1 files changed, 142 insertions, 0 deletions
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/utils/AlternateIdChecker.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/utils/AlternateIdChecker.java
new file mode 100644
index 000000000..1be1a9085
--- /dev/null
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/utils/AlternateIdChecker.java
@@ -0,0 +1,142 @@
+/*
+ * ============LICENSE_START========================================================
+ * Copyright (c) 2024 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.utils;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
+import org.onap.cps.ncmp.api.impl.inventory.InventoryPersistence;
+import org.onap.cps.ncmp.api.impl.yangmodels.YangModelCmHandle;
+import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
+import org.onap.cps.spi.exceptions.DataNodeNotFoundException;
+import org.springframework.stereotype.Service;
+
+@Service
+@Slf4j
+@RequiredArgsConstructor
+public class AlternateIdChecker {
+
+    private final InventoryPersistence inventoryPersistence;
+
+    private static final String NO_CURRENT_ALTERNATE_ID = "";
+
+    /**
+     * Check if the alternate can be applied to the given cm handle (id).
+     * Conditions:
+     * - proposed alternate is blank (it wil be ignored)
+     * - proposed alternate is same as current (no change)
+     * - proposed alternate is not in use for a different cm handle (in the DB)
+     *
+     * @param cmHandleId cm handle id
+     * @param proposedAlternateId proposed alternate id
+     * @return true if the new alternate id not in use or equal to current alternate id, false otherwise
+     */
+    public boolean canApplyAlternateId(final String cmHandleId, final String proposedAlternateId) {
+        String currentAlternateId = "";
+        try {
+            final YangModelCmHandle yangModelCmHandle = inventoryPersistence.getYangModelCmHandle(cmHandleId);
+            currentAlternateId = yangModelCmHandle.getAlternateId();
+        } catch (final DataNodeNotFoundException dataNodeNotFoundException) {
+            // work with blank current alternate id
+        }
+        return this.canApplyAlternateId(cmHandleId, currentAlternateId, proposedAlternateId);
+    }
+
+    /**
+     * Check if the alternate can be applied to the given cm handle.
+     * Conditions:
+     * - proposed alternate is blank (it wil be ignored)
+     * - proposed alternate is same as current (no change)
+     * - proposed alternate is not in use for a different cm handle (in the DB)
+     *
+     * @param cmHandleId   cm handle id
+     * @param currentAlternateId current alternate id
+     * @param proposedAlternateId new alternate id
+     * @return true if the new alternate id not in use or equal to current alternate id, false otherwise
+     */
+    public boolean canApplyAlternateId(final String cmHandleId,
+                                       final String currentAlternateId,
+                                       final String proposedAlternateId) {
+        if (StringUtils.isBlank(currentAlternateId)) {
+            if (alternateIdAlreadyInDb(proposedAlternateId)) {
+                log.warn("Alternate id update ignored, cannot update cm handle {}, alternate id is already "
+                    + "assigned to a different cm handle", cmHandleId);
+                return false;
+            }
+            return true;
+        }
+        if (currentAlternateId.equals(proposedAlternateId)) {
+            return true;
+        }
+        log.warn("Alternate id update ignored, cannot update cm handle {}, already has an alternate id of {}",
+            cmHandleId, currentAlternateId);
+        return false;
+    }
+
+    /**
+     * Check all alternate ids of a batch of NEW cm handles.
+     * Includes cross-checks in the batch itself for duplicates. Only the first entry encountered wil be accepted.
+     * This method can only be used for NEW cm handle registrations NOT for updating existing ones
+     *
+     * @param newNcmpServiceCmHandles the proposed new cm handles
+     * @return collection of cm handles ids which are acceptable
+     */
+    public Collection<String> getIdsOfCmHandlesWithAcceptableAlternateId(
+                                    final Collection<NcmpServiceCmHandle> newNcmpServiceCmHandles) {
+        final Set<String> acceptedAlternateIds = new HashSet<>(newNcmpServiceCmHandles.size());
+        final Collection<String> acceptedCmHandleIds = new ArrayList<>(newNcmpServiceCmHandles.size());
+        for (final NcmpServiceCmHandle ncmpServiceCmHandle : newNcmpServiceCmHandles) {
+            final String cmHandleId = ncmpServiceCmHandle.getCmHandleId();
+            final String proposedAlternateId = ncmpServiceCmHandle.getAlternateId();
+            final boolean isAcceptable;
+            if (StringUtils.isEmpty(proposedAlternateId)) {
+                isAcceptable = true;
+            } else {
+                if (acceptedAlternateIds.contains(proposedAlternateId)) {
+                    isAcceptable = false;
+                    log.warn("Alternate id update ignored, cannot update cm handle {}, alternate id is already "
+                        + "assigned to a different cm handle (in this batch)", cmHandleId);
+                } else {
+                    isAcceptable = canApplyAlternateId(cmHandleId, NO_CURRENT_ALTERNATE_ID, proposedAlternateId);
+                }
+            }
+            if (isAcceptable) {
+                acceptedAlternateIds.add(proposedAlternateId);
+                acceptedCmHandleIds.add(cmHandleId);
+            }
+        }
+        return acceptedCmHandleIds;
+    }
+
+    private boolean alternateIdAlreadyInDb(final String alternateId) {
+        try {
+            inventoryPersistence.getCmHandleDataNodeByAlternateId(alternateId);
+        } catch (final DataNodeNotFoundException dataNodeNotFoundException) {
+            return false;
+        }
+        return true;
+    }
+
+}