From 8ba57e36e643fbc48ea323dc1d41b54d6d3858f0 Mon Sep 17 00:00:00 2001
From: mappu <mappu04@gmail.com>
Date: Mon, 4 Jun 2018 16:54:10 +1200
Subject: [PATCH] support /userlist[@botname] commands in group chat

---
 NTFServer.go | 67 +++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 48 insertions(+), 19 deletions(-)

diff --git a/NTFServer.go b/NTFServer.go
index cf9d20c..c56062a 100644
--- a/NTFServer.go
+++ b/NTFServer.go
@@ -24,6 +24,7 @@ const (
 type NTFServer struct {
 	bot         *telegram.BotAPI
 	hubMessages chan upstreamMessage
+	botName     string
 	chatName    string
 	inviteLink  string
 	configFile  string
@@ -86,6 +87,8 @@ func NewNTFServer(configFile string, verbose bool) (*NTFServer, error) {
 
 	log.Printf("Connected to telegram as '%s'", bot.Self.UserName)
 
+	ret.botName = bot.Self.UserName
+
 	// Groupchat properties
 
 	if ret.IsSetupMode() {
@@ -434,9 +437,8 @@ func (this *NTFServer) HandleGroupMessage(update telegram.Update) error {
 	}
 
 	if len(update.Message.Text) > 0 {
-		// Actual chat message
-		// Find the responsible user to send it to the upstream hub, using their account
 
+		// Find the responsible user's upstream connection
 		userID := int64(update.Message.From.ID)
 		hubNick, ok := this.config.KnownUsers[userID]
 		if !ok {
@@ -448,14 +450,31 @@ func (this *NTFServer) HandleGroupMessage(update telegram.Update) error {
 			return fmt.Errorf("Couldn't send public message for user '%d' (%s) unexpectedly missing upstream connection!", userID, hubNick)
 		}
 
-		// Also add it to the coalesce buffer so that we don't replay it from someone else's NMDC connection
-		this.Coalesce(hubNick, update.Message.Text)
+		// Intercept some bot commands
 
-		// Submit to NMDC
-		err := conn.SayPublic(update.Message.Text)
-		if err != nil {
-			log.Printf("Failed to deliver message '%s': %s", update.Message.Text, err.Error())
-			this.GroupChatSayHTML(fmt.Sprintf("<i>Couldn't sync message '%s' because: %s</i>", html.EscapeString(update.Message.Text), html.EscapeString(err.Error())))
+		if update.Message.Text == "/userlist" || update.Message.Text == "/userlist@"+this.botName {
+			// Display native userlist inside the groupchat
+
+			usernames, err := this.getUserlistText(conn)
+			if err != nil {
+				this.GroupChatSayHTML("<i>Can't get userlist for you (internal error)</i>")
+			}
+
+			this.GroupChatSayHTML(fmt.Sprintf("<i>Online users:</i> %s", html.EscapeString(usernames)))
+
+		} else {
+
+			// Actual chat message
+
+			// Also add it to the coalesce buffer so that we don't replay it from someone else's NMDC connection
+			this.Coalesce(hubNick, update.Message.Text)
+
+			// Submit to NMDC
+			err := conn.SayPublic(update.Message.Text)
+			if err != nil {
+				log.Printf("Failed to deliver message '%s': %s", update.Message.Text, err.Error())
+				this.GroupChatSayHTML(fmt.Sprintf("<i>Couldn't sync message '%s' because: %s</i>", html.EscapeString(update.Message.Text), html.EscapeString(err.Error())))
+			}
 		}
 	}
 
@@ -490,6 +509,24 @@ func (this *NTFServer) GroupChatSayHTML(str string) error {
 	return err
 }
 
+func (this *NTFServer) getUserlistText(conn *libnmdc.HubConnection) (string, error) {
+	usernames := make([]string, 0)
+	err := conn.Users(func(umap *map[string]libnmdc.UserInfo) error {
+		for k, _ := range *umap {
+			usernames = append(usernames, k)
+		}
+		return nil
+	})
+
+	if err != nil {
+		log.Printf("Error retrieving userlist: %s", err.Error())
+		return "", err
+	}
+
+	sort.Strings(usernames)
+	return strings.Join(usernames, " "), nil
+}
+
 func (this *NTFServer) HandleDirectMessage(update telegram.Update) error {
 
 	// Registration workflow
@@ -576,20 +613,12 @@ func (this *NTFServer) HandleDirectMessage(update telegram.Update) error {
 			return respond("Can't get userlist for you (No upstream hub connection)")
 		}
 
-		usernames := make([]string, 0)
-		err := conn.Users(func(umap *map[string]libnmdc.UserInfo) error {
-			for k, _ := range *umap {
-				usernames = append(usernames, k)
-			}
-			return nil
-		})
+		usernames, err := this.getUserlistText(conn)
 		if err != nil {
-			log.Printf("Error retrieving userlist: %s", err.Error())
 			return respond("Can't get userlist for you (internal error)")
 		}
 
-		sort.Strings(usernames)
-		return respond("Online users: " + strings.Join(usernames, " "))
+		return respond("Online users: " + usernames)
 
 	} else if strings.HasPrefix(msg, "/whois ") {
 		target := msg[7:]