#ifndef __C_GUI_COLOR_PICKER_HEADER__
#define __C_GUI_COLOR_PICKER_HEADER__

/**
 * Copyright (C) <2014> <Jehan-antoine vayssade>
 * Ovan/Magun contact on irrlicht-fr.org or ovan@sleek-think.ovh
 * 
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 * 
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 * 
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
**/

#include <irrlicht/IGUIElement.h>
#include <irrlicht/S3DVertex.h>

namespace irr
{
    namespace gui
    {
        class IGUIButton;
        class IGUIStaticText;
        class IGUIScrollBar;

        class CGUIColorPicker : public IGUIElement
        {
            public:
                CGUIColorPicker(IGUIEnvironment *environment, IGUIElement *parent, s32 id = 0) noexcept;
                ~CGUIColorPicker() noexcept;

                virtual void setRelativePosition(const core::recti &r);

                virtual bool OnEvent(const SEvent&) noexcept;
                virtual void updateAbsolutePosition();

                virtual void setPickedColor(const video::SColor&) noexcept;
                virtual const video::SColor& getPickedColor() const noexcept;

                virtual void setBackgroundColor(const video::SColor&) noexcept;
                virtual const video::SColor& getBackgroundColor() const noexcept;

                virtual void draw();
            protected:
                bool isGradient, isColor, isInside;
                virtual void recalculatePickedColor() noexcept;
                virtual void createAlphaTexture() noexcept;
                virtual void createGradientTexture() noexcept;
            protected:
                IGUIButton      *close;
                IGUIScrollBar   *scroll;
                video::ITexture *img[2];
            protected:
                video::SColor    pickcolor, color;
                video::SColor    background, white, black, alpha;
                core::recti      box, pickbox, gradient;
                core::vector2di  pickpos;
                int              colorpos;
        };
    }
}

#endif

#include "CGUIColorPicker.h"

#include <irrlicht/IGUIEnvironment.h>
#include <irrlicht/IGUIButton.h>
#include <irrlicht/IGUIScrollBar.h>
#include <irrlicht/IVideoDriver.h>
#include <irrlicht/irrMath.h>
#include <irrlicht/SColor.h>

namespace irr
{
    inline core::vector3df RGBftoHSV(video::SColorf rgb)
    {
        core::vector3df hsv;

        f32 M = core::max_(rgb.getRed(), rgb.getGreen(), rgb.getBlue());
        f32 m = core::min_(rgb.getRed(), rgb.getGreen(), rgb.getBlue());
        f32 C = M - m;

        if(C == 0)
            hsv.X = 0;
        else if(M <= rgb.getRed())
            hsv.X =((rgb.getGreen() - rgb.getBlue()) / C);
        else if(M <= rgb.getGreen())
            hsv.X =((rgb.getBlue() - rgb.getRed()) / C) + 2;
        else if(M <= rgb.getBlue())
            hsv.X =((rgb.getRed() - rgb.getGreen()) / C) + 4;

        hsv.X *= 60;
        if(hsv.X < 0)
            hsv.X += 360;

        hsv.Y = M;

        if(hsv.Y == 0) hsv.Z = 0;
        else hsv.Z = C / hsv.Y;

        return hsv;
    }
    namespace gui
    {
        CGUIColorPicker::CGUIColorPicker(IGUIEnvironment *environment, IGUIElement *parent, s32 id) noexcept
            : IGUIElement(EGUIET_COLOR_SELECT_DIALOG , environment, parent, id, {200, 200, 310, 360}),
              background{64, 255, 255, 255}, white{255, 255, 255, 255}, black{255, 0, 0, 0},
              colorpos(0), isGradient(false), isColor(false)
        {
            close = Environment->addButton({5, 140, 85, 156}, this, 0, L"take this color");

            scroll = Environment->addScrollBar(true, {5, 125, 85, 135}, this);
            scroll->setMin(0);
            scroll->setMax(255);
            scroll->setPos(255);

            createAlphaTexture();
            createGradientTexture();

            setPickedColor({255, 64, 64, 128});
            updateAbsolutePosition();
        }
        CGUIColorPicker::~CGUIColorPicker() noexcept
        {
            close->drop();
            scroll->drop();
            img[0]->drop();
            img[1]->drop();
        }
        void CGUIColorPicker::createAlphaTexture() noexcept
        {
            img[0] = Environment->getVideoDriver()->addTexture({16, 16}, "alpha", video::ECF_A8R8G8B8);
            u32 *tmp = (u32*) img[0]->lock();

            video::SColor color;

            #define square(colorstart, sx, sy, sz, sw)                         \\
                color = colorstart;                                            \\
                for(int y=sy; y<sw; ++y)                                       \\
                    for(int x=sx; x<sz; ++x)                                   \\
                        color.getData(&tmp[x + y*16], video::ECF_A8R8G8B8);    \\

            square(video::SColor(255, 153, 153, 153), 0, 0,  8,  8);
            square(video::SColor(255, 153, 153, 153), 8, 8, 16, 16);
            square(video::SColor(255, 102, 102, 102), 8, 0, 16,  8);
            square(video::SColor(255, 102, 102, 102), 0, 8,  8, 16);

            img[0]->unlock();
        }
        void CGUIColorPicker::createGradientTexture() noexcept
        {
            img[1] = Environment->getVideoDriver()->addTexture({15, 151}, "gradient", video::ECF_A8R8G8B8);
            u32 *tmp = (u32*) img[1]->lock();

            video::SColor from;
            video::SColor to;

            #define interpolate(colorstart, colorend, start, end)              \\
                from = colorstart;                                             \\
                to = colorend;                                                 \\
                                                                               \\
                for(int y=start; y<end; ++y)                                   \\
                {                                                              \\
                    video::SColor c = to.getInterpolated(from, (y-start)/25.f);\\
                    for(int x=0; x<15; ++x)                                    \\
                        c.getData(&tmp[x + y*15], video::ECF_A8R8G8B8);        \\
                }

            interpolate(video::SColor(255, 255, 0, 0),   video::SColor(255, 255, 0, 255),   0,  25);
            interpolate(video::SColor(255, 255, 0, 255), video::SColor(255, 0, 0, 255),    25,  50);

            interpolate(video::SColor(255, 0, 0, 255), video::SColor(255, 0, 255, 255),  50,  75);
            interpolate(video::SColor(255, 0, 255, 255), video::SColor(255, 0, 255, 0),  75, 100);

            interpolate(video::SColor(255, 0, 255, 0), video::SColor(255, 255, 255, 0), 100, 125);
            interpolate(video::SColor(255, 255, 255, 0), video::SColor(255, 255, 0, 0), 125, 151);

            img[1]->unlock();
        }
        void CGUIColorPicker::setRelativePosition(const core::recti &r)
        {
            RelativeRect.UpperLeftCorner = r.UpperLeftCorner;
            RelativeRect.LowerRightCorner.X = r.UpperLeftCorner.X + 110;
            RelativeRect.LowerRightCorner.Y = r.UpperLeftCorner.X + 160;
        }
        bool CGUIColorPicker::OnEvent(const SEvent &event) noexcept
        {
            if(event.EventType == EET_MOUSE_INPUT_EVENT)
            {
                core::vector2di pos(event.MouseInput.X, event.MouseInput.Y);

                if(event.MouseInput.Event == EMIE_LMOUSE_PRESSED_DOWN)
                {
                    isGradient = gradient.isPointInside(pos);
                    isColor = box.isPointInside(pos);
                    isInside = AbsoluteRect.isPointInside(pos);
                }

                if(event.MouseInput.Event == EMIE_LMOUSE_LEFT_UP)
                {
                    // does not work since 1.7 (i think)
                    // probably need CGUIModalScreen if this module is add to the engine
                    //if(!AbsoluteRect.isPointInside(pos) && !isInside)
                    //{
                    //    SEvent event;
                    //    event.EventType = EET_GUI_EVENT;
                    //    event.GUIEvent.Caller = this;
                    //    event.GUIEvent.Element = 0;
                    //    event.GUIEvent.EventType = EGET_ELEMENT_CLOSED;
                    //    Parent->OnEvent(event);
                    //    remove();
                    //    drop();
                    //}
                    isGradient = isColor = false;
                }

                if(isGradient)
                {
                    if(pos.X < gradient.UpperLeftCorner.X)
                        pos.X = gradient.UpperLeftCorner.X;
                    if(pos.Y < gradient.UpperLeftCorner.Y)
                        pos.Y = gradient.UpperLeftCorner.Y;

                    if(pos.X > gradient.LowerRightCorner.X)
                        pos.X = gradient.LowerRightCorner.X;
                    if(pos.Y > gradient.LowerRightCorner.Y)
                        pos.Y = gradient.LowerRightCorner.Y;

                    colorpos = pos.Y - gradient.UpperLeftCorner.Y;
                    u32 *tmp =(u32*)img[1]->lock();
                    color.set(tmp[colorpos*img[1]->getOriginalSize().Width]);
                    img[1]->unlock();
                    recalculatePickedColor();
                }

                if(isColor)
                {
                    if(pos.X < box.UpperLeftCorner.X)
                        pos.X = box.UpperLeftCorner.X;
                    if(pos.Y < box.UpperLeftCorner.Y)
                        pos.Y = box.UpperLeftCorner.Y;

                    if(pos.X > box.LowerRightCorner.X)
                        pos.X = box.LowerRightCorner.X;
                    if(pos.Y > box.LowerRightCorner.Y)
                        pos.Y = box.LowerRightCorner.Y;

                    pickpos.X = pos.X - box.UpperLeftCorner.X;
                    pickpos.Y = pos.Y - box.UpperLeftCorner.Y;
                    recalculatePickedColor();
                }

                if(isGradient || isColor)
                    return true;
            }

            if(event.EventType == EET_GUI_EVENT)
            {
                switch(event.GUIEvent.EventType)
                {
                    case EGET_BUTTON_CLICKED:
                        SEvent event;
                        event.EventType = EET_GUI_EVENT;
                        event.GUIEvent.Caller = this;
                        event.GUIEvent.Element = 0;
                        event.GUIEvent.EventType = EGET_FILE_SELECTED;
                        Parent->OnEvent(event);
                    break;
                    case EGET_SCROLL_BAR_CHANGED:
                        recalculatePickedColor();
                        return true;
                    break;
                }
            }

            return IGUIElement::OnEvent(event);
        }
        void CGUIColorPicker::recalculatePickedColor() noexcept
        {
            video::SColor hcolor = color.getInterpolated(white, pickpos.X/80.f);

            pickcolor = black.getInterpolated(hcolor, pickpos.Y/80.f);
            pickcolor.setAlpha(scroll->getPos());

            alpha = color;
            alpha.setAlpha(0);
        }
        void CGUIColorPicker::setPickedColor(const video::SColor &c) noexcept
        {
            pickcolor = c;

            core::vector3df hsv = RGBftoHSV({
                c.getRed()/255.f,
                c.getGreen()/255.f,
                c.getBlue()/255.f,
                c.getAlpha()/255.f
            });

            colorpos = 150-hsv.X/360.f*150.f;
            pickpos.X = hsv.Y*80.f;
            pickpos.Y = 80-(hsv.Z)*80.f;

            u32 *tmp =(u32*)img[1]->lock();
            color.set(tmp[colorpos*img[1]->getOriginalSize().Width]);
            img[1]->unlock();

            alpha = color;
            alpha.setAlpha(0);
        }
        const video::SColor& CGUIColorPicker::getPickedColor() const noexcept
        {
            return pickcolor;
        }
        void CGUIColorPicker::setBackgroundColor(const video::SColor &b) noexcept
        {
            background = b;
        }
        const video::SColor& CGUIColorPicker::getBackgroundColor() const noexcept
        {
            return background;
        }
        void CGUIColorPicker::updateAbsolutePosition()
        {
            IGUIElement::updateAbsolutePosition();

            box.UpperLeftCorner = AbsoluteRect.UpperLeftCorner;
            box.LowerRightCorner = AbsoluteRect.UpperLeftCorner;
            box.UpperLeftCorner.X += 5;
            box.UpperLeftCorner.Y += 5;
            box.LowerRightCorner.X += 85;
            box.LowerRightCorner.Y += 85;

            gradient.UpperLeftCorner = AbsoluteRect.UpperLeftCorner;
            gradient.LowerRightCorner = AbsoluteRect.UpperLeftCorner;
            gradient.UpperLeftCorner.X += 90;
            gradient.UpperLeftCorner.Y += 5;
            gradient.LowerRightCorner.X += 105;
            gradient.LowerRightCorner.Y += 155;

            pickbox.UpperLeftCorner = AbsoluteRect.UpperLeftCorner;
            pickbox.LowerRightCorner = AbsoluteRect.UpperLeftCorner;
            pickbox.UpperLeftCorner.X += 5;
            pickbox.UpperLeftCorner.Y += 90;
            pickbox.LowerRightCorner.X += 85;
            pickbox.LowerRightCorner.Y += 120;
        }
        void CGUIColorPicker::draw()
        {
            Environment->getSkin()->draw3DSunkenPane(
                this, background,
                false, true,
                AbsoluteRect,
                &AbsoluteClippingRect
            );

            IGUIElement::draw();

            Environment->getVideoDriver()->draw2DImage(img[1], {
                AbsoluteRect.UpperLeftCorner.X+90,
                AbsoluteRect.UpperLeftCorner.Y+5
            });

            // 2 draw because the interpolation in the diagonal is not well rendered
            Environment->getVideoDriver()->draw2DRectangle(black, box, &AbsoluteClippingRect);
            Environment->getVideoDriver()->draw2DRectangle(box, white, color, alpha, alpha, &AbsoluteClippingRect);

            {
                const core::vector2di start =  {AbsoluteRect.UpperLeftCorner.X+90,  AbsoluteRect.UpperLeftCorner.Y+5+colorpos};
                const core::vector2di end =    {AbsoluteRect.UpperLeftCorner.X+105,  AbsoluteRect.UpperLeftCorner.Y+5+colorpos};
                const core::vector2di hstart = {box.UpperLeftCorner.X,  box.UpperLeftCorner.Y+pickpos.Y};
                const core::vector2di hend =   {box.LowerRightCorner.X, box.UpperLeftCorner.Y+pickpos.Y};
                const core::vector2di vstart = {box.UpperLeftCorner.X+pickpos.X, box.UpperLeftCorner.Y};
                const core::vector2di vend =   {box.UpperLeftCorner.X+pickpos.X, box.LowerRightCorner.Y};

                Environment->getVideoDriver()->draw2DLine({ start.X,    start.Y-1}, { end.X,    end.Y-1}, white);
                Environment->getVideoDriver()->draw2DLine({ start.X,    start.Y+1}, { end.X,    end.Y+1}, white);
                Environment->getVideoDriver()->draw2DLine({hstart.X,   hstart.Y-1}, {hend.X,   hend.Y-1}, white);
                Environment->getVideoDriver()->draw2DLine({hstart.X,   hstart.Y+1}, {hend.X,   hend.Y+1}, white);
                Environment->getVideoDriver()->draw2DLine({vstart.X-1,   vstart.Y}, {vend.X-1, vend.Y  }, white);
                Environment->getVideoDriver()->draw2DLine({vstart.X+1,   vstart.Y}, {vend.X+1, vend.Y  }, white);

                Environment->getVideoDriver()->draw2DLine(start,   end, black);
                Environment->getVideoDriver()->draw2DLine(hstart, hend, black);
                Environment->getVideoDriver()->draw2DLine(vstart, vend, black);
            }

            Environment->getVideoDriver()->draw2DImage(img[0], pickbox, pickbox);
            Environment->getVideoDriver()->draw2DRectangle(
                pickcolor, pickbox,
                &AbsoluteClippingRect
            );
        }
    }
}