/* 
 * jayDSP, A cross-platform Digital Signal Processing library written in modern C++.
 * Copyright (C) 2025 Jens Ahrensfeld, All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all 
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 * File: diffusor.hpp
 * Author Jens Ahrensfeld on 26.10.2025.
 */

#ifndef DSP_DIFFUSOR_H
#define DSP_DIFFUSOR_H

#include "delay/multiDelay.hpp"
#include <common/mix.hpp>

template<typename T, size_t numCh>
class Diffusor
{
	MultiDelay<T, numCh> m_dly;
	int m_shuffle_spec[numCh];

	void print_shuffle()
	{
		std::cout << "shuffle" << std::endl;
		for (int i=0; i < numCh; i++)
		{
			std::cout << m_shuffle_spec[i] << " ";
		}
		std::cout << std::endl;
	}

	void shuffle_init(double pn)
	{
		// Shuffle spec
		for (int i=0; i < numCh; i++)
		{
			m_shuffle_spec[i] = i;
		}

		// Shuffle values
		for (int i=0; i < 2*numCh; i++)
		{
			int i1 = rand() & (numCh-1);
			int i2 = rand() & (numCh-1);
			int temp = m_shuffle_spec[i1];
			m_shuffle_spec[i1] = m_shuffle_spec[i2];
			m_shuffle_spec[i2] = temp;
		}

		// Shuffle signs
		for (int i=0; i < numCh; i++)
		{
			double z = (double)rand()/(double)RAND_MAX;
			if (z < pn)
			{
				m_shuffle_spec[i] *= (T)-1;
			}
		}

		print_shuffle();
	}
	public:
	Diffusor(uint maxDelaySize, double pn=0.5)
	: m_dly(maxDelaySize, 0)
	{
		shuffle_init(pn);
	}

	void setDelay(uint delay)
	{
		m_dly.setDelay(delay, 0);
	}

	uint getDelay()
	{
		return m_dly.getDelay();
	}

	inline T process(T in)
	{
		T temp[numCh];
		m_dly.process(in, temp);

		Shuffle<T, numCh>::inPlace(temp, m_shuffle_spec);
		Hadamard<T, numCh>::inPlace(temp);
		Householder<T, numCh>::inPlace(temp);

		return temp[0];
	}

	// In-place
	inline void process_multi(T in_out[numCh])
	{
		m_dly.process(in_out);

		Shuffle<T, numCh>::inPlace(in_out, m_shuffle_spec);
		Hadamard<T, numCh>::inPlace(in_out);
	}

	// Out-of-place
	inline void process_multi(T in[numCh], T out[numCh])
	{
		m_dly.process(in, out);

		Shuffle<T, numCh>::outOfPlace(in, out, m_shuffle_spec);
		Hadamard<T, numCh>::inPlace(out);
	}
};

#endif // DSP_DIFFUSOR_H