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

   This file is part of the JUCE 7 technical preview.
   Copyright (c) 2022 - Raw Material Software Limited

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

   For the technical preview this file cannot be licensed commercially.

   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
{

class MouseInputSourceInternal   : private AsyncUpdater
{
public:
    MouseInputSourceInternal (int i, MouseInputSource::InputSourceType type)  : index (i), inputType (type)
    {
    }

    //==============================================================================
    bool isDragging() const noexcept
    {
        return buttonState.isAnyMouseButtonDown();
    }

    Component* getComponentUnderMouse() const noexcept
    {
        return componentUnderMouse.get();
    }

    ModifierKeys getCurrentModifiers() const noexcept
    {
        return ModifierKeys::currentModifiers.withoutMouseButtons().withFlags (buttonState.getRawFlags());
    }

    ComponentPeer* getPeer() noexcept
    {
        if (! ComponentPeer::isValidPeer (lastPeer))
            lastPeer = nullptr;

        return lastPeer;
    }

    Component* findComponentAt (Point<float> screenPos)
    {
        if (auto* peer = getPeer())
        {
            auto relativePos = ScalingHelpers::unscaledScreenPosToScaled (peer->getComponent(),
                                                                          peer->globalToLocal (screenPos));
            auto& comp = peer->getComponent();

            // (the contains() call is needed to test for overlapping desktop windows)
            if (comp.contains (relativePos))
                return comp.getComponentAt (relativePos);
        }

        return nullptr;
    }

    Point<float> getScreenPosition() const noexcept
    {
        // This needs to return the live position if possible, but it mustn't update the lastScreenPos
        // value, because that can cause continuity problems.
        return ScalingHelpers::unscaledScreenPosToScaled (getRawScreenPosition());
    }

    Point<float> getRawScreenPosition() const noexcept
    {
        return unboundedMouseOffset + (inputType != MouseInputSource::InputSourceType::touch ? MouseInputSource::getCurrentRawMousePosition()
                                                                                             : lastPointerState.position);
    }

    void setScreenPosition (Point<float> p)
    {
        MouseInputSource::setRawMousePosition (ScalingHelpers::scaledScreenPosToUnscaled (p));
    }

    //==============================================================================
   #if JUCE_DUMP_MOUSE_EVENTS
    #define JUCE_MOUSE_EVENT_DBG(desc, screenPos)   DBG ("Mouse " << desc << " #" << index \
                                                            << ": " << ScalingHelpers::screenPosToLocalPos (comp, screenPos).toString() \
                                                            << " - Comp: " << String::toHexString ((pointer_sized_int) &comp));
   #else
    #define JUCE_MOUSE_EVENT_DBG(desc, screenPos)
   #endif

    void sendMouseEnter (Component& comp, const PointerState& pointerState, Time time)
    {
        JUCE_MOUSE_EVENT_DBG ("enter", pointerState.position)
        comp.internalMouseEnter (MouseInputSource (this), ScalingHelpers::screenPosToLocalPos (comp, pointerState.position), time);
    }

    void sendMouseExit (Component& comp, const PointerState& pointerState, Time time)
    {
        JUCE_MOUSE_EVENT_DBG ("exit", pointerState.position)
        comp.internalMouseExit (MouseInputSource (this), ScalingHelpers::screenPosToLocalPos (comp, pointerState.position), time);
    }

    void sendMouseMove (Component& comp, const PointerState& pointerState, Time time)
    {
        JUCE_MOUSE_EVENT_DBG ("move", pointerState.position)
        comp.internalMouseMove (MouseInputSource (this), ScalingHelpers::screenPosToLocalPos (comp, pointerState.position), time);
    }

    void sendMouseDown (Component& comp, const PointerState& pointerState, Time time)
    {
        JUCE_MOUSE_EVENT_DBG ("down", pointerState.position)
        comp.internalMouseDown (MouseInputSource (this),
                                pointerState.withPosition (ScalingHelpers::screenPosToLocalPos (comp, pointerState.position)),
                                time);
    }

    void sendMouseDrag (Component& comp, const PointerState& pointerState, Time time)
    {
        JUCE_MOUSE_EVENT_DBG ("drag", pointerState.position)
        comp.internalMouseDrag (MouseInputSource (this),
                                pointerState.withPosition (ScalingHelpers::screenPosToLocalPos (comp, pointerState.position)),
                                time);
    }

    void sendMouseUp (Component& comp, const PointerState& pointerState, Time time, ModifierKeys oldMods)
    {
        JUCE_MOUSE_EVENT_DBG ("up", pointerState.position)
        comp.internalMouseUp (MouseInputSource (this),
                              pointerState.withPosition (ScalingHelpers::screenPosToLocalPos (comp, pointerState.position)),
                              time,
                              oldMods);
    }

    void sendMouseWheel (Component& comp, Point<float> screenPos, Time time, const MouseWheelDetails& wheel)
    {
        JUCE_MOUSE_EVENT_DBG ("wheel", screenPos)
        comp.internalMouseWheel (MouseInputSource (this), ScalingHelpers::screenPosToLocalPos (comp, screenPos), time, wheel);
    }

    void sendMagnifyGesture (Component& comp, Point<float> screenPos, Time time, float amount)
    {
        JUCE_MOUSE_EVENT_DBG ("magnify", screenPos)
        comp.internalMagnifyGesture (MouseInputSource (this), ScalingHelpers::screenPosToLocalPos (comp, screenPos), time, amount);
    }

    //==============================================================================
    // (returns true if the button change caused a modal event loop)
    bool setButtons (const PointerState& pointerState, Time time, ModifierKeys newButtonState)
    {
        if (buttonState == newButtonState)
            return false;

        // (avoid sending a spurious mouse-drag when we receive a mouse-up)
        if (! (isDragging() && ! newButtonState.isAnyMouseButtonDown()))
            setPointerState (pointerState, time, false);

        // (ignore secondary clicks when there's already a button down)
        if (buttonState.isAnyMouseButtonDown() == newButtonState.isAnyMouseButtonDown())
        {
            buttonState = newButtonState;
            return false;
        }

        auto lastCounter = mouseEventCounter;

        if (buttonState.isAnyMouseButtonDown())
        {
            if (auto* current = getComponentUnderMouse())
            {
                auto oldMods = getCurrentModifiers();
                buttonState = newButtonState; // must change this before calling sendMouseUp, in case it runs a modal loop

                sendMouseUp (*current, pointerState.withPositionOffset (unboundedMouseOffset), time, oldMods);

                if (lastCounter != mouseEventCounter)
                    return true; // if a modal loop happened, then newButtonState is no longer valid.
            }

            enableUnboundedMouseMovement (false, false);
        }

        buttonState = newButtonState;

        if (buttonState.isAnyMouseButtonDown())
        {
            Desktop::getInstance().incrementMouseClickCounter();

            if (auto* current = getComponentUnderMouse())
            {
                registerMouseDown (pointerState.position, time, *current, buttonState,
                                   inputType == MouseInputSource::InputSourceType::touch);
                sendMouseDown (*current, pointerState, time);
            }
        }

        return lastCounter != mouseEventCounter;
    }

    void setComponentUnderMouse (Component* newComponent, const PointerState& pointerState, Time time)
    {
        auto* current = getComponentUnderMouse();

        if (newComponent != current)
        {
            WeakReference<Component> safeNewComp (newComponent);
            auto originalButtonState = buttonState;

            if (current != nullptr)
            {
                WeakReference<Component> safeOldComp (current);
                setButtons (pointerState, time, ModifierKeys());

                if (auto oldComp = safeOldComp.get())
                {
                    componentUnderMouse = safeNewComp;
                    sendMouseExit (*oldComp, pointerState, time);
                }

                buttonState = originalButtonState;
            }

            componentUnderMouse = safeNewComp.get();
            current = safeNewComp.get();

            if (current != nullptr)
                sendMouseEnter (*current, pointerState, time);

            revealCursor (false);
            setButtons (pointerState, time, originalButtonState);
        }
    }

    void setPeer (ComponentPeer& newPeer, const PointerState& pointerState, Time time)
    {
        if (&newPeer != lastPeer)
        {
            setComponentUnderMouse (nullptr, pointerState, time);
            lastPeer = &newPeer;
            setComponentUnderMouse (findComponentAt (pointerState.position), pointerState, time);
        }
    }

    void setPointerState (const PointerState& newPointerState, Time time, bool forceUpdate)
    {
        const auto& newScreenPos = newPointerState.position;

        if (! isDragging())
            setComponentUnderMouse (findComponentAt (newScreenPos), newPointerState, time);

        if ((newPointerState != lastPointerState) || forceUpdate)
        {
            cancelPendingUpdate();

            if (newPointerState.position != MouseInputSource::offscreenMousePos)
                lastPointerState = newPointerState;

            if (auto* current = getComponentUnderMouse())
            {
                if (isDragging())
                {
                    registerMouseDrag (newScreenPos);
                    sendMouseDrag (*current, newPointerState.withPositionOffset (unboundedMouseOffset), time);

                    if (isUnboundedMouseModeOn)
                        handleUnboundedDrag (*current);
                }
                else
                {
                    sendMouseMove (*current, newPointerState, time);
                }
            }

            revealCursor (false);
        }
    }

    //==============================================================================
    void handleEvent (ComponentPeer& newPeer, Point<float> positionWithinPeer, Time time,
                      const ModifierKeys newMods, float newPressure, float newOrientation, PenDetails pen)
    {
        lastTime = time;
        ++mouseEventCounter;
        const auto pointerState = PointerState().withPosition (newPeer.localToGlobal (positionWithinPeer))
                                                .withPressure (newPressure)
                                                .withOrientation (newOrientation)
                                                .withRotation (MouseInputSource::defaultRotation)
                                                .withTiltX (pen.tiltX)
                                                .withTiltY (pen.tiltY);

        if (isDragging() && newMods.isAnyMouseButtonDown())
        {
            setPointerState (pointerState, time, false);
        }
        else
        {
            setPeer (newPeer, pointerState, time);

            if (auto* peer = getPeer())
            {
                if (setButtons (pointerState, time, newMods))
                    return; // some modal events have been dispatched, so the current event is now out-of-date

                peer = getPeer();

                if (peer != nullptr)
                    setPointerState (pointerState, time, false);
            }
        }
    }

    Component* getTargetForGesture (ComponentPeer& peer, Point<float> positionWithinPeer,
                                    Time time, Point<float>& screenPos)
    {
        lastTime = time;
        ++mouseEventCounter;

        screenPos = peer.localToGlobal (positionWithinPeer);
        const auto pointerState = lastPointerState.withPosition (screenPos);
        setPeer (peer, pointerState, time);
        setPointerState (pointerState, time, false);
        triggerFakeMove();

        return getComponentUnderMouse();
    }

    void handleWheel (ComponentPeer& peer, Point<float> positionWithinPeer,
                      Time time, const MouseWheelDetails& wheel)
    {
        Desktop::getInstance().incrementMouseWheelCounter();
        Point<float> screenPos;

        // This will make sure that when the wheel spins in its inertial phase, any events
        // continue to be sent to the last component that the mouse was over when it was being
        // actively controlled by the user. This avoids confusion when scrolling through nested
        // scrollable components.
        if (lastNonInertialWheelTarget == nullptr || ! wheel.isInertial)
            lastNonInertialWheelTarget = getTargetForGesture (peer, positionWithinPeer, time, screenPos);
        else
            screenPos = peer.localToGlobal (positionWithinPeer);

        if (auto target = lastNonInertialWheelTarget.get())
            sendMouseWheel (*target, screenPos, time, wheel);
    }

    void handleMagnifyGesture (ComponentPeer& peer, Point<float> positionWithinPeer,
                               Time time, const float scaleFactor)
    {
        Point<float> screenPos;

        if (auto* current = getTargetForGesture (peer, positionWithinPeer, time, screenPos))
            sendMagnifyGesture (*current, screenPos, time, scaleFactor);
    }

    //==============================================================================
    Time getLastMouseDownTime() const noexcept              { return mouseDowns[0].time; }
    Point<float> getLastMouseDownPosition() const noexcept  { return ScalingHelpers::unscaledScreenPosToScaled (mouseDowns[0].position); }

    int getNumberOfMultipleClicks() const noexcept
    {
        int numClicks = 1;

        if (! isLongPressOrDrag())
        {
            for (int i = 1; i < numElementsInArray (mouseDowns); ++i)
            {
                if (mouseDowns[0].canBePartOfMultipleClickWith (mouseDowns[i], MouseEvent::getDoubleClickTimeout() * jmin (i, 2)))
                    ++numClicks;
                else
                    break;
            }
        }

        return numClicks;
    }

    bool isLongPressOrDrag() const noexcept
    {
        return movedSignificantly || lastTime > mouseDowns[0].time + RelativeTime::milliseconds (300);
    }

    bool hasMovedSignificantlySincePressed() const noexcept
    {
        return movedSignificantly;
    }

    // Deprecated method
    bool hasMouseMovedSignificantlySincePressed() const noexcept
    {
        return isLongPressOrDrag();
    }

    //==============================================================================
    void triggerFakeMove()
    {
        triggerAsyncUpdate();
    }

    void handleAsyncUpdate() override
    {
        setPointerState (lastPointerState, jmax (lastTime, Time::getCurrentTime()), true);
    }

    //==============================================================================
    void enableUnboundedMouseMovement (bool enable, bool keepCursorVisibleUntilOffscreen)
    {
        enable = enable && isDragging();
        isCursorVisibleUntilOffscreen = keepCursorVisibleUntilOffscreen;

        if (enable != isUnboundedMouseModeOn)
        {
            if ((! enable) && ((! isCursorVisibleUntilOffscreen) || ! unboundedMouseOffset.isOrigin()))
            {
                // when released, return the mouse to within the component's bounds
                if (auto* current = getComponentUnderMouse())
                    setScreenPosition (current->getScreenBounds().toFloat()
                                          .getConstrainedPoint (ScalingHelpers::unscaledScreenPosToScaled (lastPointerState.position)));
            }

            isUnboundedMouseModeOn = enable;
            unboundedMouseOffset = {};

            revealCursor (true);
        }
    }

    void handleUnboundedDrag (Component& current)
    {
        auto componentScreenBounds = ScalingHelpers::scaledScreenPosToUnscaled (current.getParentMonitorArea().reduced (2, 2).toFloat());

        if (! componentScreenBounds.contains (lastPointerState.position))
        {
            auto componentCentre = current.getScreenBounds().toFloat().getCentre();
            unboundedMouseOffset += (lastPointerState.position - ScalingHelpers::scaledScreenPosToUnscaled (componentCentre));
            setScreenPosition (componentCentre);
        }
        else if (isCursorVisibleUntilOffscreen
                  && (! unboundedMouseOffset.isOrigin())
                  && componentScreenBounds.contains (lastPointerState.position + unboundedMouseOffset))
        {
            MouseInputSource::setRawMousePosition (lastPointerState.position + unboundedMouseOffset);
            unboundedMouseOffset = {};
        }
    }

    //==============================================================================
    void showMouseCursor (MouseCursor cursor, bool forcedUpdate)
    {
        if (isUnboundedMouseModeOn && ((! unboundedMouseOffset.isOrigin()) || ! isCursorVisibleUntilOffscreen))
        {
            cursor = MouseCursor::NoCursor;
            forcedUpdate = true;
        }

        if (forcedUpdate || cursor.getHandle() != currentCursorHandle)
        {
            currentCursorHandle = cursor.getHandle();
            cursor.showInWindow (getPeer());
        }
    }

    void hideCursor()
    {
        showMouseCursor (MouseCursor::NoCursor, true);
    }

    void revealCursor (bool forcedUpdate)
    {
        MouseCursor mc (MouseCursor::NormalCursor);

        if (auto* current = getComponentUnderMouse())
            mc = current->getLookAndFeel().getMouseCursorFor (*current);

        showMouseCursor (mc, forcedUpdate);
    }

    //==============================================================================
    const int index;
    const MouseInputSource::InputSourceType inputType;
    Point<float> unboundedMouseOffset; // NB: these are unscaled coords
    PointerState lastPointerState;
    ModifierKeys buttonState;

    bool isUnboundedMouseModeOn = false, isCursorVisibleUntilOffscreen = false;

private:
    WeakReference<Component> componentUnderMouse, lastNonInertialWheelTarget;
    ComponentPeer* lastPeer = nullptr;

    void* currentCursorHandle = nullptr;
    int mouseEventCounter = 0;

    struct RecentMouseDown
    {
        RecentMouseDown() = default;

        Point<float> position;
        Time time;
        ModifierKeys buttons;
        uint32 peerID = 0;
        bool isTouch = false;

        bool canBePartOfMultipleClickWith (const RecentMouseDown& other, int maxTimeBetweenMs) const noexcept
        {
            return time - other.time < RelativeTime::milliseconds (maxTimeBetweenMs)
                    && std::abs (position.x - other.position.x) < (float) getPositionToleranceForInputType()
                    && std::abs (position.y - other.position.y) < (float) getPositionToleranceForInputType()
                    && buttons == other.buttons
                    && peerID == other.peerID;
        }

        int getPositionToleranceForInputType() const noexcept    { return isTouch ? 25 : 8;  }
    };

    RecentMouseDown mouseDowns[4];
    Time lastTime;
    bool movedSignificantly = false;

    void registerMouseDown (Point<float> screenPos, Time time, Component& component,
                            const ModifierKeys modifiers, bool isTouchSource) noexcept
    {
        for (int i = numElementsInArray (mouseDowns); --i > 0;)
            mouseDowns[i] = mouseDowns[i - 1];

        mouseDowns[0].position = screenPos;
        mouseDowns[0].time = time;
        mouseDowns[0].buttons = modifiers.withOnlyMouseButtons();
        mouseDowns[0].isTouch = isTouchSource;

        if (auto* peer = component.getPeer())
            mouseDowns[0].peerID = peer->getUniqueID();
        else
            mouseDowns[0].peerID = 0;

        movedSignificantly = false;
        lastNonInertialWheelTarget = nullptr;
    }

    void registerMouseDrag (Point<float> screenPos) noexcept
    {
        movedSignificantly = movedSignificantly || mouseDowns[0].position.getDistanceFrom (screenPos) >= 4;
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MouseInputSourceInternal)
};

//==============================================================================
MouseInputSource::MouseInputSource (MouseInputSourceInternal* s) noexcept   : pimpl (s)  {}
MouseInputSource::MouseInputSource (const MouseInputSource& other) noexcept : pimpl (other.pimpl)  {}
MouseInputSource::~MouseInputSource() noexcept {}

MouseInputSource& MouseInputSource::operator= (const MouseInputSource& other) noexcept
{
    pimpl = other.pimpl;
    return *this;
}

MouseInputSource::InputSourceType MouseInputSource::getType() const noexcept    { return pimpl->inputType; }
bool MouseInputSource::isMouse() const noexcept                                 { return (getType() == MouseInputSource::InputSourceType::mouse); }
bool MouseInputSource::isTouch() const noexcept                                 { return (getType() == MouseInputSource::InputSourceType::touch); }
bool MouseInputSource::isPen() const noexcept                                   { return (getType() == MouseInputSource::InputSourceType::pen); }
bool MouseInputSource::canHover() const noexcept                                { return ! isTouch(); }
bool MouseInputSource::hasMouseWheel() const noexcept                           { return ! isTouch(); }
int MouseInputSource::getIndex() const noexcept                                 { return pimpl->index; }
bool MouseInputSource::isDragging() const noexcept                              { return pimpl->isDragging(); }
Point<float> MouseInputSource::getScreenPosition() const noexcept               { return pimpl->getScreenPosition(); }
Point<float> MouseInputSource::getRawScreenPosition() const noexcept            { return pimpl->getRawScreenPosition();  }
ModifierKeys MouseInputSource::getCurrentModifiers() const noexcept             { return pimpl->getCurrentModifiers(); }
float MouseInputSource::getCurrentPressure() const noexcept                     { return pimpl->lastPointerState.pressure; }
bool MouseInputSource::isPressureValid() const noexcept                         { return pimpl->lastPointerState.isPressureValid(); }
float MouseInputSource::getCurrentOrientation() const noexcept                  { return pimpl->lastPointerState.orientation; }
bool MouseInputSource::isOrientationValid() const noexcept                      { return pimpl->lastPointerState.isOrientationValid(); }
float MouseInputSource::getCurrentRotation() const noexcept                     { return pimpl->lastPointerState.rotation; }
bool MouseInputSource::isRotationValid() const noexcept                         { return pimpl->lastPointerState.isRotationValid(); }
float MouseInputSource::getCurrentTilt (bool tiltX) const noexcept              { return tiltX ? pimpl->lastPointerState.tiltX : pimpl->lastPointerState.tiltY; }
bool MouseInputSource::isTiltValid (bool isX) const noexcept                    { return pimpl->lastPointerState.isTiltValid (isX); }
Component* MouseInputSource::getComponentUnderMouse() const                     { return pimpl->getComponentUnderMouse(); }
void MouseInputSource::triggerFakeMove() const                                  { pimpl->triggerFakeMove(); }
int MouseInputSource::getNumberOfMultipleClicks() const noexcept                { return pimpl->getNumberOfMultipleClicks(); }
Time MouseInputSource::getLastMouseDownTime() const noexcept                    { return pimpl->getLastMouseDownTime(); }
Point<float> MouseInputSource::getLastMouseDownPosition() const noexcept        { return pimpl->getLastMouseDownPosition(); }
bool MouseInputSource::isLongPressOrDrag() const noexcept                       { return pimpl->isLongPressOrDrag(); }
bool MouseInputSource::hasMovedSignificantlySincePressed() const noexcept       { return pimpl->hasMovedSignificantlySincePressed(); }
bool MouseInputSource::canDoUnboundedMovement() const noexcept                  { return ! isTouch(); }
void MouseInputSource::enableUnboundedMouseMovement (bool isEnabled, bool keepCursorVisibleUntilOffscreen) const
                                                                         { pimpl->enableUnboundedMouseMovement (isEnabled, keepCursorVisibleUntilOffscreen); }
bool MouseInputSource::isUnboundedMouseMovementEnabled() const           { return pimpl->isUnboundedMouseModeOn; }
bool MouseInputSource::hasMouseCursor() const noexcept                   { return ! isTouch(); }
void MouseInputSource::showMouseCursor (const MouseCursor& cursor)       { pimpl->showMouseCursor (cursor, false); }
void MouseInputSource::hideCursor()                                      { pimpl->hideCursor(); }
void MouseInputSource::revealCursor()                                    { pimpl->revealCursor (false); }
void MouseInputSource::forceMouseCursorUpdate()                          { pimpl->revealCursor (true); }
void MouseInputSource::setScreenPosition (Point<float> p)                { pimpl->setScreenPosition (p); }

void MouseInputSource::handleEvent (ComponentPeer& peer, Point<float> pos, int64 time, ModifierKeys mods,
                                    float pressure, float orientation, const PenDetails& penDetails)
{
    pimpl->handleEvent (peer, pos, Time (time), mods.withOnlyMouseButtons(), pressure, orientation, penDetails);
}

void MouseInputSource::handleWheel (ComponentPeer& peer, Point<float> pos, int64 time, const MouseWheelDetails& wheel)
{
    pimpl->handleWheel (peer, pos, Time (time), wheel);
}

void MouseInputSource::handleMagnifyGesture (ComponentPeer& peer, Point<float> pos, int64 time, float scaleFactor)
{
    pimpl->handleMagnifyGesture (peer, pos, Time (time), scaleFactor);
}

const float MouseInputSource::invalidPressure = 0.0f;
const float MouseInputSource::invalidOrientation = 0.0f;
const float MouseInputSource::invalidRotation = 0.0f;

const float MouseInputSource::invalidTiltX = 0.0f;
const float MouseInputSource::invalidTiltY = 0.0f;

const Point<float> MouseInputSource::offscreenMousePos { -10.0f, -10.0f };

// Deprecated method
bool MouseInputSource::hasMouseMovedSignificantlySincePressed() const noexcept  { return pimpl->hasMouseMovedSignificantlySincePressed(); }

//==============================================================================
struct MouseInputSource::SourceList  : public Timer
{
    SourceList()
    {
       #if JUCE_ANDROID || JUCE_IOS
        auto mainMouseInputType = MouseInputSource::InputSourceType::touch;
       #else
        auto mainMouseInputType = MouseInputSource::InputSourceType::mouse;
       #endif

        addSource (0, mainMouseInputType);
    }

    bool addSource();
    bool canUseTouch();

    MouseInputSource* addSource (int index, MouseInputSource::InputSourceType type)
    {
        auto* s = new MouseInputSourceInternal (index, type);
        sources.add (s);
        sourceArray.add (MouseInputSource (s));

        return &sourceArray.getReference (sourceArray.size() - 1);
    }

    MouseInputSource* getMouseSource (int index) noexcept
    {
        return isPositiveAndBelow (index, sourceArray.size()) ? &sourceArray.getReference (index)
                                                              : nullptr;
    }

    MouseInputSource* getOrCreateMouseInputSource (MouseInputSource::InputSourceType type, int touchIndex = 0)
    {
        if (type == MouseInputSource::InputSourceType::mouse || type == MouseInputSource::InputSourceType::pen)
        {
            for (auto& m : sourceArray)
                if (type == m.getType())
                    return &m;

            addSource (0, type);
        }
        else if (type == MouseInputSource::InputSourceType::touch)
        {
            jassert (0 <= touchIndex && touchIndex < 100); // sanity-check on number of fingers

            for (auto& m : sourceArray)
                if (type == m.getType() && touchIndex == m.getIndex())
                    return &m;

            if (canUseTouch())
                return addSource (touchIndex, type);
        }

        return nullptr;
    }

    int getNumDraggingMouseSources() const noexcept
    {
        int num = 0;

        for (auto* s : sources)
            if (s->isDragging())
                ++num;

        return num;
    }

    MouseInputSource* getDraggingMouseSource (int index) noexcept
    {
        int num = 0;

        for (auto& s : sourceArray)
        {
            if (s.isDragging())
            {
                if (index == num)
                    return &s;

                ++num;
            }
        }

        return nullptr;
    }

    void beginDragAutoRepeat (int interval)
    {
        if (interval > 0)
        {
            if (getTimerInterval() != interval)
                startTimer (interval);
        }
        else
        {
            stopTimer();
        }
    }

    void timerCallback() override
    {
        bool anyDragging = false;

        for (auto* s : sources)
        {
            // NB: when doing auto-repeat, we need to force an update of the current position and button state,
            // because on some OSes the queue can get overloaded with messages so that mouse-events don't get through..
            if (s->isDragging() && ComponentPeer::getCurrentModifiersRealtime().isAnyMouseButtonDown())
            {
                s->lastPointerState.position = s->getRawScreenPosition();
                s->triggerFakeMove();
                anyDragging = true;
            }
        }

        if (! anyDragging)
            stopTimer();
    }

    OwnedArray<MouseInputSourceInternal> sources;
    Array<MouseInputSource> sourceArray;
};

} // namespace juce