removed device_id from all entities except car. Replaced with car_id . Car -> device_id

server/internal/catalog/catalog.go

@@ -247,6 +247,7 @@ type CreateCarOptions struct {
 	ColorHex   string
 	AvatarURL  string
 	Active     *bool // optional; defaults to true
+	DeviceID   *int
 }
 
 // Validate sanity-checks dimensions and required fields.
@@ -319,6 +320,7 @@ func (s *Service) CreateCar(ctx context.Context, opts CreateCarOptions) (CarMeta
 		ColorHex:   opts.ColorHex,
 		AvatarURL:  opts.AvatarURL,
 		Active:     active,
+		DeviceID:   opts.DeviceID,
 		CreatedMs:  now,
 		UpdatedMs:  now,
 	}
@@ -345,6 +347,7 @@ type UpdateCarOptions struct {
 	Motor      *MotorSpec
 	Battery    *BatterySpec
 	Drive      *Drivetrain
+	DeviceID   *int // double pointer or *int to clear / set? Let's use *int, but to allow setting to nil (e.g. if we pass -1 or use *int), wait, actually, we can support DeviceID **int or *int. Let's use *int for now or wait, if *int is nil, it means do not update. If they want to set to a device ID, they pass a pointer. Wait! What if they want to clear it? They can pass a pointer to a negative value like -1 or we can use a double pointer. Actually, in Go, *int is very simple. Let's make it *int. If we need to clear, we can pass a device ID of -1 and map it to nil. Let's check how the JSON schema handles it. Usually *int is sufficient. Wait, let's use *int.
 }
 
 // UpdateCar applies a partial update.
@@ -403,6 +406,13 @@ func (s *Service) UpdateCar(ctx context.Context, id string, opts UpdateCarOption
 	if opts.Drive != nil {
 		c.Drive = *opts.Drive
 	}
+	if opts.DeviceID != nil {
+		if *opts.DeviceID < 0 {
+			c.DeviceID = nil
+		} else {
+			c.DeviceID = opts.DeviceID
+		}
+	}
 	c.UpdatedMs = time.Now().UnixMilli()
 
 	if c.LengthMm < minCarLengthMm || c.LengthMm > maxCarLengthMm ||

server/internal/catalog/types.go

@@ -146,6 +146,7 @@ type CarMeta struct {
 	Motor    MotorSpec   `json:"motor"`
 	Battery  BatterySpec `json:"battery"`
 	Drive    Drivetrain  `json:"drive"`
+	DeviceID *int        `json:"device_id,omitempty"` // mapped physical ESP32 device ID
 
 	// Performance envelope.
 	TopSpeedMs float64 `json:"top_speed_ms"`

server/internal/lobby/lobby.go

@@ -187,7 +187,7 @@ func (s *Service) RemoveDriver(id string) {
 	d.Status = DriverStatusOffline
 	d.LastSeenMs = time.Now().UnixMilli()
 	d.RaceID = ""
-	d.DeviceID = nil
+	d.CarID = nil
 	hook := s.onRaceRemoved
 	s.mu.Unlock()
 
@@ -244,9 +244,9 @@ func (s *Service) AddDriverToRace(driverID, raceID string) error {
 		s.mu.Unlock()
 		return ErrDriverNotFound
 	}
-	if d.DeviceID == nil {
+	if d.CarID == nil || *d.CarID == "" {
 		s.mu.Unlock()
-		return fmt.Errorf("driver %s has no device selected", driverID)
+		return fmt.Errorf("driver %s has no car selected", driverID)
 	}
 	r, ok := s.races[raceID]
 	if !ok {
@@ -306,7 +306,7 @@ func (s *Service) RemoveDriverFromRace(driverID string) {
 	}
 	d.Status = DriverStatusIdle
 	d.RaceID = ""
-	d.DeviceID = nil
+	d.CarID = nil
 	prevRaceID := d.RaceID
 	hook := s.onRaceRemoved
 	s.mu.Unlock()
@@ -349,7 +349,7 @@ func (s *Service) SetRaceStatus(raceID string, status RaceStatus) error {
 			if d, ok := s.drivers[did]; ok {
 				d.Status = DriverStatusIdle
 				d.RaceID = ""
-				d.DeviceID = nil
+				d.CarID = nil
 				affected = append(affected, *d)
 			}
 		}
@@ -454,16 +454,10 @@ func (s *Service) GetDriver(driverID string) (DriverMeta, error) {
 	return *d, nil
 }
 
-// SelectDevice assigns a physical device ID (0..127) to a driver.
-// Pass deviceID = nil to release the device.
-// Returns an error if the device is already taken by another online driver.
-func (s *Service) SelectDevice(driverID string, deviceID *int) error {
-	if deviceID != nil {
-		if *deviceID < 0 || *deviceID > 127 {
-			return fmt.Errorf("invalid device ID: must be 0..127")
-		}
-	}
-
+// SelectCar assigns a catalog car ID to a driver.
+// If carID is nil, it clears the driver's car assignment.
+// It returns an error if the car is already taken by another active driver.
+func (s *Service) SelectCar(driverID string, carID *string) error {
 	s.mu.Lock()
 	d, ok := s.drivers[driverID]
 	if !ok {
@@ -471,17 +465,17 @@ func (s *Service) SelectDevice(driverID string, deviceID *int) error {
 		return ErrDriverNotFound
 	}
 
-	// Enforce that device cannot be selected if already assigned to another driver.
-	if deviceID != nil {
+	// Enforce that car cannot be selected if already assigned to another driver.
+	if carID != nil && *carID != "" {
 		for otherID, otherD := range s.drivers {
-			if otherID != driverID && otherD.Status != DriverStatusOffline && otherD.DeviceID != nil && *otherD.DeviceID == *deviceID {
+			if otherID != driverID && otherD.Status != DriverStatusOffline && otherD.CarID != nil && *otherD.CarID == *carID {
 				s.mu.Unlock()
-				return fmt.Errorf("device %d is already taken by driver %s", *deviceID, otherID)
+				return fmt.Errorf("car %s is already taken by driver %s", *carID, otherID)
 			}
 		}
 	}
 
-	d.DeviceID = deviceID
+	d.CarID = carID
 	out := *d
 	s.mu.Unlock()
 

server/internal/lobby/lobby_test.go

@@ -75,9 +75,9 @@ func TestQuickPlayJoinsFirstRace(t *testing.T) {
 	s := NewService()
 	_, _ = s.AddDriver("d1", "Alice", "")
 	_, _ = s.AddDriver("d2", "Bob", "")
-	dev1, dev2 := 1, 2
-	_ = s.SelectDevice("d1", &dev1)
-	_ = s.SelectDevice("d2", &dev2)
+	car1, car2 := "car-1", "car-2"
+	_ = s.SelectCar("d1", &car1)
+	_ = s.SelectCar("d2", &car2)
 	r1, _ := s.QuickPlay("d1", 4)
 	r2, err := s.QuickPlay("d2", 4)
 	if err != nil {

server/internal/lobby/types.go

@@ -65,7 +65,7 @@ type DriverMeta struct {
 	LastSeenMs  int64        `json:"last_seen_ms"`
 	Country     string       `json:"country,omitempty"` // optional, for UI
 	AvatarHue   int          `json:"avatar_hue,omitempty"` // 0..360, deterministic per id
-	DeviceID    *int         `json:"-"`
+	CarID       *string      `json:"car_id,omitempty"`
 }
 
 // Snapshot is the immutable view broadcast to clients.

server/internal/races/seed/seed.go

@@ -547,8 +547,15 @@ func (r *Runner) createLive(status lobby.RaceStatus, idx int) (lobby.RaceMeta, e
 			continue
 		}
 		r.lb.SetDriverProfile(d.ID, d.Nickname, "", d.ClanID, d.ClanTag)
-		devID := i
-		_ = r.lb.SelectDevice(d.ID, &devID)
+		cars := []string{
+			"f1-2024-redbull-rb20",
+			"f1-2024-ferrari-sf24",
+			"f1-2024-mclaren-mcl38",
+			"f1-2024-mercedes-w15",
+			"f1-2024-astonmartin-amr24",
+		}
+		carID := cars[i%len(cars)]
+		_ = r.lb.SelectCar(d.ID, &carID)
 		if err := r.lb.AddDriverToRace(d.ID, meta.ID); err != nil {
 			// ignore: race may be at capacity
 		}

server/internal/races/service.go

@@ -62,8 +62,8 @@ func (s *Service) RestoreFromDB(ctx context.Context) (int, int, error) {
 		// AddDriver+SetDriverProfile and accept a no-op mirror.
 		_, _ = s.lobby.AddDriver(d.ID, d.Name, "")
 		s.lobby.SetDriverProfile(d.ID, d.Nickname, d.AvatarURL, d.ClanID, d.ClanTag)
-		if d.DeviceID != nil {
-			_ = s.lobby.SelectDevice(d.ID, d.DeviceID)
+		if d.CarID != nil {
+			_ = s.lobby.SelectCar(d.ID, d.CarID)
 		}
 	}
 	for _, r := range races {

server/internal/races/store.go

@@ -391,7 +391,7 @@ func (s *PgStore) UpsertLobbyDriver(ctx context.Context, d lobby.DriverMeta) err
 	_, err := s.pool.Exec(ctx, `
 		INSERT INTO lobby_drivers
 		    (driver_id, name, nickname, avatar_url, clan_id, clan_tag,
-		     status, current_race_id, connected_ms, last_seen_ms, device_id)
+		     status, current_race_id, connected_ms, last_seen_ms, car_id)
 		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
 		ON CONFLICT (driver_id) DO UPDATE SET
 		    name = EXCLUDED.name,
@@ -402,9 +402,9 @@ func (s *PgStore) UpsertLobbyDriver(ctx context.Context, d lobby.DriverMeta) err
 		    status = EXCLUDED.status,
 		    current_race_id = EXCLUDED.current_race_id,
 		    last_seen_ms = EXCLUDED.last_seen_ms,
-		    device_id = EXCLUDED.device_id`,
+		    car_id = EXCLUDED.car_id`,
 		d.ID, d.Name, d.Nickname, d.AvatarURL, d.ClanID, d.ClanTag,
-		string(d.Status), d.RaceID, d.ConnectedMs, d.LastSeenMs, d.DeviceID)
+		string(d.Status), d.RaceID, d.ConnectedMs, d.LastSeenMs, d.CarID)
 	if err != nil {
 		return fmt.Errorf("upsert lobby driver %s: %w", d.ID, err)
 	}
@@ -421,7 +421,7 @@ func (s *PgStore) DeleteLobbyDriver(ctx context.Context, driverID string) error
 func (s *PgStore) ListLobbyDrivers(ctx context.Context) ([]lobby.DriverMeta, error) {
 	rows, err := s.pool.Query(ctx, `
 		SELECT driver_id, name, nickname, avatar_url, clan_id, clan_tag,
-		       status, current_race_id, connected_ms, last_seen_ms, device_id
+		       status, current_race_id, connected_ms, last_seen_ms, car_id
 		FROM lobby_drivers ORDER BY last_seen_ms DESC`)
 	if err != nil {
 		return nil, err
@@ -432,7 +432,7 @@ func (s *PgStore) ListLobbyDrivers(ctx context.Context) ([]lobby.DriverMeta, err
 		var d lobby.DriverMeta
 		var status string
 		if err := rows.Scan(&d.ID, &d.Name, &d.Nickname, &d.AvatarURL, &d.ClanID, &d.ClanTag,
-			&status, &d.RaceID, &d.ConnectedMs, &d.LastSeenMs, &d.DeviceID); err != nil {
+			&status, &d.RaceID, &d.ConnectedMs, &d.LastSeenMs, &d.CarID); err != nil {
 			return nil, err
 		}
 		d.Status = lobby.DriverStatus(status)

server/internal/storage/postgres/migrations/015_driver_car_id.sql

@@ -0,0 +1,8 @@
+-- 015_driver_car_id.sql — move device_id to cars table and use car_id in lobby_drivers
+--
+-- Represents the currently selected physical ESP32 DEVICE_ID (0..127) for a car.
+-- And represents the currently selected car ID for a driver in lobby_drivers.
+
+ALTER TABLE cars ADD COLUMN IF NOT EXISTS device_id INT;
+ALTER TABLE lobby_drivers ADD COLUMN IF NOT EXISTS car_id TEXT;
+ALTER TABLE lobby_drivers DROP COLUMN IF EXISTS device_id;

server/internal/storage/postgres/pgstore.go

@@ -142,7 +142,7 @@ func (s *PgStore) loadCars(ctx context.Context) ([]catalog.CarMeta, error) {
 		       battery_voltage_v, battery_capacity_mah, battery_cells, battery_chemistry,
 		       drive, top_speed_ms, color_hex, avatar_url, active,
 		       total_distance_m, total_races, total_laps, best_lap_ms,
-		       created_ms, updated_ms
+		       created_ms, updated_ms, device_id
 		FROM cars
 		ORDER BY id`)
 	if err != nil {
@@ -161,7 +161,7 @@ func (s *PgStore) loadCars(ctx context.Context) ([]catalog.CarMeta, error) {
 			&c.Battery.VoltageV, &c.Battery.CapacityMah, &c.Battery.Cells, &c.Battery.Chemistry,
 			&c.Drive, &c.TopSpeedMs, &c.ColorHex, &c.AvatarURL, &c.Active,
 			&c.TotalDistanceM, &c.TotalRaces, &c.TotalLaps, &c.BestLapMs,
-			&c.CreatedMs, &c.UpdatedMs,
+			&c.CreatedMs, &c.UpdatedMs, &c.DeviceID,
 		); err != nil {
 			return nil, err
 		}
@@ -260,8 +260,8 @@ func (s *PgStore) UpsertCar(ctx context.Context, c catalog.CarMeta) error {
 		    battery_voltage_v, battery_capacity_mah, battery_cells, battery_chemistry,
 		    drive, top_speed_ms, color_hex, avatar_url, active,
 		    total_distance_m, total_races, total_laps, best_lap_ms,
-		    created_ms, updated_ms)
-		VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$18,$19,$20,$21,$22,$23,$24,$25,$26,$27,$28,$29,$30,$31,$32)
+		    created_ms, updated_ms, device_id)
+		VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$18,$19,$20,$21,$22,$23,$24,$25,$26,$27,$28,$29,$30,$31,$32,$33)
 		ON CONFLICT (id) DO UPDATE SET
 		    name                = EXCLUDED.name,
 		    owner_id            = EXCLUDED.owner_id,
@@ -293,7 +293,8 @@ func (s *PgStore) UpsertCar(ctx context.Context, c catalog.CarMeta) error {
 		    total_races         = EXCLUDED.total_races,
 		    total_laps          = EXCLUDED.total_laps,
 		    best_lap_ms         = EXCLUDED.best_lap_ms,
-		    updated_ms          = EXCLUDED.updated_ms`,
+		    updated_ms          = EXCLUDED.updated_ms,
+		    device_id           = EXCLUDED.device_id`,
 		c.ID, c.Name, c.OwnerID, string(c.Visibility), c.Scale,
 		c.LengthMm, c.WidthMm, c.HeightMm, c.WeightG,
 		c.Chassis.Model, c.Chassis.Material, c.Chassis.Printed,
@@ -302,7 +303,7 @@ func (s *PgStore) UpsertCar(ctx context.Context, c catalog.CarMeta) error {
 		c.Battery.VoltageV, c.Battery.CapacityMah, c.Battery.Cells, c.Battery.Chemistry,
 		string(c.Drive), c.TopSpeedMs, c.ColorHex, c.AvatarURL, c.Active,
 		c.TotalDistanceM, c.TotalRaces, c.TotalLaps, c.BestLapMs,
-		c.CreatedMs, c.UpdatedMs,
+		c.CreatedMs, c.UpdatedMs, c.DeviceID,
 	)
 	return err
 }
@@ -333,7 +334,7 @@ func (s *PgStore) UpdateCarStats(ctx context.Context, id string, fn func(*catalo
 		       battery_voltage_v, battery_capacity_mah, battery_cells, battery_chemistry,
 		       drive, top_speed_ms, color_hex, avatar_url, active,
 		       total_distance_m, total_races, total_laps, best_lap_ms,
-		       created_ms, updated_ms
+		       created_ms, updated_ms, device_id
 		FROM cars WHERE id = $1 FOR UPDATE`, id,
 	).Scan(
 		&c.ID, &c.Name, &c.OwnerID, &c.Visibility, &c.Scale,
@@ -344,7 +345,7 @@ func (s *PgStore) UpdateCarStats(ctx context.Context, id string, fn func(*catalo
 		&c.Battery.VoltageV, &c.Battery.CapacityMah, &c.Battery.Cells, &c.Battery.Chemistry,
 		&c.Drive, &c.TopSpeedMs, &c.ColorHex, &c.AvatarURL, &c.Active,
 		&c.TotalDistanceM, &c.TotalRaces, &c.TotalLaps, &c.BestLapMs,
-		&c.CreatedMs, &c.UpdatedMs,
+		&c.CreatedMs, &c.UpdatedMs, &c.DeviceID,
 	)
 	if err != nil {
 		if errors.Is(err, pgx.ErrNoRows) {

server/internal/transport/codec.go

@@ -478,6 +478,7 @@ type CarWire struct {
 
 	CreatedMs int64 `json:"created_ms"`
 	UpdatedMs int64 `json:"updated_ms"`
+	DeviceID  *int  `json:"device_id,omitempty"`
 }
 
 // CarListRequest: payload { "scope": "all|system|public|private", "owner_id": "..." }.
@@ -519,6 +520,7 @@ type CarPatch struct {
 	ColorHex    *string      `json:"color_hex,omitempty"`
 	AvatarURL   *string      `json:"avatar_url,omitempty"`
 	Active      *bool        `json:"active,omitempty"`
+	DeviceID    *int         `json:"device_id,omitempty"`
 }
 
 // CarDeleteRequest: payload { "id": "..." }.