/***************************************************************************
 *   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 BTUDPTRACKERSOCKET_H
#define BTUDPTRACKERSOCKET_H

#include <QObject>
#include <QByteArray>
#include <util/constants.h>
#include <util/bufferpool.h>
#include <ktorrent_export.h>

#ifdef ERROR
#undef ERROR
#endif

namespace net
{
class Address;
}

namespace bt
{

/**
 * @author Joris Guisson
 *
 * Class which handles communication with one or more UDP trackers.
*/
class KTORRENT_EXPORT UDPTrackerSocket : public QObject
{
    Q_OBJECT
public:
    UDPTrackerSocket();
    ~UDPTrackerSocket() override;

    enum Action {
        CONNECT = 0,
        ANNOUNCE = 1,
        SCRAPE = 2,
        ERROR = 3
    };

    /**
     * Send a connect message. As a response to this, the connectReceived
     * signal will be emitted, classes recieving this signal should check if
     * the transaction_id is the same.
     * @param tid The transaction_id
     * @param addr The address to send to
     */
    void sendConnect(Int32 tid, const net::Address & addr);

    /**
     * Send an announce message. As a response to this, the announceReceived
     * signal will be emitted, classes recieving this signal should check if
     * the transaction_id is the same.
     * @param tid The transaction_id
     * @param data The data to send (connect input structure, in UDP Tracker specifaction)
     * @param addr The address to send to
     */
    void sendAnnounce(Int32 tid, const Uint8* data, const net::Address & addr);

    /**
    * Send a scrape message. As a response to this, the scrapeReceived
    * signal will be emitted, classes recieving this signal should check if
    * the transaction_id is the same.
    * @param tid The transaction_id
    * @param data The data to send (connect input structure, in UDP Tracker specifaction)
    * @param addr The address to send to
    */
    void sendScrape(Int32 tid, const Uint8* data, const net::Address & addr);

    /**
     * If a transaction times out, this should be used to cancel it.
     * @param tid
     */
    void cancelTransaction(Int32 tid);


    /**
     * Compute a free transaction_id.
     * @return A free transaction_id
     */
    Int32 newTransactionID();

    /**
     * Set the port ot use.
     * @param p The port
     */
    static void setPort(Uint16 p);

    /// Get the port in use.
    static Uint16 getPort();

Q_SIGNALS:
    /**
     * Emitted when a connect message is received.
     * @param tid The transaction_id
     * @param connection_id The connection_id returned
     */
    void connectReceived(Int32 tid, Int64 connection_id);

    /**
     * Emitted when an announce message is received.
     * @param tid The transaction_id
     * @param buf The data
     * @param size The data size
     */
    void announceReceived(Int32 tid, const Uint8* buf, Uint32 size);

    /**
    * Emitted when a scrape message is received.
    * @param tid The transaction_id
    * @param buf The data
    * @param size The data size
    */
    void scrapeReceived(Int32 tid, const Uint8* buf, Uint32 size);

    /**
     * Signal emitted, when an error occurs during a transaction.
     * @param tid The transaction_id
     * @param error_string Potential error string
     */
    void error(Int32 tid, const QString & error_string);

private:
    void handleConnect(bt::Buffer::Ptr buf);
    void handleAnnounce(bt::Buffer::Ptr buf);
    void handleError(bt::Buffer::Ptr buf);
    void handleScrape(bt::Buffer::Ptr buf);

private:
    class Private;
    Private* d;

    static Uint16 port;
};
}

#endif
