Send last pinned message as subject on MUC join

telegram/utils.go

@@ -328,6 +328,8 @@ func (c *Client) JoinMUC(chatId int64, resource string, limit int32) {
 	if err == nil {
 		c.sendMessagesReverse(chatId, messages, false, c.jid+"/"+resource)
 	}
+
+	c.sendMUCSubject(chatId, resource)
 }
 
 func (c *Client) sendMUCStatuses(chatID int64) {
@@ -392,6 +394,26 @@ func (c *Client) sendMUCStatuses(chatID int64) {
 	)
 }
 
+func (c *Client) sendMUCSubject(chatID int64, resource string) {
+	pin, err := c.client.GetChatPinnedMessage(&client.GetChatPinnedMessageRequest{
+		ChatId: chatID,
+	})
+	mucJid := strconv.FormatInt(chatID, 10) + "@" + gateway.Jid.Bare()
+	toJid := c.jid + "/" + resource
+	if err == nil {
+		gateway.SendSubjectMessage(
+			toJid,
+			mucJid + "/" + c.getMUCNickname(c.getSenderId(pin)),
+			c.messageToText(pin, false),
+			strconv.FormatInt(pin.Id, 10),
+			c.xmpp,
+			int64(pin.Date),
+		)
+	} else {
+		gateway.SendSubjectMessage(toJid, mucJid, "", "", c.xmpp, 0)
+	}
+}
+
 func (c *Client) getMUCNickname(chatID int64) string {
 	return c.formatContact(chatID)
 }

xmpp/extensions/extensions.go

@@ -261,6 +261,11 @@ type MessageAddress struct {
 	Jid     string   `xml:"jid,attr"`
 }
 
+// EmptySubject is a dummy for MUCs to circumvent omitempty. Not registered as it would conflict with Subject field
+type EmptySubject struct {
+	XMLName xml.Name `xml:"subject"`
+}
+
 // Namespace is a namespace!
 func (c PresenceNickExtension) Namespace() string {
 	return c.XMLName.Space

xmpp/gateway/gateway.go

@@ -43,26 +43,31 @@ var DirtySessions = false
 var MessageOutgoingPermissionVersion = 0
 
 // SendMessage creates and sends a message stanza
-func SendMessage(to string, from string, body string, id string, component *xmpp.Component, reply *Reply, timestamp int64, isCarbon, isGroupchat bool, originalFrom string) {
+func SendMessage(to, from, body, id string, component *xmpp.Component, reply *Reply, timestamp int64, isCarbon, isGroupchat bool, originalFrom string) {
-	sendMessageWrapper(to, from, body, id, component, reply, timestamp, "", isCarbon, isGroupchat, originalFrom)
+	sendMessageWrapper(to, from, body, "", id, component, reply, timestamp, "", isCarbon, isGroupchat, false, originalFrom)
 }
 
 // SendServiceMessage creates and sends a simple message stanza from transport
-func SendServiceMessage(to string, body string, component *xmpp.Component) {
+func SendServiceMessage(to, body string, component *xmpp.Component) {
-	sendMessageWrapper(to, "", body, "", component, nil, 0, "", false, false, "")
+	sendMessageWrapper(to, "", body, "", "", component, nil, 0, "", false, false, false, "")
 }
 
 // SendTextMessage creates and sends a simple message stanza
-func SendTextMessage(to string, from string, body string, component *xmpp.Component) {
+func SendTextMessage(to, from, body string, component *xmpp.Component) {
-	sendMessageWrapper(to, from, body, "", component, nil, 0, "", false, false, "")
+	sendMessageWrapper(to, from, body, "", "", component, nil, 0, "", false, false, false, "")
 }
 
 // SendMessageWithOOB creates and sends a message stanza with OOB URL
-func SendMessageWithOOB(to string, from string, body string, id string, component *xmpp.Component, reply *Reply, timestamp int64, oob string, isCarbon bool, isGroupchat bool, originalFrom string) {
+func SendMessageWithOOB(to, from, body, id string, component *xmpp.Component, reply *Reply, timestamp int64, oob string, isCarbon, isGroupchat bool, originalFrom string) {
-	sendMessageWrapper(to, from, body, id, component, reply, timestamp, oob, isCarbon, isGroupchat, originalFrom)
+	sendMessageWrapper(to, from, body, "", id, component, reply, timestamp, oob, isCarbon, isGroupchat, false, originalFrom)
 }
 
-func sendMessageWrapper(to string, from string, body string, id string, component *xmpp.Component, reply *Reply, timestamp int64, oob string, isCarbon bool, isGroupchat bool, originalFrom string) {
+// SendSubjectMessage creates and sends a MUC subject
+func SendSubjectMessage(to, from, subject, id string, component *xmpp.Component, timestamp int64) {
+	sendMessageWrapper(to, from, "", subject, id, component, nil, timestamp, "", false, true, true, "")
+}
+
+func sendMessageWrapper(to, from, body, subject, id string, component *xmpp.Component, reply *Reply, timestamp int64, oob string, isCarbon, isGroupchat, forceSubject bool, originalFrom string) {
 	toJid, err := stanza.NewJid(to)
 	if err != nil {
 		log.WithFields(log.Fields{
@@ -115,6 +120,7 @@ func sendMessageWrapper(to string, from string, body string, id string, componen
 			Type: messageType,
 			Id:   id,
 		},
+		Subject: subject,
 		Body:    body,
 	}
 
@@ -132,7 +138,7 @@ func sendMessageWrapper(to string, from string, body string, id string, componen
 			message.Extensions = append(message.Extensions, extensions.NewReplyFallback(reply.Start, reply.End))
 		}
 	}
-	if !isCarbon && toJid.Resource != "" {
+	if !isGroupchat && !isCarbon && toJid.Resource != "" {
 		message.Extensions = append(message.Extensions, stanza.HintNoCopy{})
 	}
 	if timestamp != 0 {
@@ -159,6 +165,9 @@ func sendMessageWrapper(to string, from string, body string, id string, componen
 			},
 		})
 	}
+	if subject == "" && forceSubject {
+		message.Extensions = append(message.Extensions, extensions.EmptySubject{})
+	}
 
 	if isCarbon {
 		carbonMessage := extensions.ClientMessage{