/*
  NodeWiring  -  Implementation of the node network and operation control
 
  Copyright (C)         Lumiera.org
    2008,               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.
 
* *****************************************************/


#include "proc/engine/procnode.hpp"
#include "proc/engine/nodewiring.hpp"
#include "proc/engine/nodeoperation.hpp"
#include "proc/engine/nodewiringconfig.hpp"

#include "lib/meta/typelist-util.hpp"


namespace engine {

  namespace config {
    
    using lumiera::typelist::Flags;
    using lumiera::typelist::CombineFlags;
    using lumiera::typelist::DefineConfigByFlags;
    using lumiera::typelist::Instantiation;
    using lumiera::typelist::Apply;
    using lumiera::typelist::Filter;
    
    
    typedef Flags<CACHING,PROCESS,INPLACE>::Tuple AllFlags;
    
    /** build the list of all possible flag combinations */
    typedef CombineFlags<AllFlags>     AllFlagCombinations;
    
    /** build a configuration type for each of those flag combinations */
    typedef Apply<AllFlagCombinations::List, DefineConfigByFlags> AllConfigs;
              
    /** filter those configurations which actually define a wiring strategy */
    typedef Filter<AllConfigs::List, Instantiation<Strategy>::Test> PossibleConfigs;
    
    
    
    // internal details: setting up a factory for each required configuration
    
    class Alloc {}; ///////////////TODO
    
    
    template<class CONF>
    class WiringDescriptorFactory
      {
        Alloc& alloc_;
        
      public:
        WiringDescriptorFactory(Alloc& a) 
        : alloc_(a) {}
        
        WiringDescriptor&
        operator() ()  
          { 
            /////////////////////////////////////////////TODO
            
            typedef config::Strategy<CONF> Strategy;
            typedef typename config::SelectBuffProvider<>::Type BuffProvider; ////////////////////////TODO: how to extract the required flags from CONF??
            typedef ActualInvocationProcess<Strategy, BuffProvider> InvocationStateType;
            
            typedef NodeWiring<InvocationStateType> Product;
            
            Product * dummy (0);
            return *dummy;
          }
      };
    
    typedef WiringDescriptor& (FunctionType)(void);
    
    typedef ConfigSelector< WiringDescriptorFactory  ///< Factory template to instantiate 
                          , FunctionType            ///<  function signature of the Factory
                          , Alloc&                 ///<   allocator fed to all factories
                          > WiringSelector;
    
    
    struct WiringFactoryImpl
      {
        WiringSelector selector;
        
        WiringFactoryImpl (Alloc& alloc)
          : selector(config::PossibleConfigs::List(), alloc)
          { }
      };
  
  } // (END) internals (namespace config)
  
  
  /////////////////////////////TODO: define the ctor
  
  
  /** create and configure a concrete wiring descriptor to tie
   *  a ProcNode to its predecessor nodes. This includes selecting
   *  the actual StateProxy type, configuring it out of some operation
   *  control templates (policy classes). Compiling this operator function
   *  actually drives the necessary template instantiations for all cases
   *  encountered while building the node network.
   *  The created WiringDescriptor object is bulk allocated similar to the ProcNode
   *  objects for a given segment of the Timeline. It should be further configured
   *  with the actual predecessor nodes pointers and can then be used to create
   *  the new processing node to be wired up.  
   */
  WiringDescriptor&
  WiringFactory::operator() (WiringInstaller& setup, bool cache)
  {
    UNIMPLEMENTED ("build the actual wiring descriptor based on given operation options");
    
//    Bits config (FlagInfo<Config>::CODE);
//    return pImpl_->selector[config]();
    ////
   /////TODO: change the FunctionType to take an "input/output description pattern"
   /////TODO: invent such a pattern ---> buffhandle.hpp
  }
  
  
} // namespace engine