/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2011 Sandro Santilli <strk@kbt.io
 *
 * 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.
 *
 **********************************************************************
 *
 * Last port: operation/union/PointGeometryUnion.java r320 (JTS-1.12)
 *
 **********************************************************************/

#include <memory> // for unique_ptr
#include <cassert> // for assert
#include <algorithm> // for copy
#include <geos/operation/union/PointGeometryUnion.h>
#include <geos/geom/Coordinate.h>
#include <geos/geom/Point.h>
#include <geos/geom/MultiPoint.h>
#include <geos/geom/Geometry.h>
#include <geos/geom/Location.h>
#include <geos/geom/GeometryFactory.h>
#include <geos/geom/util/GeometryCombiner.h>
#include <geos/algorithm/PointLocator.h>

namespace geos {
namespace operation { // geos::operation
namespace geounion {  // geos::operation::geounion

/* public */
std::unique_ptr<geom::Geometry>
PointGeometryUnion::Union() const
{
    using namespace geom;
    using algorithm::PointLocator;
    using geom::util::GeometryCombiner;

    PointLocator locater;
    // use a set to eliminate duplicates, as required for union
    std::set<Coordinate> exteriorCoords;

    for(std::size_t i = 0, n = pointGeom.getNumGeometries(); i < n; ++i) {
        const Point* point = dynamic_cast<const Point*>(pointGeom.getGeometryN(i));
        assert(point);

        if (point->isEmpty()) {
            continue;
        }

        const Coordinate* coord = static_cast<const Coordinate*>(point->getCoordinate());
        Location loc = locater.locate(*coord, &otherGeom);
        if(loc == Location::EXTERIOR) {
            exteriorCoords.insert(*coord);
        }
    }

    // if no points are in exterior, return the other geom
    if(exteriorCoords.empty()) {
        return otherGeom.clone();
    }

    // make a puntal geometry of appropriate size
    std::unique_ptr<Geometry> ptComp;

    if(exteriorCoords.size() == 1) {
        ptComp = geomFact->createPoint(*(exteriorCoords.begin()));
    }
    else {
        ptComp = geomFact->createMultiPoint(exteriorCoords);
    }

    // add point component to the other geometry
    return GeometryCombiner::combine(ptComp.get(), &otherGeom);
}

/* public  static */
std::unique_ptr<geom::Geometry>
PointGeometryUnion::Union(const geom::Geometry& pointGeom,
                          const geom::Geometry& otherGeom)
{
    PointGeometryUnion unioner(pointGeom, otherGeom);
    return unioner.Union();
}

/* public */
PointGeometryUnion::PointGeometryUnion(const geom::Geometry& pointGeom_,
                                       const geom::Geometry& otherGeom_)
    :
    pointGeom(pointGeom_),
    otherGeom(otherGeom_)
{
    geomFact = otherGeom.getFactory();
}

} // namespace geos::operation::union
} // namespace geos::operation
} // namespace geos