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.lucene.queryparser.flexible.aqp.builders;
  
  import org.apache.lucene.index.Term;
  import org.apache.lucene.queryparser.flexible.core.QueryNodeException;
  import org.apache.lucene.queryparser.flexible.core.builders.QueryTreeBuilder;
  import org.apache.lucene.queryparser.flexible.core.nodes.FieldQueryNode;
  import org.apache.lucene.queryparser.flexible.core.nodes.QueryNode;
  import org.apache.lucene.queryparser.flexible.standard.builders.MultiPhraseQueryNodeBuilder;
  import org.apache.lucene.queryparser.flexible.standard.builders.StandardQueryBuilder;
  import org.apache.lucene.queryparser.flexible.standard.nodes.MultiPhraseQueryNode;
  import org.apache.lucene.search.MultiPhraseQuery;
  import org.apache.lucene.search.TermQuery;
  
  import java.util.LinkedList;
  import java.util.List;
  import java.util.TreeMap;
  
  /**
   * Builds a {@link MultiPhraseQuery} object from a {@link MultiPhraseQueryNode}
   * object.
   * <p>
   * Modified {@link MultiPhraseQueryNodeBuilder} - when we encounter a token
   * with position increment=0 we assume that it should be placed into the same
   * position as the previous token (i.e. it is a synonym). Make sure that
   * the tokens submitted are in proper order!
   */
  public class AqpMultiPhraseQueryNodeBuilder implements StandardQueryBuilder {
  
      public AqpMultiPhraseQueryNodeBuilder() {
          // empty constructor
      }
  
      @Override
      public MultiPhraseQuery build(QueryNode queryNode) throws QueryNodeException {
          MultiPhraseQueryNode phraseNode = (MultiPhraseQueryNode) queryNode;
  
          MultiPhraseQuery.Builder phraseQueryBuilder = new MultiPhraseQuery.Builder();
  
          List<QueryNode> children = phraseNode.getChildren();
  
          if (children != null) {
              TreeMap<Integer, List<Term>> positionTermMap = new TreeMap<>();
              Integer lastPos = null;
  
              for (QueryNode child : children) {
                  FieldQueryNode termNode = (FieldQueryNode) child;
                  TermQuery termQuery = (TermQuery) termNode
                          .getTag(QueryTreeBuilder.QUERY_TREE_BUILDER_TAGID);
  
                  int pos = termNode.getPositionIncrement();
                  if (pos == 0 && lastPos != null) {
                      pos = lastPos;
                  } else {
                      lastPos = pos;
                  }
  
                  List<Term> termList = positionTermMap.get(pos);
  
                  if (termList == null) {
                      termList = new LinkedList<>();
                      positionTermMap.put(pos, termList);
  
                  }
  
                  termList.add(termQuery.getTerm());
  
              }
  
              for (int positionIncrement : positionTermMap.keySet()) {
                  List<Term> termList = positionTermMap.get(positionIncrement);
  
                  phraseQueryBuilder.add(termList.toArray(new Term[termList.size()]),
                          positionIncrement);
  
              }
  
          }
  
          return phraseQueryBuilder.build();
  
      }
  
  }
  