Custom Slack Bot in Go

demo-bot.go

package main

import (
	"log"
	"os"
	"os/signal"
	"strconv"

	"github.com/FogCreek/victor"
	"github.com/FogCreek/victor/pkg/chat/slackRealtime"
	"github.com/FogCreek/victor/pkg/events"
	"github.com/FogCreek/victor/pkg/events/definedEvents"
)

const (
	SECRET_NUMBER = 42
	BOT_NAME = "Guess the number"
)

func getVictorConfig(args []string) victor.Config {
	if len(args) >= 2 && args[1] == "shell" {
		return victor.Config{
			ChatAdapter: "shell",
			Name:        BOT_NAME,
		}
	}

	return victor.Config{
		ChatAdapter:   "slackRealtime",
		AdapterConfig: slackRealtime.NewConfig(os.Getenv("SLACK_TOKEN")),
		Name:          BOT_NAME,
	}
}

func main() {
	victorConfig := getVictorConfig(os.Args)

	bot := victor.New(victorConfig)

	addHandlers(bot)

	// optional help built in help command
	bot.EnableHelpCommand()
	bot.Run()
	go monitorErrors(bot.ChatErrors())
	go monitorEvents(bot.ChatEvents())
	// keep the process (and bot) alive
	sigs := make(chan os.Signal, 1)
	signal.Notify(sigs, os.Interrupt)
	<-sigs

	bot.Stop()
}

func monitorErrors(errorChannel chan events.ErrorEvent) {
	for {
		err, ok := <-errorChannel
		if !ok {
			return
		}
		if err.IsFatal() {
			log.Fatal(err)
		}
		log.Println("Chat Adapter Error Event:", err)
	}
}

func monitorEvents(eventsChannel chan events.ChatEvent) {
	for {
		event, ok := <-eventsChannel
		if !ok {
			return
		}
		switch e := event.(type) {
		case *definedEvents.ConnectingEvent:
			log.Println("Connecting Event fired")
		case *definedEvents.ConnectedEvent:
			log.Println("Connected Event fired")
		case *definedEvents.UserEvent:
			log.Printf("User Event: %+v", e)
		case *definedEvents.ChannelEvent:
			log.Printf("Channel Event: %+v", e)
		default:
			log.Println("Unrecognized Chat Event:", e)
		}
	}
}

func addHandlers(r victor.Robot) {
	r.HandleCommand(&victor.HandlerDoc{
		CmdHandler:     guessFunc,
		CmdName:        "guess",
		CmdDescription: "Guess a number from 1-100",
		CmdUsage:       []string{"<number>"},
	})

	// Add default handler to show "unrecognized command" on "command" messages
	r.SetDefaultHandler(defaultFunc)
}

func guessFunc(s victor.State) {
	params := s.Fields()

	if len(params) != 1 {
		s.Chat().Send(s.Message().Channel().ID(), "please supply just 1 number")
		return
	}

	guess, err := strconv.Atoi(params[0])
	if err != nil {
		s.Chat().Send(s.Message().Channel().ID(), err.Error())
		return
	}

	if guess == SECRET_NUMBER {
		s.Chat().Send(s.Message().Channel().ID(), "Correct")
	} else {
		s.Chat().Send(s.Message().Channel().ID(), "Guess again")
	}

	return
}

func defaultFunc(s victor.State) {
	s.Chat().Send(s.Message().Channel().ID(),
		"Unrecognized command. Type `help` to see supported commands.")
}