#pragma once

#include "BsD3D9Prerequisites.h"

namespace BansheeEngine 
{
	/**
	 * @brief	Handles creation of DirectX 9 devices. Also links the devices
	 *			with created render targets.
	 */
	class BS_D3D9_EXPORT D3D9DeviceManager
	{	
	public:
		D3D9DeviceManager();
		~D3D9DeviceManager();

		/**
		 * @brief	Changes the active device to the provided device. Must be not null.
		 */
		void setActiveDevice(D3D9Device* device);

		/**
		 * @brief	Retrieves the currently active device.
		 */
		D3D9Device*	getActiveDevice();

		/**
		 * @brief	Sets the device used by the currently active render target.
		 */
		void setActiveRenderTargetDevice(D3D9Device* device);

		/**
		 * @brief	Retrieves the device used by the currently active render target.
		 */
		D3D9Device*	getActiveRenderTargetDevice();		

		/**
		 * @brief	Returns the total number of devices available.
		 */
		UINT getDeviceCount();

		/**
		 * @brief	Returns the device under the specified index.
		 */
		D3D9Device*	getDevice(UINT index);

		/**
		 * @brief	Links the provided render window with a device. The window will be 
		 *			assigned an existing device if a match one can be found, otherwise
		 *			a new device will be created.
		 */
		void linkRenderWindow(D3D9RenderWindowCore* renderWindow);

		/**
		 * @brief	Called by the devices when they're are being destroyed.
		 */
		void notifyOnDeviceDestroy(D3D9Device* device);

		/**
		 * @brief	Retrieves engine device from DX9 device.
		 */
		D3D9Device*	getDeviceFromD3D9Device(IDirect3DDevice9* d3d9Device);

	protected:
		/**
		 * @brief	Attempts to find a matching device for the provided render window. If one cannot be found a
		 *			new device is created. Found/created device is returned, as well as a list of all render windows
		 *			using that device.
		 */
		D3D9Device*	selectDevice(D3D9RenderWindowCore* renderWindow, Vector<D3D9RenderWindowCore*>& renderWindowsGroup);

		/**
		 * @brief	Finds the driver the render window belongs to.
		 */
		D3D9Driver*	findDriver(D3D9RenderWindowCore* renderWindow);

		Vector<D3D9Device*> mRenderDevices;
		D3D9Device*	mActiveDevice;
		D3D9Device*	mActiveRenderWindowDevice;		
	};
}