// NextBotBehaviorEngine.h
// Behavioral system constructed from Actions
// Author: Michael Booth, April 2006
// Copyright (c) 2007 Turtle Rock Studios, Inc. - All Rights Reserved

#ifndef _BEHAVIOR_ENGINE_H_
#define _BEHAVIOR_ENGINE_H_

#include "fmtstr.h"
#include "NextBotEventResponderInterface.h"
#include "NextBotContextualQueryInterface.h"
#include "NextBotDebug.h"

//#define DEBUG_BEHAVIOR_MEMORY
extern ConVar NextBotDebugHistory;

/**
 * Notes:
 *
 * By using return results to cause transitions, we ensure the atomic-ness
 * of these transitions. For instance, it is not possible to change to a
 * new Action and continue execution of code in the current Action.
 *
 * Creation and deletion of Actions during transitions allows passing of
 * type-safe arguments between Actions via constructors.
 *
 * Events are propagated to each Action in the hierarchy.  If an
 * action is suspended for another action, it STILL RECEIVES EVENTS
 * that are not handled by the events "above it" in the suspend stack.
 * In other words, the active Action gets the first response, and if it
 * returns CONTINUE, the Action buried beneath it can process it,
 * and so on deeper into the stack of suspended Actions.
 *
 * About events:
 * It is not possible to have event handlers instantaneously change 
 * state upon return due to out-of-order and recurrence issues, not
 * to mention deleting the state out from under itself.  Therefore,
 * events return DESIRED results, and the highest priority result
 * is executed at the next Update().
 *
 * About buried Actions causing SUSPEND_FOR results:
 * If a buried Action reacts to an event by returning a SUSPEND_FOR,
 * the new interrupting Action is put at the TOP of the stack, burying
 * whatever Action was there.
 *
 */


// forward declaration
template < typename Actor > class Action;

/**
 * The possible consequences of an Action
 */
enum ActionResultType
{ 
	CONTINUE,			// continue executing this action next frame - nothing has changed
	CHANGE_TO,			// change actions next frame
	SUSPEND_FOR,		// put the current action on hold for the new action
	DONE,				// this action has finished, resume suspended action
	SUSTAIN,			// for use with event handlers - a way to say "It's important to keep doing what I'm doing"
};


//----------------------------------------------------------------------------------------------
/**
 * Actions and Event processors return results derived from this class.
 * Do not assemble this yourself - use the Continue(), ChangeTo(), Done(), and SuspendFor()
 * methods within Action.
 */
template < typename Actor >
struct IActionResult
{
	IActionResult( ActionResultType type = CONTINUE, Action< Actor > *action = NULL, const char *reason = NULL )
	{
		m_type = type;
		m_action = action;
		m_reason = reason;
	}

	bool IsDone( void ) const
	{
		return ( m_type == DONE );
	}

	bool IsContinue( void ) const
	{
		return ( m_type == CONTINUE );
	}

	bool IsRequestingChange( void ) const
	{
		return ( m_type == CHANGE_TO || m_type == SUSPEND_FOR || m_type == DONE );
	}

	const char *GetTypeName( void ) const
	{
		switch ( m_type )
		{
		case CHANGE_TO:		return "CHANGE_TO";
		case SUSPEND_FOR:	return "SUSPEND_FOR";
		case DONE:			return "DONE";
		case SUSTAIN:		return "SUSTAIN";

		default:
		case CONTINUE:		return "CONTINUE";
		}
	}

	ActionResultType m_type;
	Action< Actor > *m_action;
	const char *m_reason;
};


//----------------------------------------------------------------------------------------------
/**
 * When an Action is executed it returns this result.
 * Do not assemble this yourself - use the Continue(), ChangeTo(), Done(), and SuspendFor()
 * methods within Action.
 */
template < typename Actor >
struct ActionResult : public IActionResult< Actor >
{
	// this is derived from IActionResult to ensure that ActionResult and EventDesiredResult cannot be silently converted
	ActionResult( ActionResultType type = CONTINUE, Action< Actor > *action = NULL, const char *reason = NULL ) : IActionResult< Actor >( type, action, reason )	{ }
};


//----------------------------------------------------------------------------------------------
/**
 * When an event is processed, it returns this DESIRED result,
 * which may or MAY NOT happen, depending on other event results
 * that occur simultaneously.
 * Do not assemble this yourself - use the TryContinue(), TryChangeTo(), TryDone(), TrySustain(),
 * and TrySuspendFor() methods within Action.
 */
enum EventResultPriorityType
{
	RESULT_NONE,		// no result
	RESULT_TRY,			// use this result, or toss it out, either is ok
	RESULT_IMPORTANT,	// try extra-hard to use this result
	RESULT_CRITICAL		// this result must be used - emit an error if it can't be
};

template < typename Actor >
struct EventDesiredResult : public IActionResult< Actor >
{
	EventDesiredResult( ActionResultType type = CONTINUE, Action< Actor > *action = NULL, EventResultPriorityType priority = RESULT_TRY, const char *reason = NULL ) : IActionResult< Actor >( type, action, reason )
	{
		m_priority = priority;
	}

	EventResultPriorityType m_priority;
};


//-------------------------------------------------------------------------------------------------------------
//-------------------------------------------------------------------------------------------------------------
/**
 * A Behavior is the root of an Action hierarchy as well as its container/manager.
 * Instantiate a Behavior with the root Action of your behavioral system, and
 * call Behavior::Update() to drive it.
 */
template < typename Actor >
class Behavior : public INextBotEventResponder, public IContextualQuery
{
public:
	DECLARE_CLASS( Behavior, INextBotEventResponder );

	Behavior( Action< Actor > *initialAction, const char *name = "" ) : m_name( name )
	{
		m_action = initialAction;
	}

	virtual ~Behavior() 
	{
		// dig down to the bottom of the action stack and delete 
		// that, so we don't leak action memory since action 
		// destructors intentionally don't delete actions
		// "buried" underneath them.
		Action< Actor > *bottomAction;
		for( bottomAction = m_action; bottomAction && bottomAction->m_buriedUnderMe; bottomAction = bottomAction->m_buriedUnderMe )
			;

		if ( bottomAction )
		{
			delete bottomAction;
		}
	}

	/**
	 * Reset this Behavior with the given Action. If this Behavior
	 * was already running, this will delete all current Actions and
	 * restart the Behavior with the new one.
	 */
	void Reset( Action< Actor > *action )
	{
		// find "bottom" action (see comment in destructor)
		Action< Actor > *bottomAction;
		for( bottomAction = m_action; bottomAction && bottomAction->m_buriedUnderMe; bottomAction = bottomAction->m_buriedUnderMe )
			;

		if ( bottomAction )
		{
			delete bottomAction;
		}

		m_action = action;
	}

	/**
	 * Return true if this Behavior contains no actions
	 */
	bool IsEmpty( void ) const
	{
		return m_action == NULL;
	}

	/**
	 * Execute this Behavior
	 */
	void Update( Actor *me, float interval )
	{
		if ( me == NULL || IsEmpty() )
		{
			return;
		}

		m_action = m_action->ApplyResult( me, this, m_action->InvokeUpdate( me, this, interval ) );

		if ( m_action && me->IsDebugging( NEXTBOT_BEHAVIOR ) )
		{
			CFmtStr msg;
			me->DisplayDebugText( msg.sprintf( "%s: %s", GetName(), m_action->DebugString() ) );
		}
	}

	/**
	 * If this Behavior has not been Update'd in a long time,
	 * call Resume() to let the system know its internal state may 
	 * be out of date.
	 */
	void Resume( Actor *me )
	{
		if ( me == NULL || IsEmpty() )
		{
			return;
		}

		m_action = m_action->ApplyResult( me, this, m_action->OnResume( me, NULL ) );

		if ( m_action && me->IsDebugging( NEXTBOT_BEHAVIOR ) )
		{
			CFmtStr msg;
			me->DisplayDebugText( msg.sprintf( "%s: %s", GetName(), m_action->DebugString() ) );
		}
	}

	const char *GetName( void ) const
	{
		return m_name;
	}

	// INextBotEventResponder propagation ----------------------------------------------------------------------
	virtual INextBotEventResponder *FirstContainedResponder( void ) const
	{
		return m_action;
	}

	virtual INextBotEventResponder *NextContainedResponder( INextBotEventResponder *current ) const
	{
		return NULL;
	}

	// IContextualQuery propagation ----------------------------------------------------------------------------
	virtual QueryResultType ShouldPickUp( const INextBot *me, CBaseEntity *item ) const		// if the desired item was available right now, should we pick it up?
	{
		QueryResultType result = ANSWER_UNDEFINED;

		if ( m_action )
		{
			// find innermost child action
			Action< Actor > *action;
			for( action = m_action; action->m_child; action = action->m_child )
				;

			// work our way through our containers
			while( action && result == ANSWER_UNDEFINED )
			{
				Action< Actor > *containingAction = action->m_parent;

				// work our way up the stack
				while( action && result == ANSWER_UNDEFINED )
				{
					result = action->ShouldPickUp( me, item );
					action = action->GetActionBuriedUnderMe();
				}

				action = containingAction;
			}
		}

		return result;
	}

	virtual QueryResultType ShouldHurry( const INextBot *me ) const					// are we in a hurry?
	{
		QueryResultType result = ANSWER_UNDEFINED;

		if ( m_action )
		{
			// find innermost child action
			Action< Actor > *action;
			for( action = m_action; action->m_child; action = action->m_child )
				;

			// work our way through our containers
			while( action && result == ANSWER_UNDEFINED )
			{
				Action< Actor > *containingAction = action->m_parent;

				// work our way up the stack
				while( action && result == ANSWER_UNDEFINED )
				{
					result = action->ShouldHurry( me );
					action = action->GetActionBuriedUnderMe();
				}

				action = containingAction;
			}
		}

		return result;
	}

	virtual QueryResultType ShouldRetreat( const INextBot *me ) const					// is it time to retreat?
	{
		QueryResultType result = ANSWER_UNDEFINED;

		if ( m_action )
		{
			// find innermost child action
			Action< Actor > *action;
			for( action = m_action; action->m_child; action = action->m_child )
				;

			// work our way through our containers
			while( action && result == ANSWER_UNDEFINED )
			{
				Action< Actor > *containingAction = action->m_parent;

				// work our way up the stack
				while( action && result == ANSWER_UNDEFINED )
				{
					result = action->ShouldRetreat( me );
					action = action->GetActionBuriedUnderMe();
				}

				action = containingAction;
			}
		}

		return result;
	}

	virtual QueryResultType IsHindrance( const INextBot *me, CBaseEntity *blocker ) const	// return true if we should wait for 'blocker' that is across our path somewhere up ahead.
	{
		QueryResultType result = ANSWER_UNDEFINED;

		if ( m_action )
		{
			// find innermost child action
			Action< Actor > *action;
			for( action = m_action; action->m_child; action = action->m_child )
				;

			// work our way through our containers
			while( action && result == ANSWER_UNDEFINED )
			{
				Action< Actor > *containingAction = action->m_parent;

				// work our way up the stack
				while( action && result == ANSWER_UNDEFINED )
				{
					result = action->IsHindrance( me, blocker );
					action = action->GetActionBuriedUnderMe();
				}

				action = containingAction;
			}
		}

		return result;		
	}


	virtual Vector SelectTargetPoint( const INextBot *me, const CBaseCombatCharacter *subject ) const		// given a subject, return the world space position we should aim at
	{
		Vector result = vec3_origin;

		if ( m_action )
		{
			// find innermost child action
			Action< Actor > *action;
			for( action = m_action; action->m_child; action = action->m_child )
				;

			// work our way through our containers
			while( action && result == vec3_origin )
			{
				Action< Actor > *containingAction = action->m_parent;

				// work our way up the stack
				while( action && result == vec3_origin )
				{
					result = action->SelectTargetPoint( me, subject );
					action = action->GetActionBuriedUnderMe();
				}

				action = containingAction;
			}
		}

		return result;		
	}


	/**
	 * Allow bot to approve of positions game movement tries to put him into.
	 * This is most useful for bots derived from CBasePlayer that go through
	 * the player movement system.
	 */
	virtual QueryResultType IsPositionAllowed( const INextBot *me, const Vector &pos ) const
	{
		QueryResultType result = ANSWER_UNDEFINED;

		if ( m_action )
		{
			// find innermost child action
			Action< Actor > *action;
			for( action = m_action; action->m_child; action = action->m_child )
				;

			// work our way through our containers
			while( action && result == ANSWER_UNDEFINED )
			{
				Action< Actor > *containingAction = action->m_parent;

				// work our way up the stack
				while( action && result == ANSWER_UNDEFINED )
				{
					result = action->IsPositionAllowed( me, pos );
					action = action->GetActionBuriedUnderMe();
				}

				action = containingAction;
			}
		}

		return result;		
	}



	virtual const CKnownEntity *SelectMoreDangerousThreat( const INextBot *me, const CBaseCombatCharacter *subject, const CKnownEntity *threat1, const CKnownEntity *threat2 ) const	// return the more dangerous of the two threats, or NULL if we have no opinion
	{
		const CKnownEntity *result = NULL;

		if ( m_action )
		{
			// find innermost child action
			Action< Actor > *action;
			for( action = m_action; action->m_child; action = action->m_child )
				;

			// work our way through our containers
			while( action && result == NULL )
			{
				Action< Actor > *containingAction = action->m_parent;

				// work our way up the stack
				while( action && result == NULL )
				{
					result = action->SelectMoreDangerousThreat( me, subject, threat1, threat2 );
					action = action->GetActionBuriedUnderMe();
				}

				action = containingAction;
			}
		}

		return result;		
	}


private:
	Action< Actor > *m_action;

	#define MAX_NAME_LENGTH 32
	CFmtStrN< MAX_NAME_LENGTH > m_name;
};


//----------------------------------------------------------------------------------------------
/**
 * Something an Actor does.
 * Actions can contain Actions, representing the precise context of the Actor's behavior.
 * A system of Actions is contained within a Behavior, which acts as the manager
 * of the Action system.
 */
template < typename Actor >
class Action : public INextBotEventResponder, public IContextualQuery
{
public:
	DECLARE_CLASS( Action, INextBotEventResponder );
	
	Action( void );
	virtual ~Action();

	virtual const char *GetName( void ) const = 0;		// return name of this action
	virtual bool IsNamed( const char *name ) const;		// return true if given name matches the name of this Action
	virtual const char *GetFullName( void ) const;		// return a temporary string showing the full lineage of this one action
	Actor *GetActor( void ) const;						// return the Actor performing this Action (valid just before OnStart() is invoked)

	//-----------------------------------------------------------------------------------------
	/**
	 * Try to start the Action. Result is immediately processed, 
	 * which can cause an immediate transition, another OnStart(), etc.
	 * An Action can count on each OnStart() being followed (eventually) with an OnEnd().
	 */
	virtual ActionResult< Actor >	OnStart( Actor *me, Action< Actor > *priorAction )							{ return Continue(); }

	/**
	 * Do the work of the Action. It is possible for Update to not be 
	 * called between a given OnStart/OnEnd pair due to immediate transitions.
	 */
	virtual ActionResult< Actor >	Update( Actor *me, float interval )											{ return Continue(); }

	// Invoked when an Action is ended for any reason
	virtual void					OnEnd( Actor *me, Action< Actor > *nextAction )								{ }

	/*
	 * When an Action is suspended by a new action.
	 * Note that only CONTINUE and DONE are valid results.  All other results will
	 * be considered as a CONTINUE.
	 */
	virtual ActionResult< Actor >	OnSuspend( Actor *me, Action< Actor > *interruptingAction )					{ return Continue(); }
	
	// When an Action is resumed after being suspended
	virtual ActionResult< Actor >	OnResume( Actor *me, Action< Actor > *interruptingAction )					{ return Continue(); }

	/**
	 * To cause a state change, use these methods to create an ActionResult to
	 * return from OnStart, Update, or OnResume. 
	 */
	ActionResult< Actor > Continue( void ) const;
	ActionResult< Actor > ChangeTo( Action< Actor > *action, const char *reason = NULL ) const;
	ActionResult< Actor > SuspendFor( Action< Actor > *action, const char *reason = NULL ) const;
	ActionResult< Actor > Done( const char *reason = NULL ) const;

	// create and return an Action to start as sub-action within this Action when it starts
	virtual Action< Actor > *InitialContainedAction( Actor *me )	{ return NULL; }

	//-----------------------------------------------------------------------------------------
	/**
	 * Override the event handler methods below to respond to events that occur during this Action
	 * NOTE: These are identical to the events in INextBotEventResponder with the addition
	 * of an actor argument and a return result. Their translators are located in the private area 
	 * below.
	 */
	virtual EventDesiredResult< Actor > OnLeaveGround( Actor *me, CBaseEntity *ground )							{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnLandOnGround( Actor *me, CBaseEntity *ground )						{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnContact( Actor *me, CBaseEntity *other, CGameTrace *result = NULL )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnMoveToSuccess( Actor *me, const Path *path )							{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnMoveToFailure( Actor *me, const Path *path, MoveToFailureType reason ) { return TryContinue(); }
	virtual EventDesiredResult< Actor > OnStuck( Actor *me )													{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnUnStuck( Actor *me )													{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnPostureChanged( Actor *me )											{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnAnimationActivityComplete( Actor *me, int activity )					{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnAnimationActivityInterrupted( Actor *me, int activity )				{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnAnimationEvent( Actor *me, animevent_t *event )						{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnIgnite( Actor *me )													{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnInjured( Actor *me, const CTakeDamageInfo &info )						{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnKilled( Actor *me, const CTakeDamageInfo &info )						{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnOtherKilled( Actor *me, CBaseCombatCharacter *victim, const CTakeDamageInfo &info )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnSight( Actor *me, CBaseEntity *subject )								{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnLostSight( Actor *me, CBaseEntity *subject )							{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnSound( Actor *me, CBaseEntity *source, const Vector &pos, KeyValues *keys )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnSpokeConcept( Actor *me, CBaseCombatCharacter *who, AIConcept_t concept, AI_Response *response )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnWeaponFired( Actor *me, CBaseCombatCharacter *whoFired, CBaseCombatWeapon *weapon )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnNavAreaChanged( Actor *me, CNavArea *newArea, CNavArea *oldArea )		{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnModelChanged( Actor *me )												{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnPickUp( Actor *me, CBaseEntity *item, CBaseCombatCharacter *giver )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnDrop( Actor *me, CBaseEntity *item )									{ return TryContinue(); }

	virtual EventDesiredResult< Actor > OnCommandAttack( Actor *me, CBaseEntity *victim )						{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCommandApproach( Actor *me, const Vector &pos, float range )			{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCommandApproach( Actor *me, CBaseEntity *goal )						{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCommandRetreat( Actor *me, CBaseEntity *threat, float range )			{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCommandPause( Actor *me, float duration )								{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCommandResume( Actor *me )											{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCommandString( Actor *me, const char *command )						{ return TryContinue(); }

	virtual EventDesiredResult< Actor > OnShoved( Actor *me, CBaseEntity *pusher )								{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnBlinded( Actor *me, CBaseEntity *blinder )							{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnTerritoryContested( Actor *me, int territoryID )						{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnTerritoryCaptured( Actor *me, int territoryID )						{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnTerritoryLost( Actor *me, int territoryID )							{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnWin( Actor *me )														{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnLose( Actor *me )														{ return TryContinue(); }

#ifdef DOTA_SERVER_DLL
	virtual EventDesiredResult< Actor > OnCommandMoveTo( Actor *me, const Vector &pos ) { return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCommandMoveToAggressive( Actor *me, const Vector &pos ) { return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCommandAttack( Actor *me, CBaseEntity *victim, bool bDeny ) { return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCastAbilityNoTarget( Actor *me, CDOTABaseAbility *ability )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCastAbilityOnPosition( Actor *me, CDOTABaseAbility *ability, const Vector &pos )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCastAbilityOnTarget( Actor *me, CDOTABaseAbility *ability, CBaseEntity *target )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnDropItem( Actor *me, const Vector &pos, CBaseEntity *item )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnPickupItem( Actor *me, CBaseEntity *item )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnPickupRune( Actor *me, CBaseEntity *item )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnStop( Actor *me )	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnFriendThreatened( Actor *me, CBaseEntity *friendly, CBaseEntity *threat ) 	{ return TryContinue(); }
	virtual EventDesiredResult< Actor > OnCancelAttack( Actor *me, CBaseEntity *pTarget ) { return TryContinue(); }
	virtual EventDesiredResult< Actor > OnDominated( Actor *me ) { return TryContinue(); }
	virtual EventDesiredResult< Actor > OnWarped( Actor *me, Vector vStartPos ) { return TryContinue(); }
#endif

	/**
	 * Event handlers must return one of these.
	 */
	EventDesiredResult< Actor > TryContinue( EventResultPriorityType priority = RESULT_TRY ) const;
	EventDesiredResult< Actor > TryChangeTo( Action< Actor > *action, EventResultPriorityType priority = RESULT_TRY, const char *reason = NULL ) const;
	EventDesiredResult< Actor > TrySuspendFor( Action< Actor > *action, EventResultPriorityType priority = RESULT_TRY, const char *reason = NULL ) const;
	EventDesiredResult< Actor > TryDone( EventResultPriorityType priority = RESULT_TRY, const char *reason = NULL ) const;
	EventDesiredResult< Actor > TryToSustain( EventResultPriorityType priority = RESULT_TRY, const char *reason = NULL ) const;


	//-----------------------------------------------------------------------------------------
	Action< Actor > *GetActiveChildAction( void ) const;
	Action< Actor > *GetParentAction( void ) const;			// the Action that I'm running inside of

	bool IsSuspended( void ) const;						// return true if we are currently suspended for another Action

	const char *DebugString( void ) const;								// return a temporary string describing the current action stack for debugging

	/**
	 * Sometimes we want to pass through other NextBots. OnContact() will always
	 * be invoked, but collision resolution can be skipped if this
	 * method returns false.
	 */
	virtual bool IsAbleToBlockMovementOf( const INextBot *botInMotion ) const	{ return true; }

	// INextBotEventResponder propagation ----------------------------------------------------------------------
	virtual INextBotEventResponder *FirstContainedResponder( void ) const;
	virtual INextBotEventResponder *NextContainedResponder( INextBotEventResponder *current ) const;


private:
	
	/**
	 * These macros are used below to translate INextBotEventResponder event methods
	 * into Action event handler methods
	 */
	#define PROCESS_EVENT( METHOD )							\
		{													\
			if ( !m_isStarted )								\
				return;										\
															\
			Action< Actor > *_action = this;				\
			EventDesiredResult< Actor > _result;			\
															\
			while( _action )								\
			{												\
				if ( m_actor && (m_actor->IsDebugging(NEXTBOT_EVENTS) || NextBotDebugHistory.GetBool()))	\
				{															\
					m_actor->DebugConColorMsg( NEXTBOT_EVENTS, Color( 100, 100, 100, 255 ), "%3.2f: %s:%s: %s received EVENT %s\n", gpGlobals->curtime, m_actor->GetDebugIdentifier(), m_behavior->GetName(), _action->GetFullName(), #METHOD );	\
				}											\
				_result = _action->METHOD( m_actor );	\
				if ( !_result.IsContinue() )				\
					break;									\
				_action = _action->GetActionBuriedUnderMe();		\
			}												\
															\
			if ( _action )									\
			{												\
				if ( m_actor && _result.IsRequestingChange() && (m_actor->IsDebugging(NEXTBOT_BEHAVIOR) || NextBotDebugHistory.GetBool()) )	\
				{																						\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 0, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, m_actor->GetDebugIdentifier(), m_behavior->GetName() ); \
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "%s ", _action->GetFullName() );			\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255,   0, 255 ), "reponded to EVENT %s with ", #METHOD );	\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0,   0, 255 ), "%s %s ", _result.GetTypeName(), _result.m_action ? _result.m_action->GetName() : "" );		\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color(   0, 255,   0, 255 ), "%s\n", _result.m_reason ? _result.m_reason : "" );	\
				}											\
															\
				_action->StorePendingEventResult( _result, #METHOD );	\
			}												\
															\
			INextBotEventResponder::METHOD();			\
		}


	#define PROCESS_EVENT_WITH_1_ARG( METHOD, ARG1 )		\
		{													\
			if ( !m_isStarted )								\
				return;										\
															\
			Action< Actor > *_action = this;				\
			EventDesiredResult< Actor > _result;			\
															\
			while( _action )								\
			{												\
				if ( m_actor && (m_actor->IsDebugging(NEXTBOT_EVENTS) || NextBotDebugHistory.GetBool()) )	\
				{															\
					m_actor->DebugConColorMsg( NEXTBOT_EVENTS, Color( 100, 100, 100, 255 ), "%3.2f: %s:%s: %s received EVENT %s\n", gpGlobals->curtime, m_actor->GetDebugIdentifier(), m_behavior->GetName(), _action->GetFullName(), #METHOD );	\
				}											\
				_result = _action->METHOD( m_actor, ARG1 );		\
				if ( !_result.IsContinue() )				\
					break;									\
				_action = _action->GetActionBuriedUnderMe();		\
			}												\
															\
			if ( _action )									\
			{												\
				if ( m_actor && (m_actor->IsDebugging(NEXTBOT_BEHAVIOR) || NextBotDebugHistory.GetBool()) && _result.IsRequestingChange() && _action )	\
				{																		\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 0, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, m_actor->GetDebugIdentifier(), m_behavior->GetName() ); \
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "%s ", _action->GetFullName() );			\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255,   0, 255 ), "reponded to EVENT %s with ", #METHOD );	\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0,   0, 255 ), "%s %s ", _result.GetTypeName(), _result.m_action ? _result.m_action->GetName() : "" );		\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color(   0, 255,   0, 255 ), "%s\n", _result.m_reason ? _result.m_reason : "" );	\
				}											\
															\
				_action->StorePendingEventResult( _result, #METHOD );	\
			}												\
															\
			INextBotEventResponder::METHOD( ARG1 );		\
		}


	#define PROCESS_EVENT_WITH_2_ARGS( METHOD, ARG1, ARG2 )	\
		{													\
			if ( !m_isStarted )								\
				return;										\
															\
			Action< Actor > *_action = this;				\
			EventDesiredResult< Actor > _result;			\
															\
			while( _action )								\
			{												\
				if ( m_actor && (m_actor->IsDebugging(NEXTBOT_EVENTS) || NextBotDebugHistory.GetBool()) )	\
				{															\
					m_actor->DebugConColorMsg( NEXTBOT_EVENTS, Color( 100, 100, 100, 255 ), "%3.2f: %s:%s: %s received EVENT %s\n", gpGlobals->curtime, m_actor->GetDebugIdentifier(), m_behavior->GetName(), _action->GetFullName(), #METHOD );	\
				}											\
				_result = _action->METHOD( m_actor, ARG1, ARG2 );		\
				if ( !_result.IsContinue() )				\
					break;									\
				_action = _action->GetActionBuriedUnderMe();				\
			}												\
															\
			if ( _action )									\
			{												\
				if ( m_actor && (m_actor->IsDebugging(NEXTBOT_BEHAVIOR) || NextBotDebugHistory.GetBool()) && _result.IsRequestingChange() && _action )	\
				{																		\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 0, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, m_actor->GetDebugIdentifier(), m_behavior->GetName() ); \
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "%s ", _action->GetFullName() );			\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255,   0, 255 ), "reponded to EVENT %s with ", #METHOD );	\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0,   0, 255 ), "%s %s ", _result.GetTypeName(), _result.m_action ? _result.m_action->GetName() : "" );		\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color(   0, 255,   0, 255 ), "%s\n", _result.m_reason ? _result.m_reason : "" );	\
				}											\
															\
				_action->StorePendingEventResult( _result, #METHOD );	\
			}												\
															\
			INextBotEventResponder::METHOD( ARG1, ARG2 );			\
		}


	#define PROCESS_EVENT_WITH_3_ARGS( METHOD, ARG1, ARG2, ARG3 )	\
		{													\
			if ( !m_isStarted )								\
				return;										\
															\
			Action< Actor > *_action = this;				\
			EventDesiredResult< Actor > _result;			\
															\
			while( _action )								\
			{												\
				if ( m_actor && (m_actor->IsDebugging(NEXTBOT_EVENTS) || NextBotDebugHistory.GetBool()) )	\
				{															\
					m_actor->DebugConColorMsg( NEXTBOT_EVENTS, Color( 100, 100, 100, 255 ), "%3.2f: %s:%s: %s received EVENT %s\n", gpGlobals->curtime, m_actor->GetDebugIdentifier(), m_behavior->GetName(), _action->GetFullName(), #METHOD );	\
				}											\
				_result = _action->METHOD( m_actor, ARG1, ARG2, ARG3 );		\
				if ( !_result.IsContinue() )				\
					break;									\
				_action = _action->GetActionBuriedUnderMe();				\
			}												\
															\
			if ( _action )									\
			{												\
				if ( m_actor && (m_actor->IsDebugging(NEXTBOT_BEHAVIOR) || NextBotDebugHistory.GetBool()) && _result.IsRequestingChange() && _action )	\
				{																		\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 0, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, m_actor->GetDebugIdentifier(), m_behavior->GetName() ); \
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "%s ", _action->GetFullName() );			\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255,   0, 255 ), "reponded to EVENT %s with ", #METHOD );	\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0,   0, 255 ), "%s %s ", _result.GetTypeName(), _result.m_action ? _result.m_action->GetName() : "" );		\
					m_actor->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color(   0, 255,   0, 255 ), "%s\n", _result.m_reason ? _result.m_reason : "" );	\
				}											\
															\
				_action->StorePendingEventResult( _result, #METHOD );	\
			}												\
															\
			INextBotEventResponder::METHOD( ARG1, ARG2, ARG3 );			\
		}


	/**
	 * Translate incoming events into Action events
	 * DO NOT OVERRIDE THESE METHODS
	 */
	virtual void OnLeaveGround( CBaseEntity *ground )					{ PROCESS_EVENT_WITH_1_ARG( OnLeaveGround, ground ); }
	virtual void OnLandOnGround( CBaseEntity *ground )					{ PROCESS_EVENT_WITH_1_ARG( OnLandOnGround, ground ); }
	virtual void OnContact( CBaseEntity *other, CGameTrace *result )	{ PROCESS_EVENT_WITH_2_ARGS( OnContact, other, result ); }
	virtual void OnMoveToSuccess( const Path *path )					{ PROCESS_EVENT_WITH_1_ARG( OnMoveToSuccess, path ); }
	virtual void OnMoveToFailure( const Path *path, MoveToFailureType reason )	{ PROCESS_EVENT_WITH_2_ARGS( OnMoveToFailure, path, reason ); }
	virtual void OnStuck( void )										{ PROCESS_EVENT( OnStuck ); }
	virtual void OnUnStuck( void )										{ PROCESS_EVENT( OnUnStuck ); }
	virtual void OnPostureChanged( void )								{ PROCESS_EVENT( OnPostureChanged ); }
	virtual void OnAnimationActivityComplete( int activity )			{ PROCESS_EVENT_WITH_1_ARG( OnAnimationActivityComplete, activity ); }
	virtual void OnAnimationActivityInterrupted( int activity )			{ PROCESS_EVENT_WITH_1_ARG( OnAnimationActivityInterrupted, activity ); }
	virtual void OnAnimationEvent( animevent_t *event )					{ PROCESS_EVENT_WITH_1_ARG( OnAnimationEvent, event ); }
	virtual void OnIgnite( void )										{ PROCESS_EVENT( OnIgnite ); }
	virtual void OnInjured( const CTakeDamageInfo &info )				{ PROCESS_EVENT_WITH_1_ARG( OnInjured, info ); }
	virtual void OnKilled( const CTakeDamageInfo &info )				{ PROCESS_EVENT_WITH_1_ARG( OnKilled, info ); }
	virtual void OnOtherKilled( CBaseCombatCharacter *victim, const CTakeDamageInfo &info )	{ PROCESS_EVENT_WITH_2_ARGS( OnOtherKilled, victim, info ); }
	virtual void OnSight( CBaseEntity *subject )						{ PROCESS_EVENT_WITH_1_ARG( OnSight, subject ); }
	virtual void OnLostSight( CBaseEntity *subject )					{ PROCESS_EVENT_WITH_1_ARG( OnLostSight, subject ); }
	virtual void OnSound( CBaseEntity *source, const Vector &pos, KeyValues *keys )					{ PROCESS_EVENT_WITH_3_ARGS( OnSound, source, pos, keys ); }
	virtual void OnSpokeConcept( CBaseCombatCharacter *who, AIConcept_t concept, AI_Response *response )	{ PROCESS_EVENT_WITH_3_ARGS( OnSpokeConcept, who, concept, response ); }
	virtual void OnWeaponFired( CBaseCombatCharacter *whoFired, CBaseCombatWeapon *weapon )			{ PROCESS_EVENT_WITH_2_ARGS( OnWeaponFired, whoFired, weapon ); }
	virtual void OnNavAreaChanged( CNavArea *newArea, CNavArea *oldArea )	{ PROCESS_EVENT_WITH_2_ARGS( OnNavAreaChanged, newArea, oldArea ); }
	virtual void OnModelChanged( void )									{ PROCESS_EVENT( OnModelChanged ); }
	virtual void OnPickUp( CBaseEntity *item, CBaseCombatCharacter *giver )	{ PROCESS_EVENT_WITH_2_ARGS( OnPickUp, item, giver ); }
	virtual void OnDrop( CBaseEntity *item )							{ PROCESS_EVENT_WITH_1_ARG( OnDrop, item ); }

	virtual void OnCommandAttack( CBaseEntity *victim )					{ PROCESS_EVENT_WITH_1_ARG( OnCommandAttack, victim ); }
	virtual void OnCommandApproach( const Vector &pos, float range )	{ PROCESS_EVENT_WITH_2_ARGS( OnCommandApproach, pos, range ); }
	virtual void OnCommandApproach( CBaseEntity *goal )					{ PROCESS_EVENT_WITH_1_ARG( OnCommandApproach, goal ); }
	virtual void OnCommandRetreat( CBaseEntity *threat, float range )	{ PROCESS_EVENT_WITH_2_ARGS( OnCommandRetreat, threat, range ); }
	virtual void OnCommandPause( float duration )						{ PROCESS_EVENT_WITH_1_ARG( OnCommandPause, duration ); }
	virtual void OnCommandResume( void )								{ PROCESS_EVENT( OnCommandResume ); }
	virtual void OnCommandString( const char *command )					{ PROCESS_EVENT_WITH_1_ARG( OnCommandString, command ); }

	virtual void OnShoved( CBaseEntity *pusher )						{ PROCESS_EVENT_WITH_1_ARG( OnShoved, pusher ); }
	virtual void OnBlinded( CBaseEntity *blinder )						{ PROCESS_EVENT_WITH_1_ARG( OnBlinded, blinder ); }
	virtual void OnTerritoryContested( int territoryID )				{ PROCESS_EVENT_WITH_1_ARG( OnTerritoryContested, territoryID ); }
	virtual void OnTerritoryCaptured( int territoryID )					{ PROCESS_EVENT_WITH_1_ARG( OnTerritoryCaptured, territoryID ); }
	virtual void OnTerritoryLost( int territoryID )						{ PROCESS_EVENT_WITH_1_ARG( OnTerritoryLost, territoryID ); }
	virtual void OnWin( void )											{ PROCESS_EVENT( OnWin ); }
	virtual void OnLose( void )											{ PROCESS_EVENT( OnLose ); }

#ifdef DOTA_SERVER_DLL
	virtual void OnCommandMoveTo( const Vector &pos ) { PROCESS_EVENT_WITH_1_ARG( OnCommandMoveTo, pos ); }
	virtual void OnCommandMoveToAggressive( const Vector &pos ) { PROCESS_EVENT_WITH_1_ARG( OnCommandMoveToAggressive, pos ); }
	virtual void OnCommandAttack( CBaseEntity *victim, bool bDeny ) { PROCESS_EVENT_WITH_2_ARGS( OnCommandAttack, victim, bDeny ); }
	virtual void OnCastAbilityNoTarget( CDOTABaseAbility *ability ) { PROCESS_EVENT_WITH_1_ARG( OnCastAbilityNoTarget, ability ); }
	virtual void OnCastAbilityOnPosition( CDOTABaseAbility *ability, const Vector &pos ) { PROCESS_EVENT_WITH_2_ARGS( OnCastAbilityOnPosition, ability, pos ); }
	virtual void OnCastAbilityOnTarget( CDOTABaseAbility *ability, CBaseEntity *target ) { PROCESS_EVENT_WITH_2_ARGS( OnCastAbilityOnTarget, ability, target ); }
	virtual void OnDropItem( const Vector &pos, CBaseEntity *item ) { PROCESS_EVENT_WITH_2_ARGS( OnDropItem, pos, item ); }
	virtual void OnPickupItem( CBaseEntity *item ) { PROCESS_EVENT_WITH_1_ARG( OnPickupItem, item ); }
	virtual void OnPickupRune( CBaseEntity *item ) { PROCESS_EVENT_WITH_1_ARG( OnPickupRune, item ); }
	virtual void OnStop() { PROCESS_EVENT( OnStop ); }
	virtual void OnFriendThreatened( CBaseEntity *friendly, CBaseEntity *threat ) { PROCESS_EVENT_WITH_2_ARGS( OnFriendThreatened, friendly, threat ); }
	virtual void OnCancelAttack( CBaseEntity *pTarget ) { PROCESS_EVENT_WITH_1_ARG( OnCancelAttack, pTarget ); }
	virtual void OnDominated() { PROCESS_EVENT( OnDominated ); }
	virtual void OnWarped( Vector vStartPos ) { PROCESS_EVENT_WITH_1_ARG( OnWarped, vStartPos ); }
#endif

	friend class Behavior< Actor>;							// the containing Behavior class
	Behavior< Actor > *m_behavior;							// the Behavior this Action is part of

	Action< Actor > *m_parent;								// the Action that contains us
	Action< Actor > *m_child;								// the ACTIVE Action we contain, top of the stack. Use m_buriedUnderMe, m_coveringMe on the child to traverse to other suspended children

	Action< Actor > *m_buriedUnderMe;						// the Action just "under" us in the stack that we will resume to when we finish
	Action< Actor > *m_coveringMe;							// the Action just "above" us in the stack that will resume to us when it finishes

	Actor *m_actor;											// only valid after OnStart()
	mutable EventDesiredResult< Actor > m_eventResult;		// set by event handlers
	bool m_isStarted;										// Action doesn't start until OnStart() is invoked
	bool m_isSuspended;										// are we suspended for another Action

	Action< Actor > *GetActionBuriedUnderMe( void ) const	// return Action just "under" us that we will resume to when we finish
	{
		return m_buriedUnderMe;
	}

	Action< Actor > *GetActionCoveringMe( void ) const		// return Action just "above" us that will resume to us when it finishes
	{
		return m_coveringMe;
	}

	/**
	 * If any Action buried underneath me has either exited
	 * or is changing to a different Action, we're "out of scope"
	 */
	bool IsOutOfScope( void ) const
	{
		for( Action< Actor > *under = GetActionBuriedUnderMe(); under; under = under->GetActionBuriedUnderMe() )
		{
			if ( under->m_eventResult.m_type == CHANGE_TO ||
				 under->m_eventResult.m_type == DONE )
			{
				return true;
			}
		}
		return false;
	}

	/**
	 * Process any pending events with the stack. This is called
	 * by the active Action on the top of the stack, and walks
	 * through any buried Actions checking for pending event results.
	 */
	ActionResult< Actor > ProcessPendingEvents( void ) const
	{
		// if an event has requested a change, honor it
		if ( m_eventResult.IsRequestingChange() )
		{
			ActionResult< Actor > result( m_eventResult.m_type, m_eventResult.m_action, m_eventResult.m_reason );

			// clear event result in case this change is a suspend and we later resume this action
			m_eventResult = TryContinue( RESULT_NONE );

			return result;
		}

		// check for pending event changes buried in the stack
		Action< Actor > *under = GetActionBuriedUnderMe();
		while( under )
		{
			if ( under->m_eventResult.m_type == SUSPEND_FOR )
			{
				// process this pending event in-place and push new Action on the top of the stack
				ActionResult< Actor > result( under->m_eventResult.m_type, under->m_eventResult.m_action, under->m_eventResult.m_reason );

				// clear event result in case this change is a suspend and we later resume this action
				under->m_eventResult = TryContinue( RESULT_NONE );

				return result;
			}

			under = under->GetActionBuriedUnderMe();
		}
		
		return Continue();
	}
	
	// given the result of this Action's work, apply the result to potentially cause a state transition
	Action< Actor > *		ApplyResult( Actor *me, Behavior< Actor > *behavior, ActionResult< Actor > result );

	/**
	 * The methods below do the bookkeeping of each event, propagate the activity through the hierarchy,
	 * and invoke the virtual event for each.
	 */
	ActionResult< Actor >	InvokeOnStart( Actor *me, Behavior< Actor > *behavior, Action< Actor > *priorAction, Action< Actor > *buriedUnderMeAction );
	ActionResult< Actor >	InvokeUpdate( Actor *me, Behavior< Actor > *behavior, float interval );
	void					InvokeOnEnd( Actor *me, Behavior< Actor > *behavior, Action< Actor > *nextAction );
	Action< Actor > *		InvokeOnSuspend( Actor *me, Behavior< Actor > *behavior, Action< Actor > *interruptingAction );
	ActionResult< Actor >	InvokeOnResume( Actor *me, Behavior< Actor > *behavior, Action< Actor > *interruptingAction );

	/**
	 * Store the given event result, attending to priorities
	 */
	void StorePendingEventResult( const EventDesiredResult< Actor > &result, const char *eventName )
	{
		if ( result.IsContinue() )
		{
			return;
		}

		if ( result.m_priority > m_eventResult.m_priority )
		{
			// new result is more important - destroy the replaced action
			if ( result.m_priority != RESULT_NONE && m_eventResult.m_action )
			{
				delete m_eventResult.m_action;
			}
			
			m_eventResult = result;
		}
		else if ( result.m_priority == m_eventResult.m_priority && m_eventResult.m_type == SUSTAIN )
		{
			// same priority as existing SUSTAIN, override

			// destroy the replaced action
			if ( m_eventResult.m_action )
			{
				delete m_eventResult.m_action;
			}

			m_eventResult = result;
		}
		else
		{
			// new result is equal or lower priority than previously stored result - discard it
			
			if ( result.m_priority == RESULT_CRITICAL )
			{				
				if ( developer.GetBool() )
				{
					DevMsg( "%3.2f: WARNING: %s::%s() RESULT_CRITICAL collision\n", gpGlobals->curtime, GetName(), eventName );
				}
			}

			if ( result.m_action )
			{
				// destroy the unused action
				delete result.m_action;
			}
		}
	}
	
	char *BuildDecoratedName( char *name, const Action< Actor > *action ) const;	// recursive name outMsg for DebugString()

	void PrintStateToConsole( void ) const;
};


//-------------------------------------------------------------------------------------------
template < typename Actor >
Action< Actor >::Action( void )
{
	m_parent = NULL;
	m_child = NULL;
	m_buriedUnderMe = NULL;
	m_coveringMe = NULL;
	m_actor = NULL;
	m_behavior = NULL;

	m_isStarted = false;
	m_isSuspended = false;
	
	m_eventResult = TryContinue( RESULT_NONE );

#ifdef DEBUG_BEHAVIOR_MEMORY
	ConColorMsg( Color( 255, 0, 255, 255 ), "%3.2f: NEW %0X\n", gpGlobals->curtime, this );
#endif
}


//-------------------------------------------------------------------------------------------
template < typename Actor >
Action< Actor >::~Action()
{
#ifdef DEBUG_BEHAVIOR_MEMORY
	ConColorMsg( Color( 255, 0, 255, 255 ), "%3.2f: DELETE %0X\n", gpGlobals->curtime, this );
#endif

	if ( m_parent )
	{
		// if I'm my parent's active child, update parent's pointer
		if ( m_parent->m_child == this )
		{
			m_parent->m_child = m_buriedUnderMe;
		}
	}

	// delete all my children.
	// our m_child pointer always points to the topmost
	// child in the stack, so work our way back thru the
	// 'buried' children and delete them.
	Action< Actor > *child, *next = NULL;
	for( child = m_child; child; child = next )
	{
		next = child->m_buriedUnderMe;
		delete child;
	}

	if ( m_buriedUnderMe )
	{
		// we're going away, so my buried sibling is now on top
		m_buriedUnderMe->m_coveringMe = NULL;
	}

	// delete any actions stacked on top of me
	if ( m_coveringMe )
	{
		// recursion will march down the chain
		delete m_coveringMe;
	}

	// delete any pending event result
	if ( m_eventResult.m_action )
	{
		delete m_eventResult.m_action;
	}
}


template < typename Actor >
bool Action< Actor >::IsNamed( const char *name ) const
{
	return FStrEq( GetName(), name );
}


template < typename Actor >
Actor *Action< Actor >::GetActor( void ) const
{
	return m_actor;
}

template < typename Actor >
ActionResult< Actor > Action< Actor >::Continue( void ) const
{
	return ActionResult< Actor >( CONTINUE, NULL, NULL );
}

template < typename Actor >
ActionResult< Actor > Action< Actor >::ChangeTo( Action< Actor > *action, const char *reason ) const
{
	return ActionResult< Actor >( CHANGE_TO, action, reason );
}

template < typename Actor >
ActionResult< Actor > Action< Actor >::SuspendFor( Action< Actor > *action, const char *reason ) const
{
	// clear any pending transitions requested by events, or this SuspendFor will
	// immediately be out of scope
	m_eventResult = TryContinue( RESULT_NONE );

	return ActionResult< Actor >( SUSPEND_FOR, action, reason );
}

template < typename Actor >
ActionResult< Actor > Action< Actor >::Done( const char *reason ) const
{
	return ActionResult< Actor >( DONE, NULL, reason );
}


//-------------------------------------------------------------------------------------------
template < typename Actor >
EventDesiredResult< Actor > Action< Actor >::TryContinue( EventResultPriorityType priority ) const
{
	return EventDesiredResult< Actor >( CONTINUE, NULL, priority );
}

template < typename Actor >
EventDesiredResult< Actor > Action< Actor >::TryChangeTo( Action< Actor > *action, EventResultPriorityType priority, const char *reason ) const
{
	return EventDesiredResult< Actor >( CHANGE_TO, action, priority, reason );
}

template < typename Actor >
EventDesiredResult< Actor > Action< Actor >::TrySuspendFor( Action< Actor > *action, EventResultPriorityType priority, const char *reason ) const
{
	return EventDesiredResult< Actor >( SUSPEND_FOR, action, priority, reason );
}

template < typename Actor >
EventDesiredResult< Actor > Action< Actor >::TryDone( EventResultPriorityType priority, const char *reason /*= NULL*/ ) const
{
	return EventDesiredResult< Actor >( DONE, NULL, priority, reason );
}

template < typename Actor >
EventDesiredResult< Actor > Action< Actor >::TryToSustain( EventResultPriorityType priority, const char *reason /*= NULL*/ ) const
{
	return EventDesiredResult< Actor >( SUSTAIN, NULL, priority, reason );
}


//-------------------------------------------------------------------------------------------
template < typename Actor >
Action< Actor > *Action< Actor >::GetActiveChildAction( void ) const
{
	return m_child;
}


//-------------------------------------------------------------------------------------------
// the Action that I'm running inside of
template < typename Actor >
Action< Actor > *Action< Actor >::GetParentAction( void ) const
{
	return m_parent;
}


//-------------------------------------------------------------------------------------------
/**
 * Return true if we are currently suspended for another Action
 */
template < typename Actor >
bool Action< Actor >::IsSuspended( void ) const
{
	return m_isSuspended;
}


//-------------------------------------------------------------------------------------------
/**
 * Start this Action.
 * The act of calling InvokeOnStart is the edge case that 'enters' a state.
 */
template < typename Actor >
ActionResult< Actor > Action< Actor >::InvokeOnStart( Actor *me, Behavior< Actor > *behavior, Action< Actor > *priorAction, Action< Actor > *buriedUnderMeAction )
{
	// debug display
	if ( (me->IsDebugging(NEXTBOT_BEHAVIOR) || NextBotDebugHistory.GetBool()) )
	{
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 150, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, me->GetDebugIdentifier(), behavior->GetName() );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color(   0, 255,   0, 255 ), " STARTING " );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), GetName() );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "\n" );
	}

	// these value must be valid before invoking OnStart, in case an OnSuspend happens 
	m_isStarted = true;
	m_actor = me;
	m_behavior = behavior;

	// maintain parent/child relationship during transitions
	if ( priorAction )
	{
		m_parent = priorAction->m_parent;
	}

	if ( m_parent )
	{
		// child pointer of an Action always points to the ACTIVE child
		// parent pointers are set when child Actions are instantiated
		m_parent->m_child = this;
	}

	// maintain stack pointers
	m_buriedUnderMe = buriedUnderMeAction;
	if ( buriedUnderMeAction )
	{
		buriedUnderMeAction->m_coveringMe = this;
	}

	// we are always on top of the stack. if our priorAction was buried, it cleared 
	// everything covering it when it ended (which happens before we start)
	m_coveringMe = NULL;

	// start the optional child action
	m_child = InitialContainedAction( me );
	if ( m_child )
	{
		// define initial parent/child relationship
		m_child->m_parent = this;

		m_child = m_child->ApplyResult( me, behavior, ChangeTo( m_child, "Starting child Action" ) );
	}

	// start ourselves
	ActionResult< Actor > result = OnStart( me, priorAction );

	return result;
}


//-------------------------------------------------------------------------------------------
template < typename Actor >
ActionResult< Actor > Action< Actor >::InvokeUpdate( Actor *me, Behavior< Actor > *behavior, float interval )
{
	// an explicit "out of scope" check is needed here to prevent any
	// pending events causing an out of scope action to linger
	if ( IsOutOfScope() )
	{
		// exit self to make this Action active and allow result to take effect on its next Update
		return Done( "Out of scope" );
	}

	if ( !m_isStarted )
	{
		// this Action has not yet begun - start it
		return ChangeTo( this, "Starting Action" );
	}

	// honor any pending event results 
	ActionResult< Actor > eventResult = ProcessPendingEvents();
	if ( !eventResult.IsContinue() )
	{
		return eventResult;
	}

	// update our child action first, since it has the most specific behavior
	if ( m_child )
	{
		m_child = m_child->ApplyResult( me, behavior, m_child->InvokeUpdate( me, behavior, interval ) );
	}

	// update ourselves
	ActionResult< Actor > result = Update( me, interval );

	return result;
}


//-------------------------------------------------------------------------------------------
/**
 * This method calls the virtual OnEnd() method for the Action, its children, and Actions
 * stacked on top of it.
 * It does NOT delete resources, or disturb pointer relationships, because this Action
 * needs to remain valid for a short while as an argument to OnStart(), OnSuspend(), etc for
 * the next Action.
 * The destructor for the Action frees memory for this Action, its children, etc.
 */
template < typename Actor >
void Action< Actor >::InvokeOnEnd( Actor *me, Behavior< Actor > *behavior, Action< Actor > *nextAction )
{
	if ( !m_isStarted )
	{
		// we are not started (or never were)
		return;
	}

	if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) || NextBotDebugHistory.GetBool() )
	{
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 150, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, me->GetDebugIdentifier(), behavior->GetName() );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0,   0, 255 ), " ENDING " );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), GetName() );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "\n" );
	}

	// we are no longer started
	m_isStarted = false;

	// tell child Action(s) to leave (but don't disturb the list itself)
	Action< Actor > *child, *next = NULL;
	for( child = m_child; child; child = next )
	{
		next = child->m_buriedUnderMe;
		child->InvokeOnEnd( me, behavior, nextAction );
	}

	// leave ourself
	OnEnd( me, nextAction );

	// leave any Actions stacked on top of me
	if ( m_coveringMe )
	{
		m_coveringMe->InvokeOnEnd( me, behavior, nextAction );
	}
}


//-------------------------------------------------------------------------------------------
/**
 * Just invoke OnSuspend - when the interrupting Action is started it will
 * update our buried/covered pointers.
 * OnSuspend may cause this Action to exit.
 */
template < typename Actor >
Action< Actor > * Action< Actor >::InvokeOnSuspend( Actor *me, Behavior< Actor > *behavior, Action< Actor > *interruptingAction )
{
	if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) || NextBotDebugHistory.GetBool() )
	{
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 150, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, me->GetDebugIdentifier(), behavior->GetName() );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0, 255, 255 ), " SUSPENDING " );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), GetName() );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "\n" );
	}

	// suspend child Action
	if ( m_child )
	{
		m_child = m_child->InvokeOnSuspend( me, behavior, interruptingAction );
	}

	// suspend ourselves
	m_isSuspended = true;
	ActionResult< Actor > result = OnSuspend( me, interruptingAction );

	if ( result.IsDone() )
	{
		// we want to be replaced instead of suspended
		InvokeOnEnd( me, behavior, NULL );

		Action< Actor > * buried = GetActionBuriedUnderMe();

		delete this;

		// new Action on top of the stack
		return buried;
	}

	// we are still on top of the stack at this moment
	return this;
}


//-------------------------------------------------------------------------------------------
template < typename Actor >
ActionResult< Actor > Action< Actor >::InvokeOnResume( Actor *me, Behavior< Actor > *behavior, Action< Actor > *interruptingAction )
{
	if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) || NextBotDebugHistory.GetBool() )
	{
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 150, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, me->GetDebugIdentifier(), behavior->GetName() );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0, 255, 255 ), " RESUMING " );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), GetName() );
		me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "\n" );
	}

	if ( !m_isSuspended )
	{
		// we were never suspended
		return Continue();
	}

	if ( m_eventResult.IsRequestingChange() )
	{
		// this Action is not actually being Resumed, because a change
		// is already pending from a prior event
		return Continue();
	}

	// resume ourselves
	m_isSuspended = false;
	m_coveringMe = NULL;

	if ( m_parent )
	{
		// we are once again our parent's active child
		m_parent->m_child = this;
	}

	// resume child Action
	if ( m_child )
	{
		m_child = m_child->ApplyResult( me, behavior, m_child->InvokeOnResume( me, behavior, interruptingAction ) );
	}

	// actually resume ourselves
	ActionResult< Actor > result = OnResume( me, interruptingAction );

	return result;
}


//-------------------------------------------------------------------------------------------
/**
 * Given the result of this Action's work, apply the result to potentially create a new Action
 */
template < typename Actor >
Action< Actor > *Action< Actor >::ApplyResult( Actor *me, Behavior< Actor > *behavior, ActionResult< Actor > result )
{
	Action< Actor > *newAction = result.m_action;

	switch( result.m_type )
	{
		//-----------------------------------------------------------------------------------------------------
		// transition to new Action
		case CHANGE_TO:
		{
			if ( newAction == NULL )
			{
				DevMsg( "Error: Attempted CHANGE_TO to a NULL Action\n" );
				AssertMsg( false, "Action: Attempted CHANGE_TO to a NULL Action" );
				return this;
			}
	
			// debug display
			if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) || NextBotDebugHistory.GetBool() )
			{
				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 150, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, me->GetDebugIdentifier(), behavior->GetName() );
				
				if ( this == newAction )
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0,   0, 255 ), "START " );
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), newAction->GetName() );
				}
				else
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), this->GetName() );
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0,   0, 255 ), " CHANGE_TO " );
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), newAction->GetName() );
				}
						
				if ( result.m_reason )
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 150, 255, 150, 255 ), "  (%s)\n", result.m_reason );
				}
				else
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "\n" );
				}
			}

			// we are done
			this->InvokeOnEnd( me, behavior, newAction );

			// start the new Action
			ActionResult< Actor > startResult = newAction->InvokeOnStart( me, behavior, this, this->m_buriedUnderMe );

			// discard ended action
			if ( this != newAction )
			{
				delete this;
			}

			// debug display
			if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) )
			{
				newAction->PrintStateToConsole();
			}

			// apply result of starting the Action
			return newAction->ApplyResult( me, behavior, startResult );
		}
		
		//-----------------------------------------------------------------------------------------------------
		// temporarily suspend ourselves for the newAction, covering it on the stack
		case SUSPEND_FOR:
		{
			// interrupting Action always goes on the TOP of the stack - find it
			Action< Actor > *topAction = this;
			while ( topAction->m_coveringMe )
			{
				topAction = topAction->m_coveringMe;
			}

			// debug display
			if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) || NextBotDebugHistory.GetBool() )
			{
				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 150, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, me->GetDebugIdentifier(), behavior->GetName() );

				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), this->GetName() );
				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0, 255, 255 ), " caused " );
				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), topAction->GetName() );
				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255,   0, 255, 255 ), " to SUSPEND_FOR " );
				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), newAction->GetName() );

				if ( result.m_reason )
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 150, 255, 150, 255 ), "  (%s)\n", result.m_reason );
				}
				else
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "\n" );
				}
			}
			
			// suspend the Action we just covered up				
			topAction = topAction->InvokeOnSuspend( me, behavior, newAction );

			// begin the interrupting Action.
			ActionResult< Actor > startResult = newAction->InvokeOnStart( me, behavior, topAction, topAction );

			// debug display
			if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) )
			{
				newAction->PrintStateToConsole();
			}
			
			return newAction->ApplyResult( me, behavior, startResult );
		}

		//-----------------------------------------------------------------------------------------------------
		case DONE:
		{
			// resume buried action
			Action< Actor > *resumedAction = this->m_buriedUnderMe;

			// we are finished
			this->InvokeOnEnd( me, behavior, resumedAction );

			// debug display
			if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) || NextBotDebugHistory.GetBool() )
			{
				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 150, 255 ), "%3.2f: %s:%s: ", gpGlobals->curtime, me->GetDebugIdentifier(), behavior->GetName() );

				me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), this->GetName() );

				if ( resumedAction )
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color(   0, 255,   0, 255 ), " DONE, RESUME " );
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), resumedAction->GetName() );
				}
				else
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color(   0, 255,   0, 255 ), " DONE." );
				}

				if ( result.m_reason )
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 150, 255, 150, 255 ), "  (%s)\n", result.m_reason );
				}
				else
				{
					me->DebugConColorMsg( NEXTBOT_BEHAVIOR, Color( 255, 255, 255, 255 ), "\n" );
				}
			}

			if ( resumedAction == NULL )
			{
				// all Actions complete
				delete this;
				return NULL;
			}

			// resume uncovered action
			ActionResult< Actor > resumeResult = resumedAction->InvokeOnResume( me, behavior, this );

			// debug display
			if ( me->IsDebugging( NEXTBOT_BEHAVIOR ) )
			{
				resumedAction->PrintStateToConsole();
			}

			// discard ended action
			delete this;

			// apply result of OnResume()
			return resumedAction->ApplyResult( me, behavior, resumeResult );
		}

		case CONTINUE:
		case SUSTAIN:
		default:
		{
			// no change, continue the current action next frame
			return this;
		}
	}
}


//-------------------------------------------------------------------------------------------
/**
 * Propagate events to sub actions
 */
template < typename Actor >
INextBotEventResponder *Action< Actor >::FirstContainedResponder( void ) const
{
	return GetActiveChildAction();
}

template < typename Actor >
INextBotEventResponder *Action< Actor >::NextContainedResponder( INextBotEventResponder *current ) const
{
	return NULL;
}


//-------------------------------------------------------------------------------------------
/**
 * Return a temporary string describing the current action stack for debugging
 */
template < typename Actor >
const char *Action< Actor >::DebugString( void ) const
{
	static char str[ 256 ];

	str[0] = '\000';

	// find root
	const Action< Actor > *root = this; 
	while ( root->m_parent )
	{
		root = root->m_parent;
	}

	return BuildDecoratedName( str, root );
}


//-------------------------------------------------------------------------------------------
template < typename Actor >
char *Action< Actor >::BuildDecoratedName( char *name, const Action< Actor > *action ) const
{
	const int fudge = 256;
	
	// add the name of the given action
	Q_strcat( name, action->GetName(), fudge );
	
	// add any contained actions
	const Action< Actor > *child = action->GetActiveChildAction();
	if ( child )
	{
		Q_strcat( name, "( ", fudge );
		BuildDecoratedName( name, child );
		Q_strcat( name, " )", fudge );		
	}
	
	// append buried actions
	const Action< Actor > *buried = action->GetActionBuriedUnderMe();
	if ( buried )
	{
		Q_strcat( name, "<<", fudge );		
		BuildDecoratedName( name, buried );		
	}
	
	return name;
}


//-------------------------------------------------------------------------------------------
/**
 * Return a temporary string showing the full lineage of this one action
 */
template < typename Actor >
const char *Action< Actor >::GetFullName( void ) const
{
	const int fudge = 256;
	static char str[ fudge ];

	str[0] = '\000';
	
	const int maxStack = 64;
	const char *nameStack[ maxStack ];
	int stackIndex = 0;

	for( const Action< Actor > *action = this; 
		 stackIndex < maxStack && action; 
		 action = action->m_parent )
	{
		nameStack[ stackIndex++ ] = action->GetName();
	}
	
	// assemble name
	int i;
	for( i = stackIndex-1; i; --i )
	{
		Q_strcat( str, nameStack[ i ], fudge );
		Q_strcat( str, "/", fudge );
	}

	Q_strcat( str, nameStack[ 0 ], fudge );
	
	/*
	for( i = 0; i < stackIndex-1; ++i )
	{
		Q_strcat( str, " )", fudge );		
	}
	*/

	return str;
}


//-------------------------------------------------------------------------------------------
template < typename Actor >
void Action< Actor >::PrintStateToConsole( void ) const
{
	// emit the Behavior name
	//ConColorMsg( Color( 255, 255, 255, 255 ), "%s: ", m_behavior->GetName() );

	// build the state string
	const char *msg = DebugString();
	
	const int colorCount = 6;
	Color colorTable[ colorCount ];
	colorTable[ 0 ].SetColor( 255, 150, 150, 255 );
	colorTable[ 1 ].SetColor( 150, 255, 150, 255 );
	colorTable[ 2 ].SetColor( 150, 150, 255, 255 );
	colorTable[ 3 ].SetColor( 255, 255, 150, 255 );
	colorTable[ 4 ].SetColor(  50, 255, 255, 255 );
	colorTable[ 5 ].SetColor( 255, 150, 255, 255 );
	
	// output the color-coded state string
	const int maxBufferSize = 256;
	char buffer[ maxBufferSize ];

	int colorIndex = 0;
	int buriedLevel = 0;
	
	char *outMsg = buffer;
	for( const char *c = msg; *c != '\000'; ++c )
	{
		*outMsg = *c;
		++outMsg;

		if ( *c == '(' )
		{
			*outMsg = '\000';
			
			Color color = colorTable[ colorIndex ];

			if ( buriedLevel )
			{
				// draw buried labels darkly
				color.SetColor( color.r() * 0.5, color.g() * 0.5, color.b() * 0.5, 255 );
				++buriedLevel;
			}
			
			ConColorMsg( color, buffer );
			
			colorIndex = ( colorIndex + 1 ) % colorCount;
			
			outMsg = buffer;
		}
		else if ( *c == ')' )
		{
			// emit the closing paren with next batch
			--outMsg;
			*outMsg = '\000';

			Color color = colorTable[ colorIndex ];

			if ( buriedLevel )
			{
				// draw buried labels darkly
				color.SetColor( color.r() * 0.5, color.g() * 0.5, color.b() * 0.5, 255 );

				--buriedLevel;
			}
			
			ConColorMsg( color, buffer );

			--colorIndex;
			if ( colorIndex < 0 )
				colorIndex = colorCount-1;

			outMsg = buffer;
			
			*outMsg = ')';
			++outMsg;
		}
		else if ( *c == '<' && buriedLevel == 0 )
		{
			// caught a "<<" stack push
			++c;
			
			*outMsg = '<';
			++outMsg;
			*outMsg = '\000';

			// output active substring at full brightness
			ConColorMsg( colorTable[ colorIndex ], buffer );

			outMsg = buffer;
			
			// from here until end of Action, use dim colors
			buriedLevel = 1;
		}

	}

	*outMsg = '\000';
	ConColorMsg( colorTable[ colorIndex ], buffer );
	ConColorMsg( colorTable[ colorIndex ], "\n\n" );
}





#endif // _BEHAVIOR_ENGINE_H_