// Command discord-go is a Go port of discord-rare-monitor: it consumes the
// tracker's /ws/live firehose (subscribed to rare+chat), classifies rares
// common/great, posts embeds to Discord, and relays allegiance chat.
//
// SAFETY: it runs in dry-run (log only, no Discord posts) by default. Going live
// requires BOTH a bot token AND DRY_RUN=0 — so it can never accidentally
// double-post to the production channels during the parallel run. For a parallel
// test, set a TEST token + TEST channel IDs + DRY_RUN=0.
package main

import (
	"context"
	"fmt"
	"log/slog"
	"os"
	"os/signal"
	"sort"
	"syscall"

	"github.com/bwmarrin/discordgo"
)

func main() {
	// `discord-go dump-rares` prints the common-rares set (for parity diffing
	// against the Python regex). No network, no token.
	if len(os.Args) > 1 && os.Args[1] == "dump-rares" {
		names := make([]string, 0, len(commonRares))
		for n := range commonRares {
			names = append(names, n)
		}
		sort.Strings(names)
		for _, n := range names {
			fmt.Println(n)
		}
		return
	}

	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))
	slog.SetDefault(logger)

	token := os.Getenv("DISCORD_RARE_BOT_TOKEN")
	// Dry-run unless a token is present AND DRY_RUN is explicitly "0".
	dryRun := token == "" || os.Getenv("DRY_RUN") != "0"

	wsURL := envOr("DERETH_TRACKER_WS_URL", "ws://dereth-tracker:8765/ws/live")
	monitorChar := envOr("MONITOR_CHARACTER", "Dunking Rares")

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

	var out poster
	if dryRun {
		reason := "no DISCORD_RARE_BOT_TOKEN"
		if token != "" {
			reason = "DRY_RUN != 0"
		}
		logger.Info("starting in DRY-RUN — classifying but NOT posting to Discord", "reason", reason, "ws", wsURL, "monitor", monitorChar)
		out = &logPoster{log: logger}
	} else {
		dg, err := discordgo.New("Bot " + token)
		if err != nil {
			logger.Error("discord session init failed", "err", err)
			os.Exit(1)
		}
		// REST-only: we send by channel ID, so no gateway Open()/intents needed.
		logger.Info("starting LIVE — posting to Discord", "ws", wsURL, "monitor", monitorChar)
		out = &discordPoster{
			dg:       dg,
			common:   envOr("COMMON_RARE_CHANNEL_ID", "1355328792184226014"),
			great:    envOr("GREAT_RARE_CHANNEL_ID", "1353676584334131211"),
			aclog:    envOr("ACLOG_CHANNEL_ID", "1349649482786275328"),
			sawato:   envOr("SAWATOLIFE_CHANNEL_ID", "1387323032271327423"),
			iconsDir: envOr("ICONS_DIR", "icons"),
			log:      logger,
		}
	}

	b := &bot{wsURL: wsURL, monitorChar: monitorChar, out: out, log: logger}
	go b.run(ctx)

	<-ctx.Done()
	logger.Info("shutdown signal received")
}

func envOr(key, def string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return def
}