/*
 *  This file is part of RawTherapee.
 *
 *  Copyright (c) 2004-2010 Gabor Horvath <hgabor@rawtherapee.com>
 *
 *  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 <https://www.gnu.org/licenses/>.
 */
#include <cstdio>

#include "colortemp.h"
#include "image16.h"
#include "imagefloat.h"
#include "image8.h"
#include "rt_math.h"

namespace
{

void getScanline8(const uint16_t *red, const uint16_t *green, const uint16_t *blue, int width, unsigned char* buffer)
{
    for (int i = 0, ix = 0; i < width; i++) {
        buffer[ix++] = rtengine::uint16ToUint8Rounded(red[i]);
        buffer[ix++] = rtengine::uint16ToUint8Rounded(green[i]);
        buffer[ix++] = rtengine::uint16ToUint8Rounded(blue[i]);
    }
}

void getScanline16(const uint16_t *red, const uint16_t *green, const uint16_t *blue, int width, unsigned short* buffer)
{
    for (int i = 0, ix = 0; i < width; i++) {
        buffer[ix++] = red[i];
        buffer[ix++] = green[i];
        buffer[ix++] = blue[i];
    }
}

}

using namespace rtengine;

Image16::Image16()
{
}

Image16::Image16(int w, int h)
{
    allocate(w, h);
}

Image16::~Image16()
{
}

void Image16::getScanline(int row, unsigned char* buffer, int bps, bool isFloat) const
{

    if (data == nullptr) {
        return;
    }

    if (bps == 16) {
        getScanline16(r(row), g(row), b(row), width, (unsigned short*)buffer);
    } else if (bps == 8) {
        getScanline8(r(row), g(row), b(row), width, buffer);
    }
}

void Image16::setScanline(int row, const unsigned char* buffer, int bps, unsigned int numSamples)
{

    if (data == nullptr) {
        return;
    }

    switch (sampleFormat) {
        case (IIOSF_UNSIGNED_CHAR): {
            int ix = 0;

            if (numSamples == 1) {
                for (int i = 0; i < width; ++i) {
                    r(row, i) = g(row, i) = b(row, i) = static_cast<unsigned short>(buffer[ix++]) * 257;
                }
            } else {
                for (int i = 0; i < width; ++i) {
                    r(row, i) = static_cast<unsigned short>(buffer[ix++]) * 257;
                    g(row, i) = static_cast<unsigned short>(buffer[ix++]) * 257;
                    b(row, i) = static_cast<unsigned short>(buffer[ix++]) * 257;
                }
            }

            break;
        }

        case (IIOSF_UNSIGNED_SHORT): {
            const unsigned short* sbuffer = (const unsigned short*) buffer;
            int ix = 0;

            for (int i = 0; i < width; ++i) {
                r(row, i) = sbuffer[ix++];
                g(row, i) = sbuffer[ix++];
                b(row, i) = sbuffer[ix++];
            }

            break;
        }

        default:
            // Other types are ignored, but could be implemented if necessary
            break;
    }

    /*
     * Not used for now
     *
     */
}

Image16* Image16::copy() const
{

    Image16* cp = new Image16(width, height);
    copyData(cp);
    return cp;
}

Image16* Image16::copySubRegion (int x, int y, int width, int height)
{
    Image16* cp = NULL;
    int realWidth  = LIM<int>(x + width,  0, this->width)  - x;
    int realHeight = LIM<int>(y + height, 0, this->height) - y;

    if (realWidth > 0 && realHeight > 0) {
        cp = new Image16 (realWidth, realHeight);
        copyData(cp, x, y, realWidth, realHeight);
    }

    return cp;
}

void Image16::getStdImage(const ColorTemp &ctemp, int tran, Imagefloat* image, const PreviewProps &pp) const
{

    // compute channel multipliers
    float rm = 1.f, gm = 1.f, bm = 1.f;

    if (ctemp.getTemp() >= 0) {
        double drm, dgm, dbm;
        ctemp.getMultipliers(drm, dgm, dbm);
        rm = drm;
        gm = dgm;
        bm = dbm;

        rm = 1.f / rm;
        gm = 1.f / gm;
        bm = 1.f / bm;
        float mul_lum = 0.299f * rm + 0.587f * gm + 0.114f * bm;
        rm /= mul_lum;
        gm /= mul_lum;
        bm /= mul_lum;
    }

    int sx1, sy1, sx2, sy2;

    transform(pp, tran, sx1, sy1, sx2, sy2);

    int imwidth = image->getWidth(); // Destination image
    int imheight = image->getHeight(); // Destination image

    if (((tran & TR_ROT) == TR_R90) || ((tran & TR_ROT) == TR_R270)) {
        int swap = imwidth;
        imwidth = imheight;
        imheight = swap;
    }

    int maxx = width; // Source image
    int maxy = height; // Source image
    int mtran = tran & TR_ROT;
    int skip = pp.getSkip();

    //if ((sx1 + skip*imwidth)>maxx) imwidth -- ; // we have a boundary condition that can cause errors

    // improve speed by integrating the area division into the multipliers
    // switched to using ints for the red/green/blue channel buffer.
    // Incidentally this improves accuracy too.
    float area = skip * skip;
    float rm2 = rm;
    float gm2 = gm;
    float bm2 = bm;
    rm /= area;
    gm /= area;
    bm /= area;

#ifdef _OPENMP
    #pragma omp parallel
    {
#endif
        AlignedBuffer<float> abR(imwidth);
        AlignedBuffer<float> abG(imwidth);
        AlignedBuffer<float> abB(imwidth);
        float *lineR  = abR.data;
        float *lineG  = abG.data;
        float *lineB =  abB.data;

#ifdef _OPENMP
        #pragma omp for
#endif

        // Iterating all the rows of the destination image
        for (int iy = 0; iy < imheight; iy++) {
            if (skip == 1) {
                // special case (speedup for 1:1 scale)
                // i: source image, first line of the current destination row
                int src_y = sy1 + iy;

                // overflow security check, not sure that it's necessary
                if (src_y >= maxy) {
                    continue;
                }

                for (int dst_x = 0, src_x = sx1; dst_x < imwidth; dst_x++, src_x++) {
                    // overflow security check, not sure that it's necessary
                    if (src_x >= maxx) {
                        continue;
                    }

                    lineR[dst_x] = CLIP(rm2 * r(src_y, src_x));
                    lineG[dst_x] = CLIP(gm2 * g(src_y, src_x));
                    lineB[dst_x] = CLIP(bm2 * b(src_y, src_x));
                }
            } else {
                // source image, first line of the current destination row
                int src_y = sy1 + skip * iy;

                if (src_y >= maxy) {
                    continue;
                }

                for (int dst_x = 0, src_x = sx1; dst_x < imwidth; dst_x++, src_x += skip) {
                    if (src_x >= maxx) {
                        continue;
                    }

                    int src_sub_width = MIN(maxx - src_x, skip);
                    int src_sub_height = MIN(maxy - src_y, skip);

                    float rtot, gtot, btot; // RGB accumulators
                    rtot = gtot = btot = 0.;

                    for (int src_sub_y = 0; src_sub_y < src_sub_height; src_sub_y++)
                        for (int src_sub_x = 0; src_sub_x < src_sub_width; src_sub_x++) {
                            rtot += r(src_y + src_sub_y, src_x + src_sub_x);
                            gtot += g(src_y + src_sub_y, src_x + src_sub_x);
                            btot += b(src_y + src_sub_y, src_x + src_sub_x);
                        }

                    // convert back to gamma and clip
                    if (src_sub_width == skip && src_sub_height == skip) {
                        // Common case where the sub-region is complete
                        lineR[dst_x] = CLIP(rm * rtot);
                        lineG[dst_x] = CLIP(gm * gtot);
                        lineB[dst_x] = CLIP(bm * btot);
                    } else {
                        // computing a special factor for this incomplete sub-region
                        float larea = src_sub_width * src_sub_height;
                        lineR[dst_x] = CLIP(rm2 * rtot / larea);
                        lineG[dst_x] = CLIP(gm2 * gtot / larea);
                        lineB[dst_x] = CLIP(bm2 * btot / larea);
                    }
                }
            }

            if (mtran == TR_NONE)
                for (int dst_x = 0, src_x = sx1; dst_x < imwidth; dst_x++, src_x += skip) {
                    image->r(iy, dst_x) = lineR[dst_x];
                    image->g(iy, dst_x) = lineG[dst_x];
                    image->b(iy, dst_x) = lineB[dst_x];
                } else if (mtran == TR_R180)
                for (int dst_x = 0; dst_x < imwidth; dst_x++) {
                    image->r(imheight - 1 - iy, imwidth - 1 - dst_x) = lineR[dst_x];
                    image->g(imheight - 1 - iy, imwidth - 1 - dst_x) = lineG[dst_x];
                    image->b(imheight - 1 - iy, imwidth - 1 - dst_x) = lineB[dst_x];
                } else if (mtran == TR_R90)
                for (int dst_x = 0, src_x = sx1; dst_x < imwidth; dst_x++, src_x += skip) {
                    image->r(dst_x, imheight - 1 - iy) = lineR[dst_x];
                    image->g(dst_x, imheight - 1 - iy) = lineG[dst_x];
                    image->b(dst_x, imheight - 1 - iy) = lineB[dst_x];
                } else if (mtran == TR_R270)
                for (int dst_x = 0, src_x = sx1; dst_x < imwidth; dst_x++, src_x += skip) {
                    image->r(imwidth - 1 - dst_x, iy) = lineR[dst_x];
                    image->g(imwidth - 1 - dst_x, iy) = lineG[dst_x];
                    image->b(imwidth - 1 - dst_x, iy) = lineB[dst_x];
                }
        }

#ifdef _OPENMP
    }
#endif
#undef GCLIP
}

// Parallelized transformation; create transform with cmsFLAGS_NOCACHE!
void Image16::ExecCMSTransform(cmsHTRANSFORM hTransform)
{
    //cmsDoTransform(hTransform, data, data, planestride);

    // LittleCMS cannot parallelize planar setups -- Hombre: LCMS2.4 can! But it we use this new feature, memory allocation have to be modified too
    // so build temporary buffers to allow multi processor execution
#ifdef _OPENMP
    #pragma omp parallel
#endif
    {
        AlignedBuffer<unsigned short> buffer(width * 3);

#ifdef _OPENMP
        #pragma omp for schedule(static)
#endif

        for (int y = 0; y < height; y++)
        {
            unsigned short *p = buffer.data, *pR = r(y), *pG = g(y), *pB = b(y);

            for (int x = 0; x < width; x++) {
                *(p++) = *(pR++);
                *(p++) = *(pG++);
                *(p++) = *(pB++);
            }

            cmsDoTransform(hTransform, buffer.data, buffer.data, width);

            p = buffer.data;
            pR = r(y);
            pG = g(y);
            pB = b(y);

            for (int x = 0; x < width; x++) {
                *(pR++) = *(p++);
                *(pG++) = *(p++);
                *(pB++) = *(p++);
            }
        } // End of parallelization
    }
}

// // Parallelized transformation; create transform with cmsFLAGS_NOCACHE!
// void Image16::ExecCMSTransform(cmsHTRANSFORM hTransform, const LabImage &labImage, int cx, int cy)
// {
//     // LittleCMS cannot parallelize planar Lab float images
//     // so build temporary buffers to allow multi processor execution
// #ifdef _OPENMP
//     #pragma omp parallel
// #endif
//     {
//         AlignedBuffer<float> bufferLab(width * 3);
//         AlignedBuffer<unsigned short> bufferRGB(width * 3);

// #ifdef _OPENMP
//         #pragma omp for schedule(static)
// #endif

//         for (int y = cy; y < cy + height; y++)
//         {
//             unsigned short *pRGB, *pR, *pG, *pB;
//             float *pLab, *pL, *pa, *pb;

//             pLab= bufferLab.data;
//             pL = labImage.L[y] + cx;
//             pa = labImage.a[y] + cx;
//             pb = labImage.b[y] + cx;

//             for (int x = 0; x < width; x++) {
//                 *(pLab++) = *(pL++)  / 327.68f;
//                 *(pLab++) = *(pa++)  / 327.68f;
//                 *(pLab++) = *(pb++)  / 327.68f;
//             }

//             cmsDoTransform (hTransform, bufferLab.data, bufferRGB.data, width);

//             pRGB = bufferRGB.data;
//             pR = r(y - cy);
//             pG = g(y - cy);
//             pB = b(y - cy);

//             for (int x = 0; x < width; x++) {
//                 *(pR++) = *(pRGB++);
//                 *(pG++) = *(pRGB++);
//                 *(pB++) = *(pRGB++);
//             }
//         } // End of parallelization
//     }
// }