/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

#include <QObject> // Compiler flags, keep first

#ifdef Q_OS_SYMBIAN

#include <coemain.h>

#endif // Q_OS_SYMBIAN

#include "cxutils.h"

#include "cxesysutil.h"

#include "cxesettings.h"

#include "cxediskmonitor.h"

#include "cxediskmonitorprivate.h"

namespace

{

    const int MONITORING_INTERVAL = 2*1000; // in milliseconds

    const int UNKNOWN = -1;

}

/*!

* Constructor.

*/

CxeDiskMonitorPrivate::CxeDiskMonitorPrivate(CxeSettings &settings)

    : mSettings(settings),

      mTimer(),

#ifdef Q_OS_SYMBIAN

      mFs(CCoeEnv::Static()->FsSession()),

      mCameraDrive(CxeSysUtil::getCameraDrive(mFs)),

#endif // Q_OS_SYMBIAN

      mTriggerLevelBytes(UNKNOWN),

      mLatestFreeBytes(UNKNOWN)

{

    CX_DEBUG_ENTER_FUNCTION();

    CX_DEBUG_EXIT_FUNCTION();

}

/*!

* Destructor.

*/

CxeDiskMonitorPrivate::~CxeDiskMonitorPrivate()

{

    CX_DEBUG_ENTER_FUNCTION();

    stop();

    CX_DEBUG_EXIT_FUNCTION();

}

/*!

* Slot for checking if the available disk space is below warning trigger level.

*/

void CxeDiskMonitorPrivate::checkSpace()

{

    CX_DEBUG_ENTER_FUNCTION();

    qint64 previousFree(mLatestFreeBytes);

    // Get the current free space.

    mLatestFreeBytes = free(false);

    // TESTING >>>

    /*

    static qint64 TEST = 20*1000*1000;

    TEST /= 2;

    mLatestFreeBytes = TEST;

    */

    // <<< TESTING

    // If space has changed during monitoring, signal it now.

    if (previousFree != mLatestFreeBytes && isMonitoring()) {

        CX_DEBUG(("CxeDiskMonitorPrivate - Disk space changed %d -> %d bytes", previousFree, mLatestFreeBytes));

        emit diskSpaceChanged();

    }

    // Only emit warning if trigger level is set to some positive value.

    // Otherwise updating cached free space value is enough.

    if (mTriggerLevelBytes != UNKNOWN && mLatestFreeBytes < mTriggerLevelBytes) {

        CX_DEBUG(("[WARNING] CxeDiskMonitorPrivate - Disk space low!"));

        emit diskSpaceLow();

    }

    CX_DEBUG_EXIT_FUNCTION();

}

/*!

* Set the warning level of free disk space.

* When free disk space falls below this limit, diskSpaceLow() signal is emitted.

* @param bytes Limit in bytes.

*/

void CxeDiskMonitorPrivate::setLowWarningLevel(qint64 bytes)

{

    mTriggerLevelBytes = bytes;

}

/*!

* Start monitoring disk space.

*/

void CxeDiskMonitorPrivate::start()

{

    if (!mTimer.isActive()) {

        connect(&mTimer, SIGNAL(timeout()), this, SLOT(checkSpace()), Qt::UniqueConnection);

        mTimer.start(MONITORING_INTERVAL);

    }

}

/*!

* Stop monitoring disk space.

*/

void CxeDiskMonitorPrivate::stop()

{

    mTimer.stop();

    mLatestFreeBytes = UNKNOWN;

}

/*!

* Is monitoring ongoing at the moment.

*/

bool CxeDiskMonitorPrivate::isMonitoring() const

{

    return mTimer.isActive();

}

/*!

* Get free disk space for Camera use in bytes.

* @param cached Can cached value be used.

* If true (default value), value of last constant-interval-check is used (if it exists).

* If false (or there's no cached value), forced reading of free space is done now.

* This may cause significant delay compared to returning cached value.

*/

qint64 CxeDiskMonitorPrivate::free(bool cached) const

{

    qint64 value(0);

    if (cached && mLatestFreeBytes != UNKNOWN) {

        value = mLatestFreeBytes;

    } else {

        value = CxeSysUtil::spaceAvailable(mFs, mCameraDrive, mSettings);

    }

    return value;

}

// end of file