package main

import (
	"context"
	"crypto/tls"
	"errors"
	"flag"
	"fmt"
	"log/slog"
	"net"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/gofiber/fiber/v3"
)

func run(ctx context.Context, path string) error {
	config, err := loadStartup(path)
	if err != nil {
		return err
	}
	data, err := loadSnapshots(config.Snapshots, config.DispatcherID)
	if err != nil {
		return err
	}
	slog.Info("test configurations loaded", "dispatcher_id", data.dispatcherID, "tasks", len(data.tasks))
	if err = os.MkdirAll(config.Feedback, 0700); err != nil {
		return fmt.Errorf("create private feedback directory: %w", err)
	}
	info, err := os.Stat(config.Feedback)
	if err != nil {
		return err
	}
	if !info.IsDir() || info.Mode().Perm()&0077 != 0 {
		return errors.New("feedback directory must be private")
	}
	b, err := connectBroker(config.BrokerURL, data)
	if err != nil {
		return err
	}
	defer b.conn.Close()
	slog.Info("isolated MQ topology ready", "dispatcher_id", data.dispatcherID)
	listener, err := net.Listen("tcp", config.Listen)
	if err != nil {
		return fmt.Errorf("listen: %w", err)
	}
	defer listener.Close()
	if config.TLSCert != "" {
		pair, e := tls.LoadX509KeyPair(config.TLSCert, config.TLSKey)
		if e != nil {
			return fmt.Errorf("load configured TLS pair: %w", e)
		}
		listener = tls.NewListener(listener, &tls.Config{Certificates: []tls.Certificate{pair}, MinVersion: tls.VersionTLS12})
	}
	s := newService(data, config.DispatcherSecret)
	s.feedbackDir = config.Feedback
	s.publish = b.publish
	child, cancel := context.WithCancel(ctx)
	defer cancel()
	errs := make(chan error, 2)
	go func() { errs <- b.consume(child, s) }()
	go func() { errs <- s.app.Listener(listener, fiber.ListenConfig{DisableStartupMessage: true}) }()
	slog.Info("SaaS test server listening", "address", listener.Addr().String(), "tls", config.TLSCert != "", "automatic_commands", false)
	select {
	case <-ctx.Done():
		err = nil
	case err = <-errs:
		if err == nil && ctx.Err() == nil {
			err = errors.New("SaaS test server stopped unexpectedly")
		}
	}
	cancel()
	if shutdownErr := s.app.ShutdownWithTimeout(5 * time.Second); shutdownErr != nil {
		err = errors.Join(err, fmt.Errorf("HTTP shutdown: %w", shutdownErr))
	}
	// Closing the listener/connection unblocks both workers; do not leave consumers behind.
	listener.Close()
	b.conn.Close()
	slog.Info("SaaS test server stopped")
	return err
}

func main() {
	var path string
	flag.StringVar(&path, "config", "", "private startup JSON (required)")
	flag.Parse()
	if path == "" || flag.NArg() != 0 {
		fmt.Fprintln(os.Stderr, "usage: saas-server --config /path/server.json")
		os.Exit(2)
	}
	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer cancel()
	if err := run(ctx, path); err != nil {
		slog.Error("SaaS test server failed", "error", err)
		os.Exit(1)
	}
}