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

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

   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 6 End-User License
   Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).

   End User License Agreement: www.juce.com/juce-6-licence
   Privacy Policy: www.juce.com/juce-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.

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

namespace juce
{

Desktop::Desktop()
    : mouseSources (new MouseInputSource::SourceList()),
      masterScaleFactor ((float) getDefaultMasterScale()),
      nativeDarkModeChangeDetectorImpl (createNativeDarkModeChangeDetectorImpl())
{
    displays.reset (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 (int index) const noexcept
{
    return desktopComponents [index];
}

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

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

        if (c->isVisible())
        {
            auto relative = c->getLocalPoint (nullptr, screenPosition);

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

    return nullptr;
}

//==============================================================================
LookAndFeel& Desktop::getDefaultLookAndFeel() noexcept
{
    if (auto lf = currentLookAndFeel.get())
        return *lf;

    if (defaultLookAndFeel == nullptr)
        defaultLookAndFeel.reset (new LookAndFeel_V4());

    auto lf = defaultLookAndFeel.get();
    jassert (lf != nullptr);
    currentLookAndFeel = lf;
    return *lf;
}

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

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

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

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

void Desktop::componentBroughtToFront (Component* c)
{
    auto 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* l)   { focusListeners.add (l); }
void Desktop::removeFocusChangeListener (FocusChangeListener* l)   { focusListeners.remove (l); }
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).
    focusListeners.call ([currentFocus = WeakReference<Component> { Component::getCurrentlyFocusedComponent() }] (FocusChangeListener& l)
    {
        l.globalFocusChanged (currentFocus.get());
    });
}

//==============================================================================
void Desktop::addDarkModeSettingListener    (DarkModeSettingListener* l)  { darkModeSettingListeners.add (l); }
void Desktop::removeDarkModeSettingListener (DarkModeSettingListener* l)  { darkModeSettingListeners.remove (l); }

void Desktop::darkModeChanged()  { darkModeSettingListeners.call ([] (DarkModeSettingListener& l) { l.darkModeSettingChanged(); }); }

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

    lastFakeMouseMove = getMousePositionFloat();
}

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

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

void Desktop::removeGlobalMouseListener (MouseListener* listener)
{
    JUCE_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);
            auto pos = target->getLocalPoint (nullptr, lastFakeMouseMove);
            auto now = Time::getCurrentTime();

            const MouseEvent me (getMainMouseSource(), pos, ModifierKeys::currentModifiers, 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& l) { l.mouseDrag (me); });
            else
                mouseListeners.callChecked (checker, [&] (MouseListener& l) { l.mouseMove (me); });
        }
    }
}

//==============================================================================
void Desktop::setKioskModeComponent (Component* componentToUse, 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 (auto* 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 (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 (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
{
    JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED

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

bool Desktop::isHeadless() const noexcept
{
    return displays->displays.isEmpty();
}

} // namespace juce