/*****************************************************************************
The Dark Mod GPL Source Code

This file is part of the The Dark Mod Source Code, originally based
on the Doom 3 GPL Source Code as published in 2011.

The Dark Mod Source Code 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 3 of the License,
or (at your option) any later version. For details, see LICENSE.TXT.

Project: The Dark Mod (http://www.thedarkmod.com/)

******************************************************************************/

#ifndef __AI_MIND_H__
#define __AI_MIND_H__

#include "Memory.h"
#include "States/State.h"
#include "./Queue.h"

namespace ai
{

class Mind
{
private:
	// The reference to the owning entity
	idEntityPtr<idAI> _owner;

	StateQueue _stateQueue;

	// The structure holding all the variables
	Memory _memory;

	// This holds the id of the subsystem whose turn it is next frame
	SubsystemId _subsystemIterator;

	// TRUE if the the State is about to be switched the next frame
	bool _switchState;

	// A temporary variable to hold dying states
	// This is needed to avoid immediate destruction of states upon switching
	StatePtr _recycleBin;

public:
	Mind(idAI* owner);

	void PrintStateQueue(idStr string); // grayman #3559 - print the states currently in the state queue

	/**
	 * greebo: This should be called each frame to let the AI
	 *         think. This distributes the call to the various
	 *         subsystem's Think() methods, maybe in an interleaved way.
	 */
	virtual void Think();

	/**
	 * greebo: Switches the Mind to the named State. The currently active
	 *         State will be pushed back in the queue and is postponed 
	 *         until the new State is finished.
	 */
	virtual void PushState(const idStr& stateName);
	virtual void PushState(const StatePtr& state);

	/**
	 * greebo: Ends the current state - the Mind will pick the next State
	 *         from the StateQueue or create a new Idle State if none is available.
	 *
	 * @returns: TRUE if there are still States in the queue after this one is finished.
	 */
	virtual bool EndState();

	/**
	 * greebo: Sets the new state of this mind (this can be Idle, Combat).
	 * This new state REPLACES the currently active one.
	 */
	virtual void SwitchState(const idStr& stateName);
	virtual void SwitchState(const StatePtr& state);

	/**
	 * greebo: Removes all States from the Queue.
	 */
	virtual void ClearStates();

	/**
	 * greebo: Returns TRUE if no states are in the StateQueue
	 */
	virtual bool IsEmpty()
	{
		return _stateQueue.empty();
	}

	/**
	 * grayman #3714 - Initialize the state queue
	 */
	virtual void InitStateQueue();

	/**
	 * Returns the reference to the current state (can be NULL).
	 */
	ID_INLINE const StatePtr& GetState() const {
		assert(_stateQueue.size() > 0);
		return _stateQueue.front();
	}

	// Returns the Memory structure, which holds the various mind variables
	ID_INLINE Memory& GetMemory() {
		return _memory;
	}

	/**
	* SZ: This method tests to see if the target can be reached.
	* If it can't, then the AI chooses another action.
	*
	* This method often switches the AI to a new state.
	*
	* @returns: TRUE if combat mode was entered, FALSE otherwise
	*/
	virtual bool PerformCombatCheck();
	/**
	* SZ: setTarget should only be called when the combat threshold has been
	* reached and the AI needs to try to attack something.
	* The only alert that does not set a target is sound.
	* In the case of sound, the AI will keep running at the source of the noise
	* and executing the running search until it sees or bumps into the player
	*
	* @return true if a target was found
	* @return false if no target found
	*
	* SophisticatedZombie Note: Note that this method and setTarget are mutually exclusive
	* as they clear flags that the other needs. 
	*/
	virtual bool SetTarget();

	// Save/Restore routines
	virtual void Save(idSaveGame* savefile) const;
	virtual void Restore(idRestoreGame* savefile);
};
typedef std::shared_ptr<Mind> MindPtr;

} // namespace ai

#endif /* __AI_MIND_H__ */