#include "OgreItemBufferQueryManager.h"
#include <OgreLogManager.h>
#include <OgreStringConverter.h>
#include <vector>
#include <OgreSubEntity.h>

namespace Ogre {

//----------------------------------------------------------------------- 
ItemBufferQueryManager::ItemBufferQueryManager(PlatformHierarchyInterface *hierarchyInterface, 
											   Viewport *vp,
											   const bool renderPatches):
PlatformQueryManager(hierarchyInterface, vp), mRenderPatchesForItemBuffer(renderPatches)
{
}
//-----------------------------------------------------------------------
bool ItemBufferQueryManager::ShootRay(const Ray &ray, 
									  std::vector<Mesh *> *visibleMeshes, 
									  bool isGlobalLine)
{
    // run OGRE ray shooting query
    return false;
}
//-----------------------------------------------------------------------
void ItemBufferQueryManager::ComputeCameraVisibility(const Camera &camera,
			    InfoContainer<GtpVisibility::NodeInfo> *visibleNodes,
			    InfoContainer<GtpVisibility::MeshInfo> *visibleGeometry,
				InfoContainer<GtpVisibility::PatchInfo> *visiblePatches,
			    bool relativeVisibility)
{
	// initialise item buffer (if not already initialised)
	InitItemBuffer(visibleNodes, visibleGeometry, visiblePatches);

	// we need access to the scene manager and the rendersystem
	PlatformHierarchyInterface *pfHierarchyInterface = 
		dynamic_cast<PlatformHierarchyInterface *>(mHierarchyInterface);

	SceneManager *sm = pfHierarchyInterface->GetSceneManager();

	// --- Render scene with item buffer (i.e., objects with their id as color codes)

	// const_cast allowed because camera is not changed in renderScene
	Camera *pCam = const_cast<Camera *>(&camera); 

	// disable overlays, reset them later
	bool overlayEnabled = mViewport->getOverlaysEnabled();
	mViewport->setOverlaysEnabled(false);

	// set item buffer (must be provided by scene manager)
	bool useItemBuffer = true;
	sm->setOption("UseItemBuffer", &useItemBuffer);
	
	// clear background with black (i.e., not a valid item id)
	ColourValue bg = mViewport->getBackgroundColour();
	mViewport->setBackgroundColour(ColourValue(0, 0, 0, 0));
	pfHierarchyInterface->GetRenderSystem()->clearFrameBuffer(FBT_COLOUR | FBT_DEPTH);

	//-- render item buffer
	sm->_renderScene(pCam, mViewport, false);
    //mViewport->getTarget()->update();

//for(int j=0; j<10000000; j++)	printf("wait");


	//---- collect results
	int dimx = 0;
	int dimy = 0;

	// get frame buffer
	uchar *buf = mViewport->getTarget()->getBufferContents(dimx, dimy);

	int n = mRenderPatchesForItemBuffer ? (int)visiblePatches->size() : (int)visibleGeometry->size();

	std::stringstream d; d << "dimx: " << dimx << ", dimy: " << dimy;
	LogManager::getSingleton().logMessage(d.str());

	// loop through frame buffer & collect visible pixels
	for (int idx = 0; idx < dimy * dimx * 3; idx += 3)
	{
		//-- decode color code to receive id
		int id = buf[idx] << 16;
		id += buf[idx + 1] << 8;
		id += buf[idx + 2];

		//std::stringstream d; d << "myid: " << (int)buf[idx] << " " << (int)buf[idx + 1] << " " << (int)buf[idx + 2];
		//LogManager::getSingleton().logMessage(d.str());

		// if valid id <= add visibility (id values start at 1)
		if ((id > 0) && (id < n))
		{
			if (mRenderPatchesForItemBuffer)
			{
				((*visiblePatches)[id]).AddVisibility(1, 1);
			}
			else
			{
				((*visibleGeometry)[id]).AddVisibility(1, 1);
			}
		}
	}

	//-- reset options

	// don't need item buffer anymore
	useItemBuffer = false;
	sm->setOption("UseItemBuffer", &useItemBuffer);
	// reset initialised - flag
	mWasInitialised = false;
	// reset old overlay status
	mViewport->setOverlaysEnabled(overlayEnabled);
	// reset background color
	mViewport->setBackgroundColour(bg);

	// delete array storing the frame buffer
	delete [] buf;
}
//-----------------------------------------------------------------------
void ItemBufferQueryManager::InitItemBuffer(
				InfoContainer<GtpVisibility::NodeInfo> *visibleNodes,
			    InfoContainer<GtpVisibility::MeshInfo> *visibleGeometry,
				InfoContainer<GtpVisibility::PatchInfo> *visiblePatches)
{
	if (mWasInitialised)
		return;

	mWasInitialised = true;

	SceneManager *sm = 
		dynamic_cast<PlatformHierarchyInterface *>(mHierarchyInterface)->GetSceneManager();

	SceneManager::EntityIterator it = sm->getEntityIterator();

	// TODO: make this more efficient
	visibleGeometry->clear();
	visibleNodes->clear();
	visiblePatches->clear();

	int id = 0;

	/* We can either use patches or meshes. If patches are used, an unique id must
	   be given each patch. Otherwise the same id must be given to all patches belonging
	   to the same mesh.
    */
	while (it.hasMoreElements())
	{
		Entity *ent = it.getNext();

		for (int i = 0; i < (int)ent->getNumSubEntities(); ++i)
		{
			SubEntity *subEnt = ent->getSubEntity(i);

			if (mRenderPatchesForItemBuffer)
			{
				++ id;
				visiblePatches->push_back(GtpVisibility::PatchInfo(subEnt, 0, 0));
			}
				
			subEnt->setId(id);
			//subEnt->setId((41 << 16) + (4 << 8) + 60);
			//subEnt->setId((2 << 16) + (4 << 8) + 60);
		}
			
		if (!mRenderPatchesForItemBuffer)
		{
			visibleGeometry->push_back(GtpVisibility::MeshInfo(ent, 0, 0));
			++ id;
		}
	}
}

/*
//-----------------------------------------------------------------------
Entity* VisibilityOctreeSceneManager::createEntity(const String& entityName, 
													const String& meshName)
{
	Entity *ent = SceneManager::createEntity(entityName, meshName);

	for (int i = 0; i < (int)ent->getNumSubEntities(); ++i)
	{
		ent->getSubEntity(i)->setId(mCurrentEntityId);
	}

	// increase counter of entity id values
	++ mCurrentEntityId;

	return ent;
}
*/
} // namespace Ogre