#include <iostream>
#include <sstream>
#include <boost/geometry/geometries/geometries.hpp>
#include <boost/geometry/strategies/strategies.hpp>
#include <boost/geometry/algorithms/correct.hpp>
#include <boost/geometry/io/wkt/wkt.hpp>
#include <boost/geometry/io/dsv/write.hpp>
#include <boost/geometry/iterators/point_iterator.hpp>

namespace bg = boost::geometry;

typedef bg::model::point<double, 2, bg::cs::cartesian> point_type;
typedef bg::model::polygon<point_type> polygon_type;

int main()
{
    polygon_type poly, poly_copy;
    bg::read_wkt("POLYGON((0 0,0 10,10 10,10 0,0 0))", poly);
    point_type new_first;
    bg::read_wkt("POINT(1 1)", new_first);

    typedef bg::point_iterator<polygon_type> iterator;

    std::cout << "initial polygon (wkt): " << bg::wkt(poly) << std::endl;
    std::cout << "initial polygon (dsv): " << bg::dsv(poly) << std::endl;
    std::cout << "first point: " << bg::wkt(*bg::points_begin(poly))
              << std::endl;
    std::cout << "new first point: " << bg::wkt(new_first) << std::endl;
    *bg::points_begin(poly) = new_first;
    std::cout << "modified polygon(wkt): " << bg::wkt(poly) << std::endl;
    std::cout << "modified polygon(dsv): " << bg::dsv(poly) << std::endl;

    std::stringstream sstr;
    sstr << bg::wkt(poly);
    bg::read_wkt(sstr.str(), poly_copy);
    std::cout << "copy of modified via WKT (wkt): " << bg::wkt(poly_copy)
              << std::endl;
    std::cout << "copy of modified via WKT (dsv): " << bg::dsv(poly_copy)
              << std::endl;

    bg::correct(poly);
    std::cout << "trying to correct the invalid polygon" << std::endl;
    std::cout << "corrected polygon (wkt): " <<  bg::wkt(poly) << std::endl;
    std::cout << "corrected polygon (dsv): " <<  bg::dsv(poly) << std::endl;

    return 0;
}