/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#include "prefixopt.h"

#include "CLucene.h"

#include "cpixsearch.h"

#include "cpixstrtools.h"

#include "cluceneext.h"

namespace Cpix {

	using namespace lucene::search;

	using namespace lucene::index;

	PrefixOptQueryRewriter::PrefixOptQueryRewriter(

			int maxPrefixLength, 

			const wchar_t* optimizedField, 

			const wchar_t* prefixField )

	: 	maxPrefixLength_( maxPrefixLength ),

		optimizedField_( optimizedField ),

		prefixField_( prefixField )

	{}

	PrefixOptQueryRewriter::~PrefixOptQueryRewriter()

	{}

	std::auto_ptr<Query> PrefixOptQueryRewriter::rewrite(auto_ptr<Query> query)

	{

		PrefixQuery* wildq = 

			dynamic_cast<PrefixQuery*>( query.get() );

		if ( wildq )

		{

			Term* term = wildq->getPrefix(false);

			if ( optimizedField_ == term->field() )

			{

				int length = wcslen( term->text() );

				if ( length != -1 && length <= maxPrefixLength_ )

				{

					// rewrite term

					std::wstring text( term->text() ); 

					text = text.substr(0, length); 

					term = lucene::util::freeref( _CLNEW Term(prefixField_.c_str(), text.c_str()) );

					// rewrite query

					std::auto_ptr<Query> ret( new TermQuery( term ) );

					query.reset(); // delete old

					return ret; // return ownership 

				}

			}

		}

		BooleanQuery* boolq = 

			dynamic_cast<BooleanQuery*>( query.get() ); 

		if ( boolq ) 

		{

			// Just modify the query

			Cpt::auto_array<BooleanClause*> clauses( new BooleanClause*[boolq->getClauseCount() + 1]);  

			boolq->getClauses( clauses.get() );

			for ( int i = 0; i < boolq->getClauseCount(); i++ ) 

			{

				// Transfer ownership to stack

				std::auto_ptr<Query> clauseq(

					clauses.get()[i]->query );

				clauses.get()[i]->query = 0;

				// Rewrite and restore ownership

				clauseq = rewrite( clauseq );

				clauses.get()[i]->query = clauseq.release(); 

			}

		}

		return query; // return ownership 

	}

}