package main

import (
	"context"
	"os"
	"os/signal"
	"syscall"
	"time"

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

	discordadapter "gitea.nik4nao.com/nik/home-services/discord-bot/internal/adapters/primary/discord"
	"gitea.nik4nao.com/nik/home-services/discord-bot/internal/adapters/secondary/gateway"
	"gitea.nik4nao.com/nik/home-services/discord-bot/internal/app"
	"gitea.nik4nao.com/nik/home-services/discord-bot/internal/config"
	"gitea.nik4nao.com/nik/home-services/discord-bot/internal/logger"
	"gitea.nik4nao.com/nik/home-services/discord-bot/internal/telemetry"
)

var version = "dev"

func main() {
	_ = godotenv.Load()

	// Config is loaded before logger setup so fatal startup errors still stop early.
	cfg, err := config.Load()
	if err != nil {
		os.Stderr.WriteString("config error: " + err.Error() + "\n")
		os.Exit(1)
	}

	log := logger.New(cfg.LogFormat, cfg.LogLevel)
	log.Info("starting discord-bot",
		"version", version,
		"ha_gateway_addr", cfg.HAGatewayAddr,
		"discord_token", redactToken(cfg.DiscordToken),
		"log_level", cfg.LogLevel,
		"log_format", cfg.LogFormat,
	)

	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()
	ctx = logger.WithLogger(ctx, log)

	// Telemetry is optional; an empty OTEL endpoint installs no-op providers.
	shutdown, err := telemetry.Setup(ctx, "discord-bot", version, cfg)
	if err != nil {
		log.Error("telemetry setup failed", "err", err)
		os.Exit(1)
	}
	if cfg.OTELEndpoint != "" {
		log.Info("telemetry enabled", "endpoint", cfg.OTELEndpoint)
	} else {
		log.Debug("telemetry disabled")
	}

	haClient, err := gateway.New(ctx, cfg.HAGatewayAddr, log)
	if err != nil {
		log.Error("ha-gateway client setup failed", "err", err)
		os.Exit(1)
	}
	defer func() {
		if err := haClient.Close(); err != nil {
			log.Error("ha-gateway client close failed", "err", err)
		}
	}()

	commandApp := app.NewCommandApp(haClient)

	// Discord-specific wiring stays at the edge so the app layer remains transport-agnostic.
	session, err := discordgo.New("Bot " + cfg.DiscordToken)
	if err != nil {
		log.Error("create discord session failed", "err", err)
		os.Exit(1)
	}
	session.Identify.Intents = discordgo.IntentsGuilds

	handler := discordadapter.NewHandler(commandApp)
	handler.Register(session)

	if err := session.Open(); err != nil {
		log.Error("open discord session failed", "err", err)
		os.Exit(1)
	}
	log.Info("discord session ready", "bot_user", session.State.User.Username)

	if err := discordadapter.RegisterCommands(session, cfg.GuildID); err != nil {
		log.Error("register discord commands failed", "err", err)
		os.Exit(1)
	}

	scope := "global"
	if cfg.GuildID != "" {
		scope = cfg.GuildID
	}
	log.Info("discord bot started", "command_scope", scope, "ha_gateway_addr", cfg.HAGatewayAddr, "version", version)

	<-ctx.Done()
	log.Info("shutdown signal received, closing session")

	if err := session.Close(); err != nil {
		log.Error("close discord session failed", "err", err)
	}
	log.Info("shutdown complete")

	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	if err := shutdown(shutdownCtx); err != nil {
		log.Error("telemetry shutdown error", "err", err)
	}
}

// redactToken logs only a short prefix so startup logs remain useful without
// leaking the full Discord bot token.
func redactToken(token string) string {
	if token == "" {
		return "[not set]"
	}
	if len(token) <= 8 {
		return "[set]"
	}
	return token[:8] + "..."
}