MLH-1336 Sets tags FF true for all new tenants by default

repository/src/main/java/org/apache/atlas/services/TagsV2AutoEnabler.java

@@ -0,0 +1,97 @@
+package org.apache.atlas.services;
+
+import org.apache.atlas.exception.AtlasBaseException;
+import org.apache.atlas.repository.Constants;
+import org.apache.atlas.repository.graphdb.AtlasGraph;
+import org.apache.atlas.repository.graphdb.AtlasGraphQuery;
+import org.apache.atlas.repository.graphdb.AtlasVertex;
+import org.apache.atlas.repository.store.graph.v2.AtlasGraphUtilsV2;
+import org.apache.atlas.service.FeatureFlag;
+import org.apache.atlas.service.FeatureFlagStore;
+import org.apache.atlas.store.AtlasTypeDefStore;
+import org.apache.atlas.typesystem.types.DataTypes;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import javax.annotation.PostConstruct;
+import javax.inject.Inject;
+import java.util.Iterator;
+
+
+/**
+ * Automatically enables Tag V2 for new Atlas instances
+ * where no classification types are present. This ensures new customer tenants get the
+ * latest tag propagation version by default.
+ */
+@Component
+public class TagsV2AutoEnabler {
+    private static final Logger LOG = LoggerFactory.getLogger(TagsV2AutoEnabler.class);
+
+    private static final String CLASSIFICATION_TYPE = "classification";
+    private static final String ENABLE_JANUS_OPTIMISATION_KEY = FeatureFlag.ENABLE_JANUS_OPTIMISATION.getKey();
+
+    // Property keys for type system vertices
+    private static final String VERTEX_TYPE_PROPERTY_KEY = Constants.VERTEX_TYPE_PROPERTY_KEY;
+    private static final String TYPE_CATEGORY_PROPERTY_KEY = Constants.TYPE_CATEGORY_PROPERTY_KEY;
+    private static final String VERTEX_TYPE = AtlasGraphUtilsV2.VERTEX_TYPE; // "typeSystem"
+
+    private final AtlasTypeDefStore typeDefStore;
+    private final AtlasGraph graph;
+
+    @Inject
+    public TagsV2AutoEnabler(AtlasTypeDefStore typeDefStore, AtlasGraph graph) {
+        this.typeDefStore = typeDefStore;
+        this.graph = graph;
+    }
+
+    @PostConstruct
+    public void checkAndEnableJanusOptimisation() throws AtlasBaseException {
+        try {
+            LOG.info("Starting auto-enable check for Janus optimization...");
+
+            boolean isTagV2Enabled = FeatureFlagStore.isTagV2Enabled();
+            if (isTagV2Enabled) {
+                LOG.info("Tags v2 optimization is already enabled, skipping auto-enable check");
+                return;
+            }
+
+            // Check if there are any classification types present
+            boolean hasClassificationTypes = hasClassificationTypes();
+
+            if (!hasClassificationTypes) {
+                LOG.info("No classification types found - enabling Tags V2 for new tenant");
+                FeatureFlagStore.setFlag(ENABLE_JANUS_OPTIMISATION_KEY, "true");
+                LOG.info("Successfully enabled Tags V2 feature flag");
+            } else {
+                LOG.info("Classification types found - keeping existing configuration (Tags v2 disabled)");
+            }
+
+        } catch (Exception e) {
+            LOG.error("Error during auto-enable check for Tags v2 optimization", e);
+            throw e;
+        }
+    }
+
+    /**
+     * Optimized method to check if any classification types exist
+     * Uses direct graph query instead of loading all typedefs
+     * @return true if classification types exist, false otherwise
+     */
+    private boolean hasClassificationTypes() throws AtlasBaseException {
+        try {
+            // Query for any vertex that is a type system vertex with TRAIT category
+            AtlasGraphQuery query = graph.query().has(VERTEX_TYPE_PROPERTY_KEY, VERTEX_TYPE)
+                    .has(TYPE_CATEGORY_PROPERTY_KEY, DataTypes.TypeCategory.TRAIT);
+
+            Iterator<AtlasVertex> results = query.vertices().iterator();
+            boolean hasClassifications = results.hasNext();
+
+            LOG.info("Found classification types: {}", hasClassifications);
+            return hasClassifications;
+        } catch (Exception e) {
+            LOG.error("Error checking for classification types", e);
+            throw new AtlasBaseException("Error checking for classification types", e);
+        }
+    }
+}