// Command membershipd is the unibus control-plane service: room metadata,
// member directory, sealed key distribution, and the media blob store. The data
// plane is NATS — if --nats-url is empty it starts an embedded nats-server with
// JetStream so the whole stack runs with `go run` and nothing to install.
package main

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

	server "github.com/nats-io/nats-server/v2/server"

	"github.com/enmanuel/unibus/pkg/blobstore"
	"github.com/enmanuel/unibus/pkg/embeddednats"
	"github.com/enmanuel/unibus/pkg/membership"
)

func main() {
	var (
		natsURL   = flag.String("nats-url", "", "external NATS url; empty starts an embedded server")
		httpPort  = flag.String("http-port", "8470", "HTTP port for the control-plane API")
		dbPath    = flag.String("db", "./local_files/unibus.db", "SQLite database path")
		storeDir  = flag.String("store-dir", "./local_files/blobs", "blob store directory")
		natsPort  = flag.Int("nats-port", 4250, "embedded NATS listen port (when --nats-url empty)")
		natsStore = flag.String("nats-store", "./local_files/jetstream", "embedded JetStream store dir")
	)
	flag.Parse()

	log.SetFlags(log.LstdFlags | log.Lmsgprefix)
	log.SetPrefix("[membershipd] ")

	// Data plane: embedded or external NATS.
	var ns *server.Server
	natsClientURL := *natsURL
	if natsClientURL == "" {
		var err error
		ns, err = embeddednats.Start(*natsStore, *natsPort)
		if err != nil {
			log.Fatalf("start embedded nats: %v", err)
		}
		natsClientURL = embeddednats.ClientURL(ns)
		log.Printf("embedded NATS (JetStream) ready: %s", natsClientURL)
	} else {
		log.Printf("using external NATS: %s", natsClientURL)
	}

	// Control plane: SQLite store + blob store + HTTP API.
	store, err := membership.Open(*dbPath)
	if err != nil {
		log.Fatalf("open membership store: %v", err)
	}
	defer store.Close()
	log.Printf("membership store: %s", *dbPath)

	blobs, err := blobstore.New(*storeDir)
	if err != nil {
		log.Fatalf("open blob store: %v", err)
	}
	log.Printf("blob store: %s", *storeDir)

	srv := membership.NewServer(store, blobs)
	addr := "127.0.0.1:" + *httpPort
	httpSrv := &http.Server{Addr: addr, Handler: srv}

	go func() {
		log.Printf("HTTP control-plane API: http://%s", addr)
		log.Printf("  health: http://%s/healthz", addr)
		if err := httpSrv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("http server: %v", err)
		}
	}()

	// Graceful shutdown on SIGINT/SIGTERM.
	stop := make(chan os.Signal, 1)
	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
	<-stop
	log.Printf("shutting down...")

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	_ = httpSrv.Shutdown(ctx)
	if ns != nil {
		ns.Shutdown()
		ns.WaitForShutdown()
	}
	log.Printf("bye")
}