Initial support for message formatting

Allows for the user to define how messages are formatted back and forth
between Discord and IRC.

Co-authored-by: Qais Patankar <[email protected]>

bridge/bridge.go

@@ -36,6 +36,9 @@ type Config struct {
 	IRCPuppetPrejoinCommands   []string
 	IRCListenerPrejoinCommands []string
 
+	DiscordFormat map[string]string // formatting for non-PRIVMSG relays from IRC to Discord
+	IRCFormat     string            // format for messages relayed in simple mode
+
 	// NoTLS constrols whether to use TLS at all when connecting to the IRC server
 	NoTLS bool
 

bridge/irc_connection.go

@@ -124,12 +124,15 @@ func (i *ircConnection) OnPrivateMessage(e *irc.Event) {
 		}
 
 		d := i.manager.bridge.discord
+		msg := i.manager.formatDiscordMessage("PM", e, e.Message(), "")
+
+		// if we have an empty message
+		if msg == "" {
+			return // do nothing, Discord doesn't like those
+		}
 
 		i.introducePM(e.Nick)
 
-		msg := fmt.Sprintf(
-			"%s,%s - %s@%s: %s", e.Connection.Server, e.Source,
-			e.Nick, i.manager.bridge.Config.Discriminator, e.Message())
 		_, err := d.ChannelMessageSend(i.pmDiscordChannel, msg)
 		if err != nil {
 			log.Warnln("Could not send PM", i.discord, err)

bridge/irc_listener.go

@@ -13,11 +13,12 @@ type ircListener struct {
 	bridge *Bridge
 
 	joinQuitCallbacks map[string]int
+	relayNickTrackID  int
 }
 
 func newIRCListener(dib *Bridge, webIRCPass string) *ircListener {
 	irccon := irc.IRC(dib.Config.IRCListenerName, "discord")
-	listener := &ircListener{irccon, dib, nil}
+	listener := &ircListener{irccon, dib, nil, 0}
 
 	dib.SetupIRCConnection(irccon, "discord.", "fd75:f5f5:226f::")
 	listener.SetDebugMode(dib.Config.Debug)
@@ -39,6 +40,8 @@ func newIRCListener(dib *Bridge, webIRCPass string) *ircListener {
 		listener.JoinChannels()
 	})
 
+	listener.AddCallback("NICK", listener.nickTrackNick)
+
 	// Note that this might override SetupNickTrack!
 	listener.OnJoinQuitSettingChange()
 
@@ -66,6 +69,51 @@ func (i *ircListener) nickTrackNick(event *irc.Event) {
 	}
 }
 
+func userOnChannelFix(user string, channel irc.Channel) bool {
+	if _, ok := channel.Users[user]; ok {
+		return true
+	}
+
+	// work around nicks being prefixed with mode characters for some reason
+	for _, c := range "!$~&@%+" {
+		if _, ok := channel.Users[string(c)+user]; ok {
+			return true
+		}
+	}
+
+	return false
+}
+
+func (i *ircListener) OnNickRelayToDiscord(event *irc.Event) {
+	newNick := event.Message()
+	message := i.bridge.ircManager.formatDiscordMessage(event.Code, event, newNick, "")
+
+	// if the message is empty...
+	if message == "" {
+		return // do nothing, Discord doesn't like empty messages anyway
+	}
+
+	msg := IRCMessage{
+		Username: "",
+		Message:  message,
+	}
+
+	for _, m := range i.bridge.mappings {
+		channel := m.IRCChannel
+		channelObj, ok := i.Connection.Channels[channel]
+		if !ok {
+			continue
+		}
+
+		if !userOnChannelFix(newNick, channelObj) {
+			continue
+		}
+
+		msg.IRCChannel = channel
+		i.bridge.discordMessagesChan <- msg
+	}
+}
+
 // From irc_nicktrack.go.
 func (i *ircListener) nickTrackQuit(e *irc.Event) {
 	for k := range i.Connection.Channels {
@@ -76,8 +124,11 @@ func (i *ircListener) nickTrackQuit(e *irc.Event) {
 func (i *ircListener) OnJoinQuitSettingChange() {
 	// Clear Nicktrack QUIT callback as it races with this
 	i.ClearCallback("QUIT")
-	i.ClearCallback("NICK")
-	i.AddCallback("NICK", i.nickTrackNick)
+
+	if i.relayNickTrackID != 0 {
+		i.RemoveCallback("NICK", i.relayNickTrackID)
+		i.relayNickTrackID = 0
+	}
 
 	// If remove callbacks...
 	if !i.bridge.Config.ShowJoinQuit {
@@ -90,6 +141,8 @@ func (i *ircListener) OnJoinQuitSettingChange() {
 		return
 	}
 
+	i.relayNickTrackID = i.AddCallback("NICK", i.OnNickRelayToDiscord)
+
 	callbacks := []string{"JOIN", "PART", "QUIT", "KICK"}
 	cbs := make(map[string]int, len(callbacks))
 	for _, cb := range callbacks {
@@ -112,29 +165,33 @@ func (i *ircListener) OnJoinQuitCallback(event *irc.Event) {
 		return
 	}
 
-	who := event.Nick
-	message := event.Nick
-	id := " (" + event.User + "@" + event.Host + ") "
+	message := ""
+	content := ""
+	target := ""
+	manager := i.bridge.ircManager
 
 	switch event.Code {
 	case "JOIN":
-		message += " joined" + id
+		message = manager.formatDiscordMessage(event.Code, event, "", "")
 	case "PART":
-		message += " left" + id
 		if len(event.Arguments) > 1 {
-			message += ": " + event.Arguments[1]
+			content = event.Arguments[1]
 		}
+		message = manager.formatDiscordMessage(event.Code, event, content, "")
 	case "QUIT":
-		message += " quit" + id
-
-		reason := event.Nick
+		content := event.Nick
 		if len(event.Arguments) == 1 {
-			reason = event.Arguments[0]
+			content = event.Arguments[0]
 		}
-		message += "Quit: " + reason
+		message = manager.formatDiscordMessage(event.Code, event, content, "")
 	case "KICK":
-		who = event.Arguments[1]
-		message = event.Arguments[1] + " was kicked by " + event.Nick + ": " + event.Arguments[2]
+		target, content = event.Arguments[1], event.Arguments[2]
+		message = manager.formatDiscordMessage(event.Code, event, content, target)
+	}
+
+	// if the message is empty...
+	if message == "" {
+		return // do nothing, Discord doesn't like empty messages anyway
 	}
 
 	msg := IRCMessage{
@@ -149,10 +206,10 @@ func (i *ircListener) OnJoinQuitCallback(event *irc.Event) {
 			channel := m.IRCChannel
 			channelObj, ok := i.Connection.Channels[channel]
 			if !ok {
-				log.WithField("channel", channel).WithField("who", who).Warnln("Trying to process QUIT. Channel not found in irc listener cache.")
+				log.WithField("channel", channel).WithField("who", event.Nick).Warnln("Trying to process QUIT. Channel not found in irc listener cache.")
 				continue
 			}
-			if _, ok := channelObj.Users[who]; !ok {
+			if _, ok := channelObj.Users[event.Nick]; !ok {
 				continue
 			}
 			msg.IRCChannel = channel

bridge/irc_manager.go

@@ -337,6 +337,18 @@ func (m *IRCManager) generateNickname(discord DiscordUser) string {
 	return newNick
 }
 
+func (m *IRCManager) formatIRCMessage(message *DiscordMessage, content string) string {
+	msg := m.bridge.Config.IRCFormat
+	length := len(message.Author.Username)
+	msg = strings.ReplaceAll(msg, "${USER}", message.Author.Username[:1]+"\u200B"+message.Author.Username[1:length])
+	msg = strings.ReplaceAll(msg, "${DISCRIMINATOR}", message.Author.Discriminator)
+	msg = strings.ReplaceAll(msg, "${CONTENT}", content)
+
+	// we don't do trimming and later checks here, IRC doesn't mind blank messages or at least doesn't complain
+	// as loudly as Discord
+	return msg
+}
+
 // SendMessage sends a broken down Discord Message to a particular IRC channel.
 func (m *IRCManager) SendMessage(channel string, msg *DiscordMessage) {
 	if m.ircIgnoredDiscord(msg.Author.ID) {
@@ -351,14 +363,8 @@ func (m *IRCManager) SendMessage(channel string, msg *DiscordMessage) {
 
 	// Person is appearing offline (or the bridge is running in Simple Mode)
 	if !ok {
-		length := len(msg.Author.Username)
 		for _, line := range strings.Split(content, "\n") {
-			m.bridge.ircListener.Privmsg(channel, fmt.Sprintf(
-				"<%s#%s> %s",
-				msg.Author.Username[:1]+"\u200B"+msg.Author.Username[1:length],
-				msg.Author.Discriminator,
-				line,
-			))
+			m.bridge.ircListener.Privmsg(channel, m.formatIRCMessage(msg, line))
 		}
 		return
 	}
@@ -392,6 +398,22 @@ func (m *IRCManager) SendMessage(channel string, msg *DiscordMessage) {
 	}
 }
 
+func (m *IRCManager) formatDiscordMessage(msgFormat string, e *irc.Event, content string, target string) string {
+	msg := ""
+	if format, ok := m.bridge.Config.DiscordFormat[strings.ToLower(msgFormat)]; ok && format != "" {
+		msg = format
+		msg = strings.ReplaceAll(msg, "${NICK}", e.Nick)
+		msg = strings.ReplaceAll(msg, "${IDENT}", e.User)
+		msg = strings.ReplaceAll(msg, "${HOST}", e.Host)
+		msg = strings.ReplaceAll(msg, "${CONTENT}", content)
+		msg = strings.ReplaceAll(msg, "${TARGET}", target)
+		msg = strings.ReplaceAll(msg, "${SERVER}", e.Connection.Server)
+		msg = strings.ReplaceAll(msg, "${DISCRIMINATOR}", m.bridge.Config.Discriminator)
+	}
+
+	return strings.Trim(msg, " ")
+}
+
 // RequestChannels finds all the Discord channels this user belongs to,
 // and then find pairings in the global pairings list
 // Currently just returns all participating IRC channels

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"os"
 	"os/signal"
 	"path/filepath"
@@ -92,10 +93,21 @@ func main() {
 	//
 	viper.SetDefault("irc_puppet_prejoin_commands", []string{"MODE ${NICK} +D"})
 	ircPuppetPrejoinCommands := viper.GetStringSlice("irc_puppet_prejoin_commands") // Commands for each connection to send before joining channels
+	rawDiscordFormat := viper.GetStringMapString("discord_format")
+	var discordFormat map[string]string
+	if df, err := setupDiscordFormat(rawDiscordFormat); err == nil {
+		discordFormat = df
+	} else {
+		log.WithError(err).Fatal("discord_format setting is invalid")
+		return
+	}
 	//
 	viper.SetDefault("avatar_url", "https://ui-avatars.com/api/?name=${USERNAME}")
 	avatarURL := viper.GetString("avatar_url")
 	//
+	viper.SetDefault("irc_format", "<${USER}#${DISCRIMINATOR}> ${CONTENT}")
+	ircFormat := viper.GetString("irc_format")
+	//
 	viper.SetDefault("irc_listener_name", "~d")
 	ircUsername := viper.GetString("irc_listener_name") // Name for IRC-side bot, for listening to messages.
 	// Name to Connect to IRC puppet account with
@@ -140,7 +152,9 @@ func main() {
 		AvatarURL:                  avatarURL,
 		Discriminator:              discriminator,
 		DiscordBotToken:            discordBotToken,
+		DiscordFormat:              discordFormat,
 		GuildID:                    guildID,
+		IRCFormat:                  ircFormat,
 		IRCListenerName:            ircUsername,
 		IRCServer:                  ircServer,
 		IRCServerPass:              ircPassword,
@@ -219,6 +233,14 @@ func main() {
 		}
 		dib.Config.DiscordIgnores = discordIgnores
 
+		rawDiscordFormat := viper.GetStringMapString("discord_format")
+		if discordFormat, err := setupDiscordFormat(rawDiscordFormat); err == nil {
+			dib.Config.DiscordFormat = discordFormat
+		} else {
+			log.WithError(err).Error("discord_format setting is invalid, this setting has not been updated")
+		}
+		dib.Config.IRCFormat = viper.GetString("irc_format")
+
 		chans := viper.GetStringMapString("channel_mappings")
 		equalChans := reflect.DeepEqual(chans, channelMappings)
 		if !equalChans {
@@ -259,6 +281,34 @@ func setupHostmaskMatchers(hostmasks []string) []glob.Glob {
 	return matchers
 }
 
+func setupDiscordFormat(discordFormat map[string]string) (map[string]string, error) {
+	var err error
+	// lowercase to match that YAML lowercases it
+	discordFormatDefaults := map[string]string{
+		"pm":   "${SERVER},${NICK}!${IDENT}@${HOST} - ${NICK}@${DISCRIMINATOR}: ${CONTENT}",
+		"join": "_${NICK} joined (${IDENT}@${HOST})_",
+		"part": "_${NICK} left (${IDENT}@${HOST}) - ${CONTENT}_",
+		"quit": "_${NICK} quit (${IDENT}@${HOST}) - Quit: ${CONTENT}_",
+		"kick": "_${TARGET} was kicked by ${NICK} - ${CONTENT}_",
+		"nick": "_${NICK} changed nick to ${CONTENT}_",
+	}
+
+	for ev, format := range discordFormatDefaults {
+		if df, ok := discordFormat[ev]; !ok || df == "" {
+			discordFormat[ev] = format
+		}
+	}
+
+	for ev := range discordFormat {
+		if _, ok := discordFormatDefaults[ev]; !ok {
+			err = fmt.Errorf("Unknown format key %s", ev)
+			break
+		}
+	}
+
+	return discordFormat, err
+}
+
 func SetLogDebug(debug bool) {
 	logger := log.StandardLogger()
 	if debug {