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

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

   JUCE is an open source library subject to commercial or open-source
   licensing.

   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
   27th April 2017).

   End User License Agreement: www.juce.com/juce-5-licence
   Privacy Policy: www.juce.com/juce-5-privacy-policy

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

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

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

Desktop::Desktop()
    : mouseSources (new MouseInputSource::SourceList()),
      mouseClickCounter (0), mouseWheelCounter (0),
      kioskModeComponent (nullptr),
      kioskModeReentrant (false),
      allowedOrientations (allOrientations),
      masterScaleFactor ((float) getDefaultMasterScale())
{
    displays = new Displays (*this);
}

Desktop::~Desktop()
{
    setScreenSaverEnabled (true);
    animator.cancelAllAnimations (false);

    jassert (instance == this);
    instance = nullptr;

    // doh! If you don't delete all your windows before exiting, you're going to
    // be leaking memory!
    jassert (desktopComponents.size() == 0);
}

Desktop& JUCE_CALLTYPE Desktop::getInstance()
{
    if (instance == nullptr)
        instance = new Desktop();

    return *instance;
}

Desktop* Desktop::instance = nullptr;

//==============================================================================
int Desktop::getNumComponents() const noexcept
{
    return desktopComponents.size();
}

Component* Desktop::getComponent (const int index) const noexcept
{
    return desktopComponents [index];
}

Component* Desktop::findComponentAt (Point<int> screenPosition) const
{
    ASSERT_MESSAGE_MANAGER_IS_LOCKED

    for (int i = desktopComponents.size(); --i >= 0;)
    {
        Component* const c = desktopComponents.getUnchecked(i);

        if (c->isVisible())
        {
            const Point<int> relative (c->getLocalPoint (nullptr, screenPosition));

            if (c->contains (relative))
                return c->getComponentAt (relative);
        }
    }

    return nullptr;
}

//==============================================================================
LookAndFeel& Desktop::getDefaultLookAndFeel() noexcept
{
    if (currentLookAndFeel == nullptr)
    {
        if (defaultLookAndFeel == nullptr)
            defaultLookAndFeel = new LookAndFeel_V4();

        currentLookAndFeel = defaultLookAndFeel;
    }

    return *currentLookAndFeel;
}

void Desktop::setDefaultLookAndFeel (LookAndFeel* newDefaultLookAndFeel)
{
    ASSERT_MESSAGE_MANAGER_IS_LOCKED
    currentLookAndFeel = newDefaultLookAndFeel;

    for (int i = getNumComponents(); --i >= 0;)
        if (Component* const c = getComponent (i))
            c->sendLookAndFeelChange();
}

//==============================================================================
void Desktop::addDesktopComponent (Component* const c)
{
    jassert (c != nullptr);
    jassert (! desktopComponents.contains (c));
    desktopComponents.addIfNotAlreadyThere (c);
}

void Desktop::removeDesktopComponent (Component* const c)
{
    desktopComponents.removeFirstMatchingValue (c);
}

void Desktop::componentBroughtToFront (Component* const c)
{
    const int index = desktopComponents.indexOf (c);
    jassert (index >= 0);

    if (index >= 0)
    {
        int newIndex = -1;

        if (! c->isAlwaysOnTop())
        {
            newIndex = desktopComponents.size();

            while (newIndex > 0 && desktopComponents.getUnchecked (newIndex - 1)->isAlwaysOnTop())
                --newIndex;

            --newIndex;
        }

        desktopComponents.move (index, newIndex);
    }
}

//==============================================================================
Point<int> Desktop::getMousePosition()
{
    return getMousePositionFloat().roundToInt();
}

Point<float> Desktop::getMousePositionFloat()
{
    return getInstance().getMainMouseSource().getScreenPosition();
}

void Desktop::setMousePosition (Point<int> newPosition)
{
    getInstance().getMainMouseSource().setScreenPosition (newPosition.toFloat());
}

Point<int> Desktop::getLastMouseDownPosition()
{
    return getInstance().getMainMouseSource().getLastMouseDownPosition().roundToInt();
}

int Desktop::getMouseButtonClickCounter() const noexcept    { return mouseClickCounter; }
int Desktop::getMouseWheelMoveCounter() const noexcept      { return mouseWheelCounter; }

void Desktop::incrementMouseClickCounter() noexcept         { ++mouseClickCounter; }
void Desktop::incrementMouseWheelCounter() noexcept         { ++mouseWheelCounter; }

const Array<MouseInputSource>& Desktop::getMouseSources() const noexcept        { return mouseSources->sourceArray; }
int Desktop::getNumMouseSources() const noexcept                                { return mouseSources->sources.size(); }
int Desktop::getNumDraggingMouseSources() const noexcept                        { return mouseSources->getNumDraggingMouseSources(); }
MouseInputSource* Desktop::getMouseSource (int index) const noexcept            { return mouseSources->getMouseSource (index); }
MouseInputSource* Desktop::getDraggingMouseSource (int index) const noexcept    { return mouseSources->getDraggingMouseSource (index); }
MouseInputSource Desktop::getMainMouseSource() const noexcept                   { return MouseInputSource (mouseSources->sources.getUnchecked(0)); }
void Desktop::beginDragAutoRepeat (int interval)                                { mouseSources->beginDragAutoRepeat (interval); }

//==============================================================================
void Desktop::addFocusChangeListener    (FocusChangeListener* const listener)   { focusListeners.add (listener); }
void Desktop::removeFocusChangeListener (FocusChangeListener* const listener)   { focusListeners.remove (listener); }
void Desktop::triggerFocusCallback()                                            { triggerAsyncUpdate(); }

void Desktop::handleAsyncUpdate()
{
    // The component may be deleted during this operation, but we'll use a SafePointer rather than a
    // BailOutChecker so that any remaining listeners will still get a callback (with a null pointer).
    WeakReference<Component> currentFocus (Component::getCurrentlyFocusedComponent());
    focusListeners.call (&FocusChangeListener::globalFocusChanged, currentFocus);
}

//==============================================================================
void Desktop::resetTimer()
{
    if (mouseListeners.size() == 0)
        stopTimer();
    else
        startTimer (100);

    lastFakeMouseMove = getMousePositionFloat();
}

ListenerList<MouseListener>& Desktop::getMouseListeners()
{
    resetTimer();
    return mouseListeners;
}

void Desktop::addGlobalMouseListener (MouseListener* const listener)
{
    ASSERT_MESSAGE_MANAGER_IS_LOCKED
    mouseListeners.add (listener);
    resetTimer();
}

void Desktop::removeGlobalMouseListener (MouseListener* const listener)
{
    ASSERT_MESSAGE_MANAGER_IS_LOCKED
    mouseListeners.remove (listener);
    resetTimer();
}

void Desktop::timerCallback()
{
    if (lastFakeMouseMove != getMousePositionFloat())
        sendMouseMove();
}

void Desktop::sendMouseMove()
{
    if (! mouseListeners.isEmpty())
    {
        startTimer (20);

        lastFakeMouseMove = getMousePositionFloat();

        if (auto* target = findComponentAt (lastFakeMouseMove.roundToInt()))
        {
            Component::BailOutChecker checker (target);
            const Point<float> pos (target->getLocalPoint (nullptr, lastFakeMouseMove));
            const Time now (Time::getCurrentTime());

            const MouseEvent me (getMainMouseSource(), pos, ModifierKeys::getCurrentModifiers(), MouseInputSource::invalidPressure,
                                 MouseInputSource::invalidOrientation, MouseInputSource::invalidRotation,
                                 MouseInputSource::invalidTiltX, MouseInputSource::invalidTiltY,
                                 target, target, now, pos, now, 0, false);

            if (me.mods.isAnyMouseButtonDown())
                mouseListeners.callChecked (checker, &MouseListener::mouseDrag, me);
            else
                mouseListeners.callChecked (checker, &MouseListener::mouseMove, me);
        }
    }
}


//==============================================================================
Desktop::Displays::Displays (Desktop& desktop)   { init (desktop); }
Desktop::Displays::~Displays()  {}

const Desktop::Displays::Display& Desktop::Displays::getMainDisplay() const noexcept
{
    ASSERT_MESSAGE_MANAGER_IS_LOCKED
    jassert (displays.getReference(0).isMain);
    return displays.getReference(0);
}

const Desktop::Displays::Display& Desktop::Displays::getDisplayContaining (Point<int> position) const noexcept
{
    ASSERT_MESSAGE_MANAGER_IS_LOCKED
    const Display* best = &displays.getReference(0);
    double bestDistance = 1.0e10;

    for (int i = displays.size(); --i >= 0;)
    {
        const Display& d = displays.getReference(i);

        if (d.totalArea.contains (position))
        {
            best = &d;
            break;
        }

        const double distance = d.totalArea.getCentre().getDistanceFrom (position);

        if (distance < bestDistance)
        {
            bestDistance = distance;
            best = &d;
        }
    }

    return *best;
}

RectangleList<int> Desktop::Displays::getRectangleList (bool userAreasOnly) const
{
    ASSERT_MESSAGE_MANAGER_IS_LOCKED
    RectangleList<int> rl;

    for (int i = 0; i < displays.size(); ++i)
    {
        const Display& d = displays.getReference(i);
        rl.addWithoutMerging (userAreasOnly ? d.userArea : d.totalArea);
    }

    return rl;
}

Rectangle<int> Desktop::Displays::getTotalBounds (bool userAreasOnly) const
{
    return getRectangleList (userAreasOnly).getBounds();
}

bool operator== (const Desktop::Displays::Display& d1, const Desktop::Displays::Display& d2) noexcept;
bool operator== (const Desktop::Displays::Display& d1, const Desktop::Displays::Display& d2) noexcept
{
    return d1.userArea == d2.userArea
        && d1.totalArea == d2.totalArea
        && d1.scale == d2.scale
        && d1.isMain == d2.isMain;
}

bool operator!= (const Desktop::Displays::Display& d1, const Desktop::Displays::Display& d2) noexcept;
bool operator!= (const Desktop::Displays::Display& d1, const Desktop::Displays::Display& d2) noexcept
{
    return ! (d1 == d2);
}

void Desktop::Displays::init (Desktop& desktop)
{
    findDisplays (desktop.getGlobalScaleFactor());
}

void Desktop::Displays::refresh()
{
    Array<Display> oldDisplays;
    oldDisplays.swapWith (displays);

    init (Desktop::getInstance());

    if (oldDisplays != displays)
    {
        for (int i = ComponentPeer::getNumPeers(); --i >= 0;)
            if (ComponentPeer* const peer = ComponentPeer::getPeer (i))
                peer->handleScreenSizeChange();
    }
}

//==============================================================================
void Desktop::setKioskModeComponent (Component* componentToUse, const bool allowMenusAndBars)
{
    if (kioskModeReentrant)
        return;

    const ScopedValueSetter<bool> setter (kioskModeReentrant, true, false);

    if (kioskModeComponent != componentToUse)
    {
        // agh! Don't delete or remove a component from the desktop while it's still the kiosk component!
        jassert (kioskModeComponent == nullptr || ComponentPeer::getPeerFor (kioskModeComponent) != nullptr);

        if (Component* const oldKioskComp = kioskModeComponent)
        {
            kioskModeComponent = nullptr; // (to make sure that isKioskMode() returns false when resizing the old one)
            setKioskComponent (oldKioskComp, false, allowMenusAndBars);
            oldKioskComp->setBounds (kioskComponentOriginalBounds);
        }

        kioskModeComponent = componentToUse;

        if (kioskModeComponent != nullptr)
        {
            // Only components that are already on the desktop can be put into kiosk mode!
            jassert (ComponentPeer::getPeerFor (kioskModeComponent) != nullptr);

            kioskComponentOriginalBounds = kioskModeComponent->getBounds();
            setKioskComponent (kioskModeComponent, true, allowMenusAndBars);
        }
    }
}

//==============================================================================
void Desktop::setOrientationsEnabled (const int newOrientations)
{
    if (allowedOrientations != newOrientations)
    {
        // Dodgy set of flags being passed here! Make sure you specify at least one permitted orientation.
        jassert (newOrientations != 0 && (newOrientations & ~allOrientations) == 0);

        allowedOrientations = newOrientations;
        allowedOrientationsChanged();
    }
}

int Desktop::getOrientationsEnabled() const noexcept
{
    return allowedOrientations;
}

bool Desktop::isOrientationEnabled (const DisplayOrientation orientation) const noexcept
{
    // Make sure you only pass one valid flag in here...
    jassert (orientation == upright || orientation == upsideDown
              || orientation == rotatedClockwise || orientation == rotatedAntiClockwise);

    return (allowedOrientations & orientation) != 0;
}

void Desktop::setGlobalScaleFactor (float newScaleFactor) noexcept
{
    ASSERT_MESSAGE_MANAGER_IS_LOCKED

    if (masterScaleFactor != newScaleFactor)
    {
        masterScaleFactor = newScaleFactor;
        displays->refresh();
    }
}
