/***************************************************************************
 *   Copyright (C) 2008 by Joris Guisson and Ivan Vasic                    *
 *   joris.guisson@gmail.com                                               *
 *   ivasic@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 BTCHUNKSELECTORINTERFACE_H
#define BTCHUNKSELECTORINTERFACE_H

#include <util/constants.h>
#include <ktorrent_export.h>

namespace bt
{
class BitSet;
class Downloader;
class PeerManager;
class ChunkManager;
class PieceDownloader;

/**
* @author Joris Guisson
*
* Interface class for selecting chunks to download.
*/
class KTORRENT_EXPORT ChunkSelectorInterface
{
public:
    ChunkSelectorInterface();
    virtual ~ChunkSelectorInterface();

    /**
     * Initialize the chunk selector, will be called automatically when
     * the ChunkSelector is set.
     * @param cman The ChunkManager
     * @param downer The Downloader
     * @param pman The PeerManager
     */
    virtual void init(ChunkManager* cman, Downloader* downer, PeerManager* pman);

    /**
     * Select which chunk to download for a PieceDownloader.
     * @param pd The PieceDownloader
     * @param chunk Index of chunk gets stored here
     * @return true upon succes, false otherwise
     */
    virtual bool select(PieceDownloader* pd, Uint32 & chunk) = 0;

    /**
     * Select a range of chunks to download from a webseeder.
     * @param from First chunk of the range
     * @param to Last chunk of the range
     * @param max_len Maximum length of range
     * @return true if everything is OK
     */
    virtual bool selectRange(Uint32 & from, Uint32 & to, Uint32 max_len);

    /**
     * Data has been checked, and these chunks are OK.
     * @param ok_chunks The ok_chunks
     * @param from First chunk of check
     * @param to Last chunk of check
     */
    virtual void dataChecked(const BitSet & ok_chunks, Uint32 from, Uint32 to) = 0;

    /**
     * A range of chunks has been reincluded. This is called when a user
     * reselects a file for download.
     * @param from The first chunk
     * @param to The last chunk
     */
    virtual void reincluded(Uint32 from, Uint32 to) = 0;

    /**
     * Reinsert a chunk. This is called when a chunk is corrupted or downloading it failed (hash doesn't match)
     * The selector should make sure that this is added again
     * @param chunk The chunk
     */
    virtual void reinsert(Uint32 chunk) = 0;

protected:
    ChunkManager* cman;
    Downloader* downer;
    PeerManager* pman;
};
}

#endif
