refactor: extract shared player.ID type and GenerateID to player package

Both game and snake packages had identical PlayerID types and the snake
package imported game.GenerateID. Now both use player.ID and
player.GenerateID from the shared player package.

features/c4game/handlers.go

@@ -18,6 +18,7 @@ import (
 	"github.com/ryanhamamura/c4/features/c4game/components"
 	"github.com/ryanhamamura/c4/features/c4game/pages"
 	"github.com/ryanhamamura/c4/game"
+	"github.com/ryanhamamura/c4/player"
 )
 
 func HandleGamePage(store *game.GameStore, sessions *scs.SessionManager, queries *repository.Queries) http.HandlerFunc {
@@ -30,15 +31,15 @@ func HandleGamePage(store *game.GameStore, sessions *scs.SessionManager, queries
 			return
 		}
 
-		playerID := game.PlayerID(sessions.GetString(r.Context(), "player_id"))
+		playerID := player.ID(sessions.GetString(r.Context(), "player_id"))
 		if playerID == "" {
-			playerID = game.PlayerID(game.GenerateID(8))
+			playerID = player.ID(player.GenerateID(8))
 			sessions.Put(r.Context(), "player_id", string(playerID))
 		}
 
 		userID := sessions.GetString(r.Context(), "user_id")
 		if userID != "" {
-			playerID = game.PlayerID(userID)
+			playerID = player.ID(userID)
 		}
 
 		nickname := sessions.GetString(r.Context(), "nickname")
@@ -95,10 +96,10 @@ func HandleGameEvents(store *game.GameStore, nc *nats.Conn, sessions *scs.Sessio
 			return
 		}
 
-		playerID := game.PlayerID(sessions.GetString(r.Context(), "player_id"))
+		playerID := player.ID(sessions.GetString(r.Context(), "player_id"))
 		userID := sessions.GetString(r.Context(), "user_id")
 		if userID != "" {
-			playerID = game.PlayerID(userID)
+			playerID = player.ID(userID)
 		}
 
 		myColor := gi.GetPlayerColor(playerID)
@@ -185,10 +186,10 @@ func HandleDropPiece(store *game.GameStore, sessions *scs.SessionManager) http.H
 			return
 		}
 
-		playerID := game.PlayerID(sessions.GetString(r.Context(), "player_id"))
+		playerID := player.ID(sessions.GetString(r.Context(), "player_id"))
 		userID := sessions.GetString(r.Context(), "user_id")
 		if userID != "" {
-			playerID = game.PlayerID(userID)
+			playerID = player.ID(userID)
 		}
 
 		myColor := gi.GetPlayerColor(playerID)
@@ -229,10 +230,10 @@ func HandleSendChat(store *game.GameStore, nc *nats.Conn, sessions *scs.SessionM
 			return
 		}
 
-		playerID := game.PlayerID(sessions.GetString(r.Context(), "player_id"))
+		playerID := player.ID(sessions.GetString(r.Context(), "player_id"))
 		userID := sessions.GetString(r.Context(), "user_id")
 		if userID != "" {
-			playerID = game.PlayerID(userID)
+			playerID = player.ID(userID)
 		}
 
 		myColor := gi.GetPlayerColor(playerID)
@@ -298,10 +299,10 @@ func HandleSetNickname(store *game.GameStore, sessions *scs.SessionManager) http
 
 		sessions.Put(r.Context(), "nickname", signals.Nickname)
 
-		playerID := game.PlayerID(sessions.GetString(r.Context(), "player_id"))
+		playerID := player.ID(sessions.GetString(r.Context(), "player_id"))
 		userID := sessions.GetString(r.Context(), "user_id")
 		if userID != "" {
-			playerID = game.PlayerID(userID)
+			playerID = player.ID(userID)
 		}
 
 		if gi.GetPlayerColor(playerID) == 0 {

features/snakegame/handlers.go

@@ -13,21 +13,21 @@ import (
 
 	"github.com/ryanhamamura/c4/features/snakegame/components"
 	"github.com/ryanhamamura/c4/features/snakegame/pages"
-	"github.com/ryanhamamura/c4/game"
+	"github.com/ryanhamamura/c4/player"
 	"github.com/ryanhamamura/c4/snake"
 )
 
-func getPlayerID(sessions *scs.SessionManager, r *http.Request) snake.PlayerID {
+func getPlayerID(sessions *scs.SessionManager, r *http.Request) player.ID {
 	pid := sessions.GetString(r.Context(), "player_id")
 	if pid == "" {
-		pid = game.GenerateID(8)
+		pid = player.GenerateID(8)
 		sessions.Put(r.Context(), "player_id", pid)
 	}
 	userID := sessions.GetString(r.Context(), "user_id")
 	if userID != "" {
-		return snake.PlayerID(userID)
+		return player.ID(userID)
 	}
-	return snake.PlayerID(pid)
+	return player.ID(pid)
 }
 
 func HandleSnakePage(snakeStore *snake.SnakeStore, sessions *scs.SessionManager) http.HandlerFunc {

game/persist.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/ryanhamamura/c4/db/repository"
+	"github.com/ryanhamamura/c4/player"
 
 	"github.com/rs/zerolog/log"
 )
@@ -109,19 +110,19 @@ func gameFromRow(row *repository.Game) (*Game, error) {
 func playersFromRows(rows []*repository.GamePlayer) []*Player {
 	players := make([]*Player, 0, len(rows))
 	for _, row := range rows {
-		player := &Player{
+		p := &Player{
 			Nickname: row.Nickname,
 			Color:    int(row.Color),
 		}
 
 		if row.UserID != nil {
-			player.UserID = row.UserID
+			p.UserID = row.UserID
-			player.ID = PlayerID(*row.UserID)
+			p.ID = player.ID(*row.UserID)
 		} else if row.GuestPlayerID != nil {
-			player.ID = PlayerID(*row.GuestPlayerID)
+			p.ID = player.ID(*row.GuestPlayerID)
 		}
 
-		players = append(players, player)
+		players = append(players, p)
 	}
 	return players
 }

game/store.go

@@ -2,11 +2,10 @@ package game
 
 import (
 	"context"
-	"crypto/rand"
-	"encoding/hex"
 	"sync"
 
 	"github.com/ryanhamamura/c4/db/repository"
+	"github.com/ryanhamamura/c4/player"
 )
 
 type PlayerSession struct {
@@ -40,7 +39,7 @@ func (gs *GameStore) makeNotify(gameID string) func() {
 }
 
 func (gs *GameStore) Create() *GameInstance {
-	id := GenerateID(4)
+	id := player.GenerateID(4)
 	gi := NewGameInstance(id)
 	gi.queries = gs.queries
 	gi.notify = gs.makeNotify(id)
@@ -107,12 +106,6 @@ func (gs *GameStore) Delete(id string) error {
 	return nil
 }
 
-func GenerateID(size int) string {
-	b := make([]byte, size)
-	_, _ = rand.Read(b)
-	return hex.EncodeToString(b)
-}
-
 type GameInstance struct {
 	game    *Game
 	gameMu  sync.RWMutex
@@ -166,7 +159,7 @@ func (gi *GameInstance) GetGame() *Game {
 	return gi.game
 }
 
-func (gi *GameInstance) GetPlayerColor(pid PlayerID) int {
+func (gi *GameInstance) GetPlayerColor(pid player.ID) int {
 	gi.gameMu.RLock()
 	defer gi.gameMu.RUnlock()
 	for _, p := range gi.game.Players {

game/types.go

@@ -1,11 +1,13 @@
 package game
 
-import "encoding/json"
+import (
+	"encoding/json"
 
-type PlayerID string
+	"github.com/ryanhamamura/c4/player"
+)
 
 type Player struct {
-	ID       PlayerID
+	ID       player.ID
 	UserID   *string // UUID for authenticated users, nil for guests
 	Nickname string
 	Color    int // 1 = Red, 2 = Yellow

player/player.go

@@ -0,0 +1,18 @@
+// Package player provides shared identity types used across game packages.
+package player
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+)
+
+// ID uniquely identifies a player within a session. For authenticated users
+// this is their user UUID; for guests it's a random hex string.
+type ID string
+
+// GenerateID returns a random hex string of 2*size characters.
+func GenerateID(size int) string {
+	b := make([]byte, size)
+	_, _ = rand.Read(b)
+	return hex.EncodeToString(b)
+}

snake/persist.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/ryanhamamura/c4/db/repository"
+	"github.com/ryanhamamura/c4/player"
 
 	"github.com/rs/zerolog/log"
 )
@@ -122,19 +123,19 @@ func snakeGameFromRow(row *repository.Game) (*SnakeGame, error) {
 func snakePlayersFromRows(rows []*repository.GamePlayer) []*Player {
 	players := make([]*Player, 0, len(rows))
 	for _, row := range rows {
-		player := &Player{
+		p := &Player{
 			Nickname: row.Nickname,
 			Slot:     int(row.Slot),
 		}
 
 		if row.UserID != nil {
-			player.UserID = row.UserID
+			p.UserID = row.UserID
-			player.ID = PlayerID(*row.UserID)
+			p.ID = player.ID(*row.UserID)
 		} else if row.GuestPlayerID != nil {
-			player.ID = PlayerID(*row.GuestPlayerID)
+			p.ID = player.ID(*row.GuestPlayerID)
 		}
 
-		players = append(players, player)
+		players = append(players, p)
 	}
 	return players
 }

snake/store.go

@@ -5,7 +5,7 @@ import (
 	"sync"
 
 	"github.com/ryanhamamura/c4/db/repository"
-	"github.com/ryanhamamura/c4/game"
+	"github.com/ryanhamamura/c4/player"
 )
 
 type SnakeStore struct {
@@ -38,7 +38,7 @@ func (ss *SnakeStore) Create(width, height int, mode GameMode, speed int) *Snake
 	if speed <= 0 {
 		speed = DefaultSpeed
 	}
-	id := game.GenerateID(4)
+	id := player.GenerateID(4)
 	sg := &SnakeGame{
 		ID: id,
 		State: &GameState{
@@ -172,7 +172,7 @@ func (si *SnakeGameInstance) GetGame() *SnakeGame {
 	return si.game.snapshot()
 }
 
-func (si *SnakeGameInstance) GetPlayerSlot(pid PlayerID) int {
+func (si *SnakeGameInstance) GetPlayerSlot(pid player.ID) int {
 	si.gameMu.RLock()
 	defer si.gameMu.RUnlock()
 	for i, p := range si.game.Players {

snake/types.go

@@ -3,6 +3,8 @@ package snake
 import (
 	"encoding/json"
 	"time"
+
+	"github.com/ryanhamamura/c4/player"
 )
 
 type Direction int
@@ -78,10 +80,8 @@ const (
 	StatusFinished
 )
 
-type PlayerID string
-
 type Player struct {
-	ID       PlayerID
+	ID       player.ID
 	UserID   *string
 	Nickname string
 	Slot     int // 0-7