/****************************************************************************

**

** 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.

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#ifndef PEERWIRECLIENT_H

#define PEERWIRECLIENT_H

#include <QBitArray>

#include <QList>

#include <QTcpSocket>

QT_BEGIN_NAMESPACE

class QHostAddress;

class QTimerEvent;

QT_END_NAMESPACE

class TorrentPeer;

struct TorrentBlock

{

    inline TorrentBlock(int p, int o, int l)

        : pieceIndex(p), offset(o), length(l)

    {

    }

    inline bool operator==(const TorrentBlock &other) const

    {

        return pieceIndex == other.pieceIndex

                && offset == other.offset

                && length == other.length;

    }

    int pieceIndex;

    int offset;

    int length;

};

class PeerWireClient : public QTcpSocket

{

    Q_OBJECT

public:

    enum PeerWireStateFlag {

        ChokingPeer = 0x1,

        InterestedInPeer = 0x2,

        ChokedByPeer = 0x4,

        PeerIsInterested = 0x8

    };

    Q_DECLARE_FLAGS(PeerWireState, PeerWireStateFlag)

    PeerWireClient(const QByteArray &peerId, QObject *parent = 0);

    void initialize(const QByteArray &infoHash, int pieceCount);

    void setPeer(TorrentPeer *peer);

    TorrentPeer *peer() const;

    // State

    inline PeerWireState peerWireState() const { return pwState; }

    QBitArray availablePieces() const;

    QList<TorrentBlock> incomingBlocks() const;

    // Protocol

    void chokePeer();

    void unchokePeer();

    void sendInterested();

    void sendKeepAlive();

    void sendNotInterested();

    void sendPieceNotification(int piece);

    void sendPieceList(const QBitArray &bitField);

    void requestBlock(int piece, int offset, int length);

    void cancelRequest(int piece, int offset, int length);

    void sendBlock(int piece, int offset, const QByteArray &data);

    // Rate control

    qint64 writeToSocket(qint64 bytes);

    qint64 readFromSocket(qint64 bytes);

    qint64 downloadSpeed() const;

    qint64 uploadSpeed() const;

    bool canTransferMore() const;

    qint64 bytesAvailable() const { return incomingBuffer.size() + QTcpSocket::bytesAvailable(); }

    qint64 socketBytesAvailable() const { return socket.bytesAvailable(); }

    qint64 socketBytesToWrite() const { return socket.bytesToWrite(); }

    void setReadBufferSize(int size);

signals:

    void infoHashReceived(const QByteArray &infoHash);

    void readyToTransfer();

    void choked();

    void unchoked();

    void interested();

    void notInterested();

    void piecesAvailable(const QBitArray &pieces);

    void blockRequested(int pieceIndex, int begin, int length);

    void blockReceived(int pieceIndex, int begin, const QByteArray &data);

    void bytesReceived(qint64 size);

protected slots:

    void connectToHostImplementation(const QString &hostName,

                                     quint16 port, OpenMode openMode = ReadWrite);

    void diconnectFromHostImplementation();

protected:

    void timerEvent(QTimerEvent *event);

    qint64 readData(char *data, qint64 maxlen);

    qint64 readLineData(char *data, qint64 maxlen);

    qint64 writeData(const char *data, qint64 len);

private slots:

    void sendHandShake();

    void processIncomingData();

    void socketStateChanged(QAbstractSocket::SocketState state);

private:

    // Data waiting to be read/written

    QByteArray incomingBuffer;

    QByteArray outgoingBuffer;

    struct BlockInfo {

        int pieceIndex;

        int offset;

        int length;

        QByteArray block;

    };

    QList<BlockInfo> pendingBlocks;

    int pendingBlockSizes;

    QList<TorrentBlock> incoming;

    enum PacketType {

        ChokePacket = 0,

        UnchokePacket = 1,

        InterestedPacket = 2,

        NotInterestedPacket = 3,

        HavePacket = 4,

        BitFieldPacket = 5,

        RequestPacket = 6,

        PiecePacket = 7,

        CancelPacket = 8

    };

    // State

    PeerWireState pwState;

    bool receivedHandShake;

    bool gotPeerId;

    bool sentHandShake;

    int nextPacketLength;

    // Upload/download speed records

    qint64 uploadSpeedData[8];

    qint64 downloadSpeedData[8];

    int transferSpeedTimer;

    // Timeout handling

    int timeoutTimer;

    int pendingRequestTimer;

    bool invalidateTimeout;

    int keepAliveTimer;

    // Checksum, peer ID and set of available pieces

    QByteArray infoHash;

    QByteArray peerIdString;

    QBitArray peerPieces;

    TorrentPeer *torrentPeer;

    QTcpSocket socket;

};

Q_DECLARE_OPERATORS_FOR_FLAGS(PeerWireClient::PeerWireState)

#endif