fix(telemetry): preserve regen sign

Author: malys

lib/src/main/java/com/evsuite/hardware/telemetry/ConsumptionCalculator.kt

@@ -77,8 +77,10 @@ class ConsumptionCalculator(
         val previous = smoothedValue
         val previousAt = smoothedAtMs
         val deltaMs = previousAt?.let { timestampMs - it }
+        val signChanged = previous != null && previous * current < 0.0
         val value = if (
-            previous == null || deltaMs == null || deltaMs <= 0L || deltaMs > MAX_SAMPLE_GAP_MS
+            previous == null || deltaMs == null || deltaMs <= 0L ||
+            deltaMs > MAX_SAMPLE_GAP_MS || signChanged
         ) {
             current
         } else {

lib/src/test/java/com/evsuite/hardware/telemetry/ConsumptionCalculatorTest.kt

@@ -36,6 +36,16 @@ class ConsumptionCalculatorTest {
         assertEquals(-20.0, value.value!!, 1e-9)
     }
 
+    @Test fun `dashboard smoothing resets when consumption changes to regeneration`() {
+        val calculator = ConsumptionCalculator()
+        calculator.add(0L, 18f, 90f)
+
+        val regeneration = calculator.add(1_000L, -18f, 90f)
+
+        assertEquals(-20.0, regeneration.rawInstantaneous.value!!, 1e-9)
+        assertEquals(-20.0, regeneration.smoothedInstantaneous.value!!, 1e-9)
+    }
+
     @Test fun `dashboard value uses a five second exponential moving average`() {
         val calculator = ConsumptionCalculator()
         calculator.add(0L, 18f, 90f)