#ifndef DIST_REGION_H
#define DIST_REGION_H

#include <cmath>
#include <random>
#include "../Random.h"
#include "../../Assertions.h"
#include "Normal.h"

namespace Distribution {

	/** normal distribution */
	template <typename T> class Region {

	private:

		const T mu;
		const T a;
		const T h;
		const T sigma;

	public:

		/** ctor */
		Region(const T mu, const T a) : mu(mu), a(a), h(1.0/(2*2*a)), sigma(std::exp(0) / (2*h*std::sqrt(2*M_PI))) {

		}

		/** get probability for the given value */
		T getProbability(const T val) const {
			const T diff = std::abs(val - mu);
			if (diff < a)	{return h;}
			//if (diff < a+b)	{const float p = 1.0f-(diff-a)/b; return p*h;}
			//return 0;
			const T diff2 = ((val - mu) < 0) ? (val - mu + a) : (val - mu - a);
			return Distribution::Normal<T>::getProbability(0, sigma, diff2) / 2;

		}

		/** get the probability for the given value */
		static T getProbability(const T mu, const T a, const T val) {
			Region<T> dist(mu, a);
			return dist.getProbability(val);
		}

	};

}


#endif // DIST_REGION_H