content: package org.apache.lucene.search.vectorhighlight;
  /**
   * 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.
   */
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.lucene.index.IndexReader;
  import org.apache.lucene.index.Term;
  import org.apache.lucene.search.BooleanClause;
  import org.apache.lucene.search.BooleanQuery;
  import org.apache.lucene.search.DisjunctionMaxQuery;
  import org.apache.lucene.search.FuzzyQuery;
  import org.apache.lucene.search.MultiTermQuery;
  import org.apache.lucene.search.PhraseQuery;
  import org.apache.lucene.search.PrefixQuery;
  import org.apache.lucene.search.Query;
  import org.apache.lucene.search.TermQuery;
  import org.apache.lucene.search.TermRangeQuery;
  import org.apache.lucene.search.WildcardQuery;
  import org.apache.lucene.search.regex.RegexQuery;
  import org.apache.lucene.search.vectorhighlight.FieldTermStack.TermInfo;
  
  /**
   * FieldQuery breaks down query object into terms/phrases and keep
   * them in QueryPhraseMap structure.
   */
  public class FieldQuery {
  
    final boolean fieldMatch;
  
    // fieldMatch==true,  Map<fieldName,QueryPhraseMap>
    // fieldMatch==false, Map<null,QueryPhraseMap>
    Map<String, QueryPhraseMap> rootMaps = new HashMap<String, QueryPhraseMap>();
  
    // fieldMatch==true,  Map<fieldName,setOfTermsInQueries>
    // fieldMatch==false, Map<null,setOfTermsInQueries>
    Map<String, Set<String>> termSetMap = new HashMap<String, Set<String>>();
  
    int termOrPhraseNumber; // used for colored tag support
  
    // The maximum number of different matching terms accumulated from any one MultiTermQuery
    private static final int MAX_MTQ_TERMS = 1024;
  
    FieldQuery( Query query, IndexReader reader, boolean phraseHighlight, boolean fieldMatch ) throws IOException {
      this.fieldMatch = fieldMatch;
      List<Query> flatQueries = new ArrayList<Query>();
      flatten( query, reader, flatQueries );
      saveTerms( flatQueries, reader );
      Collection<Query> expandQueries = expand( flatQueries );
  
      for( Query flatQuery : expandQueries ){
        QueryPhraseMap rootMap = getRootMap( flatQuery );
        rootMap.add( flatQuery, reader );
        if( !phraseHighlight && flatQuery instanceof PhraseQuery ){
          PhraseQuery pq = (PhraseQuery)flatQuery;
          if( pq.getTerms().length > 1 ){
            for( Term term : pq.getTerms() )
              rootMap.addTerm( term, flatQuery.getBoost() );
          }
        }
      }
    }
    
    /** For backwards compatibility you can initialize FieldQuery without
     * an IndexReader, which is only required to support MultiTermQuery
     */
    FieldQuery( Query query, boolean phraseHighlight, boolean fieldMatch ) throws IOException {
      this (query, null, phraseHighlight, fieldMatch);
    }
  
    void flatten( Query sourceQuery, IndexReader reader, Collection<Query> flatQueries ) throws IOException{
      if( sourceQuery instanceof BooleanQuery ){
        BooleanQuery bq = (BooleanQuery)sourceQuery;
        for( BooleanClause clause : bq.getClauses() ){
          if( !clause.isProhibited() )
            flatten( clause.getQuery(), reader, flatQueries );
        }
      }
      else if( sourceQuery instanceof DisjunctionMaxQuery ){
        DisjunctionMaxQuery dmq = (DisjunctionMaxQuery)sourceQuery;
        for( Query query : dmq ){
          flatten( query, reader, flatQueries );
        }
      }
      else if( sourceQuery instanceof TermQuery ){
        if( !flatQueries.contains( sourceQuery ) )
          flatQueries.add( sourceQuery );
      }
      else if (sourceQuery instanceof MultiTermQuery && reader != null) {
        MultiTermQuery copy = (MultiTermQuery) sourceQuery.clone();
        copy.setRewriteMethod(new MultiTermQuery.TopTermsScoringBooleanQueryRewrite(MAX_MTQ_TERMS));
        BooleanQuery mtqTerms = (BooleanQuery) copy.rewrite(reader);
        flatten(mtqTerms, reader, flatQueries);
      }
      else if( sourceQuery instanceof PhraseQuery ){
        if( !flatQueries.contains( sourceQuery ) ){
          PhraseQuery pq = (PhraseQuery)sourceQuery;
          if( pq.getTerms().length > 1 )
            flatQueries.add( pq );
          else if( pq.getTerms().length == 1 ){
            flatQueries.add( new TermQuery( pq.getTerms()[0] ) );
          }
        }
      }
      // else discard queries
    }
    
    /*
     * Create expandQueries from flatQueries.
     * 
     * expandQueries := flatQueries + overlapped phrase queries
     * 
     * ex1) flatQueries={a,b,c}
     *      => expandQueries={a,b,c}
     * ex2) flatQueries={a,"b c","c d"}
     *      => expandQueries={a,"b c","c d","b c d"}
     */
    Collection<Query> expand( Collection<Query> flatQueries ){
      List<Query> expandQueries = new ArrayList<Query>();
      for( Iterator<Query> i = flatQueries.iterator(); i.hasNext(); ){
        Query query = i.next();
        i.remove();
        expandQueries.add( query );
        if( !( query instanceof PhraseQuery ) ) continue;
        for( Iterator<Query> j = flatQueries.iterator(); j.hasNext(); ){
          Query qj = j.next();
          if( !( qj instanceof PhraseQuery ) ) continue;
          checkOverlap( expandQueries, (PhraseQuery)query, (PhraseQuery)qj );
        }
      }
      return expandQueries;
    }
  
    /*
     * Check if PhraseQuery A and B have overlapped part.
     * 
     * ex1) A="a b", B="b c" => overlap; expandQueries={"a b c"}
     * ex2) A="b c", B="a b" => overlap; expandQueries={"a b c"}
     * ex3) A="a b", B="c d" => no overlap; expandQueries={}
     */
    private void checkOverlap( Collection<Query> expandQueries, PhraseQuery a, PhraseQuery b ){
      if( a.getSlop() != b.getSlop() ) return;
      Term[] ats = a.getTerms();
      Term[] bts = b.getTerms();
      if( fieldMatch && !ats[0].field().equals( bts[0].field() ) ) return;
      checkOverlap( expandQueries, ats, bts, a.getSlop(), a.getBoost() );
      checkOverlap( expandQueries, bts, ats, b.getSlop(), b.getBoost() );
    }
  
    /*
     * Check if src and dest have overlapped part and if it is, create PhraseQueries and add expandQueries.
     * 
     * ex1) src="a b", dest="c d"       => no overlap
     * ex2) src="a b", dest="a b c"     => no overlap
     * ex3) src="a b", dest="b c"       => overlap; expandQueries={"a b c"}
     * ex4) src="a b c", dest="b c d"   => overlap; expandQueries={"a b c d"}
     * ex5) src="a b c", dest="b c"     => no overlap
     * ex6) src="a b c", dest="b"       => no overlap
     * ex7) src="a a a a", dest="a a a" => overlap;
     *                                     expandQueries={"a a a a a","a a a a a a"}
     * ex8) src="a b c d", dest="b c"   => no overlap
     */
    private void checkOverlap( Collection<Query> expandQueries, Term[] src, Term[] dest, int slop, float boost ){
      // beginning from 1 (not 0) is safe because that the PhraseQuery has multiple terms
      // is guaranteed in flatten() method (if PhraseQuery has only one term, flatten()
      // converts PhraseQuery to TermQuery)
      for( int i = 1; i < src.length; i++ ){
        boolean overlap = true;
        for( int j = i; j < src.length; j++ ){
          if( ( j - i ) < dest.length && !src[j].text().equals( dest[j-i].text() ) ){
            overlap = false;
            break;
          }
        }
        if( overlap && src.length - i < dest.length ){
          PhraseQuery pq = new PhraseQuery();
          for( Term srcTerm : src )
            pq.add( srcTerm );
          for( int k = src.length - i; k < dest.length; k++ ){
            pq.add( new Term( src[0].field(), dest[k].text() ) );
          }
          pq.setSlop( slop );
          pq.setBoost( boost );
          if(!expandQueries.contains( pq ) )
            expandQueries.add( pq );
        }
      }
    }
    
    QueryPhraseMap getRootMap( Query query ){
      String key = getKey( query );
      QueryPhraseMap map = rootMaps.get( key );
      if( map == null ){
        map = new QueryPhraseMap( this );
        rootMaps.put( key, map );
      }
      return map;
    }
    
    /*
     * Return 'key' string. 'key' is the field name of the Query.
     * If not fieldMatch, 'key' will be null.
     */
    private String getKey( Query query ){
      if( !fieldMatch ) return null;
      if( query instanceof TermQuery )
        return ((TermQuery)query).getTerm().field();
      else if ( query instanceof PhraseQuery ){
        PhraseQuery pq = (PhraseQuery)query;
        Term[] terms = pq.getTerms();
        return terms[0].field();
      }
      else if (query instanceof FuzzyQuery) {
        return ((FuzzyQuery)query).getTerm().field();
      }
      else if (query instanceof PrefixQuery) {
        return ((PrefixQuery)query).getPrefix().field();
      }
      else if (query instanceof RegexQuery) {
        return ((RegexQuery)query).getTerm().field();
      }
      else if (query instanceof TermRangeQuery) {
        return ((TermRangeQuery)query).getField();
      }
      else if (query instanceof WildcardQuery) {
        return ((WildcardQuery)query).getTerm().field();
      }
      else
        throw new RuntimeException( "query \"" + query.toString() + "\" must be flatten first." );
    }
  
    /*
     * Save the set of terms in the queries to termSetMap.
     * 
     * ex1) q=name:john
     *      - fieldMatch==true
     *          termSetMap=Map<"name",Set<"john">>
     *      - fieldMatch==false
     *          termSetMap=Map<null,Set<"john">>
     *          
     * ex2) q=name:john title:manager
     *      - fieldMatch==true
     *          termSetMap=Map<"name",Set<"john">,
     *                         "title",Set<"manager">>
     *      - fieldMatch==false
     *          termSetMap=Map<null,Set<"john","manager">>
     *          
     * ex3) q=name:"john lennon"
     *      - fieldMatch==true
     *          termSetMap=Map<"name",Set<"john","lennon">>
     *      - fieldMatch==false
     *          termSetMap=Map<null,Set<"john","lennon">>
     */
      void saveTerms( Collection<Query> flatQueries, IndexReader reader ) throws IOException{
      for( Query query : flatQueries ){
        Set<String> termSet = getTermSet( query );
        if( query instanceof TermQuery )
          termSet.add( ((TermQuery)query).getTerm().text() );
        else if( query instanceof PhraseQuery ){
          for( Term term : ((PhraseQuery)query).getTerms() )
            termSet.add( term.text() );
        }
        else if (query instanceof MultiTermQuery && reader != null) {
          BooleanQuery mtqTerms = (BooleanQuery) query.rewrite(reader);
          for (BooleanClause clause : mtqTerms.getClauses()) {
            termSet.add (((TermQuery) clause.getQuery()).getTerm().text());
          }
        }
        else
          throw new RuntimeException( "query \"" + query.toString() + "\" must be flatten first." );
      }
    }
    
    private Set<String> getTermSet( Query query ){
      String key = getKey( query );
      Set<String> set = termSetMap.get( key );
      if( set == null ){
        set = new HashSet<String>();
        termSetMap.put( key, set );
      }
      return set;
    }
    
    Set<String> getTermSet( String field ){
      return termSetMap.get( fieldMatch ? field : null );
    }
  
    /**
     * 
     * @param fieldName
     * @param term
     * @return QueryPhraseMap
     */
    public QueryPhraseMap getFieldTermMap( String fieldName, String term ){
      QueryPhraseMap rootMap = getRootMap( fieldName );
      return rootMap == null ? null : rootMap.subMap.get( term );
    }
  
    /**
     * 
     * @param fieldName
     * @param phraseCandidate
     * @return QueryPhraseMap
     */
    public QueryPhraseMap searchPhrase( String fieldName, final List<TermInfo> phraseCandidate ){
      QueryPhraseMap root = getRootMap( fieldName );
      if( root == null ) return null;
      return root.searchPhrase( phraseCandidate );
    }
    
    private QueryPhraseMap getRootMap( String fieldName ){
      return rootMaps.get( fieldMatch ? fieldName : null );
    }
    
    int nextTermOrPhraseNumber(){
      return termOrPhraseNumber++;
    }
    
    public static class QueryPhraseMap {
  
      boolean terminal;
      int slop;   // valid if terminal == true and phraseHighlight == true
      float boost;  // valid if terminal == true
      int termOrPhraseNumber;   // valid if terminal == true
      FieldQuery fieldQuery;
      Map<String, QueryPhraseMap> subMap = new HashMap<String, QueryPhraseMap>();
      
      public QueryPhraseMap( FieldQuery fieldQuery ){
        this.fieldQuery = fieldQuery;
      }
  
      void addTerm( Term term, float boost ){
        QueryPhraseMap map = getOrNewMap( subMap, term.text() );
        map.markTerminal( boost );
      }
      
      private QueryPhraseMap getOrNewMap( Map<String, QueryPhraseMap> subMap, String term ){
        QueryPhraseMap map = subMap.get( term );
        if( map == null ){
          map = new QueryPhraseMap( fieldQuery );
          subMap.put( term, map );
        }
        return map;
      }
  
        void add( Query query, IndexReader reader ) throws IOException {
        if( query instanceof TermQuery ){
          addTerm( ((TermQuery)query).getTerm(), query.getBoost() );
        }
        else if( query instanceof PhraseQuery ){
          PhraseQuery pq = (PhraseQuery)query;
          Term[] terms = pq.getTerms();
          Map<String, QueryPhraseMap> map = subMap;
          QueryPhraseMap qpm = null;
          for( Term term : terms ){
            qpm = getOrNewMap( map, term.text() );
            map = qpm.subMap;
          }
          qpm.markTerminal( pq.getSlop(), pq.getBoost() );
        }
        else
          throw new RuntimeException( "query \"" + query.toString() + "\" must be flatten first." );
      }
      
      public QueryPhraseMap getTermMap( String term ){
        return subMap.get( term );
      }
      
      private void markTerminal( float boost ){
        markTerminal( 0, boost );
      }
      
      private void markTerminal( int slop, float boost ){
        this.terminal = true;
        this.slop = slop;
        this.boost = boost;
        this.termOrPhraseNumber = fieldQuery.nextTermOrPhraseNumber();
      }
      
      public boolean isTerminal(){
        return terminal;
      }
      
      public int getSlop(){
        return slop;
      }
      
      public float getBoost(){
        return boost;
      }
      
      public int getTermOrPhraseNumber(){
        return termOrPhraseNumber;
      }
      
      public QueryPhraseMap searchPhrase( final List<TermInfo> phraseCandidate ){
        QueryPhraseMap currMap = this;
        for( TermInfo ti : phraseCandidate ){
          currMap = currMap.subMap.get( ti.getText() );
          if( currMap == null ) return null;
        }
        return currMap.isValidTermOrPhrase( phraseCandidate ) ? currMap : null;
      }
      
      public boolean isValidTermOrPhrase( final List<TermInfo> phraseCandidate ){
        // check terminal
        if( !terminal ) return false;
  
        // if the candidate is a term, it is valid
        if( phraseCandidate.size() == 1 ) return true;
  
        // else check whether the candidate is valid phrase
        // compare position-gaps between terms to slop
        int pos = phraseCandidate.get( 0 ).getPosition();
        for( int i = 1; i < phraseCandidate.size(); i++ ){
          int nextPos = phraseCandidate.get( i ).getPosition();
          if( Math.abs( nextPos - pos - 1 ) > slop ) return false;
          pos = nextPos;
        }
        return true;
      }
    }
  }
  