit/userbridge.go
index d7c4c97d..018f659a 100644
--- a/mm-go-irckit/userbridge.go
+++ b/mm-go-irckit/userbridge.go
@@ -145,11 +145,22 @@ func (u *User) handleDirectMessageEvent(event *bridge.DirectMessageEvent) {
 		}
 	}
 
-	prefixUser := event.Sender.User
-	if event.Sender.Me {
-		prefixUser = event.Receiver.User
+	text := ""
+	prefix := ""
+	suffix := ""
+	showContext := false
+	maxlen := 440
+	if event.Event == "dm_topic" {
+		text = event.Text
+		showContext = false
+		maxlen = 0
+	} else {
+		prefixUser := event.Sender.User
+		if event.Sender.Me {
+			prefixUser = event.Receiver.User
+		}
+		text, prefix, suffix, showContext, maxlen = u.handleMessageThreadContext(prefixUser, event.MessageID, event.ParentID, event.Event, event.Text)
 	}
-	text, prefix, suffix, showContext, maxlen := u.handleMessageThreadContext(prefixUser, event.MessageID, event.ParentID, event.Event, event.Text)
 
 	lexer := ""
 	codeBlockBackTick := false