/*
 * Copyright (C) 2007-2014 Xagasoft, All rights reserved.
 *
 * This file is part of the libbu++ library and is released under the
 * terms of the license contained in the file LICENSE.
 */

#ifndef BU_ATOM_H
#define BU_ATOM_H

#include <stdint.h>
#include <memory>
#include "bu/config.h"
#include "bu/exceptionbase.h"

namespace Bu
{
    /**
     *
     *@ingroup Containers
     */
    template <typename t, typename talloc=std::allocator<t> >
    class Atom
    {
    private:
        typedef class Atom<t, talloc> MyType;

    public:
        Atom() :
            pData( NULL )
        {
        }

        Atom( const MyType &oth ) :
            pData( NULL )
        {
            if( oth.pData )
                set( *oth.pData );
        }

        Atom( const t &oth ) :
            pData( NULL )
        {
            set( oth );
        }

        virtual ~Atom()
        {
            clear();
        }

        bool has() const
        {
            return (pData != NULL);
        }

        void set( const t &val )
        {
            clear();
            pData = ta.allocate( 1 );
            ta.construct( pData, val );
        }

        t &get()
        {
            if( !pData )
                throw Bu::ExceptionBase("Not set");
            return *pData;
        }

        const t &get() const
        {
            if( !pData )
                throw Bu::ExceptionBase("Not set");
            return *pData;
        }

        void clear()
        {
            if( pData )
            {
                ta.destroy( pData );
                ta.deallocate( pData, 1 );
                pData = NULL;
            }
        }

        operator const t &() const
        {
            if( !pData )
                throw Bu::ExceptionBase("Not set");
            return *pData;
        }
        
        operator t &()
        {
            if( !pData )
                throw Bu::ExceptionBase("Not set");
            return *pData;
        }

        MyType &operator =( const t &oth )
        {
            set( oth );

            return *this;
        }
        
        MyType &operator =( const MyType &oth )
        {
            if( oth.pData )
                set( *oth.pData );

            return *this;
        }
        
        bool operator ==( const MyType &oth )
        {
            return (*pData) == (*oth.pData);
        }

        bool operator ==( const t &oth )
        {
            return (*pData) == oth;
        }

        t *operator ->()
        {
            if( !pData )
                throw Bu::ExceptionBase("Not set");
            return pData;
        }

        t &operator *()
        {
            if( !pData )
                throw Bu::ExceptionBase("Not set");
            return *pData;
        }

    private:
        t *pData;
        talloc ta;
    };
}

#endif