openingbook.h

/*
    This file is part of Cute Chess.
    Copyright (C) 2008-2018 Cute Chess authors

    Cute Chess 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 3 of the License, or
    (at your option) any later version.

    Cute Chess 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 Cute Chess.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef OPENING_BOOK_H
#define OPENING_BOOK_H

#include <QtGlobal>
#include <QMultiMap>
#include "board/genericmove.h"

class QString;
class QDataStream;
class PgnGame;
class PgnStream;


class LIB_EXPORT OpeningBook
{
    public:
        enum AccessMode
        {
            Ram,    
            Disk    
        };

        struct Entry
        {
            Chess::GenericMove move;
            quint16 weight;
        };

        OpeningBook(AccessMode mode = Ram);
        virtual ~OpeningBook();
        
        int import(const PgnGame& pgn, int maxMoves);
        int import(PgnStream& in, int maxMoves);
        
        Chess::GenericMove move(quint64 key) const;

        QList<Entry> entries(quint64 key) const;

        bool read(const QString& filename);

        bool write(const QString& filename) const;


    protected:
        friend LIB_EXPORT QDataStream& operator>>(QDataStream& in, OpeningBook* book);
        friend LIB_EXPORT QDataStream& operator<<(QDataStream& out, const OpeningBook* book);

        typedef QMultiMap<quint64, Entry> Map;

        virtual int entrySize() const = 0;

        void addEntry(const Entry& entry, quint64 key);
        
        virtual Entry readEntry(QDataStream& in, quint64* key) const = 0;
        
        virtual void writeEntry(const Map::const_iterator& it,
                    QDataStream& out) const = 0;

    private:
        QList<Entry> entriesFromDisk(quint64 key) const;

        AccessMode m_mode;
        QString m_filename;
        Map m_map;
};

extern LIB_EXPORT QDataStream& operator>>(QDataStream& in, OpeningBook* book);

extern LIB_EXPORT QDataStream& operator<<(QDataStream& out, const OpeningBook* book);

#endif // OPENING_BOOK_H