/*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
**]  All rights reserved.
*
* vi:ts=4 sw=4 tw=75
*
* Distributable under the terms and conditions of the 2-clause BSD license;
* see the file COPYING for a complete text of the license.
*
**************************************************************************/

#ifndef _MOOF_CORE_HH_
#define _MOOF_CORE_HH_

#include <string>

#include <boost/shared_ptr.hpp>

#include <Moof/Dispatch.hh>
#include <Moof/Error.hh>
#include <Moof/Layer.hh>


namespace Mf {


/**
 * The core is essentially a stack of layers.  While running, it updates
 * each layer from the bottom up every timestep.  It also draws each layer
 * from the bottom up, adhering to the maximum frame-rate.  Events are sent
 * to each layer from the top down until a layer signals the event was
 * handled.  The core is also responsible for firing timers on time.  The
 * core will continue running as long as there are layers on the stack.
 */

class Core
{
public:

	Core();
	
	// loads settings: rngseed, timestep, framerate, showfps
	void init();

	int getFps() const;

	void push(LayerP layer);	// push a layer onto the top
	LayerP pop();				// pop the top layer
	LayerP pop(Layer* layer);	// pops a specific layer and layers above it
	void clear();				// remove all layers (the core will stop)

	int getSize() const;		// get the size of the stack

	// set this machine in motion
	void run();

	Dispatch::Handler addHandler(const std::string& event,
								 const Dispatch::Function& callback);
	Dispatch::Handler addHandler(const std::string& event,
								 const Dispatch::Function& callback,
								 Dispatch::Handler handler);

	void dispatch(const std::string& event,
				  const Dispatch::Message* message = 0);

private:

	class Impl;
	boost::shared_ptr<Impl> mImpl;
};

extern Core core;


/*
 * Some classes and subsystems require certain backend libraries to be
 * initialized.  This is the mechanism to accomplish that.  Classes which
 * rely on any backend libraries just need to instantiate this class as a
 * member.  Backend cleanup will occur automagically when there are no more
 * instances.
 */

class Backend
{
public:

	Backend();
	~Backend();

	static bool isInitialized();
	static const Error& getError();
};


} // namespace Mf

#endif // _MOOF_CORE_HH_