/***************************************************************************
 *   Copyright (C) 2005 by Joris Guisson                                   *
 *   joris.guisson@gmail.com                                               *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program 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 General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
 ***************************************************************************/
#ifndef BTUTPEX_H
#define BTUTPEX_H

#include <map>
#include <ktorrent_export.h>
#include <net/address.h>
#include <util/constants.h>
#include <peer/peermanager.h>
#include "peerprotocolextension.h"

namespace bt
{
class Peer;
class BEncoder;

/**
 * @author Joris Guisson <joris.guisson@gmail.com>
 *
 * Class which handles µTorrent's peer exchange
*/
class KTORRENT_EXPORT UTPex : public PeerProtocolExtension, public PeerManager::PeerVisitor
{
public:
    UTPex(Peer* peer, Uint32 id);
    ~UTPex() override;

    /**
     * Handle a PEX packet
     * @param packet The packet
     * @param size The size of the packet
     */
    void handlePacket(const Uint8* packet, Uint32 size) override;

    /// Do we need to update PEX (should happen every minute)
    bool needsUpdate() const override;

    /// Send a new PEX packet to the Peer
    void update() override;

    /// Change the ID used in the extended packets
    void changeID(Uint32 nid)
    {
        id = nid;
    }

    /// Globally disable or enabled PEX
    static void setEnabled(bool on)
    {
        pex_enabled = on;
    }

    /// Is PEX enabled globally
    static bool isEnabled()
    {
        return pex_enabled;
    }
private:
    void encode(BEncoder & enc, const std::map<Uint32, net::Address> & ps);
    void encodeFlags(BEncoder & enc, const std::map<Uint32, Uint8> & flags);
    void visit(const bt::Peer::Ptr p) override;

private:
    std::map<Uint32, net::Address> peers;
    TimeStamp last_updated;
    static bool pex_enabled;

    std::map<Uint32, net::Address> added;
    std::map<Uint32, Uint8> flags;
    std::map<Uint32, net::Address> npeers;
};

}

#endif
