/****************************************************************************
**
** 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 TORRENTCLIENT_H
#define TORRENTCLIENT_H

#include <QBitArray>
#include <QHostAddress>
#include <QList>

class MetaInfo;
class PeerWireClient;
class TorrentClientPrivate;
class TorrentPeer;
class TorrentPiece;
QT_BEGIN_NAMESPACE
class QTimerEvent;
QT_END_NAMESPACE

class TorrentPeer {
public:
    QHostAddress address;
    quint16 port;
    QString id;
    bool interesting;
    bool seed;
    uint lastVisited;
    uint connectStart;
    uint connectTime;
    QBitArray pieces;
    int numCompletedPieces;

    inline bool operator==(const TorrentPeer &other)
    {
        return port == other.port
            && address == other.address
            && id == other.id;
    }
};

class TorrentClient : public QObject
{
    Q_OBJECT

public:
    enum State {
        Idle,
        Paused,
        Stopping,
        Preparing,
        Searching,
        Connecting,
        WarmingUp,
        Downloading,
        Endgame,
        Seeding
    };
    enum Error {
        UnknownError,
        TorrentParseError,
        InvalidTrackerError,
        FileError,
        ServerError
    };

    TorrentClient(QObject *parent = 0);
    ~TorrentClient();

    bool setTorrent(const QString &fileName);
    bool setTorrent(const QByteArray &torrentData);
    MetaInfo metaInfo() const;

    void setMaxConnections(int connections);
    int maxConnections() const;

    void setDestinationFolder(const QString &directory);
    QString destinationFolder() const;

    void setDumpedState(const QByteArray &dumpedState);
    QByteArray dumpedState() const;

    // Progress and stats for download feedback.
    qint64 progress() const;
    void setDownloadedBytes(qint64 bytes);
    qint64 downloadedBytes() const;
    void setUploadedBytes(qint64 bytes);
    qint64 uploadedBytes() const;
    int connectedPeerCount() const;
    int seedCount() const;
   
    // Accessors for the tracker
    QByteArray peerId() const;
    QByteArray infoHash() const;
    quint16 serverPort() const;

    // State and error.
    State state() const;
    QString stateString() const;
    Error error() const;
    QString errorString() const;

signals:
    void stateChanged(TorrentClient::State state);
    void error(TorrentClient::Error error);

    void downloadCompleted();
    void peerInfoUpdated();
    
    void dataSent(int uploadedBytes);
    void dataReceived(int downloadedBytes);
    void progressUpdated(int percentProgress);
    void downloadRateUpdated(int bytesPerSecond);
    void uploadRateUpdated(int bytesPerSecond);

    void stopped();

public slots:
    void start();
    void stop();
    void setPaused(bool paused);
    void setupIncomingConnection(PeerWireClient *client);

protected slots:
    void timerEvent(QTimerEvent *event);

private slots:
    // File management
    void sendToPeer(int readId, int pieceIndex, int begin, const QByteArray &data);
    void fullVerificationDone();
    void pieceVerified(int pieceIndex, bool ok);
    void handleFileError();

    // Connection handling
    void connectToPeers();
    QList<TorrentPeer *> weighedFreePeers() const;
    void setupOutgoingConnection();
    void initializeConnection(PeerWireClient *client);
    void removeClient();
    void peerPiecesAvailable(const QBitArray &pieces);
    void peerRequestsBlock(int pieceIndex, int begin, int length);
    void blockReceived(int pieceIndex, int begin, const QByteArray &data);
    void peerWireBytesWritten(qint64 bytes);
    void peerWireBytesReceived(qint64 bytes);
    int blocksLeftForPiece(const TorrentPiece *piece) const;

    // Scheduling
    void scheduleUploads();
    void scheduleDownloads();
    void schedulePieceForClient(PeerWireClient *client);
    void requestMore(PeerWireClient *client);
    int requestBlocks(PeerWireClient *client, TorrentPiece *piece, int maxBlocks);
    void peerChoked();
    void peerUnchoked();

    // Tracker handling
    void addToPeerList(const QList<TorrentPeer> &peerList);
    void trackerStopped();

    // Progress
    void updateProgress(int progress = -1);

private:
    TorrentClientPrivate *d;
    friend class TorrentClientPrivate;
};

#endif