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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   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
{

//==============================================================================
static int numAlwaysOnTopPeers = 0;
bool juce_areThereAnyAlwaysOnTopWindows()  { return numAlwaysOnTopPeers > 0; }

//==============================================================================
template<typename WindowHandleType>
class LinuxComponentPeer  : public ComponentPeer
{
public:
    LinuxComponentPeer (Component& comp, int windowStyleFlags, WindowHandleType parentToAddTo)
        : ComponentPeer (comp, windowStyleFlags),
          isAlwaysOnTop (comp.isAlwaysOnTop())
    {
        // it's dangerous to create a window on a thread other than the message thread..
        JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED

        if (isAlwaysOnTop)
            ++numAlwaysOnTopPeers;

        repainter = std::make_unique<LinuxRepaintManager> (*this);

        windowH = XWindowSystem::getInstance()->createWindow (parentToAddTo, this);
        parentWindow = parentToAddTo;

        setTitle (component.getName());

        getNativeRealtimeModifiers = []() -> ModifierKeys { return XWindowSystem::getInstance()->getNativeRealtimeModifiers(); };
    }

    ~LinuxComponentPeer() override
    {
        // it's dangerous to delete a window on a thread other than the message thread..
        JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED

        repainter = nullptr;
        XWindowSystem::getInstance()->destroyWindow (windowH);

        if (isAlwaysOnTop)
            --numAlwaysOnTopPeers;
    }

    //==============================================================================
    void* getNativeHandle() const override
    {
        return (void*) windowH;
    }

    //==============================================================================
    void setBounds (const Rectangle<int>& newBounds, bool isNowFullScreen) override
    {
        bounds = newBounds.withSize (jmax (1, newBounds.getWidth()),
                                     jmax (1, newBounds.getHeight()));

        updateScaleFactorFromNewBounds (bounds, false);

        auto physicalBounds = (parentWindow == 0 ? Desktop::getInstance().getDisplays().logicalToPhysical (bounds)
                               : bounds * currentScaleFactor);

        WeakReference<Component> deletionChecker (&component);

        XWindowSystem::getInstance()->setBounds (windowH, physicalBounds, isNowFullScreen);

        fullScreen = isNowFullScreen;

        if (deletionChecker != nullptr)
        {
            updateBorderSize();
            handleMovedOrResized();
        }
    }

    Point<int> getScreenPosition (bool physical) const
    {
        auto parentPosition = XWindowSystem::getInstance()->getParentScreenPosition();

        auto screenBounds = (parentWindow == 0 ? bounds
                                               : bounds.translated (parentPosition.x, parentPosition.y));

        if (physical)
            return Desktop::getInstance().getDisplays().logicalToPhysical (screenBounds.getTopLeft());

        return screenBounds.getTopLeft();
    }

    Rectangle<int> getBounds() const override
    {
        return bounds;
    }

    BorderSize<int> getFrameSize() const override
    {
        return windowBorder;
    }

    using ComponentPeer::localToGlobal;
    Point<float> localToGlobal (Point<float> relativePosition) override
    {
        return relativePosition + getScreenPosition (false).toFloat();
    }

    using ComponentPeer::globalToLocal;
    Point<float> globalToLocal (Point<float> screenPosition) override
    {
        return screenPosition   - getScreenPosition (false).toFloat();
    }

    //==============================================================================
    StringArray getAvailableRenderingEngines() override
    {
        return { "Software Renderer" };
    }

    void setVisible (bool shouldBeVisible) override
    {
        XWindowSystem::getInstance()->setVisible (windowH, shouldBeVisible);
    }

    void setTitle (const String& title) override
    {
        XWindowSystem::getInstance()->setTitle (windowH, title);
    }

    void setMinimised (bool shouldBeMinimised) override
    {
        if (shouldBeMinimised)
            XWindowSystem::getInstance()->setMinimised (windowH, shouldBeMinimised);
        else
            setVisible (true);
    }

    bool isMinimised() const override
    {
        return XWindowSystem::getInstance()->isMinimised (windowH);
    }

    void setFullScreen (bool shouldBeFullScreen) override
    {
        auto r = lastNonFullscreenBounds; // (get a copy of this before de-minimising)

        setMinimised (false);

        if (fullScreen != shouldBeFullScreen)
        {
            if (shouldBeFullScreen)
                r = Desktop::getInstance().getDisplays().getMainDisplay().userArea;

            if (! r.isEmpty())
                setBounds (ScalingHelpers::scaledScreenPosToUnscaled (component, r), shouldBeFullScreen);

            component.repaint();
        }
    }

    bool isFullScreen() const override
    {
        return fullScreen;
    }

    bool contains (Point<int> localPos, bool trueIfInAChildWindow) const override
    {
        if (! bounds.withZeroOrigin().contains (localPos))
            return false;

        for (int i = Desktop::getInstance().getNumComponents(); --i >= 0;)
        {
            auto* c = Desktop::getInstance().getComponent (i);

            if (c == &component)
                break;

            if (! c->isVisible())
                continue;

            if (auto* peer = c->getPeer())
                if (peer->contains (localPos + bounds.getPosition() - peer->getBounds().getPosition(), true))
                    return false;
        }

        if (trueIfInAChildWindow)
            return true;

        return XWindowSystem::getInstance()->contains (windowH, localPos * currentScaleFactor);
    }

    void toFront (bool makeActive) override
    {
        if (makeActive)
        {
            setVisible (true);
            grabFocus();
        }

        XWindowSystem::getInstance()->toFront (windowH, makeActive);
        handleBroughtToFront();
    }

    void toBehind (ComponentPeer* other) override
    {
        if (auto* otherPeer = dynamic_cast<LinuxComponentPeer*> (other))
        {
            if (otherPeer->styleFlags & windowIsTemporary)
                return;

            setMinimised (false);
            XWindowSystem::getInstance()->toBehind (windowH, otherPeer->windowH);
        }
        else
        {
            jassertfalse; // wrong type of window?
        }
    }

    bool isFocused() const override
    {
        return XWindowSystem::getInstance()->isFocused (windowH);
    }

    void grabFocus() override
    {
        if (XWindowSystem::getInstance()->grabFocus (windowH))
            isActiveApplication = true;
    }

    //==============================================================================
    void repaint (const Rectangle<int>& area) override
    {
        repainter->repaint (area.getIntersection (bounds.withZeroOrigin()));
    }

    void performAnyPendingRepaintsNow() override
    {
        repainter->performAnyPendingRepaintsNow();
    }

    void setIcon (const Image& newIcon) override
    {
        XWindowSystem::getInstance()->setIcon (windowH, newIcon);
    }

    double getPlatformScaleFactor() const noexcept override
    {
        return currentScaleFactor;
    }

    void setAlpha (float) override                                  {}
    bool setAlwaysOnTop (bool) override                             { return false; }
    void textInputRequired (Point<int>, TextInputTarget&) override  {}

    //==============================================================================
    void addOpenGLRepaintListener (Component* dummy)
    {
        if (dummy != nullptr)
            glRepaintListeners.addIfNotAlreadyThere (dummy);
    }

    void removeOpenGLRepaintListener (Component* dummy)
    {
        if (dummy != nullptr)
            glRepaintListeners.removeAllInstancesOf (dummy);
    }

    void repaintOpenGLContexts()
    {
        for (auto* c : glRepaintListeners)
            c->handleCommandMessage (0);
    }

    //==============================================================================
    WindowHandleType getParentWindow()                 { return parentWindow; }
    void setParentWindow (WindowHandleType newParent)  { parentWindow = newParent; }

    //==============================================================================
    void updateWindowBounds()
    {
        jassert (windowH != 0);
        if (windowH != 0)
        {
            auto physicalBounds = XWindowSystem::getInstance()->getWindowBounds (windowH, parentWindow);

            updateScaleFactorFromNewBounds (physicalBounds, true);

            bounds = (parentWindow == 0 ? Desktop::getInstance().getDisplays().physicalToLogical (physicalBounds)
                                        : physicalBounds / currentScaleFactor);
        }
    }

    void updateBorderSize()
    {
        if ((styleFlags & windowHasTitleBar) == 0)
            windowBorder = {};
        else if (windowBorder.getTopAndBottom() == 0 && windowBorder.getLeftAndRight() == 0)
            windowBorder = XWindowSystem::getInstance()->getBorderSize (windowH);
    }

    //==============================================================================
    static bool isActiveApplication;
    bool focused = false;

private:
    //==============================================================================
    class LinuxRepaintManager   : public Timer
    {
    public:
        LinuxRepaintManager (LinuxComponentPeer& p)  : peer (p)  {}

        void timerCallback() override
        {
            if (XWindowSystem::getInstance()->getNumPaintsPending (peer.windowH) > 0)
                return;

            if (! regionsNeedingRepaint.isEmpty())
            {
                stopTimer();
                performAnyPendingRepaintsNow();
            }
            else if (Time::getApproximateMillisecondCounter() > lastTimeImageUsed + 3000)
            {
                stopTimer();
                image = Image();
            }
        }

        void repaint (Rectangle<int> area)
        {
            if (! isTimerRunning())
                startTimer (repaintTimerPeriod);

            regionsNeedingRepaint.add (area * peer.currentScaleFactor);
        }

        void performAnyPendingRepaintsNow()
        {
            if (XWindowSystem::getInstance()->getNumPaintsPending (peer.windowH) > 0)
            {
                startTimer (repaintTimerPeriod);
                return;
            }

            auto originalRepaintRegion = regionsNeedingRepaint;
            regionsNeedingRepaint.clear();
            auto totalArea = originalRepaintRegion.getBounds();

            if (! totalArea.isEmpty())
            {
                if (image.isNull() || image.getWidth() < totalArea.getWidth()
                     || image.getHeight() < totalArea.getHeight())
                {
                    image = XWindowSystem::getInstance()->createImage (totalArea.getWidth(), totalArea.getHeight(),
                                                                       useARGBImagesForRendering);
                }

                startTimer (repaintTimerPeriod);

                RectangleList<int> adjustedList (originalRepaintRegion);
                adjustedList.offsetAll (-totalArea.getX(), -totalArea.getY());

                if (XWindowSystem::getInstance()->canUseARGBImages())
                    for (auto& i : originalRepaintRegion)
                        image.clear (i - totalArea.getPosition());

                {
                    auto context = peer.getComponent().getLookAndFeel()
                                     .createGraphicsContext (image, -totalArea.getPosition(), adjustedList);

                    context->addTransform (AffineTransform::scale ((float) peer.currentScaleFactor));
                    peer.handlePaint (*context);
                }

                for (auto& i : originalRepaintRegion)
                   XWindowSystem::getInstance()->blitToWindow (peer.windowH, image, i, totalArea);
            }

            lastTimeImageUsed = Time::getApproximateMillisecondCounter();
            startTimer (repaintTimerPeriod);
        }

    private:
        enum { repaintTimerPeriod = 1000 / 100 };

        LinuxComponentPeer& peer;
        Image image;
        uint32 lastTimeImageUsed = 0;
        RectangleList<int> regionsNeedingRepaint;

        bool useARGBImagesForRendering = XWindowSystem::getInstance()->canUseARGBImages();

        JUCE_DECLARE_NON_COPYABLE (LinuxRepaintManager)
    };

    //==============================================================================
    void updateScaleFactorFromNewBounds (const Rectangle<int>& newBounds, bool isPhysical)
    {
        Point<int> translation = (parentWindow != 0 ? getScreenPosition (isPhysical) : Point<int>());

        auto newScaleFactor = Desktop::getInstance().getDisplays().findDisplayForRect (newBounds.translated (translation.x, translation.y), isPhysical).scale
                                 / Desktop::getInstance().getGlobalScaleFactor();

        if (! approximatelyEqual (newScaleFactor, currentScaleFactor))
        {
            currentScaleFactor = newScaleFactor;
            scaleFactorListeners.call ([&] (ScaleFactorListener& l) { l.nativeScaleFactorChanged (currentScaleFactor); });
        }
    }

    //==============================================================================
    std::unique_ptr<LinuxRepaintManager> repainter;

    WindowHandleType windowH = {}, parentWindow = {}, keyProxy = {};
    Rectangle<int> bounds;
    BorderSize<int> windowBorder;
    bool fullScreen = false, isAlwaysOnTop = false;
    double currentScaleFactor = 1.0;
    Array<Component*> glRepaintListeners;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (LinuxComponentPeer)
};

template<typename WindowHandleType>
bool LinuxComponentPeer<WindowHandleType>::isActiveApplication = false;

//==============================================================================
ComponentPeer* Component::createNewPeer (int styleFlags, void* nativeWindowToAttachTo)
{
    return new LinuxComponentPeer<::Window> (*this, styleFlags, (::Window) nativeWindowToAttachTo);
}

//==============================================================================
JUCE_API bool JUCE_CALLTYPE Process::isForegroundProcess()    { return LinuxComponentPeer<::Window>::isActiveApplication; }

JUCE_API void JUCE_CALLTYPE Process::makeForegroundProcess()  {}
JUCE_API void JUCE_CALLTYPE Process::hide()                   {}

//==============================================================================
void Desktop::setKioskComponent (Component* comp, bool enableOrDisable, bool)
{
    if (enableOrDisable)
        comp->setBounds (getDisplays().findDisplayForRect (comp->getScreenBounds()).totalArea);
}

void Displays::findDisplays (float masterScale)
{
    displays = XWindowSystem::getInstance()->findDisplays (masterScale);

    if (! displays.isEmpty())
        updateToLogical();
}

bool Desktop::canUseSemiTransparentWindows() noexcept
{
    return XWindowSystem::getInstance()->canUseSemiTransparentWindows();
}

static bool screenSaverAllowed = true;

void Desktop::setScreenSaverEnabled (bool isEnabled)
{
    if (screenSaverAllowed != isEnabled)
    {
        screenSaverAllowed = isEnabled;
        XWindowSystem::getInstance()->setScreenSaverEnabled (screenSaverAllowed);
    }
}

bool Desktop::isScreenSaverEnabled()
{
    return screenSaverAllowed;
}

double Desktop::getDefaultMasterScale()                             { return 1.0; }

Desktop::DisplayOrientation Desktop::getCurrentOrientation() const  { return upright; }
void Desktop::allowedOrientationsChanged()                          {}

//==============================================================================
bool MouseInputSource::SourceList::addSource()
{
    if (sources.isEmpty())
    {
        addSource (0, MouseInputSource::InputSourceType::mouse);
        return true;
    }

    return false;
}

bool MouseInputSource::SourceList::canUseTouch()
{
    return false;
}

Point<float> MouseInputSource::getCurrentRawMousePosition()
{
    return Desktop::getInstance().getDisplays().physicalToLogical (XWindowSystem::getInstance()->getCurrentMousePosition());
}

void MouseInputSource::setRawMousePosition (Point<float> newPosition)
{
    XWindowSystem::getInstance()->setMousePosition (Desktop::getInstance().getDisplays().logicalToPhysical (newPosition));
}

//==============================================================================
void* CustomMouseCursorInfo::create() const
{
    return XWindowSystem::getInstance()->createCustomMouseCursorInfo (image, hotspot);
}

void MouseCursor::deleteMouseCursor (void* cursorHandle, bool)
{
    if (cursorHandle != nullptr)
        XWindowSystem::getInstance()->deleteMouseCursor (cursorHandle);
}

void* MouseCursor::createStandardMouseCursor (MouseCursor::StandardCursorType type)
{
    return XWindowSystem::getInstance()->createStandardMouseCursor (type);
}

void MouseCursor::showInWindow (ComponentPeer* peer) const
{
    if (peer != nullptr)
        XWindowSystem::getInstance()->showCursor ((::Window) peer->getNativeHandle(), getHandle());
}

//==============================================================================
template<typename WindowHandleType>
static LinuxComponentPeer<WindowHandleType>* getPeerForDragEvent (Component* sourceComp)
{
    if (sourceComp == nullptr)
        if (auto* draggingSource = Desktop::getInstance().getDraggingMouseSource (0))
            sourceComp = draggingSource->getComponentUnderMouse();

    if (sourceComp != nullptr)
        if (auto* lp = dynamic_cast<LinuxComponentPeer<::Window>*> (sourceComp->getPeer()))
            return lp;

    jassertfalse;  // This method must be called in response to a component's mouseDown or mouseDrag event!
    return nullptr;
}

bool DragAndDropContainer::performExternalDragDropOfFiles (const StringArray& files, bool canMoveFiles,
                                                           Component* sourceComp, std::function<void()> callback)
{
    if (files.isEmpty())
        return false;

    if (auto* peer = getPeerForDragEvent<::Window> (sourceComp))
        return XWindowSystem::getInstance()->externalDragFileInit (peer, files, canMoveFiles, std::move (callback));

    // This method must be called in response to a component's mouseDown or mouseDrag event!
    jassertfalse;
    return false;
}

bool DragAndDropContainer::performExternalDragDropOfText (const String& text, Component* sourceComp,
                                                          std::function<void()> callback)
{
    if (text.isEmpty())
        return false;

    if (auto* peer = getPeerForDragEvent<::Window> (sourceComp))
        return XWindowSystem::getInstance()->externalDragTextInit (peer, text, std::move (callback));

    // This method must be called in response to a component's mouseDown or mouseDrag event!
    jassertfalse;
    return false;
}

//==============================================================================
void SystemClipboard::copyTextToClipboard (const String& clipText)
{
    XWindowSystem::getInstance()->copyTextToClipboard (clipText);
}

String SystemClipboard::getTextFromClipboard()
{
    return XWindowSystem::getInstance()->getTextFromClipboard();
}

//==============================================================================
bool KeyPress::isKeyCurrentlyDown (int keyCode)
{
    return XWindowSystem::getInstance()->isKeyCurrentlyDown (keyCode);
}

void LookAndFeel::playAlertSound()
{
    std::cout << "\a" << std::flush;
}

//==============================================================================
#if JUCE_MODAL_LOOPS_PERMITTED
void JUCE_CALLTYPE NativeMessageBox::showMessageBox (AlertWindow::AlertIconType iconType,
                                                     const String& title, const String& message,
                                                     Component*)
{
    AlertWindow::showMessageBox (iconType, title, message);
}
#endif

void JUCE_CALLTYPE NativeMessageBox::showMessageBoxAsync (AlertWindow::AlertIconType iconType,
                                                          const String& title, const String& message,
                                                          Component* associatedComponent,
                                                          ModalComponentManager::Callback* callback)
{
    AlertWindow::showMessageBoxAsync (iconType, title, message, {}, associatedComponent, callback);
}

bool JUCE_CALLTYPE NativeMessageBox::showOkCancelBox (AlertWindow::AlertIconType iconType,
                                                      const String& title, const String& message,
                                                      Component* associatedComponent,
                                                      ModalComponentManager::Callback* callback)
{
    return AlertWindow::showOkCancelBox (iconType, title, message, {}, {}, associatedComponent, callback);
}

int JUCE_CALLTYPE NativeMessageBox::showYesNoCancelBox (AlertWindow::AlertIconType iconType,
                                                        const String& title, const String& message,
                                                        Component* associatedComponent,
                                                        ModalComponentManager::Callback* callback)
{
    return AlertWindow::showYesNoCancelBox (iconType, title, message, {}, {}, {},
                                            associatedComponent, callback);
}

int JUCE_CALLTYPE NativeMessageBox::showYesNoBox (AlertWindow::AlertIconType iconType,
                                                  const String& title, const String& message,
                                                  Component* associatedComponent,
                                                  ModalComponentManager::Callback* callback)
{
    return AlertWindow::showOkCancelBox (iconType, title, message, TRANS ("Yes"), TRANS ("No"),
                                         associatedComponent, callback);
}

//==============================================================================
Image juce_createIconForFile (const File&)
{
    return {};
}

void juce_LinuxAddRepaintListener (ComponentPeer* peer, Component* dummy)
{
    if (auto* linuxPeer = dynamic_cast<LinuxComponentPeer<::Window>*> (peer))
        linuxPeer->addOpenGLRepaintListener (dummy);
}

void juce_LinuxRemoveRepaintListener (ComponentPeer* peer, Component* dummy)
{
    if (auto* linuxPeer = dynamic_cast<LinuxComponentPeer<::Window>*> (peer))
        linuxPeer->removeOpenGLRepaintListener (dummy);
}

} // namespace juce