/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the QtSensors module of the Qt Toolkit.
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** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
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** General Public License version 2.1 requirements will be met:
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** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
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** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
**
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** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
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** $QT_END_LICENSE$
**
****************************************************************************/

#include "qslamgesturerecognizer.h"
#include "qtsensorgesturesensorhandler.h"

#include <QtCore/qmath.h>

QT_BEGIN_NAMESPACE

QSlamSensorGestureRecognizer::QSlamSensorGestureRecognizer(QObject *parent) :
    QSensorGestureRecognizer(parent),
    orientationReading(0),
    accelRange(0),
    active(0),
    lastX(0),
    lastY(0),
    lastZ(0),
    detectedX(0),
    detecting(0),
    accelX(0),
    roll(0),
    resting(0)
{
}

QSlamSensorGestureRecognizer::~QSlamSensorGestureRecognizer()
{
}

void QSlamSensorGestureRecognizer::create()
{
    timer = new QTimer(this);
    connect(timer,SIGNAL(timeout()),this,SLOT(checkForSlam()));
    timer->setSingleShot(true);
    timer->setInterval(500);
}


QString QSlamSensorGestureRecognizer::id() const
{
    return QString("QtSensors.slam");
}

bool QSlamSensorGestureRecognizer::start()
{
    if (QtSensorGestureSensorHandler::instance()->startSensor(QtSensorGestureSensorHandler::Accel)) {
        if (QtSensorGestureSensorHandler::instance()->startSensor(QtSensorGestureSensorHandler::Orientation)) {
            active = true;
            accelRange = QtSensorGestureSensorHandler::instance()->accelRange;
            connect(QtSensorGestureSensorHandler::instance(),SIGNAL(orientationReadingChanged(QOrientationReading *)),
                    this,SLOT(orientationReadingChanged(QOrientationReading *)));

            connect(QtSensorGestureSensorHandler::instance(),SIGNAL(accelReadingChanged(QAccelerometerReading *)),
                    this,SLOT(accelChanged(QAccelerometerReading *)));
        } else {
            QtSensorGestureSensorHandler::instance()->stopSensor(QtSensorGestureSensorHandler::Accel);
            active = false;
        }
    } else {
        active = false;
    }
    return active;
}

bool QSlamSensorGestureRecognizer::stop()
{
    QtSensorGestureSensorHandler::instance()->stopSensor(QtSensorGestureSensorHandler::Accel);
    QtSensorGestureSensorHandler::instance()->stopSensor(QtSensorGestureSensorHandler::Orientation);
    disconnect(QtSensorGestureSensorHandler::instance(),SIGNAL(orientationReadingChanged(QOrientationReading *)),
            this,SLOT(orientationReadingChanged(QOrientationReading *)));

    disconnect(QtSensorGestureSensorHandler::instance(),SIGNAL(accelReadingChanged(QAccelerometerReading *)),
            this,SLOT(accelChanged(QAccelerometerReading *)));
    active = false;
    return active;
}

bool QSlamSensorGestureRecognizer::isActive()
{
    return active;
}

void QSlamSensorGestureRecognizer::orientationReadingChanged(QOrientationReading *reading)
{
    orientationReading = reading;
}

#define SLAM_DETECTION_FACTOR 0.15 // 5.85

#define SLAM_Y_DEGREES 15

#define RADIANS_TO_DEGREES 57.2957795

void QSlamSensorGestureRecognizer::accelChanged(QAccelerometerReading *reading)
{
    const qreal x = reading->x();
    const qreal y = reading->y();
    const qreal z = reading->z();

    if (qAbs(lastX - x) < 2 && qAbs(lastY - y) < 2 && qAbs(lastZ - z) < 2) {
        resting = true;
    } else {
        resting = false;
    }

    if (restingList.count() > 5)
        restingList.removeLast();
    restingList.insert(0, resting);

    if (xList.count() > 15)
        xList.removeLast();
    xList.insert(0, x);

    if (orientationReading == 0)
        return;

    const qreal difference = lastX - x;

    roll = qAtan(x / qSqrt(y*y + z*z)) * RADIANS_TO_DEGREES;

    if (!timer->isActive()
            && detecting
            && (orientationReading->orientation() == QOrientationReading::RightUp
                || orientationReading->orientation() == QOrientationReading::LeftUp)
            && resting) {
        timer->start();
    }

    if (!detecting
            && orientationReading->orientation() == QOrientationReading::TopUp
            && roll < SLAM_Y_DEGREES
            && (difference > accelRange * SLAM_DETECTION_FACTOR
                || difference < -accelRange * SLAM_DETECTION_FACTOR)) {
        detectedX = x;
        // start of gesture
        detecting = true;
        if (difference > 0)
            wasNegative = false;
        else
            wasNegative = true;
        restingList.clear();
    }

    lastX = x;
    lastY = y;
    lastZ = z;
}

void QSlamSensorGestureRecognizer:: checkForSlam()
{

    for (int i = 0; i < restingList.count() - 1; i++) {
        if (!restingList.at(i)) {
            detecting = false;
            return;
        }
    }

    if (detecting && (orientationReading->orientation() == QOrientationReading::RightUp // 3 or 4
                      || orientationReading->orientation() == QOrientationReading::LeftUp)) {
        Q_EMIT slam();
        Q_EMIT detected("slam");
    }

    detecting = false;
}

QT_END_NAMESPACE