refactor: simplify jt808 mileage state

modules/services/vehicle-stat-service/src/main/java/com/lingniu/ingest/vehiclestat/jt808/Jt808DailyMileageState.java

@@ -18,7 +18,6 @@ public final class Jt808DailyMileageState {
     private Instant lastEventTime;
     private double firstTotalMileageKm = Double.NaN;
     private double lastTotalMileageKm = Double.NaN;
-    private double odometerMileageKm;
     private int acceptedPoints;
     private int totalMileageSamples;
     private int outOfOrderPoints;
@@ -50,7 +49,6 @@ public final class Jt808DailyMileageState {
             Instant lastEventTime,
             double firstTotalMileageKm,
             double lastTotalMileageKm,
-            double odometerMileageKm,
             int acceptedPoints,
             int totalMileageSamples,
             int outOfOrderPoints,
@@ -60,7 +58,6 @@ public final class Jt808DailyMileageState {
         state.lastEventTime = lastEventTime;
         state.firstTotalMileageKm = firstTotalMileageKm;
         state.lastTotalMileageKm = lastTotalMileageKm;
-        state.odometerMileageKm = odometerMileageKm;
         state.acceptedPoints = acceptedPoints;
         state.totalMileageSamples = totalMileageSamples;
         state.outOfOrderPoints = outOfOrderPoints;
@@ -112,11 +109,9 @@ public final class Jt808DailyMileageState {
         if (current < lastTotalMileageKm) {
             odometerAnomalies++;
             lastTotalMileageKm = current;
-            odometerMileageKm = 0.0;
             return;
         }
         lastTotalMileageKm = current;
-        odometerMileageKm = current - firstTotalMileageKm;
     }
 
     private OptionalDouble totalMileageDifference() {
@@ -160,10 +155,6 @@ public final class Jt808DailyMileageState {
         return lastEventTime;
     }
 
-    public double odometerMileageKm() {
-        return odometerMileageKm;
-    }
-
     public double lastTotalMileageKm() {
         return lastTotalMileageKm;
     }

modules/services/vehicle-stat-service/src/main/java/com/lingniu/ingest/vehiclestat/jt808/RedisJt808MileageStateStore.java

@@ -66,7 +66,6 @@ public final class RedisJt808MileageStateStore implements Jt808MileageStateStore
             PointSnapshot lastPoint,
             Double firstTotalMileageKm,
             Double lastTotalMileageKm,
-            double odometerMileageKm,
             int acceptedPoints,
             Integer totalMileageSamples,
             int outOfOrderPoints,
@@ -83,7 +82,6 @@ public final class RedisJt808MileageStateStore implements Jt808MileageStateStore
                     null,
                     finiteOrNull(state.firstTotalMileageKm()),
                     finiteOrNull(state.lastTotalMileageKm()),
-                    state.odometerMileageKm(),
                     state.acceptedPoints(),
                     state.totalMileageSamples(),
                     state.outOfOrderPoints(),
@@ -100,7 +98,6 @@ public final class RedisJt808MileageStateStore implements Jt808MileageStateStore
                     restoredLastEventTime(),
                     nanIfNull(firstTotalMileageKm),
                     nanIfNull(lastTotalMileageKm),
-                    odometerMileageKm,
                     acceptedPoints,
                     restoredTotalMileageSamples(),
                     outOfOrderPoints,

modules/services/vehicle-stat-service/src/test/java/com/lingniu/ingest/vehiclestat/jt808/Jt808DailyMileageStateTest.java

@@ -19,7 +19,6 @@ class Jt808DailyMileageStateTest {
 
         assertThat(state.acceptedPoints()).isEqualTo(1);
         assertThat(state.totalMileageSamples()).isEqualTo(1);
-        assertThat(state.odometerMileageKm()).isZero();
         assertThat(state.firstTotalMileageKm()).isEqualTo(100.0);
         assertThat(state.lastTotalMileageKm()).isEqualTo(100.0);
         assertThat(state.toVehicleDailyStatResult()).isEmpty();
@@ -28,7 +27,7 @@ class Jt808DailyMileageStateTest {
     }
 
     @Test
-    void orderedPointUpdatesGpsSpeedAndOdometerMileage() {
+    void orderedPointsCalculateDailyMileageFromTotalMileageDifference() {
         Jt808DailyMileageState state = Jt808DailyMileageState.empty("VIN001", "VIN001", "13900000001",
                 LocalDate.of(2026, 6, 30));
         state.apply(point("2026-06-30T00:00:00Z", 120.000000, 30.000000, 36.0, 100.0));
@@ -37,7 +36,6 @@ class Jt808DailyMileageStateTest {
 
         assertThat(state.acceptedPoints()).isEqualTo(2);
         assertThat(state.totalMileageSamples()).isEqualTo(2);
-        assertThat(state.odometerMileageKm()).isCloseTo(1.2, offset(0.000001));
         assertThat(state.firstTotalMileageKm()).isEqualTo(100.0);
         assertThat(state.lastTotalMileageKm()).isEqualTo(101.2);
         assertThat(state.toVehicleDailyStatResult()).isPresent();
@@ -66,7 +64,6 @@ class Jt808DailyMileageStateTest {
 
         state.apply(point("2026-06-30T00:01:40Z", 120.010370, 30.000000, 36.0, 99.5));
 
-        assertThat(state.odometerMileageKm()).isZero();
         assertThat(state.odometerAnomalies()).isEqualTo(1);
         assertThat(state.toVehicleDailyStatResult()).isEmpty();
     }
@@ -79,13 +76,12 @@ class Jt808DailyMileageStateTest {
 
         state.apply(point("2026-06-30T00:01:00Z", 120.000100, 30.000000, 36.0, 200.0));
 
-        assertThat(state.odometerMileageKm()).isEqualTo(100.0);
         assertThat(state.odometerAnomalies()).isZero();
         assertThat(state.toVehicleDailyStatResult().orElseThrow().dailyMileageKm()).hasValue(100.0);
     }
 
     @Test
-    void gpsDistanceIsFallbackWhenTotalMileageIsMissing() {
+    void totalMileageIsRequiredForDailyMileageMetric() {
         Jt808DailyMileageState state = Jt808DailyMileageState.empty("VIN001", "VIN001", "13900000001",
                 LocalDate.of(2026, 6, 30));
         state.apply(point("2026-06-30T00:00:00Z", 120.000000, 30.000000, 36.0, null));

modules/services/vehicle-stat-service/src/test/java/com/lingniu/ingest/vehiclestat/jt808/RedisJt808MileageStateStoreTest.java

@@ -2,6 +2,7 @@ package com.lingniu.ingest.vehiclestat.jt808;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
 import org.springframework.data.redis.core.StringRedisTemplate;
 import org.springframework.data.redis.core.ValueOperations;
 
@@ -31,14 +32,17 @@ class RedisJt808MileageStateStoreTest {
 
         store.save(state);
 
+        ArgumentCaptor<String> json = ArgumentCaptor.forClass(String.class);
         verify(values).set(
                 org.mockito.ArgumentMatchers.eq("vehicle:mileage:jt808:daily:2026-06-30:VIN001"),
-                org.mockito.ArgumentMatchers.contains("\"vehicleKey\":\"VIN001\""),
+                json.capture(),
                 org.mockito.ArgumentMatchers.eq(Duration.ofDays(3)));
+        assertThat(json.getValue()).contains("\"vehicleKey\":\"VIN001\"");
+        assertThat(json.getValue()).doesNotContain("odometerMileageKm");
     }
 
     @Test
-    void loadsStateFromJson() {
+    void loadsStateFromLegacyJson() {
         StringRedisTemplate redis = mock(StringRedisTemplate.class);
         @SuppressWarnings("unchecked")
         ValueOperations<String, String> values = mock(ValueOperations.class);