/***************************************************************************
 *   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 BTPEERINTERFACE_H
#define BTPEERINTERFACE_H

#include <ktorrent_export.h>
#include <util/constants.h>
#include <util/bitset.h>
#include <peer/peerid.h>


namespace bt
{

/**
 * @author Joris Guisson
 * @brief Interface for a Peer
 *
 * This is the interface for a Peer, it allows other classes to
 * get statistics about a Peer, and provides some basic functionality provided by a Peer.
*/
class KTORRENT_EXPORT PeerInterface
{
public:
    /**
        Constructor, initialize the PeerID and the number of chunks
        @param peer_id The PeerID
        @param num_chunks The number of chunks
    */
    PeerInterface(const PeerID & peer_id, Uint32 num_chunks);
    virtual ~PeerInterface();

    struct Stats {
        /// IP address of peer (dotted notation)
        QString ip_address;
        /// Host name of the peer
        QString hostname;
        /// The client (Azureus, BitComet, ...)
        QString client;
        /// Download rate (bytes/s)
        bt::Uint32 download_rate;
        /// Upload rate (bytes/s)
        bt::Uint32 upload_rate;
        /// Choked or not
        bool choked;
        /// Snubbed or not (i.e. we haven't received a piece for a minute)
        bool snubbed;
        /// Percentage of file which the peer has
        float perc_of_file;
        /// Does this peer support DHT
        bool dht_support;
        /// Amount of data uploaded
        bt::Uint64 bytes_uploaded;
        /// Amount of data downloaded
        bt::Uint64 bytes_downloaded;
        /// Advanced choke algorithm score
        double aca_score;
        /// Flag to indicate if this peer has an upload slot
        bool has_upload_slot;
        /// Is the peer interested
        bool interested;
        /// Am I interested in the peer
        bool am_interested;
        /// Whether or not this connection is encrypted
        bool encrypted;
        /// Number of upload requests queued
        bt::Uint32 num_up_requests;
        /// Number of outstanding download requests queued
        bt::Uint32 num_down_requests;
        /// Supports the fast extensions
        bool fast_extensions;
        /// Is this a peer on the local network
        bool local;
        /// Whether or not the peer supports the extension protocol
        bool extension_protocol;
        /// Max number of outstanding requests (reqq in extended protocol handshake)
        bt::Uint32 max_request_queue;
        /// Time the peer choked us
        TimeStamp time_choked;
        /// Time the peer unchoked us
        TimeStamp time_unchoked;
        /// The transport protocol used by the peer
        bt::TransportProtocol transport_protocol;
        /// Is this a partial seed
        bool partial_seed;

        /// Get the address of the peer (hostname if it is valid, IP otherwise)
        QString address() const
        {
            return hostname.isEmpty() ? ip_address : hostname;
        }
    };

    /// Get the Peer's statistics
    const Stats & getStats() const
    {
        return stats;
    }

    /**
        Kill the Peer, will ensure the PeerManager closes the connection, and cleans things up.
    */
    virtual void kill() = 0;

    /// See if the peer has been killed.
    bool isKilled() const
    {
        return killed;
    }

    /**
        Get the average download speed since the last unchoke in bytes/sec
     */
    virtual bt::Uint32 averageDownloadSpeed() const = 0;

    /// Get the Peer's BitSet
    const BitSet & getBitSet() const
    {
        return pieces;
    }

    /// Get the Peer's ID
    const PeerID & getPeerID() const
    {
        return peer_id;
    }

    /// Is the Peer choked
    bool isChoked() const
    {
        return stats.choked;
    }

    /// Is the Peer interested
    bool isInterested() const
    {
        return stats.interested;
    }

    /// Are we interested in the Peer
    bool areWeInterested() const
    {
        return stats.am_interested;
    }

    /// Are we choked for the Peer
    bool areWeChoked() const
    {
        return !stats.has_upload_slot || paused;
    }

    /// See if the peer supports DHT
    bool isDHTSupported() const
    {
        return stats.dht_support;
    }

    /// Get the time when this Peer choked us
    TimeStamp getChokeTime() const
    {
        return stats.time_choked;
    }

    /// Get the time when this Peer unchoked us
    TimeStamp getUnchokeTime() const
    {
        return stats.time_unchoked;
    }

    /// See if the peer is a seeder.
    bool isSeeder() const
    {
        return pieces.allOn();
    }

    /// Peer is allowed to download chunk (used for superseeding)
    virtual void chunkAllowed(bt::Uint32 chunk) = 0;

    /// Handle a received packet
    virtual void handlePacket(const bt::Uint8* packet, bt::Uint32 size) = 0;


protected:
    mutable PeerInterface::Stats stats;
    bool paused;
    bool killed;
    PeerID peer_id;
    BitSet pieces;
};

}

#endif
