/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

struct ColourComponentSlider  : public Slider
{
    ColourComponentSlider (const String& name)  : Slider (name)
    {
        setRange (0.0, 255.0, 1.0);
    }

    String getTextFromValue (double value) override
    {
        return String::toHexString ((int) value).toUpperCase().paddedLeft ('0', 2);
    }

    double getValueFromText (const String& text) override
    {
        return (double) text.getHexValue32();
    }
};

//==============================================================================
class ColourSelector::ColourSpaceView  : public Component
{
public:
    ColourSpaceView (ColourSelector& cs, float& hue, float& sat, float& val, int edgeSize)
        : owner (cs), h (hue), s (sat), v (val), edge (edgeSize)
    {
        addAndMakeVisible (marker);
        setMouseCursor (MouseCursor::CrosshairCursor);
    }

    void paint (Graphics& g) override
    {
        if (colours.isNull())
        {
            auto width = getWidth() / 2;
            auto height = getHeight() / 2;
            colours = Image (Image::RGB, width, height, false);

            Image::BitmapData pixels (colours, Image::BitmapData::writeOnly);

            for (int y = 0; y < height; ++y)
            {
                auto val = 1.0f - y / (float) height;

                for (int x = 0; x < width; ++x)
                {
                    auto sat = x / (float) width;
                    pixels.setPixelColour (x, y, Colour (h, sat, val, 1.0f));
                }
            }
        }

        g.setOpacity (1.0f);
        g.drawImageTransformed (colours,
                                RectanglePlacement (RectanglePlacement::stretchToFit)
                                    .getTransformToFit (colours.getBounds().toFloat(),
                                                        getLocalBounds().reduced (edge).toFloat()),
                                false);
    }

    void mouseDown (const MouseEvent& e) override
    {
        mouseDrag (e);
    }

    void mouseDrag (const MouseEvent& e) override
    {
        auto sat =        (e.x - edge) / (float) (getWidth()  - edge * 2);
        auto val = 1.0f - (e.y - edge) / (float) (getHeight() - edge * 2);

        owner.setSV (sat, val);
    }

    void updateIfNeeded()
    {
        if (lastHue != h)
        {
            lastHue = h;
            colours = {};
            repaint();
        }

        updateMarker();
    }

    void resized() override
    {
        colours = {};
        updateMarker();
    }

private:
    ColourSelector& owner;
    float& h;
    float& s;
    float& v;
    float lastHue = 0;
    const int edge;
    Image colours;

    struct ColourSpaceMarker  : public Component
    {
        ColourSpaceMarker()
        {
            setInterceptsMouseClicks (false, false);
        }

        void paint (Graphics& g) override
        {
            g.setColour (Colour::greyLevel (0.1f));
            g.drawEllipse (1.0f, 1.0f, getWidth() - 2.0f, getHeight() - 2.0f, 1.0f);
            g.setColour (Colour::greyLevel (0.9f));
            g.drawEllipse (2.0f, 2.0f, getWidth() - 4.0f, getHeight() - 4.0f, 1.0f);
        }
    };

    ColourSpaceMarker marker;

    void updateMarker()
    {
        auto markerSize = jmax (14, edge * 2);
        auto area = getLocalBounds().reduced (edge);

        marker.setBounds (Rectangle<int> (markerSize, markerSize)
                            .withCentre (area.getRelativePoint (s, 1.0f - v)));
    }

    JUCE_DECLARE_NON_COPYABLE (ColourSpaceView)
};

//==============================================================================
class ColourSelector::HueSelectorComp  : public Component
{
public:
    HueSelectorComp (ColourSelector& cs, float& hue, int edgeSize)
        : owner (cs), h (hue), edge (edgeSize)
    {
        addAndMakeVisible (marker);
    }

    void paint (Graphics& g) override
    {
        ColourGradient cg;
        cg.isRadial = false;
        cg.point1.setXY (0.0f, (float) edge);
        cg.point2.setXY (0.0f, (float) getHeight());

        for (float i = 0.0f; i <= 1.0f; i += 0.02f)
            cg.addColour (i, Colour (i, 1.0f, 1.0f, 1.0f));

        g.setGradientFill (cg);
        g.fillRect (getLocalBounds().reduced (edge));
    }

    void resized() override
    {
        auto markerSize = jmax (14, edge * 2);
        auto area = getLocalBounds().reduced (edge);

        marker.setBounds (Rectangle<int> (getWidth(), markerSize)
                            .withCentre (area.getRelativePoint (0.5f, h)));
    }

    void mouseDown (const MouseEvent& e) override
    {
        mouseDrag (e);
    }

    void mouseDrag (const MouseEvent& e) override
    {
        owner.setHue ((e.y - edge) / (float) (getHeight() - edge * 2));
    }

    void updateIfNeeded()
    {
        resized();
    }

private:
    ColourSelector& owner;
    float& h;
    const int edge;

    struct HueSelectorMarker  : public Component
    {
        HueSelectorMarker()
        {
            setInterceptsMouseClicks (false, false);
        }

        void paint (Graphics& g) override
        {
            auto cw = (float) getWidth();
            auto ch = (float) getHeight();

            Path p;
            p.addTriangle (1.0f, 1.0f,
                           cw * 0.3f, ch * 0.5f,
                           1.0f, ch - 1.0f);

            p.addTriangle (cw - 1.0f, 1.0f,
                           cw * 0.7f, ch * 0.5f,
                           cw - 1.0f, ch - 1.0f);

            g.setColour (Colours::white.withAlpha (0.75f));
            g.fillPath (p);

            g.setColour (Colours::black.withAlpha (0.75f));
            g.strokePath (p, PathStrokeType (1.2f));
        }
    };

    HueSelectorMarker marker;

    JUCE_DECLARE_NON_COPYABLE (HueSelectorComp)
};

//==============================================================================
class ColourSelector::SwatchComponent   : public Component
{
public:
    SwatchComponent (ColourSelector& cs, int itemIndex)
        : owner (cs), index (itemIndex)
    {
    }

    void paint (Graphics& g) override
    {
        auto col = owner.getSwatchColour (index);

        g.fillCheckerBoard (getLocalBounds().toFloat(), 6.0f, 6.0f,
                            Colour (0xffdddddd).overlaidWith (col),
                            Colour (0xffffffff).overlaidWith (col));
    }

    void mouseDown (const MouseEvent&) override
    {
        PopupMenu m;
        m.addItem (1, TRANS("Use this swatch as the current colour"));
        m.addSeparator();
        m.addItem (2, TRANS("Set this swatch to the current colour"));

        m.showMenuAsync (PopupMenu::Options().withTargetComponent (this),
                         ModalCallbackFunction::forComponent (menuStaticCallback, this));
    }

private:
    ColourSelector& owner;
    const int index;

    static void menuStaticCallback (int result, SwatchComponent* comp)
    {
        if (comp != nullptr)
        {
            if (result == 1)  comp->setColourFromSwatch();
            if (result == 2)  comp->setSwatchFromColour();
        }
    }

    void setColourFromSwatch()
    {
        owner.setCurrentColour (owner.getSwatchColour (index));
    }

    void setSwatchFromColour()
    {
        if (owner.getSwatchColour (index) != owner.getCurrentColour())
        {
            owner.setSwatchColour (index, owner.getCurrentColour());
            repaint();
        }
    }

    JUCE_DECLARE_NON_COPYABLE (SwatchComponent)
};

//==============================================================================
class ColourSelector::ColourPreviewComp  : public Component
{
public:
    ColourPreviewComp (ColourSelector& cs, bool isEditable)
        : owner (cs)
    {
        colourLabel.setFont (labelFont);
        colourLabel.setJustificationType (Justification::centred);

        if (isEditable)
        {
            colourLabel.setEditable (true);

            colourLabel.onEditorShow = [this]
            {
                if (auto* ed = colourLabel.getCurrentTextEditor())
                    ed->setInputRestrictions ((owner.flags & showAlphaChannel) ? 8 : 6, "1234567890ABCDEFabcdef");
            };

            colourLabel.onEditorHide = [this]
            {
                updateColourIfNecessary (colourLabel.getText());
            };
        }

        addAndMakeVisible (colourLabel);
    }

    void updateIfNeeded()
    {
        auto newColour = owner.getCurrentColour();

        if (currentColour != newColour)
        {
            currentColour = newColour;
            auto textColour = (Colours::white.overlaidWith (currentColour).contrasting());

            colourLabel.setColour (Label::textColourId,            textColour);
            colourLabel.setColour (Label::textWhenEditingColourId, textColour);
            colourLabel.setText (currentColour.toDisplayString ((owner.flags & showAlphaChannel) != 0), dontSendNotification);

            labelWidth = labelFont.getStringWidth (colourLabel.getText());

            repaint();
        }
    }

    void paint (Graphics& g) override
    {
        g.fillCheckerBoard (getLocalBounds().toFloat(), 10.0f, 10.0f,
                            Colour (0xffdddddd).overlaidWith (currentColour),
                            Colour (0xffffffff).overlaidWith (currentColour));
    }

    void resized() override
    {
        colourLabel.centreWithSize (labelWidth + 10, (int) labelFont.getHeight() + 10);
    }

private:
    void updateColourIfNecessary (const String& newColourString)
    {
        auto newColour = Colour::fromString (newColourString);

        if (newColour != currentColour)
            owner.setCurrentColour (newColour);
    }

    ColourSelector& owner;

    Colour currentColour;
    Font labelFont { 14.0f, Font::bold };
    int labelWidth = 0;
    Label colourLabel;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ColourPreviewComp)
};

//==============================================================================
ColourSelector::ColourSelector (int sectionsToShow, int edge, int gapAroundColourSpaceComponent)
    : colour (Colours::white),
      flags (sectionsToShow),
      edgeGap (edge)
{
    // not much point having a selector with no components in it!
    jassert ((flags & (showColourAtTop | showSliders | showColourspace)) != 0);

    updateHSV();

    if ((flags & showColourAtTop) != 0)
    {
        previewComponent.reset (new ColourPreviewComp (*this, (flags & editableColour) != 0));
        addAndMakeVisible (previewComponent.get());
    }

    if ((flags & showSliders) != 0)
    {
        sliders[0].reset (new ColourComponentSlider (TRANS ("red")));
        sliders[1].reset (new ColourComponentSlider (TRANS ("green")));
        sliders[2].reset (new ColourComponentSlider (TRANS ("blue")));
        sliders[3].reset (new ColourComponentSlider (TRANS ("alpha")));

        addAndMakeVisible (sliders[0].get());
        addAndMakeVisible (sliders[1].get());
        addAndMakeVisible (sliders[2].get());
        addChildComponent (sliders[3].get());

        sliders[3]->setVisible ((flags & showAlphaChannel) != 0);

        // VS2015 needs some scoping braces around this if statement to
        // avoid a compiler bug.
        for (auto& slider : sliders)
        {
            slider->onValueChange = [this] { changeColour(); };
        }
    }

    if ((flags & showColourspace) != 0)
    {
        colourSpace.reset (new ColourSpaceView (*this, h, s, v, gapAroundColourSpaceComponent));
        hueSelector.reset (new HueSelectorComp (*this, h, gapAroundColourSpaceComponent));

        addAndMakeVisible (colourSpace.get());
        addAndMakeVisible (hueSelector.get());
    }

    update (dontSendNotification);
}

ColourSelector::~ColourSelector()
{
    dispatchPendingMessages();
    swatchComponents.clear();
}

//==============================================================================
Colour ColourSelector::getCurrentColour() const
{
    return ((flags & showAlphaChannel) != 0) ? colour : colour.withAlpha ((uint8) 0xff);
}

void ColourSelector::setCurrentColour (Colour c, NotificationType notification)
{
    if (c != colour)
    {
        colour = ((flags & showAlphaChannel) != 0) ? c : c.withAlpha ((uint8) 0xff);

        updateHSV();
        update (notification);
    }
}

void ColourSelector::setHue (float newH)
{
    newH = jlimit (0.0f, 1.0f, newH);

    if (h != newH)
    {
        h = newH;
        colour = Colour (h, s, v, colour.getFloatAlpha());
        update (sendNotification);
    }
}

void ColourSelector::setSV (float newS, float newV)
{
    newS = jlimit (0.0f, 1.0f, newS);
    newV = jlimit (0.0f, 1.0f, newV);

    if (s != newS || v != newV)
    {
        s = newS;
        v = newV;
        colour = Colour (h, s, v, colour.getFloatAlpha());
        update (sendNotification);
    }
}

//==============================================================================
void ColourSelector::updateHSV()
{
    colour.getHSB (h, s, v);
}

void ColourSelector::update (NotificationType notification)
{
    if (sliders[0] != nullptr)
    {
        sliders[0]->setValue ((int) colour.getRed(),   notification);
        sliders[1]->setValue ((int) colour.getGreen(), notification);
        sliders[2]->setValue ((int) colour.getBlue(),  notification);
        sliders[3]->setValue ((int) colour.getAlpha(), notification);
    }

    if (colourSpace != nullptr)
    {
        colourSpace->updateIfNeeded();
        hueSelector->updateIfNeeded();
    }

    if (previewComponent != nullptr)
        previewComponent->updateIfNeeded();

    if (notification != dontSendNotification)
        sendChangeMessage();

    if (notification == sendNotificationSync)
        dispatchPendingMessages();
}

//==============================================================================
void ColourSelector::paint (Graphics& g)
{
    g.fillAll (findColour (backgroundColourId));

    if ((flags & showSliders) != 0)
    {
        g.setColour (findColour (labelTextColourId));
        g.setFont (11.0f);

        for (auto& slider : sliders)
        {
            if (slider->isVisible())
                g.drawText (slider->getName() + ":",
                            0, slider->getY(),
                            slider->getX() - 8, slider->getHeight(),
                            Justification::centredRight, false);
        }
    }
}

void ColourSelector::resized()
{
    const int swatchesPerRow = 8;
    const int swatchHeight = 22;

    const int numSliders = ((flags & showAlphaChannel) != 0) ? 4 : 3;
    const int numSwatches = getNumSwatches();

    const int swatchSpace = numSwatches > 0 ? edgeGap + swatchHeight * ((numSwatches + 7) / swatchesPerRow) : 0;
    const int sliderSpace = ((flags & showSliders) != 0)  ? jmin (22 * numSliders + edgeGap, proportionOfHeight (0.3f)) : 0;
    const int topSpace = ((flags & showColourAtTop) != 0) ? jmin (30 + edgeGap * 2, proportionOfHeight (0.2f)) : edgeGap;

    if (previewComponent != nullptr)
        previewComponent->setBounds (edgeGap, edgeGap, getWidth() - edgeGap * 2, topSpace - edgeGap * 2);

    int y = topSpace;

    if ((flags & showColourspace) != 0)
    {
        const int hueWidth = jmin (50, proportionOfWidth (0.15f));

        colourSpace->setBounds (edgeGap, y,
                                getWidth() - hueWidth - edgeGap - 4,
                                getHeight() - topSpace - sliderSpace - swatchSpace - edgeGap);

        hueSelector->setBounds (colourSpace->getRight() + 4, y,
                                getWidth() - edgeGap - (colourSpace->getRight() + 4),
                                colourSpace->getHeight());

        y = getHeight() - sliderSpace - swatchSpace - edgeGap;
    }

    if ((flags & showSliders) != 0)
    {
        auto sliderHeight = jmax (4, sliderSpace / numSliders);

        for (int i = 0; i < numSliders; ++i)
        {
            sliders[i]->setBounds (proportionOfWidth (0.2f), y,
                                   proportionOfWidth (0.72f), sliderHeight - 2);

            y += sliderHeight;
        }
    }

    if (numSwatches > 0)
    {
        const int startX = 8;
        const int xGap = 4;
        const int yGap = 4;
        const int swatchWidth = (getWidth() - startX * 2) / swatchesPerRow;
        y += edgeGap;

        if (swatchComponents.size() != numSwatches)
        {
            swatchComponents.clear();

            for (int i = 0; i < numSwatches; ++i)
            {
                auto* sc = new SwatchComponent (*this, i);
                swatchComponents.add (sc);
                addAndMakeVisible (sc);
            }
        }

        int x = startX;

        for (int i = 0; i < swatchComponents.size(); ++i)
        {
            auto* sc = swatchComponents.getUnchecked(i);

            sc->setBounds (x + xGap / 2,
                           y + yGap / 2,
                           swatchWidth - xGap,
                           swatchHeight - yGap);

            if (((i + 1) % swatchesPerRow) == 0)
            {
                x = startX;
                y += swatchHeight;
            }
            else
            {
                x += swatchWidth;
            }
        }
    }
}

void ColourSelector::changeColour()
{
    if (sliders[0] != nullptr)
        setCurrentColour (Colour ((uint8) sliders[0]->getValue(),
                                  (uint8) sliders[1]->getValue(),
                                  (uint8) sliders[2]->getValue(),
                                  (uint8) sliders[3]->getValue()));
}

//==============================================================================
int ColourSelector::getNumSwatches() const
{
    return 0;
}

Colour ColourSelector::getSwatchColour (int) const
{
    jassertfalse; // if you've overridden getNumSwatches(), you also need to implement this method
    return Colours::black;
}

void ColourSelector::setSwatchColour (int, const Colour&)
{
    jassertfalse; // if you've overridden getNumSwatches(), you also need to implement this method
}

} // namespace juce