// Copyright (C) 2024 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only

#include "qquick3dxrvirtualmouse_p.h"
#include "qquick3dxrview_p.h"

#include <QtQuick3D/private/qquick3dnode_p.h>
#include <QtGui/QMouseEvent>

QT_BEGIN_NAMESPACE

/*!
    \qmltype XrVirtualMouse
    \inherits Item
    \inqmlmodule QtQuick3D.Xr
    \brief Maps 3D controller input to mouse input in 2D items.

    The XrVirtualMouse provides a way to interact with \l{Qt Quick 3D Scenes with 2D Content}{2D user interfaces}
    in the 3D scene.

    It is typically used like this:

    \qml
    // XrView { id: xrView
    // XrController { id: rightController
    XrInputAction {
        id: rightTrigger
        hand: XrInputAction.RightHand
        actionId: [XrInputAction.TriggerPressed, XrInputAction.TriggerValue]
    }
    XrVirtualMouse {
        view: xrView
        source: rightController
        leftMouseButton: rightTrigger.pressed
    }
    \endqml
*/

QQuick3DXrVirtualMouse::QQuick3DXrVirtualMouse(QObject *parent) : QObject(parent)
{
    m_scrollTimer = new QTimer(this);
    m_scrollTimer->setInterval(m_scrollTimerInterval);
    connect(m_scrollTimer, SIGNAL(timeout()), this, SLOT(generateWheelEvent()));
}

/*!
    \qmlproperty bool XrVirtualMouse::rightMouseButton
    \brief Sets the state of the right mouse button.

    When set to true, the right mouse button is pressed.
*/

bool QQuick3DXrVirtualMouse::rightMouseButton() const
{
    return m_rightMouseButton;
}

/*!
    \qmlproperty bool XrVirtualMouse::leftMouseButton
    \brief Sets the state of the left mouse button.

    When set to true, the left mouse button is pressed.
*/

bool QQuick3DXrVirtualMouse::leftMouseButton() const
{
    return m_leftMouseButton;
}

/*!
    \qmlproperty bool XrVirtualMouse::middleMouseButton
    \brief Sets the state of the middle mouse button.

    When set to true, the middle mouse button is pressed.
*/

bool QQuick3DXrVirtualMouse::middleMouseButton() const
{
    return m_middleMouseButton;
}

/*!
    \qmlproperty real XrVirtualMouse::scrollWheelX
    \brief Sets the horizontal scrolling speed.

    Positive values scroll right and negative values scroll left.
    Scroll speed increases relative to distance from zero.

    \sa scrollPixelDelta
*/

float QQuick3DXrVirtualMouse::scrollWheelX() const
{
    return m_scrollWheelX;
}

/*!
    \qmlproperty real XrVirtualMouse::scrollWheelY
    \brief Sets the vertical scrolling speed.

    Positive values scroll up and negative values scroll down.
    Scroll speed increases relative to distance from zero.

    \sa scrollPixelDelta
*/

float QQuick3DXrVirtualMouse::scrollWheelY() const
{
    return m_scrollWheelY;
}

/*!
    \qmlproperty int XrVirtualMouse::scrollTimerInterval
    \brief Defines time in milliseconds between scrolling events sent to the system.
    \default 30
*/

int QQuick3DXrVirtualMouse::scrollTimerInterval() const
{
    return m_scrollTimerInterval;
}

/*!
    \qmlproperty real XrVirtualMouse::scrollPixelDelta
    \brief Defines the base distance scrolled with each scrolling event.
    \default 15

    This is the distance scrolled when the scrolling speed is 1.

    \sa scrollWheelX, scrollWheelY
*/

int QQuick3DXrVirtualMouse::scrollPixelDelta() const
{
    return m_scrollPixelDelta;
}

/*!
    \qmlproperty Node XrVirtualMouse::source
    \brief The 3D node controlling the virtual mouse.

    The \c source property is normally set to an \l XrController. Mouse events
    are generated for the position where the \l{QtQuick3D::Node::forward}{forward vector} of
    the \c source node intersects with a 2D item.
*/

QQuick3DNode *QQuick3DXrVirtualMouse::source() const
{
    return m_source;
}

/*!
    \qmlproperty XrView XrVirtualMouse::view
    \brief The XR view associated with the virtual mouse.
    Holds the view in which the virtual mouse operates.
*/

QQuick3DXrView *QQuick3DXrVirtualMouse::view() const
{
    return m_view;
}

/*!
    \qmlproperty bool XrVirtualMouse::enabled
    \brief Indicates whether the virtual mouse is enabled.
    When true, the virtual mouse sends mouse events to 2D objects in the scene.
*/

bool QQuick3DXrVirtualMouse::enabled() const
{
    return m_enabled;
}

void QQuick3DXrVirtualMouse::setRightMouseButton(bool rightMouseButton)
{
    if (m_rightMouseButton == rightMouseButton)
        return;

    m_rightMouseButton = rightMouseButton;
    emit rightMouseButtonChanged(m_rightMouseButton);
    if (m_rightMouseButton) {
        // Press
        generateEvent(QEvent::MouseButtonPress, Qt::RightButton);
    } else {
        // Release
        generateEvent(QEvent::MouseButtonRelease, Qt::RightButton);
    }
}

void QQuick3DXrVirtualMouse::setLeftMouseButton(bool leftMouseButton)
{
    if (m_leftMouseButton == leftMouseButton)
        return;

    m_leftMouseButton = leftMouseButton;
    emit leftMouseButtonChanged(m_leftMouseButton);
    if (m_leftMouseButton) {
        // Press
        generateEvent(QEvent::MouseButtonPress, Qt::LeftButton);
    } else {
        // Release
        generateEvent(QEvent::MouseButtonRelease, Qt::LeftButton);
    }
}

void QQuick3DXrVirtualMouse::setMiddleMouseButton(bool middleMouseButton)
{
    if (m_middleMouseButton == middleMouseButton)
        return;

    m_middleMouseButton = middleMouseButton;
    emit middleMouseButtonChanged(m_middleMouseButton);
    if (m_middleMouseButton) {
        // Press
        generateEvent(QEvent::MouseButtonPress, Qt::MiddleButton);
    } else {
        // Release
        generateEvent(QEvent::MouseButtonRelease, Qt::MiddleButton);
    }
}

void QQuick3DXrVirtualMouse::setScrollWheelX(float scrollWheelX)
{
    if (m_scrollWheelX == scrollWheelX)
        return;

    m_scrollWheelX = scrollWheelX;
    emit scrollWheelXChanged(m_scrollWheelX);
    if ((m_scrollTimer->isActive()) && (m_scrollWheelX == 0)) {
        m_scrollTimer->stop();
    } else if (!m_scrollTimer->isActive()) {
        m_scrollTimer->start();
    }
}

void QQuick3DXrVirtualMouse::setScrollWheelY(float scrollWheelY)
{
    if (m_scrollWheelY == scrollWheelY)
        return;

    m_scrollWheelY = scrollWheelY;
    emit scrollWheelYChanged(m_scrollWheelY);
    if ((m_scrollTimer->isActive()) && (m_scrollWheelY == 0)) {
        m_scrollTimer->stop();
    } else if (!m_scrollTimer->isActive()) {
        m_scrollTimer->start();
    }
}

void QQuick3DXrVirtualMouse::setScrollTimerInterval(int scrollTimerInterval)
{
    if (m_scrollTimerInterval == scrollTimerInterval)
        return;

    m_scrollTimerInterval = scrollTimerInterval;
    m_scrollTimer->setInterval(m_scrollTimerInterval);

    emit scrollTimerIntervalChanged(m_scrollTimerInterval);
}

void QQuick3DXrVirtualMouse::setScrollPixelDelta(int scrollPixelDelta)
{
    if (m_scrollPixelDelta == scrollPixelDelta)
        return;

    m_scrollPixelDelta = scrollPixelDelta;

    emit scrollPixelDeltaChanged(m_scrollPixelDelta);
}

void QQuick3DXrVirtualMouse::setSource(QQuick3DNode *source)
{
    if (m_source == source)
        return;

    if (!source)
        disconnect(m_source, &QQuick3DNode::sceneTransformChanged, this, &QQuick3DXrVirtualMouse::moveEvent);

    m_source = source;
    emit sourceChanged(m_source);

    if (m_source)
        connect(m_source, &QQuick3DNode::sceneTransformChanged, this, &QQuick3DXrVirtualMouse::moveEvent);
}

void QQuick3DXrVirtualMouse::setView(QQuick3DXrView *view)
{
    if (m_view == view)
        return;

    m_view = view;
    emit viewChanged(m_view);
}

void QQuick3DXrVirtualMouse::setEnabled(bool enabled)
{
    if (m_enabled == enabled)
        return;
    m_enabled = enabled;
    emit enabledChanged(m_enabled);

    // Generate mouse release event if we disable when pressed
    if (!m_enabled && (m_leftMouseButton || m_rightMouseButton || m_middleMouseButton)) {
        Qt::MouseButton button = m_leftMouseButton ? Qt::LeftButton : m_rightMouseButton ? Qt::RightButton : Qt::MiddleButton;
        m_leftMouseButton = m_rightMouseButton = m_middleMouseButton = false;
        generateEvent(QEvent::MouseButtonRelease, button);
    }
}

void QQuick3DXrVirtualMouse::moveEvent()
{
    generateEvent(QEvent::MouseMove, Qt::NoButton);
}

void QQuick3DXrVirtualMouse::generateWheelEvent()
{
    if (!m_view || !m_source || m_view->m_inDestructor || !m_enabled)
        return;

    // Get Ray
    const QVector3D origin = m_source->scenePosition();
    const QVector3D direction = m_source->forward();

    float x = 0;
    float y = 0;

    if (m_scrollWheelX > 0) {
        x = m_scrollPixelDelta * m_scrollWheelX * m_scrollWheelX;
    } else if (m_scrollWheelX < 0) {
        x = -m_scrollPixelDelta * m_scrollWheelX * m_scrollWheelX;
    }

    if (m_scrollWheelY > 0) {
        y = m_scrollPixelDelta * m_scrollWheelY * m_scrollWheelY;
    } else if (m_scrollWheelY < 0) {
        y = -m_scrollPixelDelta * m_scrollWheelY * m_scrollWheelY;
    }

    QPoint pixelDelta = QPoint(x, y);
    QPoint angleDelta = QPoint(x*8, y*8);

    // Position will be generated by QtQuick3D
    QWheelEvent *event = new QWheelEvent(QPointF(), QPointF(), pixelDelta, angleDelta,
                                         Qt::NoButton, Qt::NoModifier, Qt::NoScrollPhase, false);

    // Send to View with Ray
    if (m_view->view3d()) // no internal view3D if XrView init failed but the object is still alive, handle this gracefully
        m_view->view3d()->singlePointPick(event, origin, direction);

    // Cleanup
    delete event;
}

void QQuick3DXrVirtualMouse::generateEvent(QEvent::Type type,  Qt::MouseButton button)
{
    if (!m_view || !m_source || m_view->m_inDestructor || !m_enabled)
        return;

    // Get Ray
    const QVector3D origin = m_source->scenePosition();
    const QVector3D direction = m_source->forward();

    // Generate Pointer Event
    Qt::MouseButtons buttons = Qt::NoButton;
    if (m_leftMouseButton)
        buttons |= Qt::LeftButton;
    if (m_rightMouseButton)
        buttons |= Qt::RightButton;
    if (m_middleMouseButton)
        buttons |= Qt::MiddleButton;

    // Position will be generated by QtQuick3D
    QMouseEvent *event = new QMouseEvent(type, QPointF(), QPointF(), button, buttons, Qt::NoModifier);

    // Send to View with Ray
    if (m_view->view3d()) // no internal view3D if XrView init failed but the object is still alive, handle this gracefully
        m_view->view3d()->singlePointPick(event, origin, direction);

    // Cleanup
    delete event;
}

QT_END_NAMESPACE