Fix converter station modification issue in unbuilt state

src/main/java/org/gridsuite/modification/server/modifications/VscModification.java

@@ -51,10 +51,22 @@ public void check(Network network) throws NetworkModificationException {
                 || modificationInfos.getConverterStation2() == null) {
             throw new NetworkModificationException(MODIFY_BATTERY_ERROR, "Missing required attributes to modify the equipment");
         }
-        VscConverterStation converterStation1 = ModificationUtils.getInstance().getVscConverterStation(network, modificationInfos.getConverterStation1().getEquipmentId());
-        VscConverterStation converterStation2 = ModificationUtils.getInstance().getVscConverterStation(network, modificationInfos.getConverterStation2().getEquipmentId());
+        HvdcLine hvdcLine = ModificationUtils.getInstance().getHvdcLine(network, modificationInfos.getEquipmentId());
+
+        VscConverterStation converterStation1 = ModificationUtils.getInstance().getVscConverterStation(network, hvdcLine.getConverterStation1().getId());
+        VscConverterStation converterStation2 = ModificationUtils.getInstance().getVscConverterStation(network, hvdcLine.getConverterStation2().getId());
         checkConverterStation(modificationInfos.getConverterStation1(), converterStation1);
         checkConverterStation(modificationInfos.getConverterStation2(), converterStation2);
+
+        checkToModifyDroop();
+
+    }
+
+    private void checkToModifyDroop() {
+        // if droop is set p0 should be also
+        if (modificationInfos.getP0() == null && modificationInfos.getDroop() != null) {
+            throw new NetworkModificationException(MODIFY_VSC_ERROR, "P0 is required to modify the equipment");
+        }
     }
 
     @Override
@@ -92,8 +104,8 @@ private void modifyVsc(@NonNull Network network, @NonNull HvdcLine hvdcLine, Vsc
         operatorActivePowerLimit(hvdcLine, modificationInfos, subReportNode);
 
         // stations
-        modifyConverterStation(network, modificationInfos.getConverterStation1(), subReportNode);
-        modifyConverterStation(network, modificationInfos.getConverterStation2(), subReportNode);
+        modifyConverterStation(ModificationUtils.getInstance().getVscConverterStation(network, hvdcLine.getConverterStation1().getId()), modificationInfos.getConverterStation1(), subReportNode);
+        modifyConverterStation(ModificationUtils.getInstance().getVscConverterStation(network, hvdcLine.getConverterStation2().getId()), modificationInfos.getConverterStation2(), subReportNode);
 
         PropertiesUtils.applyProperties(hvdcLine, subReportNode, modificationInfos.getProperties(), "VscProperties");
     }
@@ -245,11 +257,11 @@ private List<ReportNode> hvdcAngleDroopActivePowerControlAdder(HvdcLine hvdcLine
         return reports;
     }
 
-    private void modifyConverterStation(Network network, ConverterStationModificationInfos converterStationModificationInfos, ReportNode subReportNode) {
+    private void modifyConverterStation(VscConverterStation converterStation, ConverterStationModificationInfos converterStationModificationInfos, ReportNode subReportNode) {
         if (converterStationModificationInfos == null || !isConverterStationModified(converterStationModificationInfos)) {
             return;
         }
-        VscConverterStation converterStation = ModificationUtils.getInstance().getVscConverterStation(network, converterStationModificationInfos.getEquipmentId());
+
         ReportNode converterStationReportNode = subReportNode.newReportNode()
             .withMessageTemplate("Converter Station", "Converter station ${id} modified")
             .withUntypedValue("id", converterStation.getId())

src/test/java/org/gridsuite/modification/server/modifications/VscModificationTest.java

@@ -63,8 +63,8 @@ protected ModificationInfos buildModification() {
                 .operatorActivePowerLimitFromSide2ToSide1(new AttributeModification<>(8F, OperationType.SET))
                 .droop(new AttributeModification<>(1F, OperationType.SET))
                 .angleDroopActivePowerControl(new AttributeModification<>(true, OperationType.SET))
-                .converterStation1(buildConverterStationWithMinMaxReactiveLimits())
-                .converterStation2(buildConverterStationWithReactiveCapabilityCurve())
+                .converterStation1(buildConverterStationWithReactiveCapabilityCurve())
+                .converterStation2(buildConverterStationWithMinMaxReactiveLimits())
                 .properties(List.of(FreePropertyInfos.builder().name(PROPERTY_NAME).value(PROPERTY_VALUE).build()))
                 .build();
     }
@@ -171,7 +171,7 @@ protected void assertAfterNetworkModificationCreation() {
             Assert.assertEquals(2, reactiveLimits1.getPointCount());
             Collection<ReactiveCapabilityCurve.Point> points = vscConverterStation1.getReactiveLimits(ReactiveCapabilityCurve.class).getPoints();
             List<ReactiveCapabilityCurve.Point> vscPoints = new ArrayList<>(points);
-            List<ReactiveCapabilityCurveModificationInfos> modificationPoints = vscModificationInfos.getConverterStation2().getReactiveCapabilityCurvePoints();
+            List<ReactiveCapabilityCurveModificationInfos> modificationPoints = vscModificationInfos.getConverterStation1().getReactiveCapabilityCurvePoints();
             if (!CollectionUtils.isEmpty(points)) {
                 IntStream.range(0, vscPoints.size())
                         .forEach(i -> {
@@ -262,6 +262,21 @@ public void testUnchangedHVDCangleDroopActivePowerControl() throws Exception {
         Assert.assertTrue(activePowerControl.isEnabled());
     }
 
+    //Test : p0 sould be required if drop is enabled
+    @Test
+    public void testHvdcAngleDroopActivePowerControlWithoutP0() {
+        var networkuuid = UUID.randomUUID();
+        Network networkWitoutExt = NetworkCreation.createWithVSC(networkuuid, true);
+        VscModificationInfos modificationInfos = (VscModificationInfos) buildModification();
+        modificationInfos.setAngleDroopActivePowerControl(new AttributeModification<>(true, OperationType.SET));
+        {
+            modificationInfos.setDroop(new AttributeModification<>(10F, OperationType.SET));
+            modificationInfos.setP0(null);
+            VscModification vscModification = new VscModification(modificationInfos);
+            Assert.assertThrows(NetworkModificationException.class, () -> vscModification.check(networkWitoutExt));
+        }
+    }
+
     @Override
     @SneakyThrows
     protected void testUpdateModificationMessage(ModificationInfos modificationInfos) {