code: /*
   * 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.skywalking.library.elasticsearch.requests.factory.v7plus.codec;
  
  import com.fasterxml.jackson.annotation.JsonProperty;
  import com.fasterxml.jackson.core.JsonParser;
  import com.fasterxml.jackson.core.JsonToken;
  import com.fasterxml.jackson.core.io.SerializedString;
  import com.fasterxml.jackson.core.type.TypeReference;
  import com.fasterxml.jackson.databind.DeserializationContext;
  import com.fasterxml.jackson.databind.JsonDeserializer;
  import com.fasterxml.jackson.databind.JsonNode;
  import com.google.common.base.Strings;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.function.Function;
  import lombok.Data;
  import lombok.extern.slf4j.Slf4j;
  import org.apache.skywalking.library.elasticsearch.response.IndexTemplate;
  import org.apache.skywalking.library.elasticsearch.response.IndexTemplates;
  
  import static java.util.stream.Collectors.toMap;
  
  @Slf4j
  final class V78IndexTemplatesDeserializer extends JsonDeserializer<IndexTemplates> {
      private static final TypeReference<List<IndexTemplateWrapper>> TYPE_REFERENCE =
          new TypeReference<List<IndexTemplateWrapper>>() {
          };
  
      @Override
      public IndexTemplates deserialize(final JsonParser p,
                                        final DeserializationContext ctxt)
          throws IOException {
          while (!p.nextFieldName(new SerializedString("index_templates"))) {
              if (p.currentName() == null) {
                  return new IndexTemplates(Collections.emptyMap());
              }
              p.skipChildren();
          }
          if (p.nextToken() != JsonToken.START_ARRAY) {
              throw new UnsupportedOperationException(
                  "this might be a new ElasticSearch version and we don't support yet");
          }
  
          final JsonNode array = p.getCodec().readTree(p);
          final List<IndexTemplate> templates = new ArrayList<>(array.size());
          for (final JsonNode node : array) {
              final String name = node.get("name").asText();
              if (Strings.isNullOrEmpty(name)) {
                  log.error("index template without a name: {}", node);
                  continue;
              }
  
              final JsonNode indexTemplateNode = node.get("index_template");
              if (indexTemplateNode == null) {
                  log.error("index template without index_template: {}", node);
                  continue;
              }
              final IndexTemplateWrapper wrapper =
                  p.getCodec().treeToValue(indexTemplateNode, IndexTemplateWrapper.class);
              wrapper.getTemplate().setName(name);
              wrapper.getTemplate().setIndexPatterns(wrapper.getIndexPatterns());
              templates.add(wrapper.getTemplate());
          }
  
          final Map<String, IndexTemplate> templateMap =
              templates.stream()
                       .collect(toMap(IndexTemplate::getName, Function.identity()));
          return new IndexTemplates(templateMap);
      }
  
      @Data
      static final class IndexTemplateWrapper {
          @JsonProperty("index_patterns")
          private List<String> indexPatterns;
          private IndexTemplate template;
      }
  }
  