Implement automatic channel joining

Avoid the need for an administrator to join the bot to channels by
implementing a configuration option allowing the passing of channels
the bot should always join to by itself upon startup.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

config.example.yaml

@@ -13,6 +13,8 @@ watbot:
     hosts:
       - annoying.example.com
   channels:  # optional, no default
+    join:
+        - crantest  # channels without a prefix character will be prefixed with "#"
     permitted:
         - '#lucy'
 

main.go

@@ -28,6 +28,7 @@ type watConfig struct {
 		Hosts []string		`yaml:"hosts"`
 	}				`yaml:"admins"`
 	Channels 	struct {
+		Join      []string	`yaml:"join"`
 		Permitted []string	`yaml:"permitted"`
 	}				`yaml:"channels"`
 	Ignores struct {
@@ -94,6 +95,7 @@ func main() {
 		Name: config.Name,
 	}
 	watConfig := wat.WatConfig{
+		AutoJoinChannels:  config.Channels.Join,
 		PermittedChannels: config.Channels.Permitted,
 		IgnoredHosts:      config.Ignores.Hosts,
 		AdminHosts:        config.Admins.Hosts,

wat/bot.go

@@ -20,6 +20,7 @@ type WatBot struct {
 type WatConfig struct {
 	AdminHosts        []string
 	IgnoredHosts      []string
+	AutoJoinChannels  []string
 	PermittedChannels []string
 }
 
@@ -36,12 +37,24 @@ func CleanNick(nick string) string {
 	return string(nick[0]) + "\u200c" + nick[1:]
 }
 
+func PrefixChannel(channel string) string {
+	// there could theoretically be other channel prefixes ..
+	if channel[0] != '#' && channel[0] != '!' {
+		channel = "#" + channel
+	}
+	return channel
+}
+
 func (w *WatBot) HandleIrcMsg(c *irc.Client, m *irc.Message) {
 	switch cmd := m.Command; cmd {
 	case "PING":
 		w.write("PONG", m.Params[0])
 	case "PRIVMSG":
 		w.Msg(m)
+	case "001":
+		for _, channel := range w.c.AutoJoinChannels {
+			w.write("JOIN", PrefixChannel(channel))
+		}
 	}
 }
 
@@ -68,7 +81,7 @@ func (w *WatBot) CanRespond(m *irc.Message) bool {
 	// if !strings.Contains(m.Prefix.Host, "") {
 	// 	return false
 	// }
-	if !w.Allowed(m.Params[0], w.c.PermittedChannels) {
+	if !w.Allowed(PrefixChannel(m.Params[0]), w.c.PermittedChannels) {
 		return false
 	}
 	return true