/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, 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 qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef FILEMANAGER_H
#define FILEMANAGER_H

#include <QBitArray>
#include <QList>
#include <QMutex>
#include <QThread>
#include <QWaitCondition>

#include "metainfo.h"

QT_BEGIN_NAMESPACE
class QByteArray;
class QFile;
class QTimerEvent;
QT_END_NAMESPACE

class FileManager : public QThread
{
    Q_OBJECT

public:
    FileManager(QObject *parent = 0);
    virtual ~FileManager();

    inline void setMetaInfo(const MetaInfo &info) { metaInfo = info; }
    inline void setDestinationFolder(const QString &directory) { destinationPath = directory; }
    
    int read(int pieceIndex, int offset, int length);
    void write(int pieceIndex, int offset, const QByteArray &data);
    void verifyPiece(int pieceIndex);
    inline qint64 totalSize() const { return totalLength; }

    inline int pieceCount() const { return numPieces; }
    int pieceLengthAt(int pieceIndex) const;

    QBitArray completedPieces() const;
    void setCompletedPieces(const QBitArray &pieces);

    QString errorString() const;

public slots:
    void startDataVerification();

signals:
    void dataRead(int id, int pieceIndex, int offset, const QByteArray &data);
    void error();
    void verificationProgress(int percent);
    void verificationDone();
    void pieceVerified(int pieceIndex, bool verified);

protected:
    void run();

private slots:
    bool verifySinglePiece(int pieceIndex);
    void wakeUp();

private:
    bool generateFiles();
    QByteArray readBlock(int pieceIndex, int offset, int length);
    bool writeBlock(int pieceIndex, int offset, const QByteArray &data);
    void verifyFileContents();

    struct WriteRequest {
        int pieceIndex;
        int offset;
        QByteArray data;
    };
    struct ReadRequest {
        int pieceIndex;
        int offset;
        int length;
        int id;
    };

    QString errString;
    QString destinationPath;
    MetaInfo metaInfo;
    QList<QFile *> files;
    QList<QByteArray> sha1s;
    QBitArray verifiedPieces;

    bool newFile;
    int pieceLength;
    qint64 totalLength;
    int numPieces;
    int readId;
    bool startVerification;
    bool quit;
    bool wokeUp;

    QList<WriteRequest> writeRequests;
    QList<ReadRequest> readRequests;
    QList<int> pendingVerificationRequests;
    QList<int> newPendingVerificationRequests;
    QList<qint64> fileSizes;

    mutable QMutex mutex;
    mutable QWaitCondition cond;
};

#endif