LcmEvent state handler refactoring

- State handler will now handle new structure of LcmEvent.
- We have 3 types of events i.e create, update and delete.
- Introduced the LcmEventCreatorHelper to delegate some of the
  responsibility of event creation based on event type and the state.
- New tests and existing refactoring
- Code rebased
- Refactored name as per group code review
- Code rebase with other commits
- Used copy constructor for deep copy operation of NcmpServiceCmhandle
  and CompositeState
- UPCOMING : Related user stories to trigger the event publishing using
  state handler.

Issue-ID: CPS-1128
Change-Id: I94b5a87d37d6a174c017ee0aa37cd0f0f74ba084
Signed-off-by: mpriyank <priyank.maheshwari@est.tech>

6 files changed, 351 insertions, 27 deletions

diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventType.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventType.java
new file mode 100644
index 000000000..f793dedb8
--- /dev/null
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventType.java
@@ -0,0 +1,38 @@
+/*
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2022 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.ncmp.api.impl.event.lcm;
+
+public enum LcmEventType {
+
+    CREATE("create"), UPDATE("update"), DELETE("delete");
+
+    private final String eventName;
+
+    private final String eventTypeTemplate = "org.onap.ncmp.cmhandle-lcm-event.%s";
+
+    LcmEventType(final String eventName) {
+        this.eventName = String.format(eventTypeTemplate, eventName);
+    }
+
+    public String getEventType() {
+        return this.eventName;
+    }
+}
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCmHandleStateHandlerImpl.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCmHandleStateHandlerImpl.java
index 9027a6eb0..fd46ee860 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCmHandleStateHandlerImpl.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCmHandleStateHandlerImpl.java
@@ -30,6 +30,7 @@ import lombok.extern.slf4j.Slf4j;
 import org.onap.cps.ncmp.api.impl.utils.YangDataConverter;
 import org.onap.cps.ncmp.api.impl.yangmodels.YangModelCmHandle;
 import org.onap.cps.ncmp.api.inventory.CmHandleState;
+import org.onap.cps.ncmp.api.inventory.CompositeState;
 import org.onap.cps.ncmp.api.inventory.CompositeStateUtils;
 import org.onap.cps.ncmp.api.inventory.InventoryPersistence;
 import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
@@ -45,15 +46,20 @@ public class LcmEventsCmHandleStateHandlerImpl implements LcmEventsCmHandleState
     private final LcmEventsCreator lcmEventsCreator;
     private final LcmEventsService lcmEventsService;
 
-
     @Override
     public void updateCmHandleState(final YangModelCmHandle yangModelCmHandle,
             final CmHandleState targetCmHandleState) {
-        if (yangModelCmHandle.getCompositeState().getCmHandleState() == targetCmHandleState) {
+
+        final CompositeState compositeState = yangModelCmHandle.getCompositeState();
+
+        if (compositeState != null && compositeState.getCmHandleState() == targetCmHandleState) {
             log.debug("CmHandle with id : {} already in state : {}", yangModelCmHandle.getId(), targetCmHandleState);
         } else {
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle =
+                    new NcmpServiceCmHandle(toNcmpServiceCmHandle(yangModelCmHandle));
             updateToSpecifiedCmHandleState(yangModelCmHandle, targetCmHandleState);
-            publishLcmEvent(yangModelCmHandle);
+            final NcmpServiceCmHandle targetNcmpServiceCmHandle = toNcmpServiceCmHandle(yangModelCmHandle);
+            publishLcmEvent(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle);
         }
 
     }
@@ -66,10 +72,10 @@ public class LcmEventsCmHandleStateHandlerImpl implements LcmEventsCmHandleState
                     .accept(yangModelCmHandle.getCompositeState());
             inventoryPersistence.saveCmHandleState(yangModelCmHandle.getId(), yangModelCmHandle.getCompositeState());
         } else if (ADVISED == targetCmHandleState) {
-            if (yangModelCmHandle.getCompositeState().getCmHandleState() == LOCKED) {
-                retryCmHandle(yangModelCmHandle);
-            } else {
+            if (yangModelCmHandle.getCompositeState() == null) {
                 registerNewCmHandle(yangModelCmHandle);
+            } else if (yangModelCmHandle.getCompositeState().getCmHandleState() == LOCKED) {
+                retryCmHandle(yangModelCmHandle);
             }
         } else if (DELETED == targetCmHandleState) {
             setCmHandleState(yangModelCmHandle, targetCmHandleState);
@@ -84,20 +90,21 @@ public class LcmEventsCmHandleStateHandlerImpl implements LcmEventsCmHandleState
     }
 
     private void registerNewCmHandle(final YangModelCmHandle yangModelCmHandle) {
+        yangModelCmHandle.setCompositeState(new CompositeState());
         setCmHandleState(yangModelCmHandle, ADVISED);
         inventoryPersistence.saveCmHandle(yangModelCmHandle);
     }
 
-    private void publishLcmEvent(final YangModelCmHandle yangModelCmHandle) {
-        final NcmpServiceCmHandle ncmpServiceCmHandle =
-                YangDataConverter.convertYangModelCmHandleToNcmpServiceCmHandle(yangModelCmHandle);
-        final String cmHandleId = ncmpServiceCmHandle.getCmHandleId();
-        final LcmEvent lcmEvent = lcmEventsCreator.populateLcmEvent(cmHandleId);
+    private void publishLcmEvent(final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle) {
+        final String cmHandleId = targetNcmpServiceCmHandle.getCmHandleId();
+        final LcmEvent lcmEvent =
+                lcmEventsCreator.populateLcmEvent(cmHandleId, targetNcmpServiceCmHandle, existingNcmpServiceCmHandle);
         lcmEventsService.publishLcmEvent(cmHandleId, lcmEvent);
     }
 
     private void updateAndSaveCmHandleState(final YangModelCmHandle yangModelCmHandle,
-                                            final CmHandleState targetCmHandleState) {
+            final CmHandleState targetCmHandleState) {
         setCmHandleState(yangModelCmHandle, targetCmHandleState);
         inventoryPersistence.saveCmHandleState(yangModelCmHandle.getId(), yangModelCmHandle.getCompositeState());
     }
@@ -105,4 +112,8 @@ public class LcmEventsCmHandleStateHandlerImpl implements LcmEventsCmHandleState
     private void setCmHandleState(final YangModelCmHandle yangModelCmHandle, final CmHandleState targetCmHandleState) {
         CompositeStateUtils.setCompositeState(targetCmHandleState).accept(yangModelCmHandle.getCompositeState());
     }
+
+    private NcmpServiceCmHandle toNcmpServiceCmHandle(final YangModelCmHandle yangModelCmHandle) {
+        return YangDataConverter.convertYangModelCmHandleToNcmpServiceCmHandle(yangModelCmHandle);
+    }
 }
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCreator.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCreator.java
index 085494aef..aef1ed9bd 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCreator.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCreator.java
@@ -21,10 +21,15 @@
 package org.onap.cps.ncmp.api.impl.event.lcm;
 
 import java.util.UUID;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
 import lombok.extern.slf4j.Slf4j;
 import org.onap.cps.ncmp.api.impl.utils.EventDateTimeFormatter;
+import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
 import org.onap.ncmp.cmhandle.event.lcm.Event;
 import org.onap.ncmp.cmhandle.event.lcm.LcmEvent;
+import org.onap.ncmp.cmhandle.event.lcm.Values;
 import org.springframework.stereotype.Component;
 
 
@@ -36,37 +41,60 @@ import org.springframework.stereotype.Component;
 public class LcmEventsCreator {
 
     /**
-     * Populate LcmEvent.
+     * Populate Lifecycle Management Event.
      *
-     * @param cmHandleId Cm Handle Identifier
-     * @return Populated Lcm Event
+     * @param cmHandleId                  cm handle identifier
+     * @param targetNcmpServiceCmHandle   target ncmp service cmhandle
+     * @param existingNcmpServiceCmHandle existing ncmp service cmhandle
+     * @return Populated LcmEvent
      */
-    public LcmEvent populateLcmEvent(final String cmHandleId) {
-        return createLcmEvent(cmHandleId);
+    public LcmEvent populateLcmEvent(final String cmHandleId, final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle) {
+        return createLcmEvent(cmHandleId, targetNcmpServiceCmHandle, existingNcmpServiceCmHandle);
     }
 
-    private LcmEvent createLcmEvent(final String cmHandleId) {
-        final LcmEvent lcmEvent = lcmEventHeader(cmHandleId);
-        lcmEvent.setEvent(lcmEventPayload(cmHandleId));
+    private LcmEvent createLcmEvent(final String cmHandleId, final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle) {
+        final LcmEventType lcmEventType =
+                LcmEventsCreatorHelper.determineEventType(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle);
+        final LcmEvent lcmEvent = lcmEventHeader(cmHandleId, lcmEventType);
+        lcmEvent.setEvent(
+                lcmEventPayload(cmHandleId, targetNcmpServiceCmHandle, existingNcmpServiceCmHandle, lcmEventType));
         return lcmEvent;
     }
 
-    private Event lcmEventPayload(final String eventCorrelationId) {
+    private Event lcmEventPayload(final String eventCorrelationId, final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle, final LcmEventType lcmEventType) {
         final Event event = new Event();
         event.setCmHandleId(eventCorrelationId);
+        final CmHandleValuesHolder cmHandleValuesHolder =
+                LcmEventsCreatorHelper.determineEventValues(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle,
+                        lcmEventType);
+        event.setOldValues(cmHandleValuesHolder.getOldValues());
+        event.setNewValues(cmHandleValuesHolder.getNewValues());
+
         return event;
     }
 
-    private LcmEvent lcmEventHeader(final String eventCorrelationId) {
+    private LcmEvent lcmEventHeader(final String eventCorrelationId, final LcmEventType lcmEventType) {
         final LcmEvent lcmEvent = new LcmEvent();
         lcmEvent.setEventId(UUID.randomUUID().toString());
         lcmEvent.setEventCorrelationId(eventCorrelationId);
         lcmEvent.setEventTime(EventDateTimeFormatter.getCurrentDateTime());
         lcmEvent.setEventSource("org.onap.ncmp");
-        lcmEvent.setEventType("org.onap.ncmp.cmhandle-lcm-event");
+        lcmEvent.setEventType(lcmEventType.getEventType());
         lcmEvent.setEventSchema("org.onap.ncmp:cmhandle-lcm-event");
-        lcmEvent.setEventSchemaVersion("v1");
+        lcmEvent.setEventSchemaVersion("1.0");
         return lcmEvent;
     }
 
-}
+    @NoArgsConstructor
+    @Getter
+    @Setter
+    static class CmHandleValuesHolder {
+
+        private Values oldValues;
+        private Values newValues;
+    }
+
+}
\ No newline at end of file
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCreatorHelper.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCreatorHelper.java
new file mode 100644
index 000000000..1f2cf97fe
--- /dev/null
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/event/lcm/LcmEventsCreatorHelper.java
@@ -0,0 +1,221 @@
+/*
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2022 Nordix Foundation
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.ncmp.api.impl.event.lcm;
+
+import static org.onap.cps.ncmp.api.impl.event.lcm.LcmEventType.CREATE;
+import static org.onap.cps.ncmp.api.impl.event.lcm.LcmEventType.DELETE;
+import static org.onap.cps.ncmp.api.impl.event.lcm.LcmEventType.UPDATE;
+import static org.onap.cps.ncmp.api.inventory.CmHandleState.DELETED;
+
+import com.google.common.collect.MapDifference;
+import com.google.common.collect.Maps;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
+import org.onap.ncmp.cmhandle.event.lcm.Values;
+
+/**
+ * LcmEventsCreatorHelper has helper methods to create LcmEvent.
+ * Determine the lcm event type i.e create,update and delete.
+ * Based on lcm event type create the LcmEvent payload.
+ */
+@Slf4j
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public class LcmEventsCreatorHelper {
+
+    /**
+     * Determining the event type based on the composite state.
+     *
+     * @param targetNcmpServiceCmHandle   target ncmpServiceCmHandle
+     * @param existingNcmpServiceCmHandle existing ncmpServiceCmHandle
+     * @return Event Type
+     */
+    public static LcmEventType determineEventType(final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle) {
+
+        if (existingNcmpServiceCmHandle.getCompositeState() == null) {
+            return CREATE;
+        } else if (targetNcmpServiceCmHandle.getCompositeState().getCmHandleState() == DELETED) {
+            return DELETE;
+        }
+        return UPDATE;
+    }
+
+    /**
+     * Determine the cmhandle value difference pair.Contains the difference in the form of oldValues and newValues.
+     *
+     * @param targetNcmpServiceCmHandle   target ncmpServiceCmHandle
+     * @param existingNcmpServiceCmHandle existing ncmpServiceCmHandle
+     * @param lcmEventType                lcm event type
+     * @return Lcm Event Value difference pair
+     */
+    public static LcmEventsCreator.CmHandleValuesHolder determineEventValues(
+            final NcmpServiceCmHandle targetNcmpServiceCmHandle, final NcmpServiceCmHandle existingNcmpServiceCmHandle,
+            final LcmEventType lcmEventType) {
+
+        if (CREATE == lcmEventType) {
+            return determineCreateEventValues(targetNcmpServiceCmHandle);
+        } else if (UPDATE == lcmEventType) {
+            return determineUpdateEventValues(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle);
+        }
+        return new LcmEventsCreator.CmHandleValuesHolder();
+
+    }
+
+    private static LcmEventsCreator.CmHandleValuesHolder determineCreateEventValues(
+            final NcmpServiceCmHandle ncmpServiceCmHandle) {
+        final LcmEventsCreator.CmHandleValuesHolder cmHandleValuesHolder = new LcmEventsCreator.CmHandleValuesHolder();
+        cmHandleValuesHolder.setNewValues(new Values());
+        cmHandleValuesHolder.getNewValues().setDataSyncEnabled(getDataSyncEnabledFlag(ncmpServiceCmHandle));
+        cmHandleValuesHolder.getNewValues()
+                .setCmHandleState(mapCmHandleStateToLcmEventCmHandleState(ncmpServiceCmHandle));
+        cmHandleValuesHolder.getNewValues().setCmHandleProperties(List.of(ncmpServiceCmHandle.getPublicProperties()));
+        return cmHandleValuesHolder;
+    }
+
+    private static LcmEventsCreator.CmHandleValuesHolder determineUpdateEventValues(
+            final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle) {
+
+        final boolean isDataSyncFlagEnabledChanged =
+                isDataSyncEnabledFlagChanged(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle);
+        final boolean isCmHandleStateChanged =
+                isCmHandleStateChanged(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle);
+        final boolean isPublicCmHandlePropertiesEqual =
+                isPublicCmHandlePropertiesEqual(targetNcmpServiceCmHandle.getPublicProperties(),
+                        existingNcmpServiceCmHandle.getPublicProperties());
+
+        final LcmEventsCreator.CmHandleValuesHolder cmHandleValuesHolder = new LcmEventsCreator.CmHandleValuesHolder();
+
+        if (isDataSyncFlagEnabledChanged || isCmHandleStateChanged || (!isPublicCmHandlePropertiesEqual)) {
+            cmHandleValuesHolder.setOldValues(new Values());
+            cmHandleValuesHolder.setNewValues(new Values());
+        } else {
+            return cmHandleValuesHolder;
+        }
+
+        if (isDataSyncFlagEnabledChanged) {
+            setDataSyncEnabledFlag(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle, cmHandleValuesHolder);
+        }
+
+        if (isCmHandleStateChanged) {
+            setCmHandleStateChange(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle, cmHandleValuesHolder);
+        }
+
+        if (!isPublicCmHandlePropertiesEqual) {
+            setPublicCmHandlePropertiesChange(targetNcmpServiceCmHandle, existingNcmpServiceCmHandle,
+                    cmHandleValuesHolder);
+        }
+
+        return cmHandleValuesHolder;
+
+    }
+
+    private static void setDataSyncEnabledFlag(final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle,
+            final LcmEventsCreator.CmHandleValuesHolder cmHandleValuesHolder) {
+
+        cmHandleValuesHolder.getOldValues().setDataSyncEnabled(getDataSyncEnabledFlag(existingNcmpServiceCmHandle));
+        cmHandleValuesHolder.getNewValues().setDataSyncEnabled(getDataSyncEnabledFlag(targetNcmpServiceCmHandle));
+
+    }
+
+    private static void setCmHandleStateChange(final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle,
+            final LcmEventsCreator.CmHandleValuesHolder cmHandleValuesHolder) {
+        cmHandleValuesHolder.getOldValues()
+                .setCmHandleState(mapCmHandleStateToLcmEventCmHandleState(existingNcmpServiceCmHandle));
+        cmHandleValuesHolder.getNewValues()
+                .setCmHandleState(mapCmHandleStateToLcmEventCmHandleState(targetNcmpServiceCmHandle));
+    }
+
+    private static void setPublicCmHandlePropertiesChange(final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle,
+            final LcmEventsCreator.CmHandleValuesHolder cmHandleValuesHolder) {
+
+        final Map<String, Map<String, String>> publicCmHandlePropertiesDifference =
+                getPublicCmHandlePropertiesDifference(targetNcmpServiceCmHandle.getPublicProperties(),
+                        existingNcmpServiceCmHandle.getPublicProperties());
+        cmHandleValuesHolder.getOldValues()
+                .setCmHandleProperties(List.of(publicCmHandlePropertiesDifference.get("oldValues")));
+        cmHandleValuesHolder.getNewValues()
+                .setCmHandleProperties(List.of(publicCmHandlePropertiesDifference.get("newValues")));
+
+    }
+
+    private static Values.CmHandleState mapCmHandleStateToLcmEventCmHandleState(
+            final NcmpServiceCmHandle ncmpServiceCmHandle) {
+        return Values.CmHandleState.fromValue(ncmpServiceCmHandle.getCompositeState().getCmHandleState().name());
+    }
+
+    private static Boolean getDataSyncEnabledFlag(final NcmpServiceCmHandle ncmpServiceCmHandle) {
+        return ncmpServiceCmHandle.getCompositeState().getDataSyncEnabled();
+    }
+
+    private static boolean isDataSyncEnabledFlagChanged(final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle) {
+
+        return !targetNcmpServiceCmHandle.getCompositeState().getDataSyncEnabled()
+                .equals(existingNcmpServiceCmHandle.getCompositeState().getDataSyncEnabled());
+    }
+
+    private static boolean isCmHandleStateChanged(final NcmpServiceCmHandle targetNcmpServiceCmHandle,
+            final NcmpServiceCmHandle existingNcmpServiceCmHandle) {
+
+        return targetNcmpServiceCmHandle.getCompositeState().getCmHandleState()
+                       != existingNcmpServiceCmHandle.getCompositeState().getCmHandleState();
+    }
+
+    private static boolean isPublicCmHandlePropertiesEqual(final Map<String, String> targetCmHandleProperties,
+            final Map<String, String> existingCmHandleProperties) {
+        if (targetCmHandleProperties.size() != existingCmHandleProperties.size()) {
+            return false;
+        }
+
+        return targetCmHandleProperties.equals(existingCmHandleProperties);
+    }
+
+    private static Map<String, Map<String, String>> getPublicCmHandlePropertiesDifference(
+            final Map<String, String> targetCmHandleProperties, final Map<String, String> existingCmHandleProperties) {
+        final Map<String, Map<String, String>> oldAndNewPropertiesDifferenceMap = new HashMap<>(2);
+
+        final MapDifference<String, String> cmHandlePropertiesDifference =
+                Maps.difference(targetCmHandleProperties, existingCmHandleProperties);
+
+        final Map<String, String> newValues = new HashMap<>(cmHandlePropertiesDifference.entriesOnlyOnLeft());
+        final Map<String, String> oldValues = new HashMap<>(cmHandlePropertiesDifference.entriesOnlyOnRight());
+
+        cmHandlePropertiesDifference.entriesDiffering().keySet().forEach(cmHandlePropertyName -> {
+            oldValues.put(cmHandlePropertyName, existingCmHandleProperties.get(cmHandlePropertyName));
+            newValues.put(cmHandlePropertyName, targetCmHandleProperties.get(cmHandlePropertyName));
+        });
+
+        oldAndNewPropertiesDifferenceMap.put("oldValues", oldValues);
+        oldAndNewPropertiesDifferenceMap.put("newValues", newValues);
+
+        return oldAndNewPropertiesDifferenceMap;
+    }
+
+}
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CompositeState.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CompositeState.java
index e8fcaabe9..bf448c568 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CompositeState.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CompositeState.java
@@ -57,8 +57,21 @@ public class CompositeState {
     /**
      * Date and Time in the format of yyyy-MM-dd'T'HH:mm:ss.SSSZ
      */
-    private static final DateTimeFormatter dateTimeFormatter = DateTimeFormatter
-            .ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+    private static final DateTimeFormatter dateTimeFormatter =
+            DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
+
+    /**
+     * Composite State copy constructor.
+     *
+     * @param compositeState Composite State
+     */
+    public CompositeState(final CompositeState compositeState) {
+        this.cmHandleState = compositeState.getCmHandleState();
+        this.lockReason = compositeState.getLockReason();
+        this.lastUpdateTime = compositeState.getLastUpdateTime();
+        this.dataSyncEnabled = compositeState.getDataSyncEnabled();
+        this.dataStores = compositeState.getDataStores();
+    }
 
 
     /**
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/models/NcmpServiceCmHandle.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/models/NcmpServiceCmHandle.java
index 963b484ed..ae40d330b 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/models/NcmpServiceCmHandle.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/models/NcmpServiceCmHandle.java
@@ -23,6 +23,7 @@ package org.onap.cps.ncmp.api.models;
 import com.fasterxml.jackson.annotation.JsonSetter;
 import com.fasterxml.jackson.annotation.Nulls;
 import java.util.Collections;
+import java.util.LinkedHashMap;
 import java.util.Map;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
@@ -51,4 +52,16 @@ public class NcmpServiceCmHandle {
     @JsonSetter(nulls = Nulls.AS_EMPTY)
     private CompositeState compositeState;
 
+    /**
+     * NcmpServiceCmHandle copy constructor.
+     *
+     * @param ncmpServiceCmHandle Ncmp Service CmHandle
+     */
+    public NcmpServiceCmHandle(final NcmpServiceCmHandle ncmpServiceCmHandle) {
+        this.cmHandleId = ncmpServiceCmHandle.getCmHandleId();
+        this.dmiProperties = new LinkedHashMap<>(ncmpServiceCmHandle.getDmiProperties());
+        this.publicProperties = new LinkedHashMap<>(ncmpServiceCmHandle.getPublicProperties());
+        this.compositeState = ncmpServiceCmHandle.getCompositeState() != null ? new CompositeState(
+                ncmpServiceCmHandle.getCompositeState()) : null;
+    }
 }