backend/bot/bot.go

package bot

import (
	"context"
	"log"

	"gitea.konchin.com/go2025/backend/tracing"
	"github.com/bwmarrin/discordgo"
	"github.com/go-resty/resty/v2"
	"github.com/spf13/viper"
	"go.uber.org/zap"
)

type CommandHandler = func(
	*discordgo.Session, *discordgo.InteractionCreate)

type Command interface {
	ApplicationCommand() *discordgo.ApplicationCommand
	Handler() CommandHandler
}

type Bot struct {
	session  *discordgo.Session
	commands map[string]Command
	aliases  map[string]int64

	Client *resty.Client
}

func New() (*Bot, error) {
	// Create Discord session
	session, err := discordgo.New(
		"Bot " + viper.GetString("discord-bot-token"))
	if err != nil {
		return nil, err
	}
	client := resty.New()
	client.SetBaseURL(viper.GetString("api-endpoint"))
	client.SetAuthToken(viper.GetString("preshared-key"))

	bot := &Bot{
		session:  session,
		commands: make(map[string]Command),

		Client: client,
	}

	bot.registerHandlers()

	go bot.fetchAliases()

	// Set intents - only need guild messages for the ciallo listener
	session.Identify.Intents = discordgo.IntentsGuildMessages |
		discordgo.IntentsDirectMessages |
		discordgo.IntentsMessageContent

	return bot, nil
}

func (b *Bot) registerSlashCommands(ctx context.Context) error {
	for _, cmd := range b.commands {
		_, err := b.session.ApplicationCommandCreate(
			b.session.State.User.ID, "", cmd.ApplicationCommand())
		if err != nil {
			tracing.Logger.Ctx(ctx).
				Error("failed to create command",
					zap.String("command", cmd.ApplicationCommand().Name),
					zap.Error(err))
			return err
		}
	}

	return nil
}

func (b *Bot) clearSlashCommands(guildID string) error {
	commands, err := b.session.ApplicationCommands(b.session.State.User.ID, guildID)
	if err != nil {
		return err
	}

	for _, cmd := range commands {
		err := b.session.ApplicationCommandDelete(b.session.State.User.ID, guildID, cmd.ID)
		if err != nil {
			log.Printf("Failed to delete command %s: %v", cmd.Name, err)
		}
	}
	return nil
}

func (b *Bot) registerHandlers() {
	b.session.AddHandler(b.onReady)
	b.session.AddHandler(b.onMessageCreate)
	b.session.AddHandler(b.onInteractionCreate)
}

func (b *Bot) RegisterCommand(newCommand func(*Bot) Command) {
	command := newCommand(b)
	b.commands[command.ApplicationCommand().Name] = command
}

func (b *Bot) onReady(
	s *discordgo.Session,
	event *discordgo.Ready,
) {
	ctx := context.Background()
	tracing.Logger.Ctx(ctx).
		Info("logged in",
			zap.String("username", s.State.User.Username),
			zap.String("discriminator", s.State.User.Discriminator))

	// For development: set your guild ID here for instant updates
	// For production: use "" for global commands
	guildID := "1377176828833169468" // Replace with your Discord server ID for faster testing

	// clear slash commands
	if err := b.clearSlashCommands(guildID); err != nil {
		log.Printf("Error clearing slash commands: %v", err)
	}

	// Register slash commands
	if err := b.registerSlashCommands(ctx); err != nil {
		tracing.Logger.Ctx(ctx).
			Error("failed to register slash commands",
				zap.Error(err))
		return
	}

	// Set bot status
	err := s.UpdateGameStatus(0, "/ping to check status")
	if err != nil {
		tracing.Logger.Ctx(ctx).
			Error("failed to set status",
				zap.Error(err))
		return
	}
}

func (b *Bot) onInteractionCreate(
	s *discordgo.Session,
	i *discordgo.InteractionCreate,
) {
	if i.Type != discordgo.InteractionApplicationCommand {
		return
	}

	command, ok := b.commands[i.ApplicationCommandData().Name]
	if ok {
		tracing.Logger.Ctx(context.Background()).
			Info("run command",
				zap.String("name", i.ApplicationCommandData().Name))
		command.Handler()(s, i)
	} else {
		tracing.Logger.Ctx(context.Background()).
			Error("command not exist",
				zap.String("name", i.ApplicationCommandData().Name))
	}
}

func (b *Bot) Start() error {
	return b.session.Open()
}

func (b *Bot) Stop() {
	if b.session != nil {
		b.session.Close()
	}
}