//
// Test Suite for geos::algorithm::distance::DiscreteFrechetDistance
//

#include <tut/tut.hpp>
// geos
#include <geos/platform.h>
#include <geos/io/WKTReader.h>
#include <geos/algorithm/distance/DiscreteFrechetDistance.h>
#include <geos/geom/PrecisionModel.h>
#include <geos/geom/GeometryFactory.h>
#include <geos/geom/Geometry.h> // required for use in unique_ptr
#include <geos/geom/Coordinate.h>
// std
#include <cmath>
#include <sstream>
#include <string>
#include <memory>

namespace geos {
	namespace geom {
		class Geometry;
	}
}

using namespace geos::geom;
using namespace geos::algorithm::distance; // for Location

namespace tut
{
	//
	// Test Group
	//

	// Test data, not used
	struct test_DiscreteFrechetDistance_data {

	typedef std::unique_ptr<Geometry> GeomPtr;

	test_DiscreteFrechetDistance_data()
		:
		pm(),
		gf(GeometryFactory::create(&pm)),
		reader(gf.get())
	{}

	static const double TOLERANCE;

	void runTest(const std::string& wkt1, const std::string& wkt2,
		     double expectedDistance)
	{
		GeomPtr g1 ( reader.read(wkt1) );
		GeomPtr g2 ( reader.read(wkt2) );

		double distance = DiscreteFrechetDistance::distance(*g1, *g2);
		double diff = std::fabs(distance-expectedDistance);
		//std::cerr << "expectedDistance:" << expectedDistance << " actual distance:" << distance << std::endl;
		ensure( diff <= TOLERANCE );
	}

	void runTest(const std::string& wkt1, const std::string& wkt2,
		     double densifyFactor, double expectedDistance)
	{
		GeomPtr g1 ( reader.read(wkt1) );
		GeomPtr g2 ( reader.read(wkt2) );

		double distance = DiscreteFrechetDistance::distance(*g1,
			*g2, densifyFactor);
		double diff = std::fabs(distance-expectedDistance);
		//std::cerr << "expectedDistance:" << expectedDistance << " actual distance:" << distance << std::endl;
		ensure( diff <= TOLERANCE );
	}

	PrecisionModel pm;
	GeometryFactory::Ptr gf;
	geos::io::WKTReader reader;

	};
	const double test_DiscreteFrechetDistance_data::TOLERANCE = 0.00001;

	typedef test_group<test_DiscreteFrechetDistance_data> group;
	typedef group::object object;

	group test_DiscreteFrechetDistance_group("geos::algorithm::distace::DiscreteFrechetDistance");



	//
	// Test Cases
	//

	// 1 - testLineSegments
	template<>
	template<>
	void object::test<1>()
	{
runTest("LINESTRING (0 0, 2 1)", "LINESTRING (0 0, 2 0)", 1.0);
	}

	// 2 - testLineSegments2
	template<>
	template<>
	void object::test<2>()
	{
runTest("LINESTRING (0 0, 2 0)", "LINESTRING (0 1, 1 2, 2 1)", 2.23606797749979);
	}

	// 3 - testLinePoints
	template<>
	template<>
	void object::test<3>()
	{
runTest("LINESTRING (0 0, 2 0)", "MULTIPOINT (0 1, 1 0, 2 1)", 1.0);
	}

	// 4 - testLinesShowingDiscretenessEffect
	//
	// Shows effects of limiting FD to vertices
	// Answer is not true Frechet distance.
	//
	template<>
	template<>
	void object::test<4>()
	{
runTest("LINESTRING (0 0, 100 0)", "LINESTRING (0 0, 50 50, 100 0)", 70.7106781186548);
// densifying provides accurate HD
runTest("LINESTRING (0 0, 100 0)", "LINESTRING (0 0, 50 50, 100 0)", 0.5, 50.0);
	}

} // namespace tut
