Support join/leaves from discord. Closes #654 (#721)

bridge/discord/discord.go

@@ -75,6 +75,8 @@ func (b *Bdiscord) Connect() error {
 	b.c.AddHandler(b.memberUpdate)
 	b.c.AddHandler(b.messageUpdate)
 	b.c.AddHandler(b.messageDelete)
+	b.c.AddHandler(b.memberAdd)
+	b.c.AddHandler(b.memberRemove)
 	err = b.c.Open()
 	if err != nil {
 		return err

bridge/discord/handlers.go

@@ -123,3 +123,45 @@ func (b *Bdiscord) memberUpdate(s *discordgo.Session, m *discordgo.GuildMemberUp
 		b.nickMemberMap[m.Member.Nick] = m.Member
 	}
 }
+
+func (b *Bdiscord) memberAdd(s *discordgo.Session, m *discordgo.GuildMemberAdd) {
+	if m.Member == nil {
+		b.Log.Warnf("Received member update with no member information: %#v", m)
+		return
+	}
+	username := m.Member.User.Username
+	if m.Member.Nick != "" {
+		username = m.Member.Nick
+	}
+
+	rmsg := config.Message{
+		Account:  b.Account,
+		Event:    config.EventJoinLeave,
+		Username: "system",
+		Text:     username + " joins",
+	}
+	b.Log.Debugf("<= Sending message from %s to gateway", b.Account)
+	b.Log.Debugf("<= Message is %#v", rmsg)
+	b.Remote <- rmsg
+}
+
+func (b *Bdiscord) memberRemove(s *discordgo.Session, m *discordgo.GuildMemberRemove) {
+	if m.Member == nil {
+		b.Log.Warnf("Received member update with no member information: %#v", m)
+		return
+	}
+	username := m.Member.User.Username
+	if m.Member.Nick != "" {
+		username = m.Member.Nick
+	}
+
+	rmsg := config.Message{
+		Account:  b.Account,
+		Event:    config.EventJoinLeave,
+		Username: "system",
+		Text:     username + " leaves",
+	}
+	b.Log.Debugf("<= Sending message from %s to gateway", b.Account)
+	b.Log.Debugf("<= Message is %#v", rmsg)
+	b.Remote <- rmsg
+}

gateway/gateway.go

@@ -174,6 +174,18 @@ func (gw *Gateway) getDestChannel(msg *config.Message, dest bridge.Bridge) []con
 		return channels
 	}
 
+	// discord join/leave is for the whole bridge, isn't a per channel join/leave
+	if msg.Event == config.EventJoinLeave && dest.Protocol == "discord" && msg.Account == dest.Account {
+		flog.Error("here")
+		for _, channel := range gw.Channels {
+			if channel.Account == msg.Account && strings.Contains(channel.Direction, "out") &&
+				gw.validGatewayDest(msg) {
+				channels = append(channels, *channel)
+			}
+		}
+		return channels
+	}
+
 	// if source channel is in only, do nothing
 	for _, channel := range gw.Channels {
 		// lookup the channel from the message