package main

import (
	"flag"
	"fmt"
	"log"
	"math/rand/v2"
	"os"
	"os/signal"
	"strconv"
	"time"

	"github.com/bwmarrin/discordgo"
	"github.com/joho/godotenv"
)

var botToken string
var announceChannelName string
var cleanDelay = 30

var confFile string

func init() {
	flag.StringVar(&confFile, "conf", ".env", ".env file w/ config variables")
	flag.Parse()
}

var joinMessages = []string{
	"<@%s> has joined <#%s>",
	"<@%s> has joined <#%s>; Join in for some nerd talk",
	"<#%[2]s> is the place to be! <@%[1]s> just joined",
	"<#%[2]s> just go a bit cooler, <@%[1]s> is now in",
	"<@%s> is hanging out in <#%s>",
}

func main() {
	envs, err := godotenv.Read(confFile)
	if err != nil {
		log.Fatalf("Unable to get environment variables: %v", err)
	}

	// set values from env
	botToken = envs["BOT_TOKEN"]
	announceChannelName = envs["ANNOUNCE_CHANNEL"]
	if delay, ok := envs["CLEAN_DELAY"]; ok {
		if d2, err := strconv.Atoi(delay); err == nil {
			cleanDelay = d2
		}
	}

	s, err := discordgo.New("Bot " + botToken)
	if err != nil {
		log.Fatal(err)
	}

	// Log all of the servers tht this bot is installed in.
	s.AddHandler(func(s *discordgo.Session, r *discordgo.Ready) {
		for _, g := range r.Guilds {
			g2, _ := s.Guild(g.ID)
			log.Printf("Bot is connected to %q.", g2.Name)
		}
	})

	// Add different capability handlers:
	s.AddHandler(voiceStatus)

	err = s.Open()
	if err != nil {
		log.Fatalf("Cannot open the session: %v", err)
	}
	defer s.Close()

	stop := make(chan os.Signal, 1)
	signal.Notify(stop, os.Interrupt)
	<-stop
}

// Handle for when someone joins a voice channel - send notification about them joining.
func voiceStatus(s *discordgo.Session, m *discordgo.VoiceStateUpdate) {
	if m.BeforeUpdate != nil || m.VoiceState == nil {
		return
	}
	channels, err := s.GuildChannels(m.VoiceState.GuildID)
	if err != nil {
		log.Printf("Unable to get channels for Guild: %s", m.VoiceState.GuildID)
		return
	}
	var announceChannel *discordgo.Channel
	for _, c := range channels {
		if c.Name == announceChannelName {
			announceChannel = c
		}
	}
	if announceChannel == nil {
		log.Printf("Unable to get announce channel for Guild: %s", m.VoiceState.GuildID)
		return
	}
	msg := joinMessages[rand.IntN(len(joinMessages))]

	sent, err := s.ChannelMessageSend(announceChannel.ID, fmt.Sprintf(msg, m.VoiceState.UserID, m.VoiceState.ChannelID))
	g, _ := s.Guild(m.VoiceState.GuildID)
	log.Default().Printf("%q has joined %q in %s", m.VoiceState.Member.DisplayName(), m.VoiceState.ChannelID, g.Name)
	if err != nil {
		log.Printf("unable to send message: %s", err)
	}
	time.AfterFunc(time.Second*time.Duration(cleanDelay), func() {
		s.ChannelMessageDelete(sent.ChannelID, sent.ID)
	})
}