bot: fix voice reconnect

fixes #10 - reconnect to discord voice properly

aria/bot.go

@@ -14,13 +14,16 @@ import (
 
 const chanTimeout = 30 * time.Second
 
+var errNotInVoice = errors.New("user not in voice")
+
 type bot struct {
 	sync.RWMutex
 	*discordgo.Session
 
 	token    string
 	prefix   string
 	keepMsg  keepMsgMap
+	voice    voiceState
 	ariaRecv <-chan *packet
 	ariaSend chan<- *request
 
@@ -38,6 +41,7 @@ type bot struct {
 
 func newBot(
 	config *config,
+	voice voiceState,
 	cliToBot <-chan *packet,
 	botToCli chan<- *request,
 	stream <-chan []byte,
@@ -58,6 +62,7 @@ func newBot(
 	}
 	b.keepMsg = config.keepMsg
 
+	b.voice = voice
 	b.stream = stream
 	b.ariaRecv = cliToBot
 	b.ariaSend = botToCli
@@ -227,15 +232,15 @@ func (b *bot) onDisconnect(_ *discordgo.Session, _ *discordgo.Disconnect) {
 	b.cancel()
 }
 
-// TODO: when ready, join all AutoJoin channels
 func (b *bot) onReady(s *discordgo.Session, r *discordgo.Ready) {
 	b.Lock()
+	b.botUser = r.User
 	defer b.Unlock()
 
-	b.botUser = r.User
+	b.recoverVoiceConnections()
 }
 
-// parse message from discord, fire cmdHandlers
+// onMessage parses message from discord and fire cmdHandlers
 func (b *bot) onMessage(s *discordgo.Session, m *discordgo.MessageCreate) {
 	b.RLock()
 	if m.Author.ID == b.botUser.ID {
@@ -275,6 +280,41 @@ func (b *bot) onMessage(s *discordgo.Session, m *discordgo.MessageCreate) {
 
 // utilities
 
+func (b *bot) recoverVoiceConnections() {
+	v := b.voice.cloneJoined()
+	for c, g := range v {
+		if err := b.joinVoice(g, c); err != nil {
+			log.Printf("failedc to recover voice: %v\n", err)
+		}
+	}
+}
+
+func (b *bot) joinVoice(guildID, channelID string) error {
+	_, err := b.ChannelVoiceJoin(guildID, channelID, false, false)
+	if err != nil {
+		return err
+	}
+	b.voice.recordJoin(guildID, channelID)
+	return nil
+}
+
+func (b *bot) disconnectVoice(guildID string) error {
+	b.Session.RLock()
+	v, ok := b.Session.VoiceConnections[guildID]
+	b.Session.RUnlock()
+
+	if !ok {
+		return errNotInVoice
+	}
+
+	if err := v.Disconnect(); err != nil {
+		return err
+	}
+
+	b.voice.recordDisconnect(v.ChannelID)
+	return nil
+}
+
 func (b *bot) resolveCommand(raw string) (cmd string) {
 	_, ok := b.cmdHandlers[raw]
 	if ok {

aria/commands.go

@@ -324,24 +324,19 @@ func (b *bot) cmdSummon(m *discordgo.Message, _ []string) {
 		return
 	}
 
-	_, err = b.ChannelVoiceJoin(g.ID, vid, false, false)
-	if err != nil {
-		log.Printf("failed to join voice: %v\n", err)
+	if err = b.joinVoice(m.GuildID, vid); err != nil {
+		log.Printf("failed to summon voice: %v\n", err)
 	}
 }
 
 func (b *bot) cmdDisconnect(m *discordgo.Message, _ []string) {
-	b.Session.RLock()
-	v, ok := b.VoiceConnections[m.GuildID]
-	b.Session.RUnlock()
-
-	if !ok {
-		sendErrorResponse(b, m.ChannelID, "Not in voice channel.")
-		return
-	}
-
-	if err := v.Disconnect(); err != nil {
-		log.Printf("failed to disconnect voice: %v\n", err)
+	if err := b.disconnectVoice(m.GuildID); err != nil {
+		switch err {
+		case errNotInVoice:
+			sendErrorResponse(b, m.ChannelID, "Not in voice channel.")
+		default:
+			log.Printf("failed to disconnect voice: %v\n", err)
+		}
 	}
 }
 

aria/launcher.go

@@ -30,6 +30,7 @@ func setupLogger() {
 
 type launcher struct {
 	config *config
+	voice  voiceState
 
 	cliToBot chan *packet
 	botToCli chan *request
@@ -39,6 +40,7 @@ type launcher struct {
 func newLauncher(config *config) *launcher {
 	return &launcher{
 		config:   config,
+		voice:    newVoiceState(),
 		cliToBot: make(chan *packet),
 		botToCli: make(chan *request),
 		stream:   make(chan []byte),
@@ -91,7 +93,7 @@ func (l *launcher) launchBot(ctx context.Context, errChan chan<- error) {
 			}
 		}
 
-		b, err := newBot(l.config, l.cliToBot, l.botToCli, l.stream)
+		b, err := newBot(l.config, l.voice, l.cliToBot, l.botToCli, l.stream)
 		if err != nil {
 			errChan <- fmt.Errorf("failed to initialize bot: %w", err)
 			return

aria/voice.go

@@ -0,0 +1,49 @@
+package aria
+
+import (
+	"sync"
+)
+
+type voice struct {
+	sync.RWMutex
+	joined map[string]string // channelID -> guildID
+}
+
+type voiceState interface {
+	// cloneJoined returns map contains channelID -> guildID
+	cloneJoined() map[string]string
+	recordJoin(guildID, channelID string)
+	recordDisconnect(channelID string)
+}
+
+func newVoiceState() voiceState {
+	return &voice{
+		joined: make(map[string]string),
+	}
+}
+
+func (v *voice) cloneJoined() map[string]string {
+	v.RLock()
+	defer v.RUnlock()
+
+	ret := make(map[string]string)
+	for k, v := range v.joined {
+		ret[k] = v
+	}
+
+	return ret
+}
+
+func (v *voice) recordJoin(guildID, channelID string) {
+	v.Lock()
+	defer v.Unlock()
+
+	v.joined[channelID] = guildID
+}
+
+func (v *voice) recordDisconnect(channelID string) {
+	v.Lock()
+	defer v.Unlock()
+
+	delete(v.joined, channelID)
+}