/**

 * Copyright 2002-2004 The Apache Software Foundation

 *

 * Licensed 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.

 */

#ifndef _lucene_search_highlighter_queryscorer_

#define _lucene_search_highlighter_queryscorer_

#if defined(_LUCENE_PRAGMA_ONCE)

# pragma once

#endif

#include <math.h> // float_t

#include "CLucene/analysis/AnalysisHeader.h"

#include "CLucene/search/SearchHeader.h"

#include "CLucene/index/IndexReader.h"

#include "CLucene/highlighter/WeightedTerm.h"

#include "CLucene/highlighter/HighlightScorer.h"

#include "CLucene/highlighter/QueryTermExtractor.h"

#include "CLucene/highlighter/TextFragment.h"

CL_NS_DEF2(search,highlight)

/**

 * {@link Scorer} implementation which scores text fragments by the number of unique query terms found.

 * This class uses the {@link QueryTermExtractor} class to process determine the query terms and 

 * their boosts to be used. 

 */

//TODO: provide option to boost score of fragments near beginning of document 

// based on fragment.getFragNum()

class QueryScorer : public HighlightScorer

{

private:

	TextFragment * _currentTextFragment;

	CL_NS(util)::CLHashSet<const TCHAR*,

		CL_NS(util)::Compare::TChar,

		CL_NS(util)::Deletor::tcArray> _uniqueTermsInFragment;

	double _totalScore;

	double _maxTermWeight;

	CL_NS(util)::LHashMap<const TCHAR*, const WeightedTerm *,

		CL_NS(util)::Compare::TChar,

		CL_NS(util)::Equals::TChar,

		CL_NS(util)::Deletor::tcArray,

		CL_NS(util)::Deletor::Object<const WeightedTerm> > _termsToFind;

public:

	/**

	* 

	* @param query a Lucene query (ideally rewritten using query.rewrite 

	* before being passed to this class and the searcher)

	*/

	QueryScorer(const Query * query);

	/**

	* 

	* @param query a Lucene query (ideally rewritten using query.rewrite 

	* before being passed to this class and the searcher)

	* @param reader used to compute IDF which can be used to a) score selected fragments better 

	* b) use graded highlights eg set font color intensity

	* @param fieldName the field on which Inverse Document Frequency (IDF) calculations are based

	*/

	QueryScorer(const Query* query, CL_NS(index)::IndexReader* reader, const TCHAR* fieldName);

	QueryScorer(WeightedTerm** weightedTerms);

	~QueryScorer();

	/* (non-Javadoc)

	 * @see org.apache.lucene.search.highlight.FragmentScorer#startFragment(org.apache.lucene.search.highlight.TextFragment)

	 */

	void startFragment(TextFragment* newFragment);

	/* (non-Javadoc)

	 * @see org.apache.lucene.search.highlight.FragmentScorer#scoreToken(org.apache.lucene.analysis.Token)

	 */

	float_t getTokenScore(CL_NS(analysis)::Token * token);

	/* (non-Javadoc)

	 * @see org.apache.lucene.search.highlight.FragmentScorer#endFragment(org.apache.lucene.search.highlight.TextFragment)

	 */

	float_t getFragmentScore();

	/* (non-Javadoc)

	 * @see org.apache.lucene.search.highlight.FragmentScorer#allFragmentsProcessed()

	 */

	void allFragmentsProcessed();

	/**

	 * 

	 * @return The highest weighted term (useful for passing to GradientFormatter to set

	 * top end of coloring scale.  

		*/

	float_t getMaxTermWeight();

private:

	void initialize(WeightedTerm** weightedTerms);

};

CL_NS_END2

#endif