/*

* 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:  VideoThumbnailDataPrivate class implementation

*

*/

// INCLUDE FILES

#include <qapplication.h>

#include <qpixmap.h>

#include <qtimer.h>

#include <mpxmediageneraldefs.h>

#include <vcxmyvideosdefs.h>

#include "videothumbnaildata_p.h"

#include "videocollectionwrapper.h"

#include "videosortfilterproxymodel.h"

#include "videothumbnailfetcher.h"

// Maximum thumbnails kept in memory.

const int THUMBNAIL_CACHE_SIZE = 60;

// Maximum of thumbnail fetches done at one background fetch round.

const int THUMBNAIL_BACKGROUND_FETCH_AMOUNT = 20;

// Milliseconds for the background fetch timer.

const int THUMBNAIL_BACKGROUND_TIMEOUT = 100;

// Milliseconds while thumbnail ready events are gathered before they 

// are signaled.

const int THUMBNAIL_READY_SIGNAL_TIMEOUT = 50;

// Priority for background thumbnail fetches.

const int BACKGROUND_FETCH_PRIORITY = 3000;

/**

 * global qHash function required fo creating hash values for TMPXItemId -keys

 */

inline uint qHash(TMPXItemId key) 

{ 

    QPair<uint, uint> keyPair(key.iId1, key.iId2); 

    return qHash(keyPair);

}

// ================= MEMBER FUNCTIONS =======================

//

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::VideoThumbnailDataPrivate()

// -----------------------------------------------------------------------------

//

VideoThumbnailDataPrivate::VideoThumbnailDataPrivate() :

    mThumbnailFetcher(0),

    mCurrentModel(0),

    mCurrentFetchIndex(0),

    mCurrentBackgroundFetchCount(0),

    mBgFetchTimer(0),

    mTbnReportTimer(0),

    mSignalsConnected(false),

    mBackgroundFetchingEnabled(true)

{

    initialize();

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::~VideoThumbnailDataPrivate()

// -----------------------------------------------------------------------------

//

VideoThumbnailDataPrivate::~VideoThumbnailDataPrivate()

{

    cleanup();

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::initialize()

// -----------------------------------------------------------------------------

//

int VideoThumbnailDataPrivate::initialize()

{

    mThumbnailData.setMaxCost(THUMBNAIL_CACHE_SIZE);

    if(!mThumbnailFetcher)

    {

        mThumbnailFetcher = new VideoThumbnailFetcher();        

    }

    if(!mBgFetchTimer)

    {

        mBgFetchTimer = new QTimer();

    }

    if(!mTbnReportTimer)

    {

        mTbnReportTimer = new QTimer();

    }

    if(connectSignals() < 0)

    {

        cleanup();

        return -1;

    }

    return 0;

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::cleanup()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::cleanup()

{

    disconnectSignals();

    delete mThumbnailFetcher;

    mThumbnailFetcher = 0;

    freeThumbnailData();

    if(mTbnReportTimer)

    {

        mTbnReportTimer->stop();

        delete mTbnReportTimer;

        mTbnReportTimer = 0;

    }

    if(mBgFetchTimer)

    {

        mBgFetchTimer->stop();

        delete mBgFetchTimer;

        mBgFetchTimer = 0;

    }

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::disconnectSignals()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::disconnectSignals()

{

    if(mSignalsConnected)

    {

        VideoSortFilterProxyModel *model = 

                VideoCollectionWrapper::instance().getModel(VideoCollectionWrapper::EAllVideos);

        if(model)

            {

            disconnect(model->sourceModel(), SIGNAL(modelReady()), this, SLOT(modelChangedSlot()));

            disconnect(model->sourceModel(), SIGNAL(modelChanged()), this, SLOT(modelChangedSlot()));

            }

		disconnect(mThumbnailFetcher, SIGNAL(thumbnailReady( QPixmap , void *, int )),

                    this, SLOT(thumbnailReadySlot( QPixmap , void *, int )));

        disconnect(mThumbnailFetcher, SIGNAL(allThumbnailsFetched()),

                 this, SLOT(allThumbnailsFetchedSlot()));          

        disconnect(mBgFetchTimer, SIGNAL(timeout()), this, SLOT(doBackgroundFetching()));

        disconnect(mTbnReportTimer, SIGNAL(timeout()), this, SLOT(reportThumbnailsReadySlot()));

    }

    mSignalsConnected = false;

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::connectSignals()

// -----------------------------------------------------------------------------

//

int VideoThumbnailDataPrivate::connectSignals()

{

    if(!mSignalsConnected)

    {

        VideoSortFilterProxyModel *model = 

                VideoCollectionWrapper::instance().getModel(VideoCollectionWrapper::EAllVideos);

        if(!model)

            return -1;

        if(!connect(mThumbnailFetcher, SIGNAL(thumbnailReady( QPixmap , void *, int )),

                    this, SLOT(thumbnailReadySlot( QPixmap , void *, int))) ||

            !connect(mThumbnailFetcher, SIGNAL(allThumbnailsFetched()),

                     this, SLOT(allThumbnailsFetchedSlot())) ||

           !connect(model->sourceModel(), SIGNAL(modelReady()), this, SLOT(modelChangedSlot())) ||

           !connect(model->sourceModel(), SIGNAL(modelChanged()), this, SLOT(modelChangedSlot())) ||

           !connect(mBgFetchTimer, SIGNAL(timeout()), this, SLOT(doBackgroundFetching())) ||

           !connect(mTbnReportTimer, SIGNAL(timeout()), this, SLOT(reportThumbnailsReadySlot())))

        {

            return -1;

        }

        QApplication *app = qApp;

        if(!connect(app, SIGNAL(aboutToQuit()), this, SLOT(aboutToQuitSlot())))

        {

            return -1;

        }

        mSignalsConnected = true;

    }

    return 0;

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::getThumbnail()

// -----------------------------------------------------------------------------

//

const QIcon* VideoThumbnailDataPrivate::getThumbnail(TMPXItemId mediaId)

{

    const QIcon *thumbnail = mThumbnailData[mediaId];

    if(!thumbnail)

    {

        return defaultThumbnail(mediaId);

    }

    return thumbnail;

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::startFetchingThumbnails()

// -----------------------------------------------------------------------------

//

int VideoThumbnailDataPrivate::startFetchingThumbnails(const QList<QModelIndex> &indexes, int priority)

{

    if(!mCurrentModel || !mThumbnailFetcher)

    {

        return -1;

    }

    if(indexes.count() == 0)

    {

        return 0;

    }

    mThumbnailFetcher->pauseFetching();

    int fetchCountBefore = mThumbnailFetcher->fetchCount();

    // Fetch the thumbnails

    for(int i = 0; i < indexes.count(); i++)

    {

        startFetchingThumbnail(mCurrentModel->getMediaIdAtIndex(indexes[i]), priority--);

    }

    int started = mThumbnailFetcher->fetchCount() - fetchCountBefore;

    mThumbnailFetcher->continueFetching();

    return started;

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::startFetchingThumbnail()

// -----------------------------------------------------------------------------

//

int VideoThumbnailDataPrivate::startFetchingThumbnail(TMPXItemId mediaId, int priority)

{

    if(!mCurrentModel || !mThumbnailFetcher)

    {

        return -1;

    }

    // Check that it's not fetched before.

    if(mThumbnailData.contains(mediaId))

    {

        return 0;

    }

    QString fileName = mCurrentModel->getMediaFilePathForId(mediaId);

    // object containing media id to be passed throught

    // thumbnail generation process.

    TMPXItemId *internal = new TMPXItemId(mediaId.iId1, mediaId.iId2);

    // Thumbnail fetcher signals into thumbnailReadySlot when thumbnail ready

    if(fileName.length() > 0)

    {

        mThumbnailFetcher->addFetch(fileName, internal, priority);

    }

    return 0;

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::doBackgroundFetching()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::doBackgroundFetching()

{

    if(!mCurrentModel || !mThumbnailFetcher)

    {

        return;

    }

    if(mCurrentBackgroundFetchCount >= THUMBNAIL_CACHE_SIZE)

    {

        return;

    }

    int maxIndex = mCurrentModel->rowCount();

    if(maxIndex == 0)

    {

        return;

    }

    // Delta to UI index where fetch has been done already.  

    int currentDelta = mCurrentBackgroundFetchCount/2;

    // How many will be fetched.  

    const int fetchAmount = THUMBNAIL_BACKGROUND_FETCH_AMOUNT/2;

    QList<QModelIndex> indexes;

    // Items after the current fetch index.

    int startIndex = mCurrentFetchIndex+currentDelta;

    int endIndex = mCurrentFetchIndex+currentDelta+fetchAmount;

    getModelIndexes(indexes, startIndex, endIndex);

    // Items before the current fetch index.

    startIndex = mCurrentFetchIndex-currentDelta-fetchAmount;

    endIndex = mCurrentFetchIndex-currentDelta;

    getModelIndexes(indexes, startIndex, endIndex);

    mCurrentBackgroundFetchCount += THUMBNAIL_BACKGROUND_FETCH_AMOUNT;

    int fetchesStarted = startFetchingThumbnails(indexes, BACKGROUND_FETCH_PRIORITY);

    // No thumbnails to fetch, start again.

    if(fetchesStarted == 0)

    {

        continueBackgroundFetch();

    }

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::getModelIndexes()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::getModelIndexes(QList<QModelIndex> &indexes, int startIndex, int endIndex)

{

    QModelIndex index;

    for(int i = startIndex; i < endIndex; i++)

    {

        if(i >= 0)

        {

            index = mCurrentModel->index(i, 0);

            if(index.isValid())

            {

                indexes.append(index);

            }

        }

    }

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::thumbnailReadySlot()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::thumbnailReadySlot(QPixmap tnData, void *internal, int error)

{

    TMPXItemId mediaId(0, 0);

    if(internal)

    {

        mediaId = *(static_cast<TMPXItemId*>(internal));

        delete internal;

    }

    else

    {

        return;

    }

    if(!error && !tnData.isNull())

    {

        mThumbnailData.insert(mediaId, new QIcon(tnData));

        // Gather list of media ids and emit thumbnailReady signals in larger set

        // when timer goes off.

        if(mTbnReportTimer && !mTbnReportTimer->isActive())

        {

            mTbnReportTimer->setSingleShot(true);

            mTbnReportTimer->start(THUMBNAIL_READY_SIGNAL_TIMEOUT);

        }

        // Save the media id for the signal.  

        mReadyThumbnailMediaIds.append(mediaId);

    }

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::reportThumbnailsReadySlot()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::reportThumbnailsReadySlot()

{

    emit thumbnailsFetched(mReadyThumbnailMediaIds);

    mReadyThumbnailMediaIds.clear();

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::allThumbnailsFetchedSlot()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::allThumbnailsFetchedSlot()

{

    continueBackgroundFetch();

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::modelChangedSlot()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::modelChangedSlot()

{

    startBackgroundFetching(mCurrentModel, mCurrentFetchIndex);

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::defaultThumbnail()

// -----------------------------------------------------------------------------

//

const QIcon* VideoThumbnailDataPrivate::defaultThumbnail(TMPXItemId mediaId)

{

    if(mediaId.iId2 == KVcxMvcMediaTypeVideo) 

    {

    }

    else

    {

    }

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::removeThumbnail()

// -----------------------------------------------------------------------------

//

bool VideoThumbnailDataPrivate::removeThumbnail(TMPXItemId mediaId)

{

    return mThumbnailData.remove(mediaId);

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::enableBackgroundFetching()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::enableBackgroundFetching(bool enable)

{

    mBackgroundFetchingEnabled = enable;

    startBackgroundFetching(mCurrentModel, 0);

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::enableThumbnailCreation()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::enableThumbnailCreation(bool enable)

{

    if(mThumbnailFetcher)

        mThumbnailFetcher->enableThumbnailCreation(enable);

}

// -----------------------------------------------------------------------------

// VideoThumbnailDataPrivate::freeThumbnailData()

// -----------------------------------------------------------------------------

//

void VideoThumbnailDataPrivate::freeThumbnailData()

{

    // Stop timers.