feat: scaffold go vehicle gateway core

go/vehicle-gateway/internal/eventbus/kafka_sink.go

@@ -0,0 +1,94 @@
+package eventbus
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/segmentio/kafka-go"
+
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
+)
+
+type Sink interface {
+	PublishRaw(context.Context, envelope.FrameEnvelope) error
+	PublishUnified(context.Context, envelope.FrameEnvelope) error
+	Close() error
+}
+
+type KafkaSink struct {
+	writer       kafkaWriter
+	rawTopics    map[envelope.Protocol]string
+	unifiedTopic string
+}
+
+type kafkaWriter interface {
+	WriteMessages(context.Context, ...kafka.Message) error
+	Close() error
+}
+
+type KafkaConfig struct {
+	Brokers      []string
+	RawTopics    map[envelope.Protocol]string
+	UnifiedTopic string
+}
+
+func NewKafkaSink(cfg KafkaConfig) (*KafkaSink, error) {
+	if len(cfg.Brokers) == 0 {
+		return nil, errors.New("kafka brokers are required")
+	}
+	return newKafkaSinkWithWriter(&kafka.Writer{
+		Addr:                   kafka.TCP(cfg.Brokers...),
+		Balancer:               &kafka.Hash{},
+		AllowAutoTopicCreation: false,
+	}, cfg), nil
+}
+
+func newKafkaSinkWithWriter(writer kafkaWriter, cfg KafkaConfig) *KafkaSink {
+	rawTopics := map[envelope.Protocol]string{
+		envelope.ProtocolGB32960:    "vehicle.raw.gb32960.v1",
+		envelope.ProtocolJT808:      "vehicle.raw.jt808.v1",
+		envelope.ProtocolYutongMQTT: "vehicle.raw.yutong-mqtt.v1",
+	}
+	for protocol, topic := range cfg.RawTopics {
+		if topic != "" {
+			rawTopics[protocol] = topic
+		}
+	}
+	unifiedTopic := cfg.UnifiedTopic
+	if unifiedTopic == "" {
+		unifiedTopic = "vehicle.event.unified.v1"
+	}
+	return &KafkaSink{writer: writer, rawTopics: rawTopics, unifiedTopic: unifiedTopic}
+}
+
+func (s *KafkaSink) PublishRaw(ctx context.Context, env envelope.FrameEnvelope) error {
+	topic, ok := s.rawTopics[env.Protocol]
+	if !ok || topic == "" {
+		return fmt.Errorf("raw topic not configured for protocol %s", env.Protocol)
+	}
+	return s.publish(ctx, topic, env)
+}
+
+func (s *KafkaSink) PublishUnified(ctx context.Context, env envelope.FrameEnvelope) error {
+	return s.publish(ctx, s.unifiedTopic, env)
+}
+
+func (s *KafkaSink) Close() error {
+	if s == nil || s.writer == nil {
+		return nil
+	}
+	return s.writer.Close()
+}
+
+func (s *KafkaSink) publish(ctx context.Context, topic string, env envelope.FrameEnvelope) error {
+	payload, err := env.MarshalJSONBytes()
+	if err != nil {
+		return err
+	}
+	return s.writer.WriteMessages(ctx, kafka.Message{
+		Topic: topic,
+		Key:   env.KafkaKey(),
+		Value: payload,
+	})
+}

go/vehicle-gateway/internal/eventbus/kafka_sink_test.go

@@ -0,0 +1,77 @@
+package eventbus
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+
+	"github.com/segmentio/kafka-go"
+
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
+)
+
+func TestKafkaSinkRoutesRawTopics(t *testing.T) {
+	writer := &recordingWriter{}
+	sink := newKafkaSinkWithWriter(writer, KafkaConfig{})
+
+	env := envelope.FrameEnvelope{Protocol: envelope.ProtocolJT808, Phone: "013307795425", MessageID: "0x0200"}
+	if err := sink.PublishRaw(context.Background(), env); err != nil {
+		t.Fatalf("PublishRaw() error = %v", err)
+	}
+	if len(writer.messages) != 1 {
+		t.Fatalf("messages = %d", len(writer.messages))
+	}
+	msg := writer.messages[0]
+	if msg.Topic != "vehicle.raw.jt808.v1" {
+		t.Fatalf("topic = %q", msg.Topic)
+	}
+	if string(msg.Key) != "JT808:013307795425" {
+		t.Fatalf("key = %q", string(msg.Key))
+	}
+	var decoded envelope.FrameEnvelope
+	if err := json.Unmarshal(msg.Value, &decoded); err != nil {
+		t.Fatalf("json.Unmarshal() error = %v", err)
+	}
+	if decoded.EventID == "" || decoded.ParseStatus != envelope.ParseOK {
+		t.Fatalf("unexpected payload defaults: %#v", decoded)
+	}
+}
+
+func TestKafkaSinkRoutesUnifiedTopic(t *testing.T) {
+	writer := &recordingWriter{}
+	sink := newKafkaSinkWithWriter(writer, KafkaConfig{UnifiedTopic: "custom.unified"})
+
+	env := envelope.FrameEnvelope{Protocol: envelope.ProtocolGB32960, VIN: "LNBVIN00000000001", MessageID: "0x02"}
+	if err := sink.PublishUnified(context.Background(), env); err != nil {
+		t.Fatalf("PublishUnified() error = %v", err)
+	}
+	if writer.messages[0].Topic != "custom.unified" {
+		t.Fatalf("topic = %q", writer.messages[0].Topic)
+	}
+	if string(writer.messages[0].Key) != "LNBVIN00000000001" {
+		t.Fatalf("key = %q", string(writer.messages[0].Key))
+	}
+}
+
+func TestKafkaSinkRejectsUnknownProtocol(t *testing.T) {
+	writer := &recordingWriter{}
+	sink := newKafkaSinkWithWriter(writer, KafkaConfig{})
+
+	err := sink.PublishRaw(context.Background(), envelope.FrameEnvelope{Protocol: envelope.Protocol("UNKNOWN")})
+	if err == nil {
+		t.Fatal("expected unknown protocol error")
+	}
+}
+
+type recordingWriter struct {
+	messages []kafka.Message
+}
+
+func (w *recordingWriter) WriteMessages(_ context.Context, messages ...kafka.Message) error {
+	w.messages = append(w.messages, messages...)
+	return nil
+}
+
+func (w *recordingWriter) Close() error {
+	return nil
+}