//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera (marko.pintera@gmail.com). All rights reserved. **********************//
#pragma once

#include "BsScriptEnginePrerequisites.h"
#include "Utility/BsModule.h"

namespace bs
{
	/** @addtogroup SBansheeEngine
	 *  @{
	 */

	/**	States the game in editor can be in. */
	enum class PlayInEditorState
	{
		Stopped,
		Playing,
		Paused
	};

	/**
	 * Handles functionality specific to running the game in editor.
	 *
	 * @note	
	 * Play-in-editor functionality is only available for managed code, but can be easily extended to native code if needed
	 * (this would involve moving play in editor code into BansheeEngine library).
	 */
	class BS_SCR_BE_EXPORT PlayInEditorManager : public Module<PlayInEditorManager>
	{
	public:
		PlayInEditorManager();

		/**	Returns the current play state of the game. */
		PlayInEditorState getState() const { return mState; }

		/**	Updates the play state of the game, making the game stop or start running. */
		void setState(PlayInEditorState state);

		/**
		 * Gets the number of seconds that have elapsed since the game was started. This time does not include time passed
		 * while the game is paused.
		 */
		float getPausableTime() const { return mPausableTime; }

		/**	Runs the game for a single frame and then pauses it. */
		void frameStep();

		/** @name Internal
		 *  @{
		 */

		/**
		 * Called once per frame.
		 *
		 * @note	Internal method.
		 */
		void update();

		/** @} */

	private:
		/**
		 * Updates the play state of the game, making the game stop or start running. Unlike setState() this will trigger
		 * the state change right away.
		 */
		void setStateImmediate(PlayInEditorState state);

		/**	Saves the current state of the scene in memory. */
		void saveSceneInMemory();

		/** Pauses or unpauses all pausable engine systems. */
		void setSystemsPauseState(bool paused);

		PlayInEditorState mState;
		PlayInEditorState mNextState;
		bool mFrameStepActive;
		bool mScheduledStateChange;

		float mPausableTime;
		HSceneObject mSavedScene;
	};

	/** @} */
}