Add gauge metric for NCMP "cmhandle states"

Issue-ID: CPS-2456
Change-Id: I1aebcc68dfdc9c48c230c74376742d67b05c0615
Signed-off-by: emaclee <lee.anjella.macabuhay@est.tech>

3 files changed, 153 insertions, 2 deletions

diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/cache/AdminCacheConfig.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/cache/AdminCacheConfig.java
new file mode 100644
index 0000000000..a29799b13f
--- /dev/null
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/cache/AdminCacheConfig.java
@@ -0,0 +1,49 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2025 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.impl.cache;
+
+import com.hazelcast.config.MapConfig;
+import com.hazelcast.map.IMap;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class AdminCacheConfig extends HazelcastCacheConfig {
+
+    private static final MapConfig adminCacheMapConfig = createMapConfig("adminCacheMapConfig");
+
+    /**
+     * Distributed instance admin cache map for cm handles by state for use of gauge metrics.
+     *
+     * @return configured map of cm handles by state.
+     */
+    @Bean
+    public IMap<String, Integer> cmHandlesByState() {
+        final IMap<String, Integer> cmHandlesByState = getOrCreateHazelcastInstance(adminCacheMapConfig).getMap(
+                "cmHandlesByState");
+        cmHandlesByState.putIfAbsent("advisedCmHandlesCount", 0);
+        cmHandlesByState.putIfAbsent("readyCmHandlesCount", 0);
+        cmHandlesByState.putIfAbsent("lockedCmHandlesCount", 0);
+        cmHandlesByState.putIfAbsent("deletingCmHandlesCount", 0);
+        cmHandlesByState.putIfAbsent("deletedCmHandlesCount", 0);
+        return cmHandlesByState;
+    }
+}
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/lcm/CmHandleStateMonitor.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/lcm/CmHandleStateMonitor.java
new file mode 100644
index 0000000000..4fd752c0d1
--- /dev/null
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/lcm/CmHandleStateMonitor.java
@@ -0,0 +1,100 @@
+/*
+ * ============LICENSE_START=======================================================
+ * Copyright (C) 2025 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.impl.inventory.sync.lcm;
+
+import com.hazelcast.map.EntryProcessor;
+import com.hazelcast.map.IMap;
+import java.util.Collection;
+import java.util.Map;
+import lombok.RequiredArgsConstructor;
+import org.onap.cps.ncmp.api.inventory.models.CompositeState;
+import org.onap.cps.ncmp.impl.inventory.models.CmHandleState;
+import org.onap.cps.ncmp.impl.inventory.sync.lcm.LcmEventsCmHandleStateHandlerImpl.CmHandleTransitionPair;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+public class CmHandleStateMonitor {
+
+    private static final String METRIC_POSTFIX = "CmHandlesCount";
+    final IMap<String, Integer> cmHandlesByState;
+
+    /**
+     * Asynchronously update the cm handle state metrics.
+     *
+     * @param cmHandleTransitionPairs cm handle transition pairs
+     */
+    @Async
+    public void updateCmHandleStateMetrics(final Collection<CmHandleTransitionPair>
+                                                       cmHandleTransitionPairs) {
+        cmHandleTransitionPairs.forEach(this::updateMetricWithStateChange);
+    }
+
+    private void updateMetricWithStateChange(final CmHandleTransitionPair cmHandleTransitionPair) {
+        final CmHandleState targetCmHandleState = cmHandleTransitionPair.getTargetYangModelCmHandle()
+                .getCompositeState().getCmHandleState();
+        if (isNew(cmHandleTransitionPair.getCurrentYangModelCmHandle().getCompositeState())) {
+            updateTargetStateCount(targetCmHandleState);
+        } else {
+            final CmHandleState previousCmHandleState = cmHandleTransitionPair.getCurrentYangModelCmHandle()
+                    .getCompositeState().getCmHandleState();
+            updatePreviousStateCount(previousCmHandleState);
+            updateTargetStateCount(targetCmHandleState);
+        }
+    }
+
+    private void updatePreviousStateCount(final CmHandleState previousCmHandleState) {
+        final String keyName = previousCmHandleState.name().toLowerCase() + METRIC_POSTFIX;
+        cmHandlesByState.executeOnKey(keyName, new DecreasingEntryProcessor());
+    }
+
+    private void updateTargetStateCount(final CmHandleState targetCmHandleState) {
+        final String keyName = targetCmHandleState.name().toLowerCase() + METRIC_POSTFIX;
+        cmHandlesByState.executeOnKey(keyName, new IncreasingEntryProcessor());
+    }
+
+    private boolean isNew(final CompositeState existingCompositeState) {
+        return (existingCompositeState == null);
+    }
+
+    static class DecreasingEntryProcessor implements EntryProcessor<String, Integer, Void> {
+        @Override
+        public Void process(final Map.Entry<String, Integer> entry) {
+            final int currentValue = entry.getValue();
+            if (currentValue > 0) {
+                entry.setValue(currentValue - 1);
+            }
+            return null;
+        }
+    }
+
+    static class IncreasingEntryProcessor implements EntryProcessor<String, Integer, Void> {
+        @Override
+        public Void process(final Map.Entry<String, Integer> entry) {
+            final int currentValue = entry.getValue();
+            entry.setValue(currentValue + 1);
+            return null;
+        }
+    }
+
+
+}
\ No newline at end of file
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/lcm/LcmEventsCmHandleStateHandlerImpl.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/lcm/LcmEventsCmHandleStateHandlerImpl.java
index e9bd37219a..3e6597ea39 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/lcm/LcmEventsCmHandleStateHandlerImpl.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/lcm/LcmEventsCmHandleStateHandlerImpl.java
@@ -1,6 +1,6 @@
 /*
  * ============LICENSE_START=======================================================
- * Copyright (C) 2022-2024 Nordix Foundation
+ * Copyright (C) 2022-2025 Nordix Foundation
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -51,6 +51,7 @@ public class LcmEventsCmHandleStateHandlerImpl implements LcmEventsCmHandleState
 
     private final InventoryPersistence inventoryPersistence;
     private final LcmEventsCmHandleStateHandlerAsyncHelper lcmEventsCmHandleStateHandlerAsyncHelper;
+    private final CmHandleStateMonitor cmHandleStateMonitor;
 
     @Override
     @Timed(value = "cps.ncmp.cmhandle.state.update.batch",
@@ -60,6 +61,7 @@ public class LcmEventsCmHandleStateHandlerImpl implements LcmEventsCmHandleState
                 prepareCmHandleTransitionBatch(cmHandleStatePerCmHandle);
         persistCmHandleBatch(cmHandleTransitionPairs);
         lcmEventsCmHandleStateHandlerAsyncHelper.publishLcmEventBatchAsynchronously(cmHandleTransitionPairs);
+        cmHandleStateMonitor.updateCmHandleStateMetrics(cmHandleTransitionPairs);
     }
 
     @Override
@@ -168,7 +170,7 @@ public class LcmEventsCmHandleStateHandlerImpl implements LcmEventsCmHandleState
     @Getter
     @Setter
     @NoArgsConstructor
-    static class CmHandleTransitionPair {
+    public static class CmHandleTransitionPair {
 
         private YangModelCmHandle currentYangModelCmHandle;
         private YangModelCmHandle targetYangModelCmHandle;