/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2005-05-25
 * Description : Refocus threaded image filter.
 *
 * SPDX-FileCopyrightText: 2005-2025 by Gilles Caulier <caulier dot gilles at gmail dot com>
 * SPDX-FileCopyrightText: 2009      by Matthias Welwarsky <matze at welwarsky dot de>
 * SPDX-FileCopyrightText: 2010      by Martin Klapetek <martin dot klapetek at gmail dot com>
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * ============================================================ */

#include "refocusfilter.h"

// C++ includes

#include <cmath>

// Qt includes

#include <QtConcurrentRun>

// Local includes

#include "dimg.h"
#include "digikam_debug.h"
#include "dcolor.h"
#include "refocusmatrix.h"
#include "digikam_globals_p.h"      // For KF6::Ki18n deprecated

namespace Digikam
{

const int MAX_MATRIX_SIZE = 25;

class Q_DECL_HIDDEN RefocusFilter::Private
{
public:

    Private() = default;

    DImg      preImage;

    int       matrixSize    = 5;

    double    radius        = 0.9;
    double    gauss         = 0.0;
    double    correlation   = 0.5;
    double    noise         = 0.01;
};

RefocusFilter::RefocusFilter(QObject* const parent)
    : DImgThreadedFilter(parent),
      d                 (new Private)
{
    initFilter();
}

RefocusFilter::RefocusFilter(DImg* const orgImage, QObject* const parent, int matrixSize, double radius,
                             double gauss, double correlation, double noise)
    : DImgThreadedFilter(orgImage, parent, QLatin1String("Refocus")),
      d                 (new Private)
{
    d->matrixSize  = matrixSize;
    d->radius      = radius;
    d->gauss       = gauss;
    d->correlation = correlation;
    d->noise       = noise;

    // initialize filter

    initFilter();

    // initialize intermediate image

    d->preImage = DImg(orgImage->width()  + 4 * MAX_MATRIX_SIZE,
                       orgImage->height() + 4 * MAX_MATRIX_SIZE,
                       orgImage->sixteenBit(), orgImage->hasAlpha());
}

RefocusFilter::~RefocusFilter()
{
    cancelFilter();
    delete d;
}

QString RefocusFilter::DisplayableName()
{
    return QString::fromUtf8(I18N_NOOP("Refocus"));
}

void RefocusFilter::filterImage()
{
    bool sb = m_orgImage.sixteenBit();
    bool a  = m_orgImage.hasAlpha();
    int w   = m_orgImage.width();
    int h   = m_orgImage.height();

    DImg img(w + 4 * MAX_MATRIX_SIZE, h + 4 * MAX_MATRIX_SIZE, sb, a);
    DImg tmp;

    // copy the original

    img.bitBltImage(&m_orgImage, 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE);

    // Create dummy top border

    tmp = m_orgImage.copy(0, 0, w, 2 * MAX_MATRIX_SIZE);
    tmp.flip(DImg::VERTICAL);
    img.bitBltImage(&tmp, 2 * MAX_MATRIX_SIZE, 0);

    // Create dummy bottom border

    tmp = m_orgImage.copy(0, h - 2 * MAX_MATRIX_SIZE, w, 2 * MAX_MATRIX_SIZE);
    tmp.flip(DImg::VERTICAL);
    img.bitBltImage(&tmp, 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE + h);

    // Create dummy left border

    tmp = m_orgImage.copy(0, 0, 2 * MAX_MATRIX_SIZE, h);
    tmp.flip(DImg::HORIZONTAL);
    img.bitBltImage(&tmp, 0, 2 * MAX_MATRIX_SIZE);

    // Create dummy right border

    tmp = m_orgImage.copy(w - 2 * MAX_MATRIX_SIZE, 0, 2 * MAX_MATRIX_SIZE, h);
    tmp.flip(DImg::HORIZONTAL);
    img.bitBltImage(&tmp, w + 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE);

    // Create dummy top/left corner

    tmp = m_orgImage.copy(0, 0, 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE);
    tmp.flip(DImg::HORIZONTAL);
    tmp.flip(DImg::VERTICAL);
    img.bitBltImage(&tmp, 0, 0);

    // Create dummy top/right corner

    tmp = m_orgImage.copy(w - 2 * MAX_MATRIX_SIZE, 0, 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE);
    tmp.flip(DImg::HORIZONTAL);
    tmp.flip(DImg::VERTICAL);
    img.bitBltImage(&tmp, w + 2 * MAX_MATRIX_SIZE, 0);

    // Create dummy bottom/left corner

    tmp = m_orgImage.copy(0, h - 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE);
    tmp.flip(DImg::HORIZONTAL);
    tmp.flip(DImg::VERTICAL);
    img.bitBltImage(&tmp, 0, h + 2 * MAX_MATRIX_SIZE);

    // Create dummy bottom/right corner

    tmp = m_orgImage.copy(w - 2 * MAX_MATRIX_SIZE, h - 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE);
    tmp.flip(DImg::HORIZONTAL);
    tmp.flip(DImg::VERTICAL);
    img.bitBltImage(&tmp, w + 2 * MAX_MATRIX_SIZE, h + 2 * MAX_MATRIX_SIZE);

    // run filter algorithm on the prepared copy

    refocusImage(img.bits(), img.width(), img.height(),
                 img.sixteenBit(), d->matrixSize, d->radius, d->gauss,
                 d->correlation, d->noise);

    // copy the result from intermediate image to final image

    m_destImage.bitBltImage(&d->preImage, 2 * MAX_MATRIX_SIZE, 2 * MAX_MATRIX_SIZE, w, h, 0, 0);
}

void RefocusFilter::refocusImage(uchar* const data, int width, int height, bool sixteenBit,
                                 int matrixSize, double radius, double gauss,
                                 double correlation, double noise)
{
    CMat* matrix = nullptr;
    (void)matrix; // To prevent cppcheck warnings.

    // Compute matrix

    qCDebug(DIGIKAM_DIMG_LOG) << "RefocusFilter::Compute matrix...";

    CMat circle, gaussian, convolution;

    RefocusMatrix::make_gaussian_convolution(gauss, &gaussian, matrixSize);
    RefocusMatrix::make_circle_convolution(radius, &circle, matrixSize);
    RefocusMatrix::init_c_mat(&convolution, matrixSize);
    RefocusMatrix::convolve_star_mat(&convolution, &gaussian, &circle);

    matrix = RefocusMatrix::compute_g_matrix(&convolution, matrixSize, correlation, noise, 0.0, true);

    RefocusMatrix::finish_c_mat(&convolution);
    RefocusMatrix::finish_c_mat(&gaussian);
    RefocusMatrix::finish_c_mat(&circle);

    // Apply deconvolution kernel to image.

    qCDebug(DIGIKAM_DIMG_LOG) << "RefocusFilter::Apply Matrix to image...";

    Args prm;
    prm.orgData    = data;
    prm.destData   = d->preImage.bits();
    prm.width      = width;
    prm.height     = height;
    prm.sixteenBit = sixteenBit;
    prm.matrix     = matrix->data;
    prm.mat_size   = 2 * matrixSize + 1;

    convolveImage(prm);

    // Clean up memory

    delete matrix;
}

void RefocusFilter::convolveImageMultithreaded(uint start, uint stop, uint y1, const Args& prm)
{
    ushort* orgData16  = reinterpret_cast<ushort*>(prm.orgData);
    ushort* destData16 = reinterpret_cast<ushort*>(prm.destData);

    double valRed, valGreen, valBlue;
    uint   x1, x2, y2;
    int    index1, index2;

    const int imageSize  = prm.width * prm.height;
    const int mat_offset = prm.mat_size / 2;

    for (x1 = start ; runningFlag() && (x1 < stop) ; ++x1)
    {
        valRed = valGreen = valBlue = 0.0;

        if (!prm.sixteenBit)        // 8 bits image.
        {
            uchar red, green, blue;
            uchar* ptr = nullptr;

            for (y2 = 0 ; runningFlag() && (y2 < prm.mat_size) ; ++y2)
            {
                int y2_matsize = y2 * prm.mat_size;

                for (x2 = 0 ; runningFlag() && (x2 < prm.mat_size) ; ++x2)
                {
                    index1 = prm.width * (y1 + y2 - mat_offset) + x1 + x2 - mat_offset;

                    // cppcheck-suppress knownConditionTrueFalse
                    if ((index1 >= 0) && (index1 < imageSize))
                    {
                        ptr                      =  &prm.orgData[index1 * 4];   // cppcheck-suppress objectIndex
                        blue                     =  ptr[0];
                        green                    =  ptr[1];                     // cppcheck-suppress objectIndex
                        red                      =  ptr[2];                     // cppcheck-suppress objectIndex
                        const double matrixValue =  prm.matrix[y2_matsize + x2];
                        valRed                   += matrixValue * red;
                        valGreen                 += matrixValue * green;
                        valBlue                  += matrixValue * blue;
                    }
                }
            }

            index2 = y1 * prm.width + x1;

            // cppcheck-suppress knownConditionTrueFalse
            if ((index2 >= 0) && (index2 < imageSize))
            {
                // To get Alpha channel value from original (unchanged)

                memcpy(&prm.destData[index2 * 4], &prm.orgData[index2 * 4], 4);
                ptr = &prm.destData[index2 * 4];                                // cppcheck-suppress objectIndex

                // Overwrite RGB values to destination.

                ptr[0] = (uchar) CLAMP(valBlue,  0.0, 255.0);
                ptr[1] = (uchar) CLAMP(valGreen, 0.0, 255.0);                   // cppcheck-suppress objectIndex
                ptr[2] = (uchar) CLAMP(valRed,   0.0, 255.0);                   // cppcheck-suppress objectIndex
            }
        }
        else                 // 16 bits image.
        {
            ushort red, green, blue;
            ushort* ptr = nullptr;

            for (y2 = 0 ; runningFlag() && (y2 < prm.mat_size) ; ++y2)
            {
                int y2_matsize = y2 * prm.mat_size;

                for (x2 = 0 ; runningFlag() && (x2 < prm.mat_size) ; ++x2)
                {
                    index1 = prm.width * (y1 + y2 - mat_offset) + x1 + x2 - mat_offset;

                    // cppcheck-suppress knownConditionTrueFalse
                    if ((index1 >= 0) && (index1 < imageSize))
                    {
                        ptr                      =  &orgData16[index1 * 4];
                        blue                     =  ptr[0];
                        green                    =  ptr[1];
                        red                      =  ptr[2];
                        const double matrixValue =  prm.matrix[y2_matsize + x2];
                        valRed                   += matrixValue * red;
                        valGreen                 += matrixValue * green;
                        valBlue                  += matrixValue * blue;
                    }
                }
            }

            index2 = y1 * prm.width + x1;

            // cppcheck-suppress knownConditionTrueFalse
            if ((index2 >= 0) && (index2 < imageSize))
            {
                // To get Alpha channel value from original (unchanged)

                memcpy(&destData16[index2 * 4], &orgData16[index2 * 4], 8);
                ptr = &destData16[index2 * 4];

                // Overwrite RGB values to destination.

                ptr[0] = (ushort) CLAMP(valBlue,  0.0, 65535.0);
                ptr[1] = (ushort) CLAMP(valGreen, 0.0, 65535.0);
                ptr[2] = (ushort) CLAMP(valRed,   0.0, 65535.0);
            }
        }
    }
}

void RefocusFilter::convolveImage(const Args& prm)
{
    int progress;

    QList<int> vals = multithreadedSteps(prm.width);

    for (int y1 = 0 ; runningFlag() && (y1 < prm.height) ; ++y1)
    {
        QList <QFuture<void> > tasks;

        for (int j = 0 ; runningFlag() && (j < vals.count() - 1) ; ++j)
        {
            tasks.append(QtConcurrent::run(

#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))

                                           &RefocusFilter::convolveImageMultithreaded, this,

#else

                                           this, &RefocusFilter::convolveImageMultithreaded,

#endif

                                           vals[j],
                                           vals[j+1],
                                           y1,
                                           prm
                                          )
            );
        }

        for (QFuture<void> t : std::as_const(tasks))
        {
            t.waitForFinished();
        }

        // Update the progress bar in dialog.

        progress = (int)(((double)y1 * 100.0) / prm.height);

        if ((progress % 5) == 0)
        {
            postProgress(progress);
        }
    }
}

FilterAction RefocusFilter::filterAction()
{
    FilterAction action(FilterIdentifier(), CurrentVersion());
    action.setDisplayableName(DisplayableName());

    action.addParameter(QLatin1String("correlation"), d->correlation);
    action.addParameter(QLatin1String("gauss"),       d->gauss);
    action.addParameter(QLatin1String("matrixSize"),  d->matrixSize);
    action.addParameter(QLatin1String("noise"),       d->noise);
    action.addParameter(QLatin1String("radius"),      d->radius);

    return action;
}

void RefocusFilter::readParameters(const Digikam::FilterAction& action)
{
    d->correlation = action.parameter(QLatin1String("correlation")).toDouble();
    d->gauss       = action.parameter(QLatin1String("gauss")).toDouble();
    d->matrixSize  = action.parameter(QLatin1String("matrixSize")).toInt();
    d->noise       = action.parameter(QLatin1String("noise")).toDouble();
    d->radius      = action.parameter(QLatin1String("radius")).toDouble();
}

int RefocusFilter::maxMatrixSize()
{
    return MAX_MATRIX_SIZE;
}

} // namespace Digikam

#include "moc_refocusfilter.cpp"
