#ifndef NAVMESHRANDOM_H
#define NAVMESHRANDOM_H

#include <random>
#include <vector>
#include "../math/DrawList.h"
#include "../geo/Point3.h"
#include "NavMeshLocation.h"

template <typename Tria> class NavMeshRandom {

	std::minstd_rand gen;
	std::uniform_real_distribution<float> dOnTriangle = std::uniform_real_distribution<float>(0.0f, 1.0f);
	const std::vector<Tria*>& triangles;
	DrawList<size_t> lst;

public:

	struct Result {
		Point3 pos;
		size_t triaIdx;
		Result(const Point3 pos, const size_t triaIdx) : pos(pos), triaIdx(triaIdx) {;}
	};

	/** ctor */
	NavMeshRandom(const std::vector<Tria*>& triangles) : triangles(triangles) {
		for (size_t idx = 0; idx < triangles.size(); ++idx) {
			lst.add(idx, triangles[idx]->getArea());
		}
	}

	/** draw a random point within the map */
	NavMeshLocation<Tria> draw() {

		const size_t idx = lst.get();
		const Tria* tria = triangles[idx];

		while (true) {
			const float u = dOnTriangle(gen);
			const float v = dOnTriangle(gen);
			if (u+v > 1) {continue;}
			const Point3 pos = tria.getA() + (tria.getAB() * u) + (tria.getAC() * v);
			return NavMeshLocation<Tria>(pos, tria);
		}

	}

};

#endif // NAVMESHRANDOM_H