/*
 *  This file is part of RawTherapee.
 *
 *  RawTherapee is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 * 
 *  RawTherapee is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  2010 Ilya Popov <ilia_popov@rambler.ru>
 *  2012 Emil Martinec <ejmartin@uchicago.edu>
 */

#ifndef CPLX_WAVELET_DEC_H_INCLUDED
#define CPLX_WAVELET_DEC_H_INCLUDED

#include <cstddef>
#include <math.h>

#include "cplx_wavelet_level.h"
#include "cplx_wavelet_filter_coeffs.h"

namespace rtengine {

	class wavelet_decomposition
	{
	public:

		typedef float internal_type;
		float *coeff0;
		bool memoryAllocationFailed;

	private:

		static const int maxlevels = 10;//should be greater than any conceivable order of decimation

		int lvltot, subsamp;
		int numThreads;
		int m_w, m_h;//dimensions

		int wavfilt_len, wavfilt_offset;
		float *wavfilt_anal;
		float *wavfilt_synth;


		wavelet_level<internal_type> * wavelet_decomp[maxlevels];

	public:

		template<typename E>
		wavelet_decomposition(E * src, int width, int height, int maxlvl, int subsampling, int skipcrop = 1, int numThreads = 1);

		~wavelet_decomposition();

		internal_type ** level_coeffs(int level) const
		{
			return wavelet_decomp[level]->subbands();
		}

		int level_W(int level) const
		{
			return wavelet_decomp[level]->width();
		}

		int level_H(int level) const
		{
			return wavelet_decomp[level]->height();
		}

		int level_stride(int level) const
		{
			return wavelet_decomp[level]->stride();
		}

		int maxlevel() const
		{
			return lvltot+1;
		}

		int subsample() const
		{
			return subsamp;
		}
		template<typename E>
		void reconstruct(E * dst);
	};

	template<typename E>
	wavelet_decomposition::wavelet_decomposition(E * src, int width, int height, int maxlvl, int subsampling, int skipcrop, int numThreads)
	: coeff0(NULL), memoryAllocationFailed(false), lvltot(0), subsamp(subsampling), numThreads(numThreads), m_w(width), m_h(height)
	{
		//initialize wavelet filters
		wavfilt_len = Daub4_len;
		wavfilt_offset = Daub4_offset;
		wavfilt_anal = new float[2*wavfilt_len];
		wavfilt_synth = new float[2*wavfilt_len];

		for (int n=0; n<2; n++) {
			for (int i=0; i<wavfilt_len; i++) {
				wavfilt_anal[wavfilt_len*(n)+i]  = Daub4_anal[n][i];
				wavfilt_synth[wavfilt_len*(n)+i] = Daub4_anal[n][wavfilt_len-1-i];
				//n=0 lopass, n=1 hipass
			}
		}

		// after coefficient rotation, data structure is:
		// wavelet_decomp[scale][channel={lo,hi1,hi2,hi3}][pixel_array]

		lvltot=0;
		E *buffer[2];
		buffer[0] = new (std::nothrow) E[(m_w/2+1)*(m_h/2+1)];
		if(buffer[0] == NULL) {
			memoryAllocationFailed = true;
			return;
		}
		buffer[1] = new (std::nothrow) E[(m_w/2+1)*(m_h/2+1)];
		if(buffer[1] == NULL) {
			memoryAllocationFailed = true;
			delete[] buffer[0];
			buffer[0] = NULL;
			return;
		}
		int bufferindex = 0;

		wavelet_decomp[lvltot] = new wavelet_level<internal_type>(src, buffer[bufferindex^1], lvltot/*level*/, subsamp, m_w, m_h, \
																  wavfilt_anal, wavfilt_anal, wavfilt_len, wavfilt_offset, skipcrop, numThreads);
		if(wavelet_decomp[lvltot]->memoryAllocationFailed)
			memoryAllocationFailed = true;
		while(lvltot < maxlvl-1) {
			lvltot++;
			bufferindex ^= 1;
			wavelet_decomp[lvltot] = new wavelet_level<internal_type>(buffer[bufferindex], buffer[bufferindex^1]/*lopass*/, lvltot/*level*/, subsamp, \
																	  wavelet_decomp[lvltot-1]->width(), wavelet_decomp[lvltot-1]->height(), \
																	  wavfilt_anal, wavfilt_anal, wavfilt_len, wavfilt_offset, skipcrop, numThreads);
			if(wavelet_decomp[lvltot]->memoryAllocationFailed)
				memoryAllocationFailed = true;
		}
		coeff0 = buffer[bufferindex^1];
		delete[] buffer[bufferindex];
	}
	
	template<typename E>
	void wavelet_decomposition::reconstruct(E * dst) { 
		if(memoryAllocationFailed)
			return;
		// data structure is wavcoeffs[scale][channel={lo,hi1,hi2,hi3}][pixel_array]
		int m_w = 0;
		int m_h2 = 0;

		for(int lvl=0;lvl<lvltot;lvl++) {
			if(m_w < wavelet_decomp[lvl]->m_w)
				m_w = wavelet_decomp[lvl]->m_w;
			if(m_h2 < wavelet_decomp[lvl]->m_h2)
				m_h2 = wavelet_decomp[lvl]->m_h2;
		}
		E *tmpLo = new (std::nothrow) E[m_w*m_h2];
		if(tmpLo == NULL) {
			memoryAllocationFailed = true;
			return;
		}

		E *tmpHi = new (std::nothrow) E[m_w*m_h2];
		if(tmpHi == NULL) {
			memoryAllocationFailed = true;
			delete[] tmpLo;
			return;
		}

		for (int lvl=lvltot; lvl>0; lvl--) {
			wavelet_decomp[lvl]->reconstruct_level(tmpLo, tmpHi, coeff0, coeff0, wavfilt_synth, wavfilt_synth, wavfilt_len, wavfilt_offset);
		}

		wavelet_decomp[0]->reconstruct_level(tmpLo, tmpHi, coeff0, dst, wavfilt_synth, wavfilt_synth, wavfilt_len, wavfilt_offset);
		delete[] coeff0;
		coeff0 = NULL;
		delete[] tmpLo;
		delete[] tmpHi;
	}

};

#endif