package main

import (
	"context"
	"errors"
	"flag"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"
)

const defaultListenAddr = ":8080"
const defaultConfigPath = "/etc/homelab-gateway/bots.yaml"

func main() {
	subcmd := ""
	if len(os.Args) > 1 && os.Args[1] != "" && os.Args[1][0] != '-' {
		subcmd = os.Args[1]
		os.Args = append([]string{os.Args[0]}, os.Args[2:]...)
	}

	switch subcmd {
	case "setwebhook":
		runSetWebhook()
	case "deletewebhook":
		runDeleteWebhook()
	case "", "serve":
		runServer()
	default:
		log.Fatalf("unknown subcommand: %s (expected: serve | setwebhook | deletewebhook)", subcmd)
	}
}

func runServer() {
	addr := flag.String("addr", envOr("LISTEN_ADDR", defaultListenAddr), "listen address")
	configPath := flag.String("config", envOr("CONFIG_PATH", defaultConfigPath), "bot routing config (YAML)")
	flag.Parse()

	cfg, err := LoadConfig(*configPath)
	if err != nil {
		log.Fatalf("load config: %v", err)
	}

	registry, err := NewRegistry(cfg)
	if err != nil {
		log.Fatalf("build registry: %v", err)
	}

	srv := &http.Server{
		Addr:              *addr,
		Handler:           NewServer(registry).Routes(),
		ReadHeaderTimeout: 5 * time.Second,
		ReadTimeout:       30 * time.Second,
		WriteTimeout:      30 * time.Second,
		IdleTimeout:       60 * time.Second,
	}

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

	go func() {
		log.Printf("homelab-gateway listening on %s (%d bot(s) loaded)", *addr, registry.Count())
		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			log.Fatalf("server: %v", err)
		}
	}()

	<-ctx.Done()
	log.Print("shutdown signal received, draining...")
	shutdownCtx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
	defer cancel()
	if err := srv.Shutdown(shutdownCtx); err != nil {
		log.Printf("graceful shutdown error: %v", err)
	}
	log.Print("bye")
}

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