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

   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.

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

#include "../../Application/jucer_Headers.h"
#include "jucer_EditingPanelBase.h"
#include "jucer_JucerDocumentEditor.h"

//==============================================================================
class EditingPanelBase::MagnifierComponent  : public Component
{
public:
    explicit MagnifierComponent (Component* c) : content (c)
    {
        addAndMakeVisible (content.get());
        childBoundsChanged (content.get());
    }

    void childBoundsChanged (Component* child)
    {
        auto childArea = getLocalArea (child, child->getLocalBounds());
        setSize (childArea.getWidth(), childArea.getHeight());
    }

    double getScaleFactor() const   { return scaleFactor; }

    void setScaleFactor (double newScale)
    {
        scaleFactor = newScale;
        content->setTransform (AffineTransform::scale ((float) scaleFactor));
    }

private:
    double scaleFactor = 1.0;
    std::unique_ptr<Component> content;
};

//==============================================================================
class ZoomingViewport   : public Viewport
{
public:
    explicit ZoomingViewport (EditingPanelBase* p) : panel (p)
    {
    }

    void mouseWheelMove (const MouseEvent& e, const MouseWheelDetails& wheel)
    {
        if (e.mods.isCtrlDown() || e.mods.isAltDown() || e.mods.isCommandDown())
            mouseMagnify (e, 1.0f / (1.0f - wheel.deltaY));
        else
            Viewport::mouseWheelMove (e, wheel);
    }

    void mouseMagnify (const MouseEvent& e, float factor)
    {
        panel->setZoom (panel->getZoom() * factor, e.x, e.y);
    }

    void dragKeyHeldDown (const bool isKeyDown)
    {
        if (isSpaceDown != isKeyDown)
        {
            isSpaceDown = isKeyDown;

            if (isSpaceDown)
            {
                auto dc = new DraggerOverlayComp();
                addAndMakeVisible (dc);
                dc->setBounds (getLocalBounds());
            }
            else
            {
                for (int i = getNumChildComponents(); --i >= 0;)
                    std::unique_ptr<DraggerOverlayComp> deleter (dynamic_cast<DraggerOverlayComp*> (getChildComponent (i)));
            }
        }
    }

private:
    EditingPanelBase* const panel;
    bool isSpaceDown = false;

    //==============================================================================
    class DraggerOverlayComp    : public Component
    {
    public:
        DraggerOverlayComp()
        {
            setMouseCursor (MouseCursor::DraggingHandCursor);
            setAlwaysOnTop (true);
        }

        void mouseDown (const MouseEvent&)
        {
            if (Viewport* viewport = findParentComponentOfClass<Viewport>())
            {
                startX = viewport->getViewPositionX();
                startY = viewport->getViewPositionY();
            }
        }

        void mouseDrag (const MouseEvent& e)
        {
            if (Viewport* viewport = findParentComponentOfClass<Viewport>())
                viewport->setViewPosition (jlimit (0, jmax (0, viewport->getViewedComponent()->getWidth() - viewport->getViewWidth()),
                                                   startX - e.getDistanceFromDragStartX()),
                                           jlimit (0, jmax (0, viewport->getViewedComponent()->getHeight() - viewport->getViewHeight()),
                                                   startY - e.getDistanceFromDragStartY()));
        }

    private:
        int startX, startY;
    };
};


//==============================================================================
EditingPanelBase::EditingPanelBase (JucerDocument& doc, Component* props, Component* editorComp)
    : document (doc),
      editor (editorComp),
      propsPanel (props)
{
    addAndMakeVisible (viewport = new ZoomingViewport (this));
    addAndMakeVisible (propsPanel);

    viewport->setViewedComponent (magnifier = new MagnifierComponent (editor));
}

EditingPanelBase::~EditingPanelBase()
{
    deleteAllChildren();
}

void EditingPanelBase::resized()
{
    const int contentW = jmax (1, getWidth() - 260);

    propsPanel->setBounds (contentW + 4, 4, jmax (100, getWidth() - contentW - 8), getHeight() - 8);

    viewport->setBounds (4, 4, contentW - 8, getHeight() - 8);

    if (document.isFixedSize())
        editor->setSize (jmax (document.getInitialWidth(),
                               roundToInt ((viewport->getWidth() - viewport->getScrollBarThickness()) / getZoom())),
                         jmax (document.getInitialHeight(),
                               roundToInt ((viewport->getHeight() - viewport->getScrollBarThickness()) / getZoom())));
    else
        editor->setSize (viewport->getWidth(),
                         viewport->getHeight());
}

void EditingPanelBase::paint (Graphics& g)
{
    g.fillAll (findColour (secondaryBackgroundColourId));
}

void EditingPanelBase::visibilityChanged()
{
    if (isVisible())
    {
        updatePropertiesList();

        if (Component* p = getParentComponent())
        {
            resized();

            if (JucerDocumentEditor* const cdh = dynamic_cast<JucerDocumentEditor*> (p->getParentComponent()))
                cdh->setViewportToLastPos (viewport, *this);

            resized();
        }
    }
    else
    {
        if (Component* p = getParentComponent())
            if (JucerDocumentEditor* const cdh = dynamic_cast<JucerDocumentEditor*> (p->getParentComponent()))
                cdh->storeLastViewportPos (viewport, *this);
    }

    editor->setVisible (isVisible());
}

double EditingPanelBase::getZoom() const
{
    return magnifier->getScaleFactor();
}

void EditingPanelBase::setZoom (double newScale)
{
    setZoom (jlimit (1.0 / 8.0, 16.0, newScale),
             viewport->getWidth() / 2,
             viewport->getHeight() / 2);
}

void EditingPanelBase::setZoom (double newScale, int anchorX, int anchorY)
{
    Point<int> anchor (editor->getLocalPoint (viewport, Point<int> (anchorX, anchorY)));

    magnifier->setScaleFactor (newScale);

    resized();

    jassert (viewport != nullptr);
    anchor = viewport->getLocalPoint (editor, anchor);

    viewport->setViewPosition (jlimit (0, jmax (0, viewport->getViewedComponent()->getWidth() - viewport->getViewWidth()),
                                       viewport->getViewPositionX() + anchor.getX() - anchorX),
                               jlimit (0, jmax (0, viewport->getViewedComponent()->getHeight() - viewport->getViewHeight()),
                                       viewport->getViewPositionY() + anchor.getY() - anchorY));
}

void EditingPanelBase::xyToTargetXY (int& x, int& y) const
{
    Point<int> pos (editor->getLocalPoint (this, Point<int> (x, y)));
    x = pos.getX();
    y = pos.getY();
}

void EditingPanelBase::dragKeyHeldDown (bool isKeyDown)
{
    ((ZoomingViewport*) viewport)->dragKeyHeldDown (isKeyDown);
}