/*=========================================================================
                                                                                
  Program:   bbtk
  Module:    $RCSfile: bbtkConnection.h,v $
  Language:  C++
  Date:      $Date: 2008/07/25 07:44:12 $
  Version:   $Revision: 1.7 $
                                                                                
  Copyright (c) CREATIS (Centre de Recherche et d'Applications en Traitement de
  l'Image). All rights reserved. See doc/license.txt or
  http://www.creatis.insa-lyon.fr/Public/bbtk/License.html for details.
                                                                                
     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.
                                                                                
=========================================================================*/
/**
 *\file
 *\brief Class bbtk::Connection
 */
/**
 *\class bbtk::Connection
 *\brief DDD
 *
 */

#ifndef __bbtkConnection_h__
#define __bbtkConnection_h__

#include "bbtkSystem.h"
#include "bbtkObject.h"

#include <string>

namespace bbtk
{

  class Factory;
  BBTK_FORWARD_DECLARE_POINTER(Factory);
  class BlackBox;
  BBTK_FORWARD_DECLARE_POINTER(BlackBox);
  class BlackBoxInputConnector;
  class BlackBoxOutputConnector;

  /// 
  typedef int IOStatus;
  /// 
  const int MODIFIED = 0;
  /// 
  const int UPTODATE = 1;
  /// 
  const int UPDATING = 2;


  class BBTK_EXPORT Connection : public Object
  {
     BBTK_OBJECT_INTERFACE(Connection);
    typedef Object Superclass;
  public:

    static Pointer New(BlackBoxPointer from, const std::string& output,
		       BlackBoxPointer to, const std::string& input,
		       const FactoryPointer f);
    static Pointer New(BlackBoxPointer from, const std::string& output,
		       BlackBoxPointer to, const std::string& input);
    /// Dtor
    //    ~Connection();

    // void Delete();
    
    /// Amont direction pipeline processing
    /// 1) call bbBackwardUpdate(this) on the upstream box
    /// 2) copies the upstream box output to the downstream box input adapting it if needed
    virtual IOStatus BackwardUpdate();

    /// Aval direction pipeline processing :
    /// 1) copies the upstream box output to the downstream box input adapting it if needed
    /// 2) call bbForwardUpdate(this) on the downstream box
    //    virtual void ForwardUpdate();

    virtual void SetModifiedStatus();
    std::string GetFullName() const; 

    /// Returns the original initial black box of the connection
    BlackBoxPointer GetOriginalBlackBoxFrom() const { return mOriginalFrom.lock(); }
    /// Returns the origianl final black box of the connection
    BlackBoxPointer GetOriginalBlackBoxTo() const { return mOriginalTo.lock(); }
    /// Returns the original output of the initial black box of the connection
    const std::string& GetOriginalBlackBoxFromOutput() const { return mOriginalOutput; }
    /// Returns the original input of the final black box of the connection
    const std::string& GetOriginalBlackBoxToInput() const { return mOriginalInput; }
    
    /// Returns the initial black box of the connection
    BlackBoxPointer GetBlackBoxFrom() const { return mFrom; }
    /// Returns the final black box of the connection
    BlackBoxPointer GetBlackBoxTo() const { return mTo; }
    /// Returns the output of the initial black box of the connection
    const std::string& GetBlackBoxFromOutput() const { return mOutput; }
    /// Returns the input of the final black box of the connection
    const std::string& GetBlackBoxToInput() const { return mInput; }

    /// Sets the initial black box of the connection
    void SetBlackBoxFrom(BlackBoxPointer b) { mFrom = b; }
    /// Sets the final black box of the connection
    void SetBlackBoxTo(BlackBoxPointer b) { mTo = b; }
    /// Sets the output of the initial black box of the connection
    void SetBlackBoxFromOutput(const std::string& o) { mOutput = o; }
    /// Sets the input of the final black box of the connection
    void SetBlackBoxToInput(const std::string& o) { mInput = o; }

    /// Checks that the connection is ok (throws error if not)
    void Check() const;
    
  protected:
    /// Black box origin of the connection
    BlackBoxPointer mFrom;
    BlackBoxWeakPointer mOriginalFrom;
    /// Output of mFrom which is connected
    std::string mOutput;
    std::string mOriginalOutput;
    /// Output connector of mFrom which is connected
    //  BlackBoxOutputConnector* mOutputConnector;
    /// Black box destination of the connection
    BlackBoxPointer mTo;
    BlackBoxWeakPointer mOriginalTo;
    /// Input of mTo which is connected
    std::string mInput;
    std::string mOriginalInput;
    /// Input connector of mTo which is connected
    //  BlackBoxInputConnector* mInputConnector;
    /// Adaptor black box if needed
    BlackBoxPointer mAdaptor;

    /// The factory used to create adaptors
    const FactoryWeakPointer mFactory;

    /// Is the connection input type is any<thing> ?
    bool mFromAny;

    /// Is the connection output type is any<thing> ?
    bool mToAny;


    /// Have to do dynamic_cast ?
    bool mDoDynamicCast;

    /// Ctor with the black box from and to and their input and output
    /// and a dummy int to differentiate from the public constructor.
    /// Sets the members but does not test compatibility (used by bbtk::AdaptiveConnection)
    //  Connection(BlackBox* from, const std::string& output,
    //	       BlackBox* to, const std::string& input, int   );
    
    void TransferData(); 

  private:
    /// Ctor 
    Connection(BlackBoxPointer from, const std::string& output,
	       BlackBoxPointer to, const std::string& input,
	       const FactoryPointer f);
    /// Ctor 
    Connection(BlackBoxPointer from, const std::string& output,
	       BlackBoxPointer to, const std::string& input);

  };

}// namespace bbtk

#endif