bot.go

package twitchircgo

import (
	"bufio"
	"fmt"
	"net"
	"net/textproto"
	"regexp"
	"strings"
	"time"
)

//The Bot object which stores irc info
type Bot struct {
	// server to connect to
	server string
	// port to connect to
	port string
	// nickname of bot
	nick string
	// channel to join - #username format
	channels []string
	// mods of channel -> currently unused
	mods map[string]bool
	// connection to irc
	conn net.Conn
	// oauth token containing chat:read and chat:write scopes
	AuthToken string
	// Event listeners
	OnMessage chan *Message
}

// NewBot is a Bot constructor
func NewBot(token string, channels []string, nick string) *Bot {
	defaultChannel := make(chan *Message)

	return &Bot{
		server:    "irc.twitch.tv",
		port:      "6667",
		nick:      nick,
		channels:  channels,
		mods:      make(map[string]bool),
		conn:      nil,
		AuthToken: token,
		OnMessage: defaultChannel}
}

//Connect and connect bot to IRC server
func (bot *Bot) Connect() {
	//close connection if it exists
	if bot.conn != nil {
		err := bot.conn.Close()
		if err != nil {
			fmt.Println("Error closing existing connection.")
		}
	}

	var err error
	fmt.Println("Attempting to connect to Twitch IRC server...")
	bot.conn, err = net.Dial("tcp", bot.server+":"+bot.port)

	if err != nil {
		fmt.Printf("Unable to connect to Twitch IRC server! Reconnecting in 10 seconds...\n")
		time.Sleep(10 * time.Second)
		bot.Connect()
	}

	fmt.Printf("Connected to IRC server %s\n\n", bot.server)

	// Initial pings need to be set
	fmt.Fprintf(bot.conn, "USER %s 8 * :%s\r\n", bot.nick, bot.nick)
	fmt.Fprintf(bot.conn, "PASS oauth:%s\r\n", bot.AuthToken)
	fmt.Fprintf(bot.conn, "NICK %s\r\n", bot.nick)
	for _, v := range bot.channels {
		fmt.Fprintf(bot.conn, "JOIN %s\r\n", v)
	}

	fmt.Fprintf(bot.conn, "CAP REQ :twitch.tv/membership\r\n")
	fmt.Fprintf(bot.conn, "CAP REQ :twitch.tv/tags\r\n")

	go bot.ReadLoop()
}

//Message to IRC channel
func (bot *Bot) Message(channel string, message string) {
	if channel[0] != '#' {
		channel = "#" + channel
	}
	if message != "" {
		fmt.Fprintf(bot.conn, "PRIVMSG "+channel+" :"+message+"\r\n")
	}

}

//ReadLoop for Bot
func (bot *Bot) ReadLoop() {
	reader := bufio.NewReader(bot.conn)
	tp := textproto.NewReader(reader)

	for {
		line, err := tp.ReadLine()

		if err != nil {
			fmt.Println("Bot read loop exited due to error")
			bot.Connect()
			break
		} else if strings.Contains(line, "PING") {
			fmt.Fprintf(bot.conn, "PONG :tmi.twitch.tv")
		} else if strings.Contains(line, ".tmi.twitch.tv PRIVMSG "+"#") {
			lineAndChannel := strings.Split(line, "PRIVMSG ")
			channelRegex := regexp.MustCompile(`#\S+`)
			channel := channelRegex.FindString(lineAndChannel[1])

			message := parseMessage(line, channel)
			bot.OnMessage <- message

		}
	}

}