refactor: use stateless identity fallback

modules/core/vehicle-identity/src/main/java/com/lingniu/ingest/identity/StatelessVehicleIdentityResolver.java

@@ -0,0 +1,34 @@
+package com.lingniu.ingest.identity;
+
+/**
+ * Stateless production fallback used when a caller has no injected identity service.
+ *
+ * <p>Persistent binding belongs to {@link MySqlVehicleIdentityService}; this resolver only keeps
+ * ingestion flowing with explicit VIN or stable external identifiers.
+ */
+public final class StatelessVehicleIdentityResolver implements VehicleIdentityResolver {
+
+    @Override
+    public VehicleIdentity resolve(VehicleIdentityLookup lookup) {
+        if (lookup == null) {
+            return unknown();
+        }
+        if (!lookup.vin().isBlank()) {
+            return new VehicleIdentity(lookup.vin(), true, VehicleIdentitySource.EXPLICIT_VIN);
+        }
+        if (!lookup.deviceId().isBlank()) {
+            return new VehicleIdentity(lookup.deviceId(), false, VehicleIdentitySource.FALLBACK_DEVICE_ID);
+        }
+        if (!lookup.phone().isBlank()) {
+            return new VehicleIdentity(lookup.phone(), false, VehicleIdentitySource.FALLBACK_PHONE);
+        }
+        if (!lookup.plate().isBlank()) {
+            return new VehicleIdentity(lookup.plate(), false, VehicleIdentitySource.FALLBACK_PLATE);
+        }
+        return unknown();
+    }
+
+    private static VehicleIdentity unknown() {
+        return new VehicleIdentity("unknown", false, VehicleIdentitySource.UNKNOWN);
+    }
+}

modules/core/vehicle-identity/src/test/java/com/lingniu/ingest/identity/StatelessVehicleIdentityResolverTest.java

@@ -0,0 +1,57 @@
+package com.lingniu.ingest.identity;
+
+import com.lingniu.ingest.api.ProtocolId;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class StatelessVehicleIdentityResolverTest {
+
+    private final StatelessVehicleIdentityResolver resolver = new StatelessVehicleIdentityResolver();
+
+    @Test
+    void explicitVinWinsWithoutPersistingAnyBinding() {
+        VehicleIdentity identity = resolver.resolve(new VehicleIdentityLookup(
+                ProtocolId.MQTT_YUTONG, "LNVIN000000000001", "13900000000", "DEV001", "粤B12345"));
+
+        assertThat(identity.vin()).isEqualTo("LNVIN000000000001");
+        assertThat(identity.resolved()).isTrue();
+        assertThat(identity.source()).isEqualTo(VehicleIdentitySource.EXPLICIT_VIN);
+    }
+
+    @Test
+    void fallsBackToStableExternalIdentifiersWithoutMarkingResolved() {
+        assertThat(resolver.resolve(new VehicleIdentityLookup(
+                ProtocolId.JT808, "", "13900000001", "DEV001", "粤B12345")))
+                .satisfies(identity -> {
+                    assertThat(identity.vin()).isEqualTo("DEV001");
+                    assertThat(identity.resolved()).isFalse();
+                    assertThat(identity.source()).isEqualTo(VehicleIdentitySource.FALLBACK_DEVICE_ID);
+                });
+
+        assertThat(resolver.resolve(new VehicleIdentityLookup(
+                ProtocolId.JT808, "", "13900000001", "", "粤B12345")))
+                .satisfies(identity -> {
+                    assertThat(identity.vin()).isEqualTo("13900000001");
+                    assertThat(identity.resolved()).isFalse();
+                    assertThat(identity.source()).isEqualTo(VehicleIdentitySource.FALLBACK_PHONE);
+                });
+
+        assertThat(resolver.resolve(new VehicleIdentityLookup(
+                ProtocolId.JT808, "", "", "", "粤B12345")))
+                .satisfies(identity -> {
+                    assertThat(identity.vin()).isEqualTo("粤B12345");
+                    assertThat(identity.resolved()).isFalse();
+                    assertThat(identity.source()).isEqualTo(VehicleIdentitySource.FALLBACK_PLATE);
+                });
+    }
+
+    @Test
+    void returnsUnknownWhenNoIdentitySignalExists() {
+        VehicleIdentity identity = resolver.resolve(new VehicleIdentityLookup(ProtocolId.JT808, "", "", "", ""));
+
+        assertThat(identity.vin()).isEqualTo("unknown");
+        assertThat(identity.resolved()).isFalse();
+        assertThat(identity.source()).isEqualTo(VehicleIdentitySource.UNKNOWN);
+    }
+}