/***************************************************************************
 *   Copyright (C) 2010 by Simon Andreas Eugster (simon.eu@gmail.com)      *
 *   This file is part of kdenlive. See www.kdenlive.org.                  *
 *                                                                         *
 *   This program 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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 ***************************************************************************/

#include "colortools.h"

#include <math.h>
#include <QColor>

//#define DEBUG_CT
#ifdef DEBUG_CT
#include <QDebug>
#endif

ColorTools::ColorTools()
{
}



QImage ColorTools::yuvColorWheel(const QSize &size, const unsigned char &Y, const float &scaling, const bool &modifiedVersion, const bool &circleOnly)
{
    QImage wheel(size, QImage::Format_ARGB32);
    if (size.width() == 0 || size.height() == 0) {
        qCritical("ERROR: Size of the color wheel must not be 0!");
        return wheel;
    }
    if (circleOnly) {
        wheel.fill(qRgba(0,0,0,0));
    }

    double dr, dg, db, dv, dmax;
    double ru, rv, rr;
    const int w = size.width();
    const int h = size.height();
    const float w2 = (float)w/2;
    const float h2 = (float)h/2;

    for (int u = 0; u < w; ++u) {
        // Transform u from {0,...,w} to [-1,1]
        double du = (double) 2*u/(w-1) - 1;
        du = scaling*du;

        for (int v = 0; v < h; ++v) {
            dv = (double) 2*v/(h-1) - 1;
            dv = scaling*dv;

            if (circleOnly) {
                // Ellipsis equation: x²/a² + y²/b² = 1
                // Here: x=ru, y=rv, a=w/2, b=h/2, 1=rr
                // For rr > 1, the point lies outside. Don't draw it.
                ru = u - w2;
                rv = v - h2;
                rr = ru*ru/(w2*w2) + rv*rv/(h2*h2);
                if (rr > 1) {
                    continue;
                }
            }

            // Calculate the RGB values from YUV
            dr = Y + 290.8*dv;
            dg = Y - 100.6*du - 148*dv;
            db = Y + 517.2*du;

            if (modifiedVersion) {
                // Scale the RGB values down, or up, to max 255
                dmax = fabs(dr);
                if (fabs(dg) > dmax) dmax = fabs(dg);
                if (fabs(db) > dmax) dmax = fabs(db);
                dmax = 255/dmax;

                dr *= dmax;
                dg *= dmax;
                db *= dmax;
            }

            // Avoid overflows (which would generate intersting patterns).
            // Note that not all possible (y,u,v) values with u,v \in [-1,1]
            // have a correct RGB representation, therefore some RGB values
            // may exceed {0,...,255}.
            if (dr < 0) dr = 0;
            if (dg < 0) dg = 0;
            if (db < 0) db = 0;
            if (dr > 255) dr = 255;
            if (dg > 255) dg = 255;
            if (db > 255) db = 255;

            wheel.setPixel(u, (h-v-1), qRgba(dr, dg, db, 255));
        }
    }

    emit signalYuvWheelCalculationFinished();
    return wheel;
}

QImage ColorTools::yuvVerticalPlane(const QSize &size, const float &angle, const float &scaling)
{
    QImage plane(size, QImage::Format_ARGB32);
    if (size.width() == 0 || size.height() == 0) {
        qCritical("ERROR: Size of the color plane must not be 0!");
        return plane;
    }

    double dr, dg, db, Y;
    const int w = size.width();
    const int h = size.height();
    const double uscaling = scaling*cos(M_PI*angle/180);
    const double vscaling = scaling*sin(M_PI*angle/180);

    for (int uv = 0; uv < w; ++uv) {
        double du = uscaling*((double)2*uv/w - 1);//(double)?
        double dv = vscaling*((double)2*uv/w - 1);

        for (int y = 0; y < h; ++y) {
            Y = (double)255*y/h;

            // See yuv2rgb, yuvColorWheel
            dr = Y + 290.8*dv;
            dg = Y - 100.6*du - 148*dv;
            db = Y + 517.2*du;
            if (dr < 0) dr = 0;
            if (dg < 0) dg = 0;
            if (db < 0) db = 0;
            if (dr > 255) dr = 255;
            if (dg > 255) dg = 255;
            if (db > 255) db = 255;

            plane.setPixel(uv, (h-y-1), qRgba(dr, dg, db, 255));

        }
    }


    return plane;

}

QImage ColorTools::rgbCurvePlane(const QSize &size, const ColorTools::ColorsRGB &color, float scaling, const QRgb &background)
{
    Q_ASSERT(scaling > 0 && scaling <= 1);

    QImage plane(size, QImage::Format_ARGB32);
    if (size.width() == 0 || size.height() == 0) {
        qCritical("ERROR: Size of the color plane must not be 0!");
        return plane;
    }

    const int w = size.width();
    const int h = size.height();

    double dcol;
    double dx, dy;

    for (int x = 0; x < w; ++x) {
        double dval = (double)255*x/(w-1);

        for (int y = 0; y < h; ++y) {
            dy = (double)y/(h-1);
            dx = (double)x/(w-1);

            if (1-scaling < 0.0001) {
                dcol = (double)255*dy;
            } else {
                dcol = (double)255 * (dy - (dy-dx)*(1-scaling));
            }

            if (color == ColorTools::COL_R) {
                plane.setPixel(x, (h-y-1), qRgb(dcol, dval, dval));
            } else if (color == ColorTools::COL_G) {
                plane.setPixel(x, (h-y-1), qRgb(dval, dcol, dval));
            } else if (color == ColorTools::COL_B){
                plane.setPixel(x, (h-y-1), qRgb(dval, dval, dcol));
            } else if (color == ColorTools::COL_A) {
                plane.setPixel(x, (h-y-1), qRgb(dcol / 255. * qRed(background), dcol / 255. * qGreen(background), dcol / 255. * qBlue(background)));
            } else {
                plane.setPixel(x, (h-y-1), qRgb(dcol, dcol, dcol));
            }

        }
    }
    return plane;
}

QImage ColorTools::yPbPrColorWheel(const QSize &size, const unsigned char &Y, const float &scaling, const bool &circleOnly)
{

    QImage wheel(size, QImage::Format_ARGB32);
    if (size.width() == 0 || size.height() == 0) {
        qCritical("ERROR: Size of the color wheel must not be 0!");
        return wheel;
    }
    if (circleOnly) {
        wheel.fill(qRgba(0,0,0,0));
    }

    double dr, dg, db, dpR;
    double rB, rR, rr;
    const int w = size.width();
    const int h = size.height();
    const float w2 = (float)w/2;
    const float h2 = (float)h/2;

    for (int b = 0; b < w; ++b) {
        // Transform pB from {0,...,w} to [-0.5,0.5]
        double dpB = (double) b/(w-1) - .5;
        dpB = scaling*dpB;

        for (int r = 0; r < h; ++r) {
            dpR = (double) r/(h-1) - .5;
            dpR = scaling*dpR;

            if (circleOnly) {
                // see yuvColorWheel
                rB = b - w2;
                rR = r - h2;
                rr = rB*rB/(w2*w2) + rR*rR/(h2*h2);
                if (rr > 1) {
                    continue;
                }
            }

            // Calculate the RGB values from YPbPr
            dr = Y + 357.5*dpR;
            dg = Y - 87.75*dpB - 182.1*dpR;
            db = Y + 451.86*dpB;

            // Avoid overflows (which would generate intersting patterns).
            // Note that not all possible (y,u,v) values with u,v \in [-1,1]
            // have a correct RGB representation, therefore some RGB values
            // may exceed {0,...,255}.
            if (dr < 0) dr = 0;
            if (dg < 0) dg = 0;
            if (db < 0) db = 0;
            if (dr > 255) dr = 255;
            if (dg > 255) dg = 255;
            if (db > 255) db = 255;

            wheel.setPixel(b, (h-r-1), qRgba(dr, dg, db, 255));
        }
    }

    return wheel;
}

QImage ColorTools::hsvHueShiftPlane(const QSize &size, const uint &S, const uint &V, const int &MIN, const int &MAX)
{
    Q_ASSERT(size.width() > 0);
    Q_ASSERT(size.height() > 0);
    Q_ASSERT(MAX > MIN);

    QImage plane(size, QImage::Format_ARGB32);

#ifdef DEBUG_CT
    qDebug() << "Requested: Saturation " << S << ", Value " << V;
    QColor colTest(-1, 256, 257);
    qDebug() << "-1 mapped to " << colTest.red() << ", 256 to " << colTest.green() << ", 257 to " << colTest.blue();
#endif

    QColor col(0, 0, 0);

    const int hueValues = MAX-MIN;

    float huediff;
    int newhue;
    for (int x = 0; x < size.width(); ++x) {
        float hue = x/(size.width() - 1.0) * 359;
        for (int y = 0; y < size.height(); ++y) {
            huediff = (1.0f - y/(size.height() - 1.0)) * hueValues + MIN;
//            qDebug() << "hue: " << hue << ", huediff: " << huediff;

            newhue = hue + huediff + 360; // Avoid negative numbers. Rest (>360) will be mapped correctly.

            col.setHsv(newhue, S, V);
            plane.setPixel(x, y, col.rgba());

        }
    }

    return plane;

}

QImage ColorTools::hsvCurvePlane(const QSize &size, const QColor &baseColor,
                                 const ComponentsHSV &xVariant, const ComponentsHSV &yVariant, const bool &shear, const float offsetY)
{
    Q_ASSERT(size.width() > 0);
    Q_ASSERT(size.height() > 0);

    /*int xMax, yMax;

    switch(xVariant) {
    case COM_H:
        xMax = 360;
        break;
    case COM_S:
    case COM_V:
        xMax = 256;
        break;
    }

    switch (yVariant) {
    case COM_H:
        yMax = 360;
        break;
    case COM_S:
    case COM_V:
        yMax = 256;
        break;
    }*/


    QImage plane(size, QImage::Format_ARGB32);

    QColor col(0, 0, 0);

    float hue, sat, val;
    hue = baseColor.hueF();
    sat = baseColor.saturationF();
    val = baseColor.valueF();

    for (int x = 0; x < size.width(); ++x) {
        switch (xVariant) {
        case COM_H:
            hue = x / (size.width()-1.0);
            break;
        case COM_S:
            sat = x / (size.width()-1.0);
            break;
        case COM_V:
            val = x / (size.width()-1.0);
            break;
        }
        for (int y = 0; y < size.height(); ++y) {
            switch (yVariant) {
            case COM_H:
                hue = 1.0 - y / (size.height()-1.0);
                break;
            case COM_S:
                sat = 1.0 - y / (size.height()-1.0);
                break;
            case COM_V:
                val = 1.0 - y / (size.height()-1.0);
                break;
            }

            col.setHsvF(hue, sat, val);

            if (!shear) {
                plane.setPixel(x, y, col.rgba());
            } else {
                plane.setPixel(x, int(2*size.height() + y - x*size.width()/size.height() - offsetY * size.height()) % size.height(), col.rgba());
            }
        }
    }

    return plane;

}










