content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.
   */
  
  package org.apache.cassandra.tcm;
  
  import java.lang.reflect.Field;
  import java.lang.reflect.Modifier;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Set;
  
  import com.google.common.collect.ImmutableMap;
  import com.google.common.collect.ImmutableSet;
  import org.junit.Test;
  
  import org.apache.cassandra.config.DatabaseDescriptor;
  import org.apache.cassandra.dht.Murmur3Partitioner;
  import org.apache.cassandra.utils.FBUtilities;
  import org.assertj.core.api.Assertions;
  
  /**
   * This test is to make sure that the fields of {@link ClusterMetadata} have a matching {@link MetadataKey} and the
   * utility functions linking key to field are maintained.
   *
   * If this test is failing it likely means a new field was added to {@link ClusterMetadata} and {@link MetadataKeys} was
   * not updated to know about it.
   */
  public class ClusterMetadataMetadataKeyTest
  {
      static
      {
          DatabaseDescriptor.clientInitialization();
      }
  
      private static final Map<String, Field> NAME_TO_KEY;
  
      static
      {
          ImmutableMap.Builder<String, Field> builder = ImmutableMap.builder();
          for (Field field : MetadataKeys.class.getDeclaredFields())
          {
              if (field.getType() == MetadataKey.class
                  && Modifier.isStatic(field.getModifiers())
                  && Modifier.isPublic(field.getModifiers()))
                  builder.put(field.getName(), field);
          }
          NAME_TO_KEY = builder.build();
      }
  
      @Test
      public void metadataKeyExists() throws IllegalAccessException
      {
          ClusterMetadata empty = new ClusterMetadata(Murmur3Partitioner.instance);
          // Theese are fields that should not have MetadataKeys and should be ignored.
          Set<String> exclude = ImmutableSet.of("metadataIdentifier",
                                                "epoch",
                                                "partitioner",
                                                "extensions",
                                                "locator");
          // Mapping of ClusterMetadata field names to MetadataKey name; mapping is only needed if the names don't match.
          Map<String, String> mapping = ImmutableMap.of("directory", "node_directory",
                                                        "placements", "data_placements");
          for (Field field : ClusterMetadata.class.getDeclaredFields())
          {
              if (Modifier.isStatic(field.getModifiers())
                  || !Modifier.isPublic(field.getModifiers())
                  || !Modifier.isFinal(field.getModifiers()))
                  continue;
              String name = field.getName();
              if (exclude.contains(name)) continue;
              if (mapping.containsKey(name))
                  name = mapping.get(name);
              String snakeName = FBUtilities.camelToSnake(name).toUpperCase(Locale.ROOT);
              Assertions.assertThat(NAME_TO_KEY.keySet())
                        .describedAs("Unable to locate MetadataKey for %s", snakeName)
                        .contains(snakeName);
              MetadataKey expectedKey = (MetadataKey) NAME_TO_KEY.get(snakeName).get(null);
              if (!MetadataKeys.CORE_METADATA.containsKey(expectedKey))
                  throw new IllegalStateException("MetadataKeys.CORE_METADATA is missing key " + expectedKey + " for field " + name);
  
              Assertions.assertThat(field.get(empty))
                        .describedAs("Extraction function does not seem to match the field %s and key %s", name, snakeName)
                        .isSameAs(MetadataKeys.CORE_METADATA.get(expectedKey).apply(empty));
          }
      }
  }
  