#ifndef ATTRACTORKERNEL_HPP
#define ATTRACTORKERNEL_HPP

#include <cstdlib>

#include "stfu/stf.hpp"

class AttractorKernel {
private:

	void allocate();
	void dealloc();

protected:

	// biggest type first, this will reduce sizeof(AttractorKernel)
	// size is now 40 (when the unsigned int are in front, it was 48)
	double* parameters;
	double* vectorNew;
	double* vectorOld;

	unsigned int numberOfParameters;
	unsigned int dimension;

	// stuff used by subclasses
	AttractorKernel(const unsigned int dimension, const unsigned int numberOfParameters);

public:

	// parameters are stored in a array of doubles
	double& operator[](const unsigned int index);
	double const& operator[](const unsigned int index) const;
	unsigned int getNumberOfParameters() const;

	virtual void generate_random_parameters() {
		for(unsigned int i = 0; i < numberOfParameters; ++i)
			parameters[i] = 2.0 * rand() / double(RAND_MAX) - 1.0;
		for(unsigned int i = 0; i < dimension; ++i)
			vectorNew[i] = vectorOld[i] = 6.0 * rand() / double(RAND_MAX) - 3.0;
	}

	// tests
	bool convergent(){
		double sum = 0.0;
		for(unsigned int i = 0; i < dimension; ++i){
			sum += (vectorNew[i] - vectorOld[i])*(vectorNew[i] - vectorOld[i]);
		}
		return sum < 1.0e-6;
	}

	bool divergent(){
		double sum = 0.0;
		for(unsigned int i = 0; i < dimension; ++i){
			sum += (vectorNew[i] - vectorOld[i])*(vectorNew[i] - vectorOld[i]);
		}
		return sum > 1.0e3;
	}

	// iterate his formula, implemented by subclasses
	virtual void operator()() = 0;

	// getter functions for teh resulta (can't be used as setters)
	double const* vector() const;
	double const* previousVector() const;
	unsigned int getDimension() const;

	// dtor, should be virtual for subclasses to be deleted
	virtual ~AttractorKernel();

	// factory function
	static AttractorKernel* createAttractorKernel(stfu::node& attractorKernel);

};


#endif // ATTRACTORKERNEL_HPP