1 files changed, 105 insertions, 0 deletions
diff --git a/catalog-be/src/main/java/org/openecomp/sdc/be/components/merge/TopologyComparator.java b/catalog-be/src/main/java/org/openecomp/sdc/be/components/merge/TopologyComparator.java
new file mode 100644
index 0000000000..8b48b0897a
--- /dev/null
+++ b/catalog-be/src/main/java/org/openecomp/sdc/be/components/merge/TopologyComparator.java
@@ -0,0 +1,105 @@
+package org.openecomp.sdc.be.components.merge;
+
+import java.util.List;
+import java.util.Map;
+
+import org.openecomp.sdc.be.dao.api.ActionStatus;
+import org.openecomp.sdc.be.dao.utils.MapUtil;
+import org.openecomp.sdc.be.exception.SdcActionException;
+import org.openecomp.sdc.be.impl.ComponentsUtils;
+import org.openecomp.sdc.be.model.Component;
+import org.openecomp.sdc.be.model.ComponentInstance;
+import org.openecomp.sdc.be.model.Resource;
+import org.openecomp.sdc.be.model.jsontitan.operations.ToscaOperationFacade;
+import org.openecomp.sdc.be.model.operations.api.StorageOperationStatus;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import fj.data.Either;
+
+@org.springframework.stereotype.Component
+public class TopologyComparator {
+
+    public static final Logger LOGGER = LoggerFactory.getLogger(TopologyComparator.class);
+
+    @javax.annotation.Resource
+    private RelationsComparator relationsComparator;
+
+    @javax.annotation.Resource
+    private ToscaOperationFacade toscaOperationFacade;
+
+    @javax.annotation.Resource
+    private ComponentsUtils componentsUtils;
+
+    /**
+     *
+     * @param oldResource the old version of the resource of which to check for topology change
+     * @param newResource the new version of the resource of which to check for topology change
+     * @return true if there was a topology change between the old resource and new resource or false otherwise
+     * in case the action to find topology change failed, an appropriate {@link ActionStatus} will be returned
+     */
+    public Either<Boolean, ActionStatus> isTopologyChanged(Resource oldResource, Resource newResource) {
+        List<ComponentInstance> oldInstances = oldResource.getComponentInstances();
+        List<ComponentInstance> newInstances = newResource.getComponentInstances();
+        if (oldInstances != null && newInstances == null || oldInstances == null && newInstances != null) {
+            return Either.left(true);
+        }
+        if (oldInstances == null && newInstances == null) {
+            return Either.left(false);
+        }
+        Map<String, ComponentInstance> oldInstancesByName = MapUtil.toMap(oldInstances, ComponentInstance::getName);
+        Map<String, ComponentInstance> newInstancesByName = MapUtil.toMap(newInstances, ComponentInstance::getName);
+        return isTopologyInstancesChanged(oldResource, newResource, oldInstancesByName, newInstancesByName);
+    }
+
+    private Either<Boolean, ActionStatus> isTopologyInstancesChanged(Resource oldResource, Resource newResource, Map<String, ComponentInstance> oldInstancesByName, Map<String, ComponentInstance> newInstancesByName) {
+        try {
+            boolean isTopologyChanged = isInstanceNamesChanged(oldInstancesByName, newInstancesByName) ||
+                                        isInstanceTypesChanged(oldInstancesByName, newInstancesByName) ||
+                                        relationsComparator.isRelationsChanged(oldResource, newResource);
+            return Either.left(isTopologyChanged);
+        } catch (SdcActionException e) {
+            LOGGER.error("failed to merge entities of previous resource %s to current resource %s. reason: %s", oldResource.getUniqueId(), newResource.getUniqueId(), e.getActionStatus(), e);
+            return Either.right(e.getActionStatus());
+        }
+    }
+
+    private boolean isInstanceTypesChanged(Map<String, ComponentInstance> oldInstancesByName, Map<String, ComponentInstance> newInstancesByName) {
+        for (Map.Entry<String, ComponentInstance> instanceByName : newInstancesByName.entrySet()) {
+            ComponentInstance oldInstance = oldInstancesByName.get(instanceByName.getKey());
+            if (!isSameToscaTypeOrOriginComponent(oldInstance, instanceByName.getValue())) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean isInstanceNamesChanged(Map<String, ComponentInstance> oldInstanceByName, Map<String, ComponentInstance> newInstancesByName) {
+        return !oldInstanceByName.keySet().equals(newInstancesByName.keySet());
+    }
+
+    private boolean isSameToscaTypeOrOriginComponent(ComponentInstance oldInstance, ComponentInstance newInstance) {
+        return isSameToscaType(oldInstance, newInstance) ||
+               isSameOriginComponent(oldInstance, newInstance);
+    }
+
+    private boolean isSameToscaType(ComponentInstance oldInstance, ComponentInstance newInstance) {
+        return oldInstance.getToscaComponentName().equals(newInstance.getToscaComponentName());
+    }
+
+    private boolean isSameOriginComponent(ComponentInstance oldInstance, ComponentInstance newInstance) {
+        if (oldInstance.getComponentUid().equals(newInstance.getComponentUid())) {
+            return true;
+        }
+        Component oldOriginCmpt = toscaOperationFacade.getToscaElement(oldInstance.getComponentUid()).left().on(storageStatus -> throwSdcActionException(storageStatus, oldInstance));
+        Component newOriginCmpt = toscaOperationFacade.getToscaElement(newInstance.getComponentUid()).left().on(storageStatus -> throwSdcActionException(storageStatus, newInstance));
+        return oldOriginCmpt.getInvariantUUID().equals(newOriginCmpt.getInvariantUUID());
+    }
+
+    private Component throwSdcActionException(StorageOperationStatus storageOperationStatus, ComponentInstance cmptInstance) {
+        LOGGER.error("failed to fetch origin node type %s for instance %s", cmptInstance.getUniqueId(), cmptInstance.getComponentUid());
+        throw new SdcActionException(componentsUtils.convertFromStorageResponse(storageOperationStatus));
+    }
+
+
+}