fix(go): backfill realtime plate from binding

go/vehicle-gateway/internal/realtime/snapshot_writer.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"encoding/json"
+	"errors"
 	"strings"
 	"time"
 
@@ -14,15 +15,24 @@ type SnapshotExecer interface {
 	ExecContext(context.Context, string, ...any) (sql.Result, error)
 }
 
+type PlateResolver interface {
+	PlateByVIN(context.Context, string) (string, error)
+}
+
 type SnapshotWriter struct {
-	exec SnapshotExecer
+	exec          SnapshotExecer
+	plateResolver PlateResolver
 }
 
 func NewSnapshotWriter(exec SnapshotExecer) *SnapshotWriter {
+	return NewSnapshotWriterWithPlateResolver(exec, nil)
+}
+
+func NewSnapshotWriterWithPlateResolver(exec SnapshotExecer, plateResolver PlateResolver) *SnapshotWriter {
 	if exec == nil {
 		panic("snapshot execer must not be nil")
 	}
-	return &SnapshotWriter{exec: exec}
+	return &SnapshotWriter{exec: exec, plateResolver: plateResolver}
 }
 
 func (w *SnapshotWriter) EnsureSchema(ctx context.Context) error {
@@ -41,6 +51,10 @@ func (w *SnapshotWriter) Update(ctx context.Context, env envelope.FrameEnvelope)
 	if !hasRealtimePayload(env) {
 		return nil
 	}
+	plate, err := w.plateForEnvelope(ctx, env)
+	if err != nil {
+		return err
+	}
 	fieldsJSON, err := marshalObject(env.Fields)
 	if err != nil {
 		return err
@@ -57,7 +71,7 @@ func (w *SnapshotWriter) Update(ctx context.Context, env envelope.FrameEnvelope)
 		strings.TrimSpace(env.VIN),
 		strings.TrimSpace(env.Phone),
 		strings.TrimSpace(env.DeviceID),
-		strings.TrimSpace(env.Plate),
+		plate,
 		strings.TrimSpace(env.MessageID),
 		env.Sequence,
 		strings.TrimSpace(env.SourceEndpoint),
@@ -69,7 +83,7 @@ func (w *SnapshotWriter) Update(ctx context.Context, env envelope.FrameEnvelope)
 	); err != nil {
 		return err
 	}
-	location, ok := realtimeLocationFromEnvelope(env, vehicleKey, fieldsJSON)
+	location, ok := realtimeLocationFromEnvelope(env, vehicleKey, fieldsJSON, plate)
 	if !ok {
 		return nil
 	}
@@ -100,6 +114,27 @@ func (w *SnapshotWriter) Update(ctx context.Context, env envelope.FrameEnvelope)
 	return err
 }
 
+func (w *SnapshotWriter) plateForEnvelope(ctx context.Context, env envelope.FrameEnvelope) (string, error) {
+	if plate := strings.TrimSpace(env.Plate); plate != "" {
+		return plate, nil
+	}
+	if w.plateResolver == nil {
+		return "", nil
+	}
+	vin := strings.TrimSpace(env.VIN)
+	if vin == "" {
+		return "", nil
+	}
+	plate, err := w.plateResolver.PlateByVIN(ctx, vin)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return "", nil
+		}
+		return "", err
+	}
+	return strings.TrimSpace(plate), nil
+}
+
 type realtimeLocationRow struct {
 	Protocol       string
 	VehicleKey     string
@@ -125,7 +160,7 @@ type realtimeLocationRow struct {
 	EventID        string
 }
 
-func realtimeLocationFromEnvelope(env envelope.FrameEnvelope, vehicleKey string, fieldsJSON string) (realtimeLocationRow, bool) {
+func realtimeLocationFromEnvelope(env envelope.FrameEnvelope, vehicleKey string, fieldsJSON string, plate string) (realtimeLocationRow, bool) {
 	latitude, okLat := numberField(env.Fields, envelope.FieldLatitude)
 	longitude, okLon := numberField(env.Fields, envelope.FieldLongitude)
 	if !okLat || !okLon {
@@ -137,7 +172,7 @@ func realtimeLocationFromEnvelope(env envelope.FrameEnvelope, vehicleKey string,
 		VIN:            strings.TrimSpace(env.VIN),
 		Phone:          strings.TrimSpace(env.Phone),
 		DeviceID:       strings.TrimSpace(env.DeviceID),
-		Plate:          strings.TrimSpace(env.Plate),
+		Plate:          plate,
 		MessageID:      strings.TrimSpace(env.MessageID),
 		Sequence:       env.Sequence,
 		SourceEndpoint: strings.TrimSpace(env.SourceEndpoint),
@@ -200,6 +235,53 @@ func numberField(fields map[string]any, key string) (float64, bool) {
 	}
 }
 
+type BindingPlateResolver struct {
+	queryer Queryer
+	table   string
+}
+
+type Queryer interface {
+	QueryRowContext(context.Context, string, ...any) *sql.Row
+}
+
+func NewBindingPlateResolver(queryer Queryer, table string) *BindingPlateResolver {
+	if queryer == nil {
+		panic("plate binding queryer must not be nil")
+	}
+	table = strings.TrimSpace(table)
+	if table == "" || !safeIdentifier(table) {
+		table = "vehicle_identity_binding"
+	}
+	return &BindingPlateResolver{queryer: queryer, table: table}
+}
+
+func (r *BindingPlateResolver) PlateByVIN(ctx context.Context, vin string) (string, error) {
+	vin = strings.TrimSpace(vin)
+	if vin == "" {
+		return "", sql.ErrNoRows
+	}
+	query := "SELECT plate FROM " + r.table + " WHERE vin = ? AND plate IS NOT NULL AND plate <> '' ORDER BY updated_at DESC LIMIT 1"
+	var plate string
+	err := r.queryer.QueryRowContext(ctx, query, vin).Scan(&plate)
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(plate), nil
+}
+
+func safeIdentifier(value string) bool {
+	if value == "" {
+		return false
+	}
+	for _, r := range value {
+		if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '_' {
+			continue
+		}
+		return false
+	}
+	return true
+}
+
 func marshalObject(value map[string]any) (string, error) {
 	if value == nil {
 		value = map[string]any{}