#ifndef COORDINATE_CALCULATION
#define COORDINATE_CALCULATION

#include "util/coordinate.hpp"

#include <boost/optional.hpp>

#include <utility>

namespace osrm
{
namespace util
{
namespace coordinate_calculation
{

namespace detail
{
const constexpr long double DEGREE_TO_RAD = 0.017453292519943295769236907684886;
const constexpr long double RAD_TO_DEGREE = 1. / DEGREE_TO_RAD;
// earth radius varies between 6,356.750-6,378.135 km (3,949.901-3,963.189mi)
// The IUGG value for the equatorial radius is 6378.137 km (3963.19 miles)
const constexpr long double EARTH_RADIUS = 6372797.560856;
}


//! Takes the squared euclidean distance of the input coordinates. Does not return meters!
std::uint64_t squaredEuclideanDistance(const Coordinate &lhs, const Coordinate &rhs);

double haversineDistance(const Coordinate first_coordinate, const Coordinate second_coordinate);

double greatCircleDistance(const Coordinate first_coordinate, const Coordinate second_coordinate);

std::pair<double, FloatCoordinate>
projectPointOnSegment(const FloatCoordinate &projected_xy_source,
                      const FloatCoordinate &projected_xy_target,
                      const FloatCoordinate &projected_xy_coordinate);

double perpendicularDistance(const Coordinate segment_source,
                             const Coordinate segment_target,
                             const Coordinate query_location);

double perpendicularDistance(const Coordinate segment_source,
                             const Coordinate segment_target,
                             const Coordinate query_location,
                             Coordinate &nearest_location,
                             double &ratio);

Coordinate centroid(const Coordinate lhs, const Coordinate rhs);

double bearing(const Coordinate first_coordinate, const Coordinate second_coordinate);

// Get angle of line segment (A,C)->(C,B)
double computeAngle(const Coordinate first, const Coordinate second, const Coordinate third);

// find the center of a circle through three coordinates
boost::optional<Coordinate> circleCenter(const Coordinate first_coordinate,
                                         const Coordinate second_coordinate,
                                         const Coordinate third_coordinate);

// find the radius of a circle through three coordinates
double circleRadius(const Coordinate first_coordinate,
                    const Coordinate second_coordinate,
                    const Coordinate third_coordinate);

// factor in [0,1]. Returns point along the straight line between from and to. 0 returns from, 1
// returns to
Coordinate interpolateLinear(double factor, const Coordinate from, const Coordinate to);

} // ns coordinate_calculation
} // ns util
} // ns osrm

#endif // COORDINATE_CALCULATION