// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#include "CSceneManager.h"
#include "IVideoDriver.h"
#include "IFileSystem.h"
#include "SAnimatedMesh.h"
#include "CMeshCache.h"
#include "IGUIEnvironment.h"
#include "IMaterialRenderer.h"
#include "IReadFile.h"
#include "IWriteFile.h"

#include "os.h"

#include "CSkinnedMesh.h"
// #include "CGLTFMeshFileLoader.h"
#include "CBillboardSceneNode.h"
#include "CAnimatedMeshSceneNode.h"
#include "CCameraSceneNode.h"
#include "CMeshSceneNode.h"
#include "CDummyTransformationSceneNode.h"
#include "CEmptySceneNode.h"

#include "CSceneCollisionManager.h"

namespace irr
{
namespace scene
{

//! constructor
CSceneManager::CSceneManager(video::IVideoDriver* driver,
		gui::ICursorControl* cursorControl, IMeshCache* cache)
: ISceneNode(0, 0), Driver(driver),
	CursorControl(cursorControl),
	ActiveCamera(0), ShadowColor(150,0,0,0), AmbientLight(0,0,0,0), Parameters(0),
	MeshCache(cache), CurrentRenderPass(ESNRP_NONE)
{
	#ifdef _DEBUG
	ISceneManager::setDebugName("CSceneManager ISceneManager");
	ISceneNode::setDebugName("CSceneManager ISceneNode");
	#endif

	// root node's scene manager
	SceneManager = this;

	if (Driver)
		Driver->grab();

	if (CursorControl)
		CursorControl->grab();

	// create mesh cache if not there already
	if (!MeshCache)
		MeshCache = new CMeshCache();
	else
		MeshCache->grab();

	// set scene parameters
	Parameters = new io::CAttributes();

	// create collision manager
	CollisionManager = new CSceneCollisionManager(this, Driver);

	// add file format loaders. add the least commonly used ones first,
	// as these are checked last

	// TODO: now that we have multiple scene managers, these should be
	// shallow copies from the previous manager if there is one.

	// MeshLoaderList.push_back(new CB3DMeshFileLoader(this));
}


//! destructor
CSceneManager::~CSceneManager()
{
	clearDeletionList();

	//! force to remove hardwareTextures from the driver
	//! because Scenes may hold internally data bounded to sceneNodes
	//! which may be destroyed twice
	if (Driver)
		Driver->removeAllHardwareBuffers();

	if (CursorControl)
		CursorControl->drop();

	if (CollisionManager)
		CollisionManager->drop();

	u32 i;
	for (i=0; i<MeshLoaderList.size(); ++i)
		MeshLoaderList[i]->drop();

	if (ActiveCamera)
		ActiveCamera->drop();
	ActiveCamera = 0;

	if (MeshCache)
		MeshCache->drop();

	if (Parameters)
		Parameters->drop();

	// remove all nodes before dropping the driver
	// as render targets may be destroyed twice

	removeAll();

	if (Driver)
		Driver->drop();
}


//! gets an animatable mesh. loads it if needed. returned pointer must not be dropped.
IAnimatedMesh* CSceneManager::getMesh(io::IReadFile* file)
{
	if (!file)
		return 0;

	io::path name = file->getFileName();
	IAnimatedMesh* msh = MeshCache->getMeshByName(name);
	if (msh)
		return msh;

	msh = getUncachedMesh(file, name, name);

	return msh;
}

// load and create a mesh which we know already isn't in the cache and put it in there
IAnimatedMesh* CSceneManager::getUncachedMesh(io::IReadFile* file, const io::path& filename, const io::path& cachename)
{
	IAnimatedMesh* msh = 0;

	// iterate the list in reverse order so user-added loaders can override the built-in ones
	s32 count = MeshLoaderList.size();
	for (s32 i=count-1; i>=0; --i)
	{
		if (MeshLoaderList[i]->isALoadableFileExtension(filename))
		{
			// reset file to avoid side effects of previous calls to createMesh
			file->seek(0);
			msh = MeshLoaderList[i]->createMesh(file);
			if (msh)
			{
				MeshCache->addMesh(cachename, msh);
				msh->drop();
				break;
			}
		}
	}

	if (!msh)
		os::Printer::log("Could not load mesh, file format seems to be unsupported", filename, ELL_ERROR);
	else
		os::Printer::log("Loaded mesh", filename, ELL_DEBUG);

	return msh;
}

//! returns the video driver
video::IVideoDriver* CSceneManager::getVideoDriver()
{
	return Driver;
}


//! adds a scene node for rendering a static mesh
//! the returned pointer must not be dropped.
IMeshSceneNode* CSceneManager::addMeshSceneNode(IMesh* mesh, ISceneNode* parent, s32 id,
	const core::vector3df& position, const core::vector3df& rotation,
	const core::vector3df& scale, bool alsoAddIfMeshPointerZero)
{
	if (!alsoAddIfMeshPointerZero && !mesh)
		return 0;

	if (!parent)
		parent = this;

	IMeshSceneNode* node = new CMeshSceneNode(mesh, parent, this, id, position, rotation, scale);
	node->drop();

	return node;
}


//! adds a scene node for rendering an animated mesh model
IAnimatedMeshSceneNode* CSceneManager::addAnimatedMeshSceneNode(IAnimatedMesh* mesh, ISceneNode* parent, s32 id,
	const core::vector3df& position, const core::vector3df& rotation,
	const core::vector3df& scale, bool alsoAddIfMeshPointerZero)
{
	if (!alsoAddIfMeshPointerZero && !mesh)
		return 0;

	if (!parent)
		parent = this;

	IAnimatedMeshSceneNode* node =
		new CAnimatedMeshSceneNode(mesh, parent, this, id, position, rotation, scale);
	node->drop();

	return node;
}


//! Adds a camera scene node to the tree and sets it as active camera.
//! \param position: Position of the space relative to its parent where the camera will be placed.
//! \param lookat: Position where the camera will look at. Also known as target.
//! \param parent: Parent scene node of the camera. Can be null. If the parent moves,
//! the camera will move too.
//! \return Returns pointer to interface to camera
ICameraSceneNode* CSceneManager::addCameraSceneNode(ISceneNode* parent,
	const core::vector3df& position, const core::vector3df& lookat, s32 id,
	bool makeActive)
{
	if (!parent)
		parent = this;

	ICameraSceneNode* node = new CCameraSceneNode(parent, this, id, position, lookat);

	if (makeActive)
		setActiveCamera(node);
	node->drop();

	return node;
}


//! Adds a billboard scene node to the scene. A billboard is like a 3d sprite: A 2d element,
//! which always looks to the camera. It is usually used for things like explosions, fire,
//! lensflares and things like that.
IBillboardSceneNode* CSceneManager::addBillboardSceneNode(ISceneNode* parent,
	const core::dimension2d<f32>& size, const core::vector3df& position, s32 id,
	video::SColor colorTop, video::SColor colorBottom
	)
{
	if (!parent)
		parent = this;

	IBillboardSceneNode* node = new CBillboardSceneNode(parent, this, id, position, size,
		colorTop, colorBottom);
	node->drop();

	return node;
}


//! Adds an empty scene node.
ISceneNode* CSceneManager::addEmptySceneNode(ISceneNode* parent, s32 id)
{
	if (!parent)
		parent = this;

	ISceneNode* node = new CEmptySceneNode(parent, this, id);
	node->drop();

	return node;
}


//! Adds a dummy transformation scene node to the scene graph.
IDummyTransformationSceneNode* CSceneManager::addDummyTransformationSceneNode(
	ISceneNode* parent, s32 id)
{
	if (!parent)
		parent = this;

	IDummyTransformationSceneNode* node = new CDummyTransformationSceneNode(
		parent, this, id);
	node->drop();

	return node;
}


//! Returns the root scene node. This is the scene node which is parent
//! of all scene nodes. The root scene node is a special scene node which
//! only exists to manage all scene nodes. It is not rendered and cannot
//! be removed from the scene.
//! \return Returns a pointer to the root scene node.
ISceneNode* CSceneManager::getRootSceneNode()
{
	return this;
}


//! Returns the current active camera.
//! \return The active camera is returned. Note that this can be NULL, if there
//! was no camera created yet.
ICameraSceneNode* CSceneManager::getActiveCamera() const
{
	return ActiveCamera;
}


//! Sets the active camera. The previous active camera will be deactivated.
//! \param camera: The new camera which should be active.
void CSceneManager::setActiveCamera(ICameraSceneNode* camera)
{
	if (camera)
		camera->grab();
	if (ActiveCamera)
		ActiveCamera->drop();

	ActiveCamera = camera;
}


//! renders the node.
void CSceneManager::render()
{
}


//! returns the axis aligned bounding box of this node
const core::aabbox3d<f32>& CSceneManager::getBoundingBox() const
{
	_IRR_DEBUG_BREAK_IF(true) // Bounding Box of Scene Manager should never be used.

	static const core::aabbox3d<f32> dummy;
	return dummy;
}


//! returns if node is culled
bool CSceneManager::isCulled(const ISceneNode* node) const
{
	const ICameraSceneNode* cam = getActiveCamera();
	if (!cam)
	{
		return false;
	}
	bool result = false;

	// has occlusion query information
	if (node->getAutomaticCulling() & scene::EAC_OCC_QUERY)
	{
		result = (Driver->getOcclusionQueryResult(const_cast<ISceneNode*>(node))==0);
	}

	// can be seen by a bounding box ?
	if (!result && (node->getAutomaticCulling() & scene::EAC_BOX))
	{
		core::aabbox3d<f32> tbox = node->getBoundingBox();
		node->getAbsoluteTransformation().transformBoxEx(tbox);
		result = !(tbox.intersectsWithBox(cam->getViewFrustum()->getBoundingBox() ));
	}

	// can be seen by a bounding sphere
	if (!result && (node->getAutomaticCulling() & scene::EAC_FRUSTUM_SPHERE))
	{
		const core::aabbox3df nbox = node->getTransformedBoundingBox();
		const float rad = nbox.getRadius();
		const core::vector3df center = nbox.getCenter();

		const float camrad = cam->getViewFrustum()->getBoundingRadius();
		const core::vector3df camcenter = cam->getViewFrustum()->getBoundingCenter();

		const float dist = (center - camcenter).getLengthSQ();
		const float maxdist = (rad + camrad) * (rad + camrad);

		result = dist > maxdist;
	}

	// can be seen by cam pyramid planes ?
	if (!result && (node->getAutomaticCulling() & scene::EAC_FRUSTUM_BOX))
	{
		SViewFrustum frust = *cam->getViewFrustum();

		//transform the frustum to the node's current absolute transformation
		core::matrix4 invTrans(node->getAbsoluteTransformation(), core::matrix4::EM4CONST_INVERSE);
		//invTrans.makeInverse();
		frust.transform(invTrans);

		core::vector3df edges[8];
		node->getBoundingBox().getEdges(edges);

		for (s32 i=0; i<scene::SViewFrustum::VF_PLANE_COUNT; ++i)
		{
			bool boxInFrustum=false;
			for (u32 j=0; j<8; ++j)
			{
				if (frust.planes[i].classifyPointRelation(edges[j]) != core::ISREL3D_FRONT)
				{
					boxInFrustum=true;
					break;
				}
			}

			if (!boxInFrustum)
			{
				result = true;
				break;
			}
		}
	}

	return result;
}


//! registers a node for rendering it at a specific time.
u32 CSceneManager::registerNodeForRendering(ISceneNode* node, E_SCENE_NODE_RENDER_PASS pass)
{
	u32 taken = 0;

	switch(pass)
	{
		// take camera if it is not already registered
	case ESNRP_CAMERA:
		{
			taken = 1;
			for (u32 i = 0; i != CameraList.size(); ++i)
			{
				if (CameraList[i] == node)
				{
					taken = 0;
					break;
				}
			}
			if (taken)
			{
				CameraList.push_back(node);
			}
		}
		break;
	case ESNRP_SKY_BOX:
		SkyBoxList.push_back(node);
		taken = 1;
		break;
	case ESNRP_SOLID:
		if (!isCulled(node))
		{
			SolidNodeList.push_back(node);
			taken = 1;
		}
		break;
	case ESNRP_TRANSPARENT:
		if (!isCulled(node))
		{
			TransparentNodeList.push_back(TransparentNodeEntry(node, camWorldPos));
			taken = 1;
		}
		break;
	case ESNRP_TRANSPARENT_EFFECT:
		if (!isCulled(node))
		{
			TransparentEffectNodeList.push_back(TransparentNodeEntry(node, camWorldPos));
			taken = 1;
		}
		break;
	case ESNRP_AUTOMATIC:
		if (!isCulled(node))
		{
			const u32 count = node->getMaterialCount();

			taken = 0;
			for (u32 i=0; i<count; ++i)
			{
				if (Driver->needsTransparentRenderPass(node->getMaterial(i)))
				{
					// register as transparent node
					TransparentNodeEntry e(node, camWorldPos);
					TransparentNodeList.push_back(e);
					taken = 1;
					break;
				}
			}

			// not transparent, register as solid
			if (!taken)
			{
				SolidNodeList.push_back(node);
				taken = 1;
			}
		}
		break;
	case ESNRP_GUI:
		if (!isCulled(node))
		{
			GuiNodeList.push_back(node);
			taken = 1;
		}

	// as of yet unused
	case ESNRP_LIGHT:
	case ESNRP_SHADOW:
	case ESNRP_NONE: // ignore this one
		break;
	}

	return taken;
}

void CSceneManager::clearAllRegisteredNodesForRendering()
{
	CameraList.clear();
	SkyBoxList.clear();
	SolidNodeList.clear();
	TransparentNodeList.clear();
	TransparentEffectNodeList.clear();
	GuiNodeList.clear();
}

//! This method is called just before the rendering process of the whole scene.
//! draws all scene nodes
void CSceneManager::drawAll()
{
	if (!Driver)
		return;

	u32 i; // new ISO for scoping problem in some compilers

	// reset all transforms
	Driver->setMaterial(video::SMaterial());
	Driver->setTransform ( video::ETS_PROJECTION, core::IdentityMatrix );
	Driver->setTransform ( video::ETS_VIEW, core::IdentityMatrix );
	Driver->setTransform ( video::ETS_WORLD, core::IdentityMatrix );
	for (i=video::ETS_COUNT-1; i>=video::ETS_TEXTURE_0; --i)
		Driver->setTransform ( (video::E_TRANSFORMATION_STATE)i, core::IdentityMatrix );
	// TODO: This should not use an attribute here but a real parameter when necessary (too slow!)
	Driver->setAllowZWriteOnTransparent(Parameters->getAttributeAsBool(ALLOW_ZWRITE_ON_TRANSPARENT));

	// do animations and other stuff.
	OnAnimate(os::Timer::getTime());

	/*!
		First Scene Node for prerendering should be the active camera
		consistent Camera is needed for culling
	*/
	camWorldPos.set(0,0,0);
	if (ActiveCamera)
	{
		ActiveCamera->render();
		camWorldPos = ActiveCamera->getAbsolutePosition();
	}

	// let all nodes register themselves
	OnRegisterSceneNode();

	//render camera scenes
	{
		CurrentRenderPass = ESNRP_CAMERA;
		Driver->getOverrideMaterial().Enabled = ((Driver->getOverrideMaterial().EnablePasses & CurrentRenderPass) != 0);

		for (i=0; i<CameraList.size(); ++i)
			CameraList[i]->render();

		CameraList.set_used(0);
	}

	// render skyboxes
	{
		CurrentRenderPass = ESNRP_SKY_BOX;
		Driver->getOverrideMaterial().Enabled = ((Driver->getOverrideMaterial().EnablePasses & CurrentRenderPass) != 0);

		for (i=0; i<SkyBoxList.size(); ++i)
			SkyBoxList[i]->render();

		SkyBoxList.set_used(0);
	}

	// render default objects
	{
		CurrentRenderPass = ESNRP_SOLID;
		Driver->getOverrideMaterial().Enabled = ((Driver->getOverrideMaterial().EnablePasses & CurrentRenderPass) != 0);

		SolidNodeList.sort(); // sort by textures

		for (i=0; i<SolidNodeList.size(); ++i)
			SolidNodeList[i].Node->render();

		SolidNodeList.set_used(0);
	}

	// render transparent objects.
	{
		CurrentRenderPass = ESNRP_TRANSPARENT;
		Driver->getOverrideMaterial().Enabled = ((Driver->getOverrideMaterial().EnablePasses & CurrentRenderPass) != 0);

		TransparentNodeList.sort(); // sort by distance from camera
		for (i=0; i<TransparentNodeList.size(); ++i)
			TransparentNodeList[i].Node->render();

		TransparentNodeList.set_used(0);
	}

	// render transparent effect objects.
	{
		CurrentRenderPass = ESNRP_TRANSPARENT_EFFECT;
		Driver->getOverrideMaterial().Enabled = ((Driver->getOverrideMaterial().EnablePasses & CurrentRenderPass) != 0);

		TransparentEffectNodeList.sort(); // sort by distance from camera

		for (i=0; i<TransparentEffectNodeList.size(); ++i)
			TransparentEffectNodeList[i].Node->render();

		TransparentEffectNodeList.set_used(0);
	}

	// render custom gui nodes
	{
		CurrentRenderPass = ESNRP_GUI;
		Driver->getOverrideMaterial().Enabled = ((Driver->getOverrideMaterial().EnablePasses & CurrentRenderPass) != 0);

		for (i=0; i<GuiNodeList.size(); ++i)
			GuiNodeList[i]->render();

		GuiNodeList.set_used(0);
	}
	clearDeletionList();

	CurrentRenderPass = ESNRP_NONE;
}


//! Adds an external mesh loader.
void CSceneManager::addExternalMeshLoader(IMeshLoader* externalLoader)
{
	if (!externalLoader)
		return;

	externalLoader->grab();
	MeshLoaderList.push_back(externalLoader);
}


//! Returns the number of mesh loaders supported by Irrlicht at this time
u32 CSceneManager::getMeshLoaderCount() const
{
	return MeshLoaderList.size();
}


//! Retrieve the given mesh loader
IMeshLoader* CSceneManager::getMeshLoader(u32 index) const
{
	if (index < MeshLoaderList.size())
		return MeshLoaderList[index];
	else
		return 0;
}


//! Returns a pointer to the scene collision manager.
ISceneCollisionManager* CSceneManager::getSceneCollisionManager()
{
	return CollisionManager;
}


//! Returns a pointer to the mesh manipulator.
IMeshManipulator* CSceneManager::getMeshManipulator()
{
	return Driver->getMeshManipulator();
}


//! Adds a scene node to the deletion queue.
void CSceneManager::addToDeletionQueue(ISceneNode* node)
{
	if (!node)
		return;

	node->grab();
	DeletionList.push_back(node);
}


//! clears the deletion list
void CSceneManager::clearDeletionList()
{
	if (DeletionList.empty())
		return;

	for (u32 i=0; i<DeletionList.size(); ++i)
	{
		DeletionList[i]->remove();
		DeletionList[i]->drop();
	}

	DeletionList.clear();
}


//! Returns the first scene node with the specified name.
ISceneNode* CSceneManager::getSceneNodeFromName(const char* name, ISceneNode* start)
{
	if (start == 0)
		start = getRootSceneNode();

	if (!strcmp(start->getName(),name))
		return start;

	ISceneNode* node = 0;

	const ISceneNodeList& list = start->getChildren();
	ISceneNodeList::const_iterator it = list.begin();
	for (; it!=list.end(); ++it)
	{
		node = getSceneNodeFromName(name, *it);
		if (node)
			return node;
	}

	return 0;
}


//! Returns the first scene node with the specified id.
ISceneNode* CSceneManager::getSceneNodeFromId(s32 id, ISceneNode* start)
{
	if (start == 0)
		start = getRootSceneNode();

	if (start->getID() == id)
		return start;

	ISceneNode* node = 0;

	const ISceneNodeList& list = start->getChildren();
	ISceneNodeList::const_iterator it = list.begin();
	for (; it!=list.end(); ++it)
	{
		node = getSceneNodeFromId(id, *it);
		if (node)
			return node;
	}

	return 0;
}


//! Returns the first scene node with the specified type.
ISceneNode* CSceneManager::getSceneNodeFromType(scene::ESCENE_NODE_TYPE type, ISceneNode* start)
{
	if (start == 0)
		start = getRootSceneNode();

	if (start->getType() == type || ESNT_ANY == type)
		return start;

	ISceneNode* node = 0;

	const ISceneNodeList& list = start->getChildren();
	ISceneNodeList::const_iterator it = list.begin();
	for (; it!=list.end(); ++it)
	{
		node = getSceneNodeFromType(type, *it);
		if (node)
			return node;
	}

	return 0;
}


//! returns scene nodes by type.
void CSceneManager::getSceneNodesFromType(ESCENE_NODE_TYPE type, core::array<scene::ISceneNode*>& outNodes, ISceneNode* start)
{
	if (start == 0)
		start = getRootSceneNode();

	if (start->getType() == type || ESNT_ANY == type)
		outNodes.push_back(start);

	const ISceneNodeList& list = start->getChildren();
	ISceneNodeList::const_iterator it = list.begin();

	for (; it!=list.end(); ++it)
	{
		getSceneNodesFromType(type, outNodes, *it);
	}
}


//! Posts an input event to the environment. Usually you do not have to
//! use this method, it is used by the internal engine.
bool CSceneManager::postEventFromUser(const SEvent& event)
{
	bool ret = false;
	ICameraSceneNode* cam = getActiveCamera();
	if (cam)
		ret = cam->OnEvent(event);

	return ret;
}


//! Removes all children of this scene node
void CSceneManager::removeAll()
{
	ISceneNode::removeAll();
	setActiveCamera(0);
	// Make sure the driver is reset, might need a more complex method at some point
	if (Driver)
		Driver->setMaterial(video::SMaterial());
}


//! Clears the whole scene. All scene nodes are removed.
void CSceneManager::clear()
{
	removeAll();
}


//! Returns interface to the parameters set in this scene.
io::IAttributes* CSceneManager::getParameters()
{
	return Parameters;
}


//! Returns current render pass.
E_SCENE_NODE_RENDER_PASS CSceneManager::getSceneNodeRenderPass() const
{
	return CurrentRenderPass;
}


//! Returns an interface to the mesh cache which is shared between all existing scene managers.
IMeshCache* CSceneManager::getMeshCache()
{
	return MeshCache;
}


//! Creates a new scene manager.
ISceneManager* CSceneManager::createNewSceneManager(bool cloneContent)
{
	CSceneManager* manager = new CSceneManager(Driver, CursorControl, MeshCache);

	if (cloneContent)
		manager->cloneMembers(this, manager);

	return manager;
}


//! Sets ambient color of the scene
void CSceneManager::setAmbientLight(const video::SColorf &ambientColor)
{
	AmbientLight = ambientColor;
}


//! Returns ambient color of the scene
const video::SColorf& CSceneManager::getAmbientLight() const
{
	return AmbientLight;
}


//! Get a skinned mesh, which is not available as header-only code
ISkinnedMesh* CSceneManager::createSkinnedMesh()
{
	return new CSkinnedMesh();
}

//! Returns a mesh writer implementation if available
IMeshWriter* CSceneManager::createMeshWriter(EMESH_WRITER_TYPE type)
{
	return 0;
}


// creates a scenemanager
ISceneManager* createSceneManager(video::IVideoDriver* driver, gui::ICursorControl* cursorcontrol)
{
	return new CSceneManager(driver, cursorcontrol, nullptr);
}


} // end namespace scene
} // end namespace irr