/*
 * socks.h - SOCKS5 TCP proxy client/server
 * Copyright (C) 2003  Justin Karneges
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

#ifndef CS_SOCKS_H
#define CS_SOCKS_H

#include "bytestream.h"

// CS_NAMESPACE_BEGIN
class QHostAddress;
class QTcpServer;
class QTcpSocket;
class SocksClient;
class SocksServer;

class SocksUDP : public QObject {
    Q_OBJECT
public:
    ~SocksUDP();

    void change(const QString &host, int port);
    void write(const QByteArray &data);

signals:
    void packetReady(const QByteArray &data);

private slots:
    void sd_activated();

private:
    class Private;
    Private *d;

    friend class SocksClient;
    SocksUDP(SocksClient *sc, const QString &host, int port, const QHostAddress &routeAddr, int routePort);
};

class SocksClient : public ByteStream {
    Q_OBJECT
public:
    enum Error { ErrConnectionRefused = ErrCustom, ErrHostNotFound, ErrProxyConnect, ErrProxyNeg, ErrProxyAuth };
    enum Method { AuthNone = 0x0001, AuthUsername = 0x0002 };
    enum Request { ReqConnect, ReqUDPAssociate };
    SocksClient(QObject *parent = nullptr);
    SocksClient(QTcpSocket *, QObject *parent = nullptr);
    ~SocksClient();

    virtual QAbstractSocket *abstractSocket() const;

    bool isIncoming() const;

    // outgoing
    void setAuth(const QString &user, const QString &pass = "");
    void connectToHost(const QString &proxyHost, int proxyPort, const QString &host, int port, bool udpMode = false);

    // incoming
    void chooseMethod(int);
    void authGrant(bool);
    void requestDeny();
    void grantConnect();
    void grantUDPAssociate(const QString &relayHost, quint16 relayPort);

    // from ByteStream
    void   close();
    qint64 bytesAvailable() const;
    qint64 bytesToWrite() const;

    // remote address
    QHostAddress peerAddress() const;
    quint16      peerPort() const;

    // udp
    QString   udpAddress() const;
    quint16   udpPort() const;
    SocksUDP *createUDP(const QString &host, int port, const QHostAddress &routeAddr, int routePort);

protected:
    qint64 writeData(const char *data, qint64 maxSize);
    qint64 readData(char *data, qint64 maxSize);

signals:
    // outgoing
    void connected();

    // incoming
    void incomingMethods(int);
    void incomingAuth(const QString &user, const QString &pass);
    void incomingConnectRequest(const QString &host, int port);
    void incomingUDPAssociateRequest();

private slots:
    void sock_connected();
    void sock_connectionClosed();
    void sock_delayedCloseFinished();
    void sock_readyRead();
    void sock_bytesWritten(qint64);
    void sock_error(int);
    void serve();

private:
    class Private;
    Private *d;

    void init();
    void resetConnection(bool clear = false);
    void do_request();
    void processOutgoing(const QByteArray &);
    void processIncoming(const QByteArray &);
    void continueIncoming();
    void writeData(const QByteArray &a);
};

class SocksServer : public QObject {
    Q_OBJECT
public:
    SocksServer(QObject *parent = nullptr);
    ~SocksServer();

    void         setServerSocket(QTcpServer *server);
    bool         isActive() const;
    bool         listen(quint16 port, bool udp = false);
    void         stop();
    int          port() const;
    QHostAddress address() const;
    SocksClient *takeIncoming();

    void writeUDP(const QHostAddress &addr, quint16 port, const QByteArray &data);

signals:
    void incomingReady();
    void incomingUDP(const QString &host, int port, const QHostAddress &addr, int sourcePort, const QByteArray &data);

private slots:
    void newConnection();
    void connectionError();
    void sd_activated();

private:
    class Private;
    Private *d;
};

// CS_NAMESPACE_END

#endif // CS_SOCKS_H
