//
// The developer of the original code and/or files is Tripwire, Inc.
// Portions created by Tripwire, Inc. are copyright (C) 2000-2018 Tripwire,
// Inc. Tripwire is a registered trademark of Tripwire, Inc.  All rights
// reserved.
// 
// This program is free software.  The contents of this file are subject
// to 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.  You may redistribute it and/or modify it
// only in compliance with the GNU General Public License.
// 
// This program is distributed in the hope that it will be useful.
// However, this program is distributed AS-IS WITHOUT ANY
// WARRANTY; INCLUDING THE IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS
// FOR A PARTICULAR PURPOSE.  Please 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// 
// Nothing in the GNU General Public License or any other license to use
// the code or files shall permit you to use Tripwire's trademarks,
// service marks, or other intellectual property without Tripwire's
// prior written consent.
// 
// If you have any questions, please contact Tripwire, Inc. at either
// info@tripwire.org or www.tripwire.org.
//
///////////////////////////////////////////////////////////////////////////////
// serializable.h -- the serializable interface
///////////////////////////////////////////////////////////////////////////////

#ifndef __SERIALIZABLE_H
#define __SERIALIZABLE_H

#ifndef __TYPES_H
#include "types.h"
#endif

#ifndef __TYPED_H
#include "typed.h"
#endif

class iSerializer;

// Some version documentation is in order here:  
//
// Objects that derive from iSerializable do not need to worry about versions, they
// should just read and write themselves to and from the serializer.
//
// Objects that wish to implement versioning should derive themselves from iTypedSerializerable.
// They should use the IMPLEMENT_TYPEDSERIALIZABLE() macro to declare their major and minor
// version number.  Neither major or minor version number can be negative and at least one
// must be greater than zero.
//
// When an object is serialized using iSerializer::WriteObject() a header will be written that 
// includes the current version number will be saved in the archive by.  Therefore 
// iSerializable::Write() implementations do not need to worry about versioning, They need only 
// write out the object in current format.
//
// When an object is read back from an archive using iSerializer::ReadObject(), 
// the version of the serialized object will be read from the header and is passed to 
// iSerializable::Read().  Each implementation of Read() should this passed in version.  
// If the version is greater than the current version Read() should throw a eSerializer
// exception. If the version is older than the current implementation, Read() should either 
// read the older format or throw an eSerializer exception.  
//
// IMPORTANT: If the version is 0 (the default parameter) then Read() it should read
// in the current format of the object. This is important if Read() is called directly.
//
// In some cases it may be desirable to not incur the overhead of the serializer writing
// header information for each serialized object.  In this case call iSerializable::Read() and 
// iSerializable::Write() directly rather than using ReadObject() and WriteObject().  

class iSerializable
{
public:
    virtual void Read (iSerializer* pSerializer, int32 version = 0) = 0;    // throw (eSerializer, eArchive)
    virtual void Write(iSerializer* pSerializer) const  = 0;                // throw (eSerializer, eArchive)
        // objects implement these methods to read and write themselves to a serializer. 

    virtual ~iSerializable() {}
};

class iTypedSerializable : public iTyped, public iSerializable
{
public:
    typedef iTypedSerializable* (*CreateFunc)();
        // Pointer to a function that creates an empty version of each typed serializable object

    virtual int32 Version() const = 0;
        // Return the current version of that this serializable object writes.
        // As a convention version number should be (major_version << 16) | minor_version.

    static int32 MkVersion(int16 major, int16 minor) { return (int32)(((uint32)major << 16) | (uint32)minor); }
    static int16 MajorVersion(int32 version) { return (int16)((uint32)version >> 16); }
    static int16 MinorVersion(int32 version) { return (int16)version; }

    virtual ~iTypedSerializable() {}
};

//////////////////////////////
// convenience macros
#define DECLARE_TYPEDSERIALIZABLE() \
    DECLARE_TYPED() \
public: \
    static iTypedSerializable* Create(); \
    virtual int32 Version() const;

#define IMPLEMENT_TYPEDSERIALIZABLE(CLASS, TYPEDSTRING, VERSION_MAJOR, VERSION_MINOR) \
    IMPLEMENT_TYPED(CLASS, TYPEDSTRING) \
    iTypedSerializable* CLASS::Create() \
    { \
        return new CLASS; \
    } \
    int32 CLASS::Version() const \
    { \
        return iTypedSerializable::MkVersion(VERSION_MAJOR, VERSION_MINOR); \
    } 

#endif // __SERIALIZABLE_H