refactor: extract GameService for Snake NATS/chat handling

Apply the same service pattern from Connect 4 to Snake game.
Handlers now receive the service and call its methods instead of
managing NATS connections directly. Also aligns heartbeat to 10s
and removes ConnectionIndicator patching (matching C4 changes).

features/snakegame/handlers.go

@@ -1,41 +1,24 @@
 package snakegame
 
 import (
-	"fmt"
+	"errors"
 	"net/http"
 	"strconv"
 	"time"
 
 	"github.com/alexedwards/scs/v2"
 	"github.com/go-chi/chi/v5"
-	"github.com/nats-io/nats.go"
 	"github.com/starfederation/datastar-go/datastar"
 
 	"github.com/ryanhamamura/games/chat"
 	chatcomponents "github.com/ryanhamamura/games/chat/components"
-	sharedcomponents "github.com/ryanhamamura/games/features/common/components"
 	"github.com/ryanhamamura/games/features/snakegame/pages"
+	"github.com/ryanhamamura/games/features/snakegame/services"
 	"github.com/ryanhamamura/games/sessions"
 	"github.com/ryanhamamura/games/snake"
 )
 
-func snakeChatColor(slot int) string {
+func HandleSnakePage(snakeStore *snake.SnakeStore, svc *services.GameService, sm *scs.SessionManager) http.HandlerFunc {
-	if slot >= 0 && slot < len(snake.SnakeColors) {
-		return snake.SnakeColors[slot]
-	}
-	return "#666"
-}
-
-func snakeChatConfig(gameID string) chatcomponents.Config {
-	return chatcomponents.Config{
-		CSSPrefix:          "snake",
-		PostURL:            fmt.Sprintf("/snake/%s/chat", gameID),
-		Color:              snakeChatColor,
-		StopKeyPropagation: true,
-	}
-}
-
-func HandleSnakePage(snakeStore *snake.SnakeStore, sm *scs.SessionManager) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		gameID := chi.URLParam(r, "id")
 		si, ok := snakeStore.Get(gameID)
@@ -77,13 +60,14 @@ func HandleSnakePage(snakeStore *snake.SnakeStore, sm *scs.SessionManager) http.
 		}
 
 		sg := si.GetGame()
-		if err := pages.GamePage(sg, mySlot, nil, snakeChatConfig(gameID), gameID).Render(r.Context(), w); err != nil {
+		chatCfg := svc.ChatConfig(gameID)
+		if err := pages.GamePage(sg, mySlot, nil, chatCfg, gameID).Render(r.Context(), w); err != nil {
 			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 		}
 	}
 }
 
-func HandleSnakeEvents(snakeStore *snake.SnakeStore, nc *nats.Conn, sm *scs.SessionManager) http.HandlerFunc {
+func HandleSnakeEvents(snakeStore *snake.SnakeStore, svc *services.GameService, sm *scs.SessionManager) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		gameID := chi.URLParam(r, "id")
 		si, ok := snakeStore.Get(gameID)
@@ -95,17 +79,25 @@ func HandleSnakeEvents(snakeStore *snake.SnakeStore, nc *nats.Conn, sm *scs.Sess
 		playerID := sessions.GetPlayerID(sm, r)
 		mySlot := si.GetPlayerSlot(playerID)
 
+		// Subscribe to game updates BEFORE creating SSE (following portigo pattern)
+		gameSub, gameCh, err := svc.SubscribeGameUpdates(gameID)
+		if err != nil {
+			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+			return
+		}
+		defer gameSub.Unsubscribe() //nolint:errcheck
+
 		sse := datastar.NewSSE(w, r, datastar.WithCompression(
 			datastar.WithBrotli(datastar.WithBrotliLevel(5)),
 		))
 
-		chatCfg := snakeChatConfig(gameID)
+		chatCfg := svc.ChatConfig(gameID)
 
 		// Chat room (multiplayer only)
 		var room *chat.Room
 		sg := si.GetGame()
 		if sg.Mode == snake.ModeMultiplayer {
-			room = chat.NewRoom(nc, snake.ChatSubject(gameID))
+			room = svc.ChatRoom(gameID)
 		}
 
 		chatMessages := func() []chat.Message {
@@ -118,36 +110,21 @@ func HandleSnakeEvents(snakeStore *snake.SnakeStore, nc *nats.Conn, sm *scs.Sess
 		patchAll := func() error {
 			si, ok = snakeStore.Get(gameID)
 			if !ok {
-				return fmt.Errorf("game not found")
+				return errors.New("game not found")
 			}
 			mySlot = si.GetPlayerSlot(playerID)
 			sg = si.GetGame()
 			return sse.PatchElementTempl(pages.GameContent(sg, mySlot, chatMessages(), chatCfg, gameID))
 		}
 
-		sendPing := func() error {
+		// Send initial render
-			return sse.PatchElementTempl(sharedcomponents.ConnectionIndicator(time.Now().UnixMilli()))
-		}
-
-		// Send initial render and ping
-		if err := sendPing(); err != nil {
-			return
-		}
 		if err := patchAll(); err != nil {
 			return
 		}
 
-		heartbeat := time.NewTicker(15 * time.Second)
+		heartbeat := time.NewTicker(10 * time.Second)
 		defer heartbeat.Stop()
 
-		// Subscribe to game updates via NATS
-		gameCh := make(chan *nats.Msg, 64)
-		gameSub, err := nc.ChanSubscribe(snake.GameSubject(gameID), gameCh)
-		if err != nil {
-			return
-		}
-		defer gameSub.Unsubscribe() //nolint:errcheck
-
 		// Chat subscription (multiplayer only)
 		var chatCh <-chan chat.Message
 		var cleanupChat func()
@@ -164,7 +141,8 @@ func HandleSnakeEvents(snakeStore *snake.SnakeStore, nc *nats.Conn, sm *scs.Sess
 				return
 
 			case <-heartbeat.C:
-				if err := sendPing(); err != nil {
+				// Heartbeat just refreshes game state
+				if err := patchAll(); err != nil {
 					return
 				}
 
@@ -231,7 +209,7 @@ type chatSignals struct {
 	ChatMsg string `json:"chatMsg"`
 }
 
-func HandleSendChat(snakeStore *snake.SnakeStore, nc *nats.Conn, sm *scs.SessionManager) http.HandlerFunc {
+func HandleSendChat(snakeStore *snake.SnakeStore, svc *services.GameService, sm *scs.SessionManager) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		gameID := chi.URLParam(r, "id")
 		si, ok := snakeStore.Get(gameID)
@@ -264,7 +242,7 @@ func HandleSendChat(snakeStore *snake.SnakeStore, nc *nats.Conn, sm *scs.Session
 			Message:  signals.ChatMsg,
 		}
 
-		room := chat.NewRoom(nc, snake.ChatSubject(gameID))
+		room := svc.ChatRoom(gameID)
 		room.Send(msg)
 
 		sse := datastar.NewSSE(w, r)

features/snakegame/routes.go

@@ -4,17 +4,17 @@ package snakegame
 import (
 	"github.com/alexedwards/scs/v2"
 	"github.com/go-chi/chi/v5"
-	"github.com/nats-io/nats.go"
 
+	"github.com/ryanhamamura/games/features/snakegame/services"
 	"github.com/ryanhamamura/games/snake"
 )
 
-func SetupRoutes(router chi.Router, snakeStore *snake.SnakeStore, nc *nats.Conn, sessions *scs.SessionManager) {
+func SetupRoutes(router chi.Router, snakeStore *snake.SnakeStore, svc *services.GameService, sessions *scs.SessionManager) {
 	router.Route("/snake/{id}", func(r chi.Router) {
-		r.Get("/", HandleSnakePage(snakeStore, sessions))
+		r.Get("/", HandleSnakePage(snakeStore, svc, sessions))
-		r.Get("/events", HandleSnakeEvents(snakeStore, nc, sessions))
+		r.Get("/events", HandleSnakeEvents(snakeStore, svc, sessions))
 		r.Post("/dir", HandleSetDirection(snakeStore, sessions))
-		r.Post("/chat", HandleSendChat(snakeStore, nc, sessions))
+		r.Post("/chat", HandleSendChat(snakeStore, svc, sessions))
 		r.Post("/join", HandleSetNickname(snakeStore, sessions))
 		r.Post("/rematch", HandleRematch(snakeStore, sessions))
 	})

features/snakegame/services/game_service.go

@@ -0,0 +1,62 @@
+// Package services provides the game service layer for Snake,
+// handling NATS subscriptions and chat room management.
+package services
+
+import (
+	"fmt"
+
+	"github.com/nats-io/nats.go"
+
+	"github.com/ryanhamamura/games/chat"
+	chatcomponents "github.com/ryanhamamura/games/chat/components"
+	"github.com/ryanhamamura/games/snake"
+)
+
+func snakeChatColor(slot int) string {
+	if slot >= 0 && slot < len(snake.SnakeColors) {
+		return snake.SnakeColors[slot]
+	}
+	return "#666"
+}
+
+// GameService manages NATS subscriptions and chat for Snake games.
+type GameService struct {
+	nc *nats.Conn
+}
+
+// NewGameService creates a new game service.
+func NewGameService(nc *nats.Conn) *GameService {
+	return &GameService{
+		nc: nc,
+	}
+}
+
+// SubscribeGameUpdates returns a NATS subscription and channel for game state updates.
+func (s *GameService) SubscribeGameUpdates(gameID string) (*nats.Subscription, <-chan *nats.Msg, error) {
+	ch := make(chan *nats.Msg, 64)
+	sub, err := s.nc.ChanSubscribe(snake.GameSubject(gameID), ch)
+	if err != nil {
+		return nil, nil, fmt.Errorf("subscribing to game updates: %w", err)
+	}
+	return sub, ch, nil
+}
+
+// ChatConfig returns the chat configuration for a game.
+func (s *GameService) ChatConfig(gameID string) chatcomponents.Config {
+	return chatcomponents.Config{
+		CSSPrefix:          "snake",
+		PostURL:            fmt.Sprintf("/snake/%s/chat", gameID),
+		Color:              snakeChatColor,
+		StopKeyPropagation: true,
+	}
+}
+
+// ChatRoom returns a chat room for a game (ephemeral, not persisted).
+func (s *GameService) ChatRoom(gameID string) *chat.Room {
+	return chat.NewRoom(s.nc, snake.ChatSubject(gameID))
+}
+
+// PublishGameUpdate sends a notification that the game state has changed.
+func (s *GameService) PublishGameUpdate(gameID string) error {
+	return s.nc.Publish(snake.GameSubject(gameID), nil)
+}

router/router.go

@@ -17,9 +17,10 @@ import (
 	"github.com/ryanhamamura/games/db/repository"
 	"github.com/ryanhamamura/games/features/auth"
 	"github.com/ryanhamamura/games/features/c4game"
-	"github.com/ryanhamamura/games/features/c4game/services"
+	c4services "github.com/ryanhamamura/games/features/c4game/services"
 	"github.com/ryanhamamura/games/features/lobby"
 	"github.com/ryanhamamura/games/features/snakegame"
+	snakeservices "github.com/ryanhamamura/games/features/snakegame/services"
 	"github.com/ryanhamamura/games/snake"
 )
 
@@ -42,12 +43,13 @@ func SetupRoutes(
 	}
 
 	// Services
-	c4Svc := services.NewGameService(nc, queries)
+	c4Svc := c4services.NewGameService(nc, queries)
+	snakeSvc := snakeservices.NewGameService(nc)
 
 	auth.SetupRoutes(router, queries, sessions)
 	lobby.SetupRoutes(router, queries, sessions, store, snakeStore)
 	c4game.SetupRoutes(router, store, c4Svc, sessions)
-	snakegame.SetupRoutes(router, snakeStore, nc, sessions)
+	snakegame.SetupRoutes(router, snakeStore, snakeSvc, sessions)
 }
 
 func setupReload(router chi.Router) {