/*
 *  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>
 */

#ifndef WAVELET_LEVEL_H_INCLUDED
#define WAVELET_LEVEL_H_INCLUDED

#include <cstddef>
#include <algorithm>

#include "wavelet.h"

namespace rtengine
{

template<class T>
inline T clip(T x, T min_value, T max_value)
{
    if(x < min_value)
        return min_value;
    if(x > max_value)
        return max_value;
    return x;
}

template <class A, class B>
void plane_copy(A ** a, B ** b, size_t w, size_t h)
{
    for(size_t j = 0; j < h; j++)
        for(size_t i = 0; i < w; i++)
            b[j][i] = static_cast<B>(a[j][i]);
}

//////////////////////////////////////////////////////////////////////////////

template<class T>
class wavelet_level
{
    // full size
    size_t m_w, m_h;

    // size of low frequency part
    size_t m_w2, m_h2;

    // distance between lines in the array of coeffs
    size_t m_pitch;

    // array of pointers to lines of coeffs
    // actually is a single contiguous data array pointed by m_coeffs[0]
    T ** m_coeffs;

    // allocation and destruction of data storage
    void create();
    void destroy();

    void dwt_2d(size_t w, size_t h);
    void idwt_2d(size_t w, size_t h, int alpha);

public:

    static const bool CLIP = true;
    
    template<class E>
    wavelet_level(E ** src, size_t w, size_t h)
    : m_w(w), m_h(h), m_w2((w+1)/2), m_h2((h+1)/2), m_pitch(0), m_coeffs(NULL)
    {
        create();
        
        decompose(src);
    }
    
    ~wavelet_level()
    {
        destroy();
    }
    
    T ** lowfreq() const
    {
        return m_coeffs;
    }
    
    size_t lfw() const
    {
        return m_w2;
    }

    size_t lfh() const
    {
        return m_h2;
    }

    template<class E>
    void decompose(E ** src);

    template<class E>
    void reconstruct(E ** dst, int alpha, bool do_clip = false);
};

//////////////////////////////////////////////////////////////////////////////

template<class T>
void wavelet_level<T>::dwt_2d(size_t w, size_t h)
{
    T * buffer = new T[std::max(w, h) + 4];
    
    for(size_t j = 0; j < h; j++)
    {
        //dwt_haar(m_coeffs[j], 1, buffer, w);
        dwt_53(m_coeffs[j], 1, buffer, w);
    }
    
    for(size_t i = 0; i < w; i++)
    {
        //dwt_haar(&m_coeffs[0][i], m_pitch, buffer, h);
        dwt_53(&m_coeffs[0][i], m_pitch, buffer, h);
    }
    
    delete buffer;
}

template<class T>
void wavelet_level<T>::idwt_2d(size_t w, size_t h, int alpha)
{
    T * buffer = new T[std::max(w, h) + 4];
    
    for(size_t j = 0; j < h; j++)
    {
        //idwt_haar(m_coeffs[j], 1, buffer, w, alpha);
        idwt_53(m_coeffs[j], 1, buffer, w, alpha);
    }
    
    for(size_t i = 0; i < w; i++)
    {
        //idwt_haar(&m_coeffs[0][i], m_pitch, buffer, h, alpha);
        idwt_53(&m_coeffs[0][i], m_pitch, buffer, h, alpha);
    }
    
    delete buffer;

}

template<class T>
void wavelet_level<T>::create()
{
    // 16-byte alignment: no effect
    //m_pitch = (((m_w*sizeof(T) + 15) / 16) * 16) / sizeof(T);
    m_pitch = m_w;
    T * data = new T[m_pitch * m_h];
    m_coeffs = new T*[m_h];
    for(size_t j = 0; j < m_h; j++)
    {
        m_coeffs[j] = data + m_pitch * j;
    }
}

template<class T>
void wavelet_level<T>::destroy()
{
    if(m_coeffs)
    {
        delete[] m_coeffs[0];
    
        delete[] m_coeffs;
    }
}

template<class T> template<class E>
void wavelet_level<T>::decompose(E ** src)
{
    plane_copy(src, m_coeffs, m_w, m_h);

    dwt_2d(m_w, m_h);
}

template<class T> template<class E>
void wavelet_level<T>::reconstruct(E ** dst, int alpha, bool do_clip)
{
    idwt_2d(m_w, m_h, alpha);

    if(do_clip)
    {
        for(size_t j = 0; j < m_h; j++)
            for(size_t i = 0; i < m_w; i++)
                m_coeffs[j][i] = clip(m_coeffs[j][i], 0, 65535);
    }

    plane_copy(m_coeffs, dst, m_w, m_h);

}

};

#endif