/*------------------------------------------------------------------------------

* Copyright (C) 2003-2006 Ben van Klinken and the CLucene Team

* 

* Distributable under the terms of either the Apache License (Version 2.0) or 

* the GNU Lesser General Public License, as specified in the COPYING file.

------------------------------------------------------------------------------*/

#ifndef _lucene_search_PhraseScorer_

#define _lucene_search_PhraseScorer_

#if defined(_LUCENE_PRAGMA_ONCE)

# pragma once

#endif

#include "clucene/search/phrasepositions.h"

#include "clucene/search/scorer.h"

#include "clucene/search/similarity.h"

CL_NS_DEF(search)

	class PhraseScorer: public Scorer {

	private:

		Weight* weight;

		float_t freq;

		bool firstTime;

		bool more;

	protected:

		uint8_t* norms;

		float_t value;

		PhraseQueue* pq;        //is used to order the list point to by first and last

		PhrasePositions* first; //Points to the first in the list of PhrasePositions

		PhrasePositions* last;  //Points to the last in the list of PhrasePositions

	public:

		//Constructor

		PhraseScorer(Weight* weight, CL_NS(index)::TermPositions** tps, 

		int32_t* positions, Similarity* similarity, uint8_t* norms);

		virtual ~PhraseScorer();

		int32_t doc() const { return first->doc; }

		bool next();

		float_t score();

		bool skipTo(int32_t target);

		void explain(int32_t doc, Explanation* ret);

		TCHAR* toString();

	protected:

		virtual float_t phraseFreq() =0;

        //Transfers the PhrasePositions from the PhraseQueue pq to

        //the PhrasePositions list with first as its first element

		void pqToList();

		//Moves first to the end of the list

		void firstToLast();

	private:

		bool doNext();

		void init();

		void sort();

	};

CL_NS_END

#endif