/****************************************************************************
**
** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (developer.feedback@nokia.com)
**
** This file is part of the HbCore module of the UI Extensions for Mobile.
**
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this file.
** Please review the following information to ensure the GNU Lesser General
** Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at developer.feedback@nokia.com.
**
****************************************************************************/

#include "hbpangesture.h"
#include "hbpangesturelogic_p.h"
#include "hbgestures_p.h"

#include "hbnamespace_p.h"
#include <hbdeviceprofile.h>

#include <QEvent>
#include <QGestureRecognizer>
#include <QGraphicsView>
#include <QMouseEvent>
#include <QGraphicsScene>


#define followedTouchPoint(te, gesture) te->touchPoints().at(followedTouchPointIndex(te, gesture))

/*!
   @hbcore
   \internal
   \class HbPanGestureLogic

   \brief

*/


/*!
    \internal
    \brief
    \return

*/
HbPanGestureLogic::HbPanGestureLogic()
{
}

HbPanGestureLogic::~HbPanGestureLogic() {}

/*!
    \internal
    \brief
    \return

*/
bool HbPanGestureLogic::isMouseEvent(QEvent::Type eventType)
{
    return eventType == QEvent::MouseButtonPress ||
            eventType == QEvent::MouseMove ||
            eventType == QEvent::MouseButtonDblClick ||
            eventType == QEvent::MouseButtonRelease;
}

/*!
    \internal
    \brief
    \return

*/
bool HbPanGestureLogic::isTouchEvent(QEvent::Type eventType)
{
    return eventType == QEvent::TouchBegin ||
            eventType == QEvent::TouchEnd ||
            eventType == QEvent::TouchUpdate;
}

/*!
    \internal
    \brief
    \return

*/
void HbPanGestureLogic::resetGesture(HbPanGesture *gesture)
{
    gesture->d_ptr->mStartPos                     = QPointF(0,0);
    gesture->d_ptr->mDeltaSinceLastTimeStamp      = QPointF(0,0);
    gesture->d_ptr->mSceneStartPos                = QPointF(0,0);
    gesture->d_ptr->mSceneLastOffset              = QPointF(0,0);
    gesture->d_ptr->mSceneOffset                  = QPointF(0,0);
    gesture->d_ptr->mSceneDeltaSinceLastTimeStamp = QPointF(0,0);
    gesture->d_ptr->mAxisX.resetRecorder();
    gesture->d_ptr->mAxisY.resetRecorder();
    gesture->d_ptr->mSceneAxisX.resetRecorder();
    gesture->d_ptr->mSceneAxisY.resetRecorder();

    gesture->setLastOffset(QPointF());
    gesture->setOffset(QPointF(0,0));
    gesture->setAcceleration(0);
    gesture->setStartPos(QPointF());

    gesture->d_ptr->mIgnoreMouseEvents = false;
    gesture->d_ptr->mFollowedTouchPointId = 0;
}

/*!
    \internal
    \brief
    \return

*/
QGestureRecognizer::Result HbPanGestureLogic::handleMousePress(
        Qt::GestureState gestureState,
        HbPanGesture *gesture,
        QObject *watched,
        QMouseEvent *me,
        qint64 currentTime )
{
    // Just ignore situations that are not interesting at all.
    if ( !( gestureState == Qt::NoGesture && me->button() == Qt::LeftButton ) )
    {
        return QGestureRecognizer::Ignore;
    }

    gesture->setHotSpot( me->globalPos() );
    gesture->setStartPos( me->globalPos() );
    gesture->setOffset( QPointF( 0,0 ) );
    gesture->setLastOffset( QPointF( 0,0 ) );
    QPointF scenePos = HbGestureUtils::mapToScene(watched, me->globalPos());
    gesture->d_ptr->mSceneStartPos       = scenePos;
    gesture->d_ptr->mSceneOffset         = HbGestureUtils::mapToScene(watched, QPointF(0,0));
    gesture->d_ptr->mSceneLastOffset     = HbGestureUtils::mapToScene(watched, QPointF(0,0));
    gesture->d_ptr->mLastTimeStamp = currentTime;


    gesture->d_ptr->mThresholdSquare = HbDefaultPanThreshold * HbDeviceProfile::current().ppmValue();
    gesture->d_ptr->mThresholdSquare = gesture->d_ptr->mThresholdSquare * gesture->d_ptr->mThresholdSquare;

    qreal velocityThreshold = HbPanVelocityUpdateThreshold * HbDeviceProfile::current().ppmValue();

    gesture->d_ptr->mAxisX.resetRecorder(velocityThreshold);
    gesture->d_ptr->mAxisY.resetRecorder(velocityThreshold);
    gesture->d_ptr->mSceneAxisX.resetRecorder(velocityThreshold);
    gesture->d_ptr->mSceneAxisY.resetRecorder(velocityThreshold);
    gesture->d_ptr->mAxisX.record( me->globalPos().x(), currentTime );
    gesture->d_ptr->mAxisY.record( me->globalPos().y(), currentTime );
    gesture->d_ptr->mSceneAxisX.record( scenePos.x(), currentTime );
    gesture->d_ptr->mSceneAxisY.record( scenePos.y(), currentTime );

    return QGestureRecognizer::MayBeGesture;
}

/*!
    \internal
    \brief
    \return

*/
QGestureRecognizer::Result HbPanGestureLogic::handleMouseMove(
        Qt::GestureState gestureState,
        HbPanGesture *gesture,
        QObject *watched,
        QMouseEvent *me,
        qint64 currentTime )
{
    if ( !me->buttons().testFlag(Qt::LeftButton))
    {
        return QGestureRecognizer::Ignore;
    }

    QPointF offset = me->globalPos() - gesture->startPos().toPoint();
    gesture->setLastOffset( gesture->offset().toPoint() );
    gesture->setOffset( offset );
    gesture->d_ptr->mSceneLastOffset = gesture->d_ptr->mSceneOffset;
    gesture->d_ptr->mSceneOffset =
            HbGestureUtils::mapToScene(watched, me->globalPos()) - gesture->d_ptr->mSceneStartPos;
    gesture->d_ptr->mLastTimeStamp = currentTime;

    QPointF scenePos = HbGestureUtils::mapToScene(watched, me->globalPos());
    gesture->d_ptr->mAxisX.record( me->globalPos().x(), currentTime );
    gesture->d_ptr->mAxisY.record( me->globalPos().y(), currentTime );
    gesture->d_ptr->mSceneAxisX.record( scenePos.x(), currentTime );
    gesture->d_ptr->mSceneAxisY.record( scenePos.y(), currentTime );


    QGraphicsView* view = qobject_cast<QGraphicsView*>(watched->parent());
    if (view) {
        QGraphicsScene* scene = view->scene();
        if (scene && scene->property(HbPrivate::OverridingGesture.latin1()).isValid() &&
            scene->property(HbPrivate::OverridingGesture.latin1()).toInt() != Qt::PanGesture) {
            return QGestureRecognizer::MayBeGesture;
        }
    }

    if (gestureState == Qt::NoGesture && (offset.x() * offset.x() + offset.y() * offset.y()) <= gesture->d_ptr->mThresholdSquare) {
        return QGestureRecognizer::MayBeGesture;
    }

    // Hotspot is updated on the press and on events after the gesture started.
    // Here we are checking the previously set gestureState.
    if (gestureState == Qt::GestureStarted || gestureState == Qt::GestureUpdated) {
        gesture->setHotSpot( me->globalPos() );
    }


    return QGestureRecognizer::TriggerGesture;
}

/*!
    \internal
    \brief
    \return

*/
QGestureRecognizer::Result HbPanGestureLogic::handleMouseRelease(
        Qt::GestureState gestureState,
        HbPanGesture *gesture,
        QObject *watched,
        QMouseEvent *me,
        qint64 currentTime)
{
    Q_UNUSED(me);
    Q_UNUSED(gesture);
    Q_UNUSED(watched);

    gesture->d_ptr->mLastTimeStamp = currentTime;

    if ( gestureState == Qt::GestureStarted || gestureState == Qt::GestureUpdated )
    {
        return QGestureRecognizer::FinishGesture;
    }
    else
    {
        QPointF offset(gesture->offset());
        bool thresholdExceeded = (offset.x() * offset.x() + offset.y() * offset.y()) > gesture->d_ptr->mThresholdSquare;
        if( thresholdExceeded ) {
            QGraphicsView* view = qobject_cast<QGraphicsView*>(watched->parent());
            if (view) {
                QGraphicsScene* scene = view->scene();
                if (scene && scene->property(HbPrivate::OverridingGesture.latin1()).isValid() &&
                    scene->property(HbPrivate::OverridingGesture.latin1()).toInt() != Qt::PanGesture) {
                    return QGestureRecognizer::CancelGesture;
                }
            }
            return QGestureRecognizer::FinishGesture;
        }

        return QGestureRecognizer::CancelGesture;
    }
}

/*!
    \internal
    \brief
    \return

*/
QGestureRecognizer::Result HbPanGestureLogic::handleTouchBegin(
        Qt::GestureState gestureState,
        HbPanGesture *gesture,
        QObject *watched,
        QTouchEvent *te,
        qint64 currentTime)
{
    gesture->d_ptr->mFollowedTouchPointId = getNextId(te);

    if(gesture->d_ptr->mFollowedTouchPointId == -1 && gestureState != Qt::NoGesture) {
        return QGestureRecognizer::FinishGesture; // if all touchpoints are released
    }

    QTouchEvent::TouchPoint tp = followedTouchPoint(te, gesture);
    QPointF scenePos = HbGestureUtils::mapToScene(watched, tp.screenPos());

    gesture->setHotSpot(tp.screenPos()) ;
    gesture->setStartPos(tp.screenPos());
    gesture->setOffset( QPointF( 0,0 ) );
    gesture->setLastOffset( QPointF( 0,0 ) );

    gesture->d_ptr->mSceneStartPos       = scenePos;
    gesture->d_ptr->mSceneOffset         = QPointF(0,0);
    gesture->d_ptr->mSceneLastOffset     = QPointF(0,0);
    gesture->d_ptr->mLastTimeStamp = currentTime;

    qreal defaultThreshold = HbDefaultPanThreshold * HbDeviceProfile::current().ppmValue();
    gesture->d_ptr->mThresholdSquare = defaultThreshold * defaultThreshold;

    gesture->d_ptr->mAxisX.resetRecorder(defaultThreshold);
    gesture->d_ptr->mAxisY.resetRecorder(defaultThreshold);
    gesture->d_ptr->mSceneAxisX.resetRecorder(defaultThreshold);
    gesture->d_ptr->mSceneAxisY.resetRecorder(defaultThreshold);
    gesture->d_ptr->mAxisY.record( tp.screenPos().y(), currentTime );
    gesture->d_ptr->mAxisX.record( tp.screenPos().x(), currentTime );
    gesture->d_ptr->mSceneAxisX.record( scenePos.x(), currentTime );
    gesture->d_ptr->mSceneAxisY.record( scenePos.y(), currentTime );

    if (gestureState != Qt::NoGesture) {
        return QGestureRecognizer::Ignore;
    } else {
        return QGestureRecognizer::MayBeGesture;
    }
}

/*!
    \internal
    \brief
    \return

*/
QGestureRecognizer::Result HbPanGestureLogic::handleTouchMove(
        Qt::GestureState gestureState,
        HbPanGesture *gesture,
        QObject *watched,
        QTouchEvent *te,
        qint64 currentTime)
{
    QTouchEvent::TouchPoint tp = followedTouchPoint(te, gesture);

    // touch event handling has already started
    // need to update position and offset
    QPointF offset = tp.screenPos() - gesture->startPos();
    if (tp.lastScreenPos() == tp.screenPos()) {
        return QGestureRecognizer::Ignore;
    }
    if (gestureState == Qt::NoGesture && (offset.x() * offset.x() + offset.y() * offset.y()) <= gesture->d_ptr->mThresholdSquare) {

        return QGestureRecognizer::MayBeGesture;
    }

    // Hotspot is updated on the press and on events after the gesture started.
    // Here we are checking the previously set gestureState.
    if (gestureState == Qt::GestureStarted || gestureState == Qt::GestureUpdated) {
        gesture->setHotSpot( tp.screenPos() );
    }

    gesture->setLastOffset( gesture->offset().toPoint() );
    gesture->setOffset( offset );
    gesture->d_ptr->mSceneLastOffset = gesture->d_ptr->mSceneOffset;
    gesture->d_ptr->mSceneOffset =
            HbGestureUtils::mapToScene(watched, tp.screenPos()) - gesture->d_ptr->mSceneStartPos;
    gesture->d_ptr->mLastTimeStamp = currentTime;

    gesture->d_ptr->mAxisX.record( tp.screenPos().x(), currentTime );
    gesture->d_ptr->mAxisY.record( tp.screenPos().y(), currentTime );
    QPointF scenePos = HbGestureUtils::mapToScene(watched, tp.screenPos());
    gesture->d_ptr->mSceneAxisX.record( scenePos.x(), currentTime );
    gesture->d_ptr->mSceneAxisY.record( scenePos.y(), currentTime );

    QGraphicsView* view = qobject_cast<QGraphicsView*>(watched->parent());
    if (view) {
        QGraphicsScene* scene = view->scene();
        if (scene && scene->property(HbPrivate::OverridingGesture.latin1()).isValid() &&
            scene->property(HbPrivate::OverridingGesture.latin1()).toInt() != Qt::PanGesture) {
            return QGestureRecognizer::MayBeGesture;
        }
    }

    return QGestureRecognizer::TriggerGesture;
}

/*!
    \internal
    \brief
    \return

*/
QGestureRecognizer::Result HbPanGestureLogic::handleTouchEnd(
        Qt::GestureState gestureState,
        HbPanGesture *gesture,
        QObject *watched,
        QTouchEvent *te,
        qint64 currentTime)
{
    Q_UNUSED(te);
    Q_UNUSED(gesture);
    Q_UNUSED(watched);

    gesture->d_ptr->mLastTimeStamp = currentTime;

    if ( gestureState == Qt::GestureStarted || gestureState == Qt::GestureUpdated )
    {
        return QGestureRecognizer::FinishGesture;
    }
    else
    {
        return QGestureRecognizer::CancelGesture;
    }
}


/*!
    \internal
    \brief
    \return

*/
QGestureRecognizer::Result HbPanGestureLogic::recognize(
        Qt::GestureState gestureState,
        HbPanGesture *gesture,
        QObject *watched,
        QEvent *event,
        qint64 currentTime)
{
    if ( isMouseEvent(event->type()) )
    {
        if (gesture->d_ptr->mIgnoreMouseEvents) {
            return QGestureRecognizer::Ignore;
        }
        QMouseEvent* me = static_cast<QMouseEvent*>(event);
        switch(event->type())
        {
        case QEvent::MouseButtonDblClick:
        case QEvent::MouseButtonPress:
            return handleMousePress(gestureState, gesture, watched, me, currentTime);
        case QEvent::MouseMove:
            return handleMouseMove(gestureState, gesture, watched, me, currentTime);
        case QEvent::MouseButtonRelease:
            return handleMouseRelease(gestureState, gesture, watched, me, currentTime);
        default: break;
        }
    }
    if (isTouchEvent(event->type()) && watched->isWidgetType() ) {

        QTouchEvent *te = static_cast<QTouchEvent *>(event);

        switch(event->type())
        {
        case QEvent::TouchBegin:
            return handleTouchBegin(gestureState, gesture, watched, te, currentTime);
        case QEvent::TouchUpdate: {
                gesture->d_ptr->mIgnoreMouseEvents = true;

                if (followedTouchPoint(te, gesture).state() == Qt::TouchPointReleased) {
                    //qDebug() << "---- Finger changed ----";
                    return handleTouchBegin(gestureState, gesture, watched, te, currentTime);
                }
                if (followedTouchPoint(te, gesture).state() == Qt::TouchPointMoved) {
                    return handleTouchMove(gestureState, gesture, watched, te, currentTime);
                }
                break;
            }
        case QEvent::TouchEnd:
            //qDebug() << "===== TOUCHEND ======" ;
            gesture->d_ptr->mIgnoreMouseEvents = false;
            return handleTouchEnd(gestureState, gesture, watched, te, currentTime);
        default:
            break;
        }
    }
    return QGestureRecognizer::Ignore;
}

/*!
    \internal
    \brief
    \return

*/
int HbPanGestureLogic::followedTouchPointIndex(QTouchEvent *te, HbPanGesture *gesture)
{
    for(int index(0); index < te->touchPoints().count(); index++) {
        if (te->touchPoints().at(index).id() == gesture->d_ptr->mFollowedTouchPointId) {
            return index;
        }
    }
    Q_ASSERT(false);
    return -1;
}

/*!
    \internal
    \brief
    \return

*/
int HbPanGestureLogic::getNextId(QTouchEvent *te)
{
    for (int i(0); i < te->touchPoints().count(); i++) {
        if (te->touchPoints().at(i).state() != Qt::TouchPointReleased) {
            return te->touchPoints().at(i).id();
        }
    }
    return -1;
}