main.go

package main

import (
	"context"
	"crypto/rand"
	"encoding/hex"
	"errors"
	"net"
	"os"
	"os/signal"
	"syscall"
	"time"

	tea "charm.land/bubbletea/v2"
	"charm.land/log/v2"
	"charm.land/wish/v2"
	"charm.land/wish/v2/activeterm"
	"charm.land/wish/v2/bubbletea"
	"charm.land/wish/v2/logging"
	"github.com/charmbracelet/ssh"
	"github.com/rasjonell/chessh/internal/app"
	"github.com/rasjonell/chessh/internal/multiplayer"
)

const (
	defaultHost        = "localhost"
	defaultPort        = "23234"
	defaultHostKeyPath = ".ssh/id_ed25519"
)

func main() {
	manager := multiplayer.NewManager()
	host := envOrDefault("CHESSH_HOST", defaultHost)
	port := envOrDefault("CHESSH_PORT", defaultPort)
	hostKeyPath := envOrDefault("CHESSH_HOST_KEY_PATH", defaultHostKeyPath)
	address := net.JoinHostPort(host, port)
	s, err := wish.NewServer(
		wish.WithAddress(address),
		wish.WithHostKeyPath(hostKeyPath),
		wish.WithMiddleware(
			bubbletea.Middleware(func(s ssh.Session) (tea.Model, []tea.ProgramOption) {
				return teaHandler(s, manager)
			}),
			activeterm.Middleware(),
			logging.Middleware(),
		),
	)
	if err != nil {
		log.Error("Could not start server", "error", err)
	}

	done := make(chan os.Signal, 1)
	signal.Notify(done, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
	log.Info("Starting SSH server", "address", address, "host_key_path", hostKeyPath)

	go func() {
		if err = s.ListenAndServe(); err != nil && !errors.Is(err, ssh.ErrServerClosed) {
			log.Error("Could not start server", "error", err)
			done <- nil
		}
	}()

	<-done
	log.Info("Stopping SSH server")

	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()

	if err := s.Shutdown(ctx); err != nil && !errors.Is(err, ssh.ErrServerClosed) {
		log.Error("Could not stop server", "error", err)
	}
}

func teaHandler(s ssh.Session, manager *multiplayer.Manager) (tea.Model, []tea.ProgramOption) {
	pty, _, _ := s.Pty()
	m := app.NewModel(pty.Term, pty.Window.Width, pty.Window.Height, manager, sessionID(), s.Context().Done())
	return m, []tea.ProgramOption{}
}

func sessionID() string {
	buf := make([]byte, 8)
	if _, err := rand.Read(buf); err != nil {
		return time.Now().Format("150405.000000000")
	}
	return hex.EncodeToString(buf)
}

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

	return fallback
}