/*
 * Copyright (C) 2007-2012 Xagasoft, All rights reserved.
 *
 * This file is part of the libgats library and is released under the
 * terms of the license contained in the file LICENSE.
 */

#ifndef GATS_STREAM_H
#define GATS_STREAM_H

#include <QIODevice>
#include <QByteArray>

namespace Gats
{
    class Object;

    class GatsStream : public QObject
    {
        Q_OBJECT;
    public:
        GatsStream( QIODevice &rStream );
        virtual ~GatsStream();

    public slots:
        /**
         * Read an object packet from the assosiated stream.  This will make
         * every effort to only read exactly enough data to describe one packet,
         * in case you want to do other things with your stream.  It will
         * automatically skip NULL byte spacing between packets, which makes
         * a convinient padding method for encrypted data streams.  Since
         * sizing information is available in the packet header exact amounts
         * of data can be read, however this function doesn't assume that it
         * can read the entire object in one operation.  If it fails to read
         * a complete packet in one call, it will keep the data it's read so
         * far buffered and return NULL, ready for another attempt.  You can
         * use the function hasReadBuffer() to deterimne if readObject()
         * has read part of an object packet or not.  If readObject returns
         * non-null then hasReadBuffer should return false on it's next call.
         */
        Gats::Object *readObject();
        
        /**
         * Works exactly like readObject, except it reads all pending objects
         * and emits a objectRead signal for each one read.  It doesn't return
         * anything.  This is perfect for connecting to a QIODevice's readRead
         * signal.
         */
        void readAllObjects();

    public:
        /**
         * Write an object 
         */
        void writeObject( Gats::Object *pObject );

        /**
         * Tells you if there is data still in the read buffer, i.e. that a
         * packet is part way through being read.  If readObject has returned
         * non-null in the most recent call, this should always be false.
         */
        bool hasReadBuffer() { return qbRead.size() > 0; }
        int getReadBufferSize() { return qbRead.size(); }

        QIODevice &getIODevice() { return rStream; }

    signals:
        void objectRead( Gats::Object *pObj );

    private:
        bool skipReadNulls();

    private:
        QIODevice &rStream;
        QByteArray qbRead;
    };
};

#endif