/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2005-2006 Refractions Research Inc.
 * Copyright (C) 2001-2002 Vivid Solutions Inc.
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation. 
 * See the COPYING file for more information.
 *
 **********************************************************************/

#include <geos/precision/CommonBitsRemover.h>
#include <geos/precision/CommonBits.h>
// for CommonCoordinateFilter inheritance
#include <geos/geom/CoordinateFilter.h>
#include <geos/geom/Coordinate.h>
#include <geos/geom/Geometry.h>
#include <geos/util.h>

#include <cassert>

#ifndef GEOS_DEBUG
#define GEOS_DEBUG 0
#endif

#ifdef GEOS_DEBUG
#include <iostream>
#endif

using namespace geos::geom;

namespace geos {
namespace precision { // geos.precision

class Translater: public geom::CoordinateFilter {

private:

	geom::Coordinate trans;

public:

	Translater(geom::Coordinate &newTrans)
		:
		trans(newTrans)
	{}

	void filter_ro(const geom::Coordinate *coord)  //Not used
    {
        ::geos::ignore_unused_variable_warning(coord);
        assert(0);
    }

	void filter_rw(geom::Coordinate *coord) const
	{
		coord->x += trans.x;
		coord->y += trans.y;
	}
};


class CommonCoordinateFilter: public geom::CoordinateFilter {
private:
	CommonBits commonBitsX;
	CommonBits commonBitsY;
public:

	void filter_rw(geom::Coordinate *coord) const
	{
        // CommonCoordinateFilter is a read-only filter
        ::geos::ignore_unused_variable_warning(coord);
		assert(0);
	}

	void filter_ro(const geom::Coordinate *coord)
	{
		commonBitsX.add(coord->x);
		commonBitsY.add(coord->y);
	}

	void getCommonCoordinate(geom::Coordinate& c)
	{
		c=Coordinate(commonBitsX.getCommon(),
			commonBitsY.getCommon());
	}

};


CommonBitsRemover::CommonBitsRemover()
{
	ccFilter=new CommonCoordinateFilter();
}

CommonBitsRemover::~CommonBitsRemover()
{
	delete ccFilter;
}

/**
 * Add a geometry to the set of geometries whose common bits are
 * being computed.  After this method has executed the
 * common coordinate reflects the common bits of all added
 * geometries.
 *
 * @param geom a Geometry to test for common bits
 */
void
CommonBitsRemover::add(const Geometry *geom)
{
	geom->apply_ro(ccFilter);
	ccFilter->getCommonCoordinate(commonCoord);
}

/**
 * The common bits of the Coordinates in the supplied Geometries.
 */
Coordinate&
CommonBitsRemover::getCommonCoordinate()
{ 
	return commonCoord;
}

/**
 * Removes the common coordinate bits from a Geometry.
 * The coordinates of the Geometry are changed.
 *
 * @param geom the Geometry from which to remove the common coordinate bits
 * @return the shifted Geometry
 */
Geometry*
CommonBitsRemover::removeCommonBits(Geometry *geom)
{
	if (commonCoord.x == 0.0 && commonCoord.y == 0.0)
		return geom;

	Coordinate invCoord(commonCoord);
	invCoord.x = -invCoord.x;
	invCoord.y = -invCoord.y;

	Translater trans(invCoord);
	geom->apply_rw(&trans);
	geom->geometryChanged();

#if GEOS_DEBUG
	std::cerr << "CommonBits removed: " << *geom << std::endl;
#endif

	return geom;
}

/**
 * Adds the common coordinate bits back into a Geometry.
 * The coordinates of the Geometry are changed.
 *
 * @param geom the Geometry to which to add the common coordinate bits
 * @return the shifted Geometry
 */
Geometry*
CommonBitsRemover::addCommonBits(Geometry *geom)
{
#if GEOS_DEBUG
	std::cerr << "CommonBits before add: " << *geom << std::endl;
#endif

	Translater trans(commonCoord);

	geom->apply_rw(&trans);
	geom->geometryChanged();

#if GEOS_DEBUG
	std::cerr << "CommonBits added: " << *geom << std::endl;
#endif

	return geom;
}

} // namespace geos.precision
} // namespace geos