/****************************************************************************
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** Copyright (C) 2016 Klaralvdalens Datakonsult AB (KDAB).
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** This file is part of the Qt3D module of the Qt Toolkit.
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****************************************************************************/

#include "qorbitcameracontroller_p.h"
#include "qorbitcameracontroller.h"
#include <QtGlobal>
#include <Qt3DRender/QCamera>
#include <Qt3DInput/QAxis>
#include <Qt3DInput/QAnalogAxisInput>
#include <Qt3DInput/QButtonAxisInput>
#include <Qt3DInput/QAction>
#include <Qt3DInput/QActionInput>
#include <Qt3DInput/QLogicalDevice>
#include <Qt3DInput/QKeyboardDevice>
#include <Qt3DInput/QMouseDevice>
#include <Qt3DInput/QMouseEvent>
#include <Qt3DLogic/QFrameAction>

QT_BEGIN_NAMESPACE

namespace Qt3DExtras {

/*!
 * \class QOrbitCameraController::QOrbitCameraController
 * \internal
 */

QOrbitCameraControllerPrivate::QOrbitCameraControllerPrivate()
    : Qt3DCore::QEntityPrivate()
    , m_camera(nullptr)
    , m_leftMouseButtonAction(new Qt3DInput::QAction())
    , m_rightMouseButtonAction(new Qt3DInput::QAction())
    , m_altButtonAction(new Qt3DInput::QAction())
    , m_shiftButtonAction(new Qt3DInput::QAction())
    , m_rxAxis(new Qt3DInput::QAxis())
    , m_ryAxis(new Qt3DInput::QAxis())
    , m_txAxis(new Qt3DInput::QAxis())
    , m_tyAxis(new Qt3DInput::QAxis())
    , m_tzAxis(new Qt3DInput::QAxis())
    , m_leftMouseButtonInput(new Qt3DInput::QActionInput())
    , m_rightMouseButtonInput(new Qt3DInput::QActionInput())
    , m_altButtonInput(new Qt3DInput::QActionInput())
    , m_shiftButtonInput(new Qt3DInput::QActionInput())
    , m_mouseRxInput(new Qt3DInput::QAnalogAxisInput())
    , m_mouseRyInput(new Qt3DInput::QAnalogAxisInput())
    , m_keyboardTxPosInput(new Qt3DInput::QButtonAxisInput())
    , m_keyboardTyPosInput(new Qt3DInput::QButtonAxisInput())
    , m_keyboardTzPosInput(new Qt3DInput::QButtonAxisInput())
    , m_keyboardTxNegInput(new Qt3DInput::QButtonAxisInput())
    , m_keyboardTyNegInput(new Qt3DInput::QButtonAxisInput())
    , m_keyboardTzNegInput(new Qt3DInput::QButtonAxisInput())
    , m_keyboardDevice(new Qt3DInput::QKeyboardDevice())
    , m_mouseDevice(new Qt3DInput::QMouseDevice())
    , m_logicalDevice(new Qt3DInput::QLogicalDevice())
    , m_frameAction(new Qt3DLogic::QFrameAction())
    , m_linearSpeed(10.0f)
    , m_lookSpeed(180.0f)
    , m_zoomInLimit(2.0f)
    , m_cameraUp(QVector3D(0.0f, 1.0f, 0.0f))
{}

void QOrbitCameraControllerPrivate::init()
{
    //// Actions

    // Left Mouse Button Action
    m_leftMouseButtonInput->setButtons(QVector<int>() << Qt::LeftButton);
    m_leftMouseButtonInput->setSourceDevice(m_mouseDevice);
    m_leftMouseButtonAction->addInput(m_leftMouseButtonInput);

    // Right Mouse Button Action
    m_rightMouseButtonInput->setButtons(QVector<int>() << Qt::RightButton);
    m_rightMouseButtonInput->setSourceDevice(m_mouseDevice);
    m_rightMouseButtonAction->addInput(m_rightMouseButtonInput);

    // Alt Button Action
    m_altButtonInput->setButtons(QVector<int>() << Qt::Key_Alt);
    m_altButtonInput->setSourceDevice(m_keyboardDevice);
    m_altButtonAction->addInput(m_altButtonInput);

    // Shift Button Action
    m_shiftButtonInput->setButtons(QVector<int>() << Qt::Key_Shift);
    m_shiftButtonInput->setSourceDevice(m_keyboardDevice);
    m_shiftButtonAction->addInput(m_shiftButtonInput);

    //// Axes

    // Mouse X
    m_mouseRxInput->setAxis(Qt3DInput::QMouseDevice::X);
    m_mouseRxInput->setSourceDevice(m_mouseDevice);
    m_rxAxis->addInput(m_mouseRxInput);

    // Mouse Y
    m_mouseRyInput->setAxis(Qt3DInput::QMouseDevice::Y);
    m_mouseRyInput->setSourceDevice(m_mouseDevice);
    m_ryAxis->addInput(m_mouseRyInput);

    // Keyboard Pos Tx
    m_keyboardTxPosInput->setButtons(QVector<int>() << Qt::Key_Right);
    m_keyboardTxPosInput->setScale(1.0f);
    m_keyboardTxPosInput->setSourceDevice(m_keyboardDevice);
    m_txAxis->addInput(m_keyboardTxPosInput);

    // Keyboard Pos Tz
    m_keyboardTzPosInput->setButtons(QVector<int>() << Qt::Key_PageUp);
    m_keyboardTzPosInput->setScale(1.0f);
    m_keyboardTzPosInput->setSourceDevice(m_keyboardDevice);
    m_tzAxis->addInput(m_keyboardTzPosInput);

    // Keyboard Pos Ty
    m_keyboardTyPosInput->setButtons(QVector<int>() << Qt::Key_Up);
    m_keyboardTyPosInput->setScale(1.0f);
    m_keyboardTyPosInput->setSourceDevice(m_keyboardDevice);
    m_tyAxis->addInput(m_keyboardTyPosInput);

    // Keyboard Neg Tx
    m_keyboardTxNegInput->setButtons(QVector<int>() << Qt::Key_Left);
    m_keyboardTxNegInput->setScale(-1.0f);
    m_keyboardTxNegInput->setSourceDevice(m_keyboardDevice);
    m_txAxis->addInput(m_keyboardTxNegInput);

    // Keyboard Neg Tz
    m_keyboardTzNegInput->setButtons(QVector<int>() << Qt::Key_PageDown);
    m_keyboardTzNegInput->setScale(-1.0f);
    m_keyboardTzNegInput->setSourceDevice(m_keyboardDevice);
    m_tzAxis->addInput(m_keyboardTzNegInput);

    // Keyboard Neg Ty
    m_keyboardTyNegInput->setButtons(QVector<int>() << Qt::Key_Down);
    m_keyboardTyNegInput->setScale(-1.0f);
    m_keyboardTyNegInput->setSourceDevice(m_keyboardDevice);
    m_tyAxis->addInput(m_keyboardTyNegInput);

    //// Logical Device

    m_logicalDevice->addAction(m_leftMouseButtonAction);
    m_logicalDevice->addAction(m_rightMouseButtonAction);
    m_logicalDevice->addAction(m_altButtonAction);
    m_logicalDevice->addAction(m_shiftButtonAction);
    m_logicalDevice->addAxis(m_rxAxis);
    m_logicalDevice->addAxis(m_ryAxis);
    m_logicalDevice->addAxis(m_txAxis);
    m_logicalDevice->addAxis(m_tyAxis);
    m_logicalDevice->addAxis(m_tzAxis);

    Q_Q(QOrbitCameraController);
    //// FrameAction

    QObject::connect(m_frameAction, SIGNAL(triggered(float)),
                     q, SLOT(_q_onTriggered(float)));

    // Disable the logical device when the entity is disabled
    QObject::connect(q, &Qt3DCore::QEntity::enabledChanged,
                     m_logicalDevice, &Qt3DInput::QLogicalDevice::setEnabled);

    q->addComponent(m_frameAction);
    q->addComponent(m_logicalDevice);
}

float clampInputs(float input1, float input2)
{
    float axisValue = input1 + input2;
    return (axisValue < -1) ? -1 : (axisValue > 1) ? 1 : axisValue;
}

float zoomDistance(QVector3D firstPoint, QVector3D secondPoint)
{
    return (secondPoint - firstPoint).lengthSquared();
}

void QOrbitCameraControllerPrivate::_q_onTriggered(float dt)
{
    if (m_camera != nullptr) {
        // Mouse input
        if (m_leftMouseButtonAction->isActive()) {
            if (m_rightMouseButtonAction->isActive()) {
                if ( zoomDistance(m_camera->position(), m_camera->viewCenter()) > m_zoomInLimit * m_zoomInLimit) {
                    // Dolly up to limit
                    m_camera->translate(QVector3D(0, 0, m_ryAxis->value()), m_camera->DontTranslateViewCenter);
                } else {
                    m_camera->translate(QVector3D(0, 0, -0.5), m_camera->DontTranslateViewCenter);
                }
            } else {
                // Translate
                m_camera->translate(QVector3D(clampInputs(m_rxAxis->value(), m_txAxis->value()) * m_linearSpeed,
                                              clampInputs(m_ryAxis->value(), m_tyAxis->value()) * m_linearSpeed,
                                              0) * dt);
                return;
            }
        }
        else if (m_rightMouseButtonAction->isActive()) {
            // Orbit
            m_camera->panAboutViewCenter((m_rxAxis->value() * m_lookSpeed) * dt, m_cameraUp);
            m_camera->tiltAboutViewCenter((m_ryAxis->value() * m_lookSpeed) * dt);
        }
        // Keyboard Input
        if (m_altButtonAction->isActive()) {
            // Orbit
            m_camera->panAboutViewCenter((m_txAxis->value() * m_lookSpeed) * dt, m_cameraUp);
            m_camera->tiltAboutViewCenter((m_tyAxis->value() * m_lookSpeed) * dt);
        } else if (m_shiftButtonAction->isActive()) {
            if (zoomDistance(m_camera->position(), m_camera->viewCenter()) > m_zoomInLimit * m_zoomInLimit) {
                // Dolly
                m_camera->translate(QVector3D(0, 0, m_tyAxis->value()), m_camera->DontTranslateViewCenter);
            } else {
                m_camera->translate(QVector3D(0, 0, -0.5), m_camera->DontTranslateViewCenter);
            }
        } else {
            // Translate
            m_camera->translate(QVector3D(clampInputs(m_leftMouseButtonAction->isActive() ? m_rxAxis->value() : 0, m_txAxis->value()) * m_linearSpeed,
                                          clampInputs(m_leftMouseButtonAction->isActive() ? m_ryAxis->value() : 0, m_tyAxis->value()) * m_linearSpeed,
                                          m_tzAxis->value() * m_linearSpeed) * dt);
        }
    }
}

QOrbitCameraController::QOrbitCameraController(Qt3DCore::QNode *parent)
    : Qt3DCore::QEntity(*new QOrbitCameraControllerPrivate, parent)
{
    Q_D(QOrbitCameraController);
    d->init();
}

QOrbitCameraController::~QOrbitCameraController()
{
}

Qt3DRender::QCamera *QOrbitCameraController::camera() const
{
    Q_D(const QOrbitCameraController);
    return d->m_camera;
}

float QOrbitCameraController::linearSpeed() const
{
    Q_D(const QOrbitCameraController);
    return d->m_linearSpeed;
}

float QOrbitCameraController::lookSpeed() const
{
    Q_D(const QOrbitCameraController);
    return d->m_lookSpeed;
}

float QOrbitCameraController::zoomInLimit() const
{
    Q_D(const QOrbitCameraController);
    return d->m_zoomInLimit;
}

void QOrbitCameraController::setCamera(Qt3DRender::QCamera *camera)
{
    Q_D(QOrbitCameraController);
    if (d->m_camera != camera) {
        d->m_camera = camera;
        emit cameraChanged();
    }
}

void QOrbitCameraController::setLinearSpeed(float linearSpeed)
{
    Q_D(QOrbitCameraController);
    if (d->m_linearSpeed != linearSpeed) {
        d->m_linearSpeed = linearSpeed;
        emit linearSpeedChanged();
    }
}

void QOrbitCameraController::setLookSpeed(float lookSpeed)
{
    Q_D(QOrbitCameraController);
    if (d->m_lookSpeed != lookSpeed) {
        d->m_lookSpeed = lookSpeed;
        emit lookSpeedChanged();
    }
}

void QOrbitCameraController::setZoomInLimit(float zoomInLimit)
{
    Q_D(QOrbitCameraController);
    if (d->m_zoomInLimit != zoomInLimit) {
        d->m_zoomInLimit = zoomInLimit;
        emit zoomInLimitChanged();
    }
}

} // Qt3DExtras

QT_END_NAMESPACE

#include "moc_qorbitcameracontroller.cpp"