feat(go): persist realtime snapshots to mysql

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

@@ -0,0 +1,128 @@
+package realtime
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"strings"
+	"time"
+
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
+)
+
+type SnapshotExecer interface {
+	ExecContext(context.Context, string, ...any) (sql.Result, error)
+}
+
+type SnapshotWriter struct {
+	exec SnapshotExecer
+}
+
+func NewSnapshotWriter(exec SnapshotExecer) *SnapshotWriter {
+	if exec == nil {
+		panic("snapshot execer must not be nil")
+	}
+	return &SnapshotWriter{exec: exec}
+}
+
+func (w *SnapshotWriter) EnsureSchema(ctx context.Context) error {
+	_, err := w.exec.ExecContext(ctx, realtimeSnapshotTableSQL)
+	return err
+}
+
+func (w *SnapshotWriter) Update(ctx context.Context, env envelope.FrameEnvelope) error {
+	vehicleKey := strings.TrimSpace(env.VehicleKey())
+	if vehicleKey == "" || strings.HasSuffix(vehicleKey, ":unknown") {
+		return nil
+	}
+	fieldsJSON, err := marshalObject(env.Fields)
+	if err != nil {
+		return err
+	}
+	parsedJSON, err := marshalObject(env.Parsed)
+	if err != nil {
+		return err
+	}
+	eventTime := nullableTime(env.EventTimeMS)
+	receivedAt := nullableTime(env.ReceivedAtMS)
+	_, err = w.exec.ExecContext(ctx, upsertRealtimeSnapshotSQL,
+		string(env.Protocol),
+		vehicleKey,
+		strings.TrimSpace(env.VIN),
+		strings.TrimSpace(env.Phone),
+		strings.TrimSpace(env.DeviceID),
+		strings.TrimSpace(env.Plate),
+		strings.TrimSpace(env.MessageID),
+		env.Sequence,
+		strings.TrimSpace(env.SourceEndpoint),
+		eventTime,
+		parsedJSON,
+		fieldsJSON,
+		receivedAt,
+		env.StableEventID(),
+	)
+	return err
+}
+
+func marshalObject(value map[string]any) (string, error) {
+	if value == nil {
+		value = map[string]any{}
+	}
+	payload, err := json.Marshal(value)
+	if err != nil {
+		return "", err
+	}
+	return string(payload), nil
+}
+
+func nullableTime(ms int64) any {
+	if ms <= 0 {
+		return nil
+	}
+	return time.UnixMilli(ms)
+}
+
+const realtimeSnapshotTableSQL = `CREATE TABLE IF NOT EXISTS vehicle_realtime_snapshot (
+  id BIGINT PRIMARY KEY AUTO_INCREMENT,
+  protocol VARCHAR(32) NOT NULL,
+  vehicle_key VARCHAR(96) NOT NULL,
+  vin VARCHAR(32) NOT NULL DEFAULT '',
+  phone VARCHAR(32) NOT NULL DEFAULT '',
+  device_id VARCHAR(96) NOT NULL DEFAULT '',
+  plate VARCHAR(32) NOT NULL DEFAULT '',
+  message_id VARCHAR(32) NOT NULL DEFAULT '',
+  sequence_id INT NOT NULL DEFAULT 0,
+  source_endpoint VARCHAR(128) NOT NULL DEFAULT '',
+  event_time DATETIME(3) NULL,
+  parsed_json JSON NOT NULL,
+  fields_json JSON NOT NULL,
+  received_at DATETIME(3) NULL,
+  event_id VARCHAR(64) NOT NULL DEFAULT '',
+  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  UNIQUE KEY uk_realtime_snapshot_vehicle (protocol, vehicle_key),
+  KEY idx_vehicle_key (vehicle_key),
+  KEY idx_vin (vin),
+  KEY idx_protocol_updated (protocol, updated_at)
+)`
+
+const upsertRealtimeSnapshotSQL = `
+INSERT INTO vehicle_realtime_snapshot
+  (protocol, vehicle_key, vin, phone, device_id, plate, message_id, sequence_id,
+   source_endpoint, event_time, parsed_json, fields_json, received_at, event_id)
+VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, CAST(? AS JSON), CAST(? AS JSON), ?, ?)
+ON DUPLICATE KEY UPDATE
+  vin = IF(VALUES(vin) <> '', VALUES(vin), vin),
+  phone = IF(VALUES(phone) <> '', VALUES(phone), phone),
+  device_id = IF(VALUES(device_id) <> '', VALUES(device_id), device_id),
+  plate = IF(VALUES(plate) <> '', VALUES(plate), plate),
+  message_id = VALUES(message_id),
+  sequence_id = VALUES(sequence_id),
+  source_endpoint = VALUES(source_endpoint),
+  event_time = VALUES(event_time),
+  parsed_json = VALUES(parsed_json),
+  fields_json = VALUES(fields_json),
+  received_at = VALUES(received_at),
+  event_id = VALUES(event_id),
+  updated_at = CURRENT_TIMESTAMP
+`