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

 Copyright (c) 2009, Charles McGarvey
 All rights reserved.
 
 Redistribution   and   use  in  source  and  binary  forms,  with  or  without
 modification, are permitted provided that the following conditions are met:
 
   * Redistributions  of  source  code  must retain the above copyright notice,
     this list of conditions and the following disclaimer.
   * 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.
 
 THIS  SOFTWARE  IS  PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND  ANY  EXPRESS  OR  IMPLIED  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED.  IN  NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 FOR  ANY  DIRECT,  INDIRECT,  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES  (INCLUDING,  BUT  NOT  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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 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
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*******************************************************************************/

#ifndef _MOOF_ENGINE_HH_
#define _MOOF_ENGINE_HH_

#include <boost/shared_ptr.hpp>

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


namespace Mf {


/**
 * The engine 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 send to each layer
 * from the top down until a layer signals the event was handled.  The engine is
 * also responsible for firing timers on time.  The engine will continue running
 * as long as there are layers on the stack.
 */

class Engine
{
public:

	~Engine() {}

	// get global instance
	static Engine& getInstance();

	// setting the video is required before you can run the engine and should
	// probably be done before adding any layers
	void setVideo(VideoP video);
	VideoP getVideo() const;

	void setTimestep(int ts);
	int getTimestep() const;

	void setMaxFps(int maxFps);	// draw rate is always capped at the timestep
	int getMaxFps() const;

	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 all layers above it
	void clear();				// remove all layers (the engine 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:

	Engine();		// use getInstance() to access the engine

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


} // namespace Mf

#endif // _MOOF_ENGINE_HH_

/** vim: set ts=4 sw=4 tw=80: *************************************************/