#ifndef INDOOR_GW3_WALKEVALUATOR_H
#define INDOOR_GW3_WALKEVALUATOR_H

#include "Structs.h"
#include "Helper.h"

#include "../../../math/Distributions.h"
#include "../../../grid/Grid.h"

namespace GW3 {

	/** interface for all evaluators that return a probability for a given walk */
	template <typename Node> class WalkEvaluator {

	public:

		/** get the probability for the given walk */
		//virtual double getProbability(const Walk<Node>& walk) const = 0;

		virtual double getProbability(const Point3 pStart, const Point3 pEnd, const WalkParams& params) const = 0;

	};


	/** evaluate the grid-node-importance importance(end) */
	template <typename Node> class WalkEvalEndNodeProbability : public WalkEvaluator<Node> {

		Grid<Node>* grid;

	public:

		WalkEvalEndNodeProbability(Grid<Node>* grid) : grid(grid) {;}

		virtual double getProbability(const Point3 pStart, const Point3 pEnd, const WalkParams& params) const override {

			(void) params;
			(void) pStart;

			const GridPoint gp = Helper<Node>::p3ToGp(pEnd);
			const Node& node = grid->getNodeFor(gp);
			const double p = node.getWalkImportance();
			return std::pow(p,10);

		}

	};



	/** evaluate the difference between head(start,end) and the requested heading */
	template <typename Node> class WalkEvalHeadingStartEnd : public WalkEvaluator<Node> {

		const double sigma;

	public:

		WalkEvalHeadingStartEnd(const double sigma = 0.04) : sigma(sigma) {;}

		virtual double getProbability(const Point3 pStart, const Point3 pEnd, const WalkParams& params) const override {

			(void) params;

			if (pStart == pEnd) {
				std::cout << "warn! start-position == end-positon" << std::endl;
				return 0;
			}

			const Heading head(pStart.xy(), pEnd.xy());
			const float diff = head.getDiffHalfRAD(params.heading);
			//const float diff = Heading::getSignedDiff(params.heading, head);
			return Distribution::Normal<double>::getProbability(0, sigma, diff);

		}

	};

	/** evaluate the difference between distance(start, end) and the requested distance */
	template <typename Node> class WalkEvalDistance : public WalkEvaluator<Node> {

		const double sigma;

	public:

		WalkEvalDistance(const double sigma = 0.1) : sigma(sigma) {;}

		virtual double getProbability(const Point3 pStart, const Point3 pEnd, const WalkParams& params) const override {

			const float walkedDistance_m = pStart.getDistance(pEnd);
			return Distribution::Normal<double>::getProbability(params.distance_m, sigma, walkedDistance_m);

		}

	};

}

#endif // INDOOR_GW3_WALKEVALUATOR_H