/*
  OUTPUT-MAPPING.hpp  -  generic interface for translation of output designations
 
  Copyright (C)         Lumiera.org
    2010,               Hermann Vosseler <Ichthyostega@web.de>
 
  This program 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 2 of the
  License, or (at your option) any later version.
 
  This program 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 this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
*/


#ifndef PROC_MOBJECT_OUTPUT_MAPPING_H
#define PROC_MOBJECT_OUTPUT_MAPPING_H

#include "proc/mobject/output-designation.hpp"
#include "lib/meta/function.hpp"
#include "lib/bool-checkable.hpp"
#include "lib/query.hpp"

#include <boost/noncopyable.hpp>



namespace mobject {
  
  namespace { // Helper to extract and rebind definition types
    
    using std::tr1::function;
    
    template<class DEF>
    class _def
      {
        typedef asset::ID<asset::Pipe> PId;
        
        template<typename FUN>
        struct Rebind;
        
        template<typename RET>
        struct Rebind<RET(DEF::*)(PId)>
          {
            typedef RET Res;
          };
        
        typedef typeof(&DEF::output) OutputMappingMemberFunc;              // GCC extension: "typeof"
        typedef Rebind<OutputMappingMemberFunc> Rebinder;
        
      public:
        typedef typename Rebinder::Res Target;
        typedef function<Target(PId)>  OutputMappingFunc;
        
      };
    
  }
  
  using lumiera::Query;
  
  
  /**
   * OutputMapping is a facility to resolve output designations.
   * For a given specification, resolution to the desired
   * target specification may be derived. Here, the 
   * type of the target specification is defined 
   * through the type parameter.
   * 
   * This is an Interface, intended to be used in the signature
   * of API functions either providing or requiring a Mapping.
   */
  template<class DEF>
  class OutputMapping
    {
      typedef _def<DEF> Setup;
      
      typedef asset::ID<asset::Pipe> PId;
      typedef asset::PPipe         PPipe;
      
    public:
      typedef typename Setup::Target   Target;
      
      size_t
      size()  const
        {
          UNIMPLEMENTED ("size of mapping table");
        }
      
      bool
      empty()  const
        {
          return 0 == size();
        }
      
      void
      clear()
        {
          UNIMPLEMENTED ("purge mapping table");
        }
    
      class Resolver
        : public lib::BoolCheckable<Resolver
        , boost::noncopyable>
        {
        public:
          Resolver () { }
          
          void
          operator= (PId newId2map)
            {
              UNIMPLEMENTED ("store new fixed mapping");
            }
          
          void
          operator= (PPipe newPipe2map)
            {
              UNIMPLEMENTED ("store new fixed mapping");
            }
          
          operator Target()
            {
              UNIMPLEMENTED ("invoke output mapping functor, maybe issue defaults query");
            }
          
          bool
          isValid()  const
            {
              UNIMPLEMENTED ("is this a NULL object, or a valid stored mapping?");
            }
          
          bool
          operator== (Target const& oval)
            {
              UNIMPLEMENTED ("compare this resolution to given other target value"); 
            }
          
          ////TODO: better use boost::operators
        };
      
      Resolver&
      operator[] (PId)
        {
          UNIMPLEMENTED ("standard lookup");
        }
      
      Resolver&
      operator[] (PPipe const& pipe)
        {
          REQUIRE (pipe);
          return (*this) [pipe->getID()];
        }
      
      Resolver&
      operator[] (Query<asset::Pipe> const& query4pipe)
        {
          UNIMPLEMENTED ("lookup by extended query");
        }
    };
  
  
  
  
} // namespace mobject
#endif