#if !defined(VOCAL_STATEINTERFACE_HXX)
#define VOCAL_STATEINTERFACE_HXX

/* ====================================================================
 * The Vovida Software License, Version 1.0 
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The names "VOCAL", "Vovida Open Communication Application Library",
 *    and "Vovida Open Communication Application Library (VOCAL)" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact vocal@vovida.org.
 *
 * 4. Products derived from this software may not be called "VOCAL", nor
 *    may "VOCAL" appear in their name, without prior written
 *    permission of Vovida Networks, Inc.
 * 
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
 * NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL VOVIDA
 * NETWORKS, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT DAMAGES
 * IN EXCESS OF $1,000, NOR FOR ANY INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * 
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by Vovida
 * Networks, Inc. and many individuals on behalf of Vovida Networks,
 * Inc.  For more information on Vovida Networks, Inc., please see
 * <http://www.vovida.org/>.
 *
 */


static const char* const StateInterface_hxx_Version = 
    "$Id: StateInterface.hxx,v 1.2 2001/08/10 04:02:04 icahoon Exp $";


#include <map>
#include <string>
#include "Writer.hxx"
#include "Stimulus.hxx"
#include "NonCopyable.hxx"


/** Infrastructure common to VOCAL.
 */
namespace Vocal 
{


/** Infrastructure in VOCAL related to "algorithms and the assignment of
 *  responsibilities between objects".<br><br>
 *
 *  See Design Patterns, ISBN 0-201-63361-2, Chapter 5.
 */
namespace Behavioral
{


class Action;


/** A concrete class representing a state in a finite state machine.<br><br>
 *
 *  The state allows an entry Action to be specified such that upon entry
 *  into the state, the entry action will be executed. The state also allows
 *  an exit action to be specified such that upon leaving the state, the
 *  exit action will be executed.<br><br>
 *
 *  A state will respond to a given Stimulus by performing a series of Actions
 *
 *
 *
 *  @see    Vocal::Behavioral::Stimulus
 *  @see    Vocal::Behavioral::Context
 *  @see    Vocal::Behavioral::Action
 */
class StateInterface : public Vocal::IO::Writer, public Vocal::NonCopyable
{

    public:


    	/** Contruct the state, given an optional name, given an optional
	 *  entry action, and given an optional exit action.
	 */
        StateInterface(
	    const char 	    * 	name	= 0,
	    Action  	    *	entry 	= 0,
	    Action  	    *	exit 	= 0
	);


    	/** Virtual destructor.
	 */
	virtual     ~StateInterface();


    	/** For the given Stimulus, the Action will be executed, and the
	 *  state machine will transition to the nextState.
	 */
	void		    addAction(
	    	    		const Stimulus 	    &	stimulus,
				Action  	    &	action,
	    	    		StateInterface      &	nextState
			    );


    	/** For the given Stimulus, the Action will be executed. If the
	 *  Action was successful, it will transition to the nextState, 
	 *  otherwise it will transition to the nextStateOnFail.
	 *
	 *  This is used only for conditional state transitions, where
	 *  an action may fail depending on external data associated
	 *  with the stimulus.
	 */
	void		    addAction(
	    	    		const Stimulus 	    &	stimulus,
				Action  	    &	action,
	    	    		StateInterface      &	nextState,
				StateInterface	    &	nextStateOnFail
			    );


    	/** Associate an entry action to be performed.
	 */
    	void        	    entryAction(Action &);


    	/** Associate an exit action to be performed.
	 */
    	void        	    exitAction(Action &);


    	/** Called when entering this state.
	 */
    	virtual void        enter() throw ();


    	/** Called to handle the given stimulus.
	 */
    	StateInterface &    stimulate(
	    	    	    	const Stimulus  &   stimulus
			    ) throw ();


    	/** Called when exiting the state.
	 */
	virtual void	    exit() throw();


    	/** Write the state to an ostream.
	 */
	virtual ostream &   writeTo(ostream &) const;


    	/** Returns the instance specific name, if given during construction.
	 */
    	virtual const string &	    name() const;


    private:

    	class	StimulusData
	{
	    public:
	    	    StimulusData(
			Action  	    &	action,
	    	    	StateInterface      &	nextState,
    	    	    	StateInterface	    *	nextStateOnFail
		    );

    	    	Action  	    &	action_;
    	    	StateInterface      &	nextState_;
    	    	StateInterface      *	nextStateOnFail_;
	};
	
    	typedef map<Stimulus, StimulusData>    StimulusTable;
    	typedef pair<Stimulus, StimulusData>   StimulusPair;
	
	StimulusTable  	    	stimulusTable_;

    	string	    	    	myName;
    	Action	    	    *	myEntry;
    	Action	    	    *	myExit;
};


} // namespace Behavioral
} // namespace Vocal


#endif // !defined(VOCAL_STATEINTERFACE_HXX)