#ifndef AREAS_HPP_CVK1NIAI
#define AREAS_HPP_CVK1NIAI

#include <vanetza/geodesy/geodesy.hpp>
#include <vanetza/units/area.hpp>
#include <boost/variant.hpp>

namespace vanetza
{
namespace geonet
{

using geodesy::CartesianPosition;
using geodesy::GeodeticPosition;
using geodesy::distance;
using geodesy::local_cartesian;

struct Circle
{
    Circle() : r(1.0 * units::si::meters) {}
    units::Length r; // radius
};

struct Rectangle
{
    Rectangle() : a(1.0 * units::si::meters), b(1.0 * units::si::meters) {}
    units::Length a; // center to long side
    units::Length b; // center to short side
};

struct Ellipse
{
    Ellipse() : a(1.0 * units::si::meters), b(1.0 * units::si::meters) {}
    units::Length a; // long semi-axis
    units::Length b; // short semi-axis
};

struct Area
{
    boost::variant<Rectangle, Ellipse, Circle> shape;
    GeodeticPosition position;
    units::Angle angle;
};

double geometric_function(const Circle&, const CartesianPosition&);
double geometric_function(const Rectangle&, const CartesianPosition&);
double geometric_function(const Ellipse&, const CartesianPosition&);
double geometric_function(const decltype(Area::shape)&, const CartesianPosition&);

/**
 * Canonicalize a point in a shape's coordinate system w.r.t. its azimuth angle
 * \param point Point to canonicalize
 * \param azimuth Azimuth angle of shape's long side
 * \return canonical position (suitable for geometric_function)
 */
CartesianPosition canonicalize(const CartesianPosition& point, units::Angle azimuth);

/**
 * Check if positon is within or at border of area
 * \param area with shape, dimensions, azimuth and center point position
 * \param position Geodetic position to check against area
 * \return true if position is inside or at border
 */
bool inside_or_at_border(const Area&, const GeodeticPosition&);

/**
 * Calculate area size in square km.
 * \param area Area object
 * \return area size
 */
units::Area area_size(const Area&);

template<class SHAPE>
bool inside_shape(const SHAPE& shape, const CartesianPosition& p)
{
    return geometric_function(shape, p) > 0.0;
}

template<class SHAPE>
bool outside_shape(const SHAPE& shape, const CartesianPosition& p)
{
    return geometric_function(shape, p) < 0.0;
}

template<class SHAPE>
bool at_shape_border(const SHAPE& shape, const CartesianPosition& p)
{
    return geometric_function(shape, p) == 0.0;
}

template<class SHAPE>
bool at_center_point(const SHAPE& shape, const CartesianPosition& p)
{
    return geometric_function(shape, p) == 1.0;
}

} // namespace geonet
} // namespace vanetza

#endif /* AREAS_HPP_CVK1NIAI */