// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2011 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file license.txt or http://www.opensource.org/licenses/mit-license.php.

#ifndef __cplusplus
# error This header can only be compiled as C++.
#endif

#ifndef __INCLUDED_PROTOCOL_H__
#define __INCLUDED_PROTOCOL_H__

#include "serialize.h"
#include <string>

//
// Message header
//  (4) message start
//  (12) command
//  (4) size
//  (4) checksum

extern unsigned char pchMessageStart[4];

class CMessageHeader
{
    public:
        CMessageHeader();
        CMessageHeader(const char* pszCommand, unsigned int nMessageSizeIn);

        std::string GetCommand() const;
        bool IsValid() const;

        IMPLEMENT_SERIALIZE
            (
             READWRITE(FLATDATA(pchMessageStart));
             READWRITE(FLATDATA(pchCommand));
             READWRITE(nMessageSize);
             if (nVersion >= 209)
             READWRITE(nChecksum);
            )

    // TODO: make private (improves encapsulation)
    public:
        enum { COMMAND_SIZE=12 };
        char pchMessageStart[sizeof(::pchMessageStart)];
        char pchCommand[COMMAND_SIZE];
        unsigned int nMessageSize;
        unsigned int nChecksum;
};

#endif // __INCLUDED_PROTOCOL_H__