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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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.atlas.discovery;
  
  import org.apache.atlas.AtlasException;
  import org.apache.atlas.model.discovery.AtlasSuggestionsResult;
  import org.apache.atlas.repository.graphdb.AtlasGraph;
  import org.apache.atlas.repository.graphdb.AtlasGraphIndexClient;
  import org.apache.atlas.type.AtlasTypeRegistry;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Collections;
  
  public class SuggestionsProviderImpl implements SuggestionsProvider {
      private static final Logger LOG = LoggerFactory.getLogger(SuggestionsProviderImpl.class);
  
      private final AtlasGraph        graph;
      private final AtlasTypeRegistry typeRegistry;
  
      public SuggestionsProviderImpl(AtlasGraph graph, AtlasTypeRegistry typeRegistry) {
          this.graph        = graph;
          this.typeRegistry = typeRegistry;
      }
  
      @Override
      public AtlasSuggestionsResult getSuggestions(String prefixString, String fieldName) {
          AtlasSuggestionsResult result = new AtlasSuggestionsResult(prefixString, fieldName);
  
          try {
              AtlasGraphIndexClient graphIndexClient = graph.getGraphIndexClient();
              String                indexFieldName   = (fieldName == null) ? null : typeRegistry.getIndexFieldName(fieldName);
  
              result.setSuggestions(graphIndexClient.getSuggestions(prefixString, indexFieldName));
          } catch (AtlasException e) {
              LOG.error("Error encountered in performing quick suggestions. Will return no suggestions.", e);
  
              result.setSuggestions(Collections.emptyList());
          }
  
          return result;
      }
  }
  