/***************************************************************************
 *   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 DHTDHT_H
#define DHTDHT_H

#include <qtimer.h>
#include <qstring.h>
#include <qmap.h>
#include <util/constants.h>
#include <util/timer.h>
#include "key.h"
#include "dhtbase.h"
#include "rpcmsg.h"


namespace net
{
class AddressResolver;
}

namespace bt
{
class SHA1Hash;
}

namespace dht
{
class Node;
class RPCServer;
class Database;
class TaskManager;
class Task;
class AnnounceTask;
class NodeLookup;
class KBucket;
class ErrMsg;
class PingReq;
class FindNodeReq;
class GetPeersReq;
class AnnounceReq;

/**
    @author Joris Guisson <joris.guisson@gmail.com>
*/
class DHT : public DHTBase
{
    Q_OBJECT
public:
    DHT();
    ~DHT() override;

    void ping(const PingReq & r);
    void findNode(const FindNodeReq & r);
    void response(const RPCMsg & r);
    void getPeers(const GetPeersReq &  r);
    void announce(const AnnounceReq & r);
    void error(const ErrMsg & r);
    void timeout(RPCMsg::Ptr r);

    /**
     * A Peer has received a PORT message, and uses this function to alert the DHT of it.
     * @param ip The IP of the peer
     * @param port The port in the PORT message
     */
    void portReceived(const QString & ip, bt::Uint16 port) override;

    /**
     * Do an announce on the DHT network
     * @param info_hash The info_hash
     * @param port The port
     * @return The task which handles this
     */
    AnnounceTask* announce(const bt::SHA1Hash & info_hash, bt::Uint16 port) override;

    /**
     * Refresh a bucket using a find node task.
     * @param id The id
     * @param bucket The bucket to refresh
     */
    NodeLookup* refreshBucket(const dht::Key & id, KBucket & bucket);

    /**
     * Do a NodeLookup.
     * @param id The id of the key to search
     */
    NodeLookup* findNode(const dht::Key & id);

    /// Do a findNode for our node id
    NodeLookup* findOwnNode();

    /// See if it is possible to start a task
    bool canStartTask() const;

    void start(const QString & table, const QString & key_file, bt::Uint16 port) override;
    void stop() override;
    void addDHTNode(const QString & host, bt::Uint16 hport) override;

    QMap<QString, int> getClosestGoodNodes(int maxNodes) override;

    /// Bootstrap from well-known nodes
    void bootstrap();

private Q_SLOTS:
    void update() override;
    void onResolverResults(net::AddressResolver* ar);
    void ownNodeLookupFinished(Task* t);
    void expireDatabaseItems();

private:
    Node* node;
    RPCServer* srv;
    Database* db;
    TaskManager* tman;
    QTimer expire_timer;
    QString table_file;
    QTimer update_timer;
    NodeLookup* our_node_lookup;
};

}

#endif
