/*
---------------------------------------------------------------------------
Open Asset Import Library (assimp)
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Copyright (c) 2006-2012, assimp team

All rights reserved.

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  following disclaimer.

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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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*/

/** @file Implementation of the DeterminePTypeHelperProcess and
 *  SortByPTypeProcess post-process steps.
*/

#include "AssimpPCH.h"

// internal headers
#include "ProcessHelper.h"
#include "SortByPTypeProcess.h"

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
SortByPTypeProcess::SortByPTypeProcess()
{
	configRemoveMeshes = 0;
}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
SortByPTypeProcess::~SortByPTypeProcess()
{
	// nothing to do here
}

// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool SortByPTypeProcess::IsActive( unsigned int pFlags) const
{
	return	(pFlags & aiProcess_SortByPType) != 0;
}

// ------------------------------------------------------------------------------------------------
void SortByPTypeProcess::SetupProperties(const Importer* pImp)
{
	configRemoveMeshes = pImp->GetPropertyInteger(AI_CONFIG_PP_SBP_REMOVE,0);
}

// ------------------------------------------------------------------------------------------------
// Update changed meshes in all nodes
void UpdateNodes(const std::vector<unsigned int>& replaceMeshIndex, aiNode* node)
{
//	std::vector<unsigned int>::const_iterator it;

	if (node->mNumMeshes)
	{
		unsigned int newSize = 0;
		for (unsigned int m = 0; m< node->mNumMeshes; ++m)
		{
			unsigned int add = node->mMeshes[m]<<2;
			for (unsigned int i = 0; i < 4;++i)
			{
				if (UINT_MAX != replaceMeshIndex[add+i])++newSize;
			}
		}
		if (!newSize)
		{
			delete[] node->mMeshes;
			node->mNumMeshes = 0;
			node->mMeshes    = NULL;
		}
		else
		{
			// Try to reuse the old array if possible
			unsigned int* newMeshes = (newSize > node->mNumMeshes 
				? new unsigned int[newSize] : node->mMeshes);

			for (unsigned int m = 0; m< node->mNumMeshes; ++m)
			{
				unsigned int add = node->mMeshes[m]<<2;
				for (unsigned int i = 0; i < 4;++i)
				{
					if (UINT_MAX != replaceMeshIndex[add+i])
						*newMeshes++ = replaceMeshIndex[add+i];
				}
			}
			if (newSize > node->mNumMeshes)
				delete[] node->mMeshes;

			node->mMeshes = newMeshes-(node->mNumMeshes = newSize);
		}
	}

	// call all subnodes recursively
	for (unsigned int m = 0; m < node->mNumChildren; ++m)
		UpdateNodes(replaceMeshIndex,node->mChildren[m]);
}

// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void SortByPTypeProcess::Execute( aiScene* pScene)
{
	if (!pScene->mNumMeshes)
	{
		DefaultLogger::get()->debug("SortByPTypeProcess skipped, there are no meshes");
		return;
	}

	DefaultLogger::get()->debug("SortByPTypeProcess begin");

	unsigned int aiNumMeshesPerPType[4] = {0,0,0,0};

	std::vector<aiMesh*> outMeshes;
	outMeshes.reserve(pScene->mNumMeshes<<1u);

	bool bAnyChanges = false;

	std::vector<unsigned int> replaceMeshIndex(pScene->mNumMeshes*4,UINT_MAX);
	std::vector<unsigned int>::iterator meshIdx = replaceMeshIndex.begin();
	for (unsigned int i = 0; i < pScene->mNumMeshes;++i)
	{
		aiMesh* const mesh = pScene->mMeshes[i];
		ai_assert(0 != mesh->mPrimitiveTypes);

		// if there's just one primitive type in the mesh there's nothing to do for us
		unsigned int num = 0;
		if (mesh->mPrimitiveTypes & aiPrimitiveType_POINT) 
		{
			++aiNumMeshesPerPType[0];
			++num;
		}
		if (mesh->mPrimitiveTypes & aiPrimitiveType_LINE)   
		{
			++aiNumMeshesPerPType[1];
			++num;
		}
		if (mesh->mPrimitiveTypes & aiPrimitiveType_TRIANGLE)
		{
			++aiNumMeshesPerPType[2];
			++num;
		}
		if (mesh->mPrimitiveTypes & aiPrimitiveType_POLYGON)
		{
			++aiNumMeshesPerPType[3];
			++num;
		}

		if (1 == num)
		{
			if (!(configRemoveMeshes & mesh->mPrimitiveTypes))
			{
				*meshIdx = (unsigned int) outMeshes.size();
				outMeshes.push_back(mesh);
			}
			else bAnyChanges = true;

			meshIdx += 4;
			continue;
		}
		bAnyChanges = true;

		// reuse our current mesh arrays for the submesh 
		// with the largest numer of primitives
		unsigned int aiNumPerPType[4] = {0,0,0,0};
		aiFace* pFirstFace = mesh->mFaces;
		aiFace* const pLastFace = pFirstFace + mesh->mNumFaces;

		unsigned int numPolyVerts = 0;
		for (;pFirstFace != pLastFace; ++pFirstFace)
		{
			if (pFirstFace->mNumIndices <= 3)
				++aiNumPerPType[pFirstFace->mNumIndices-1];
			else
			{
				++aiNumPerPType[3];
				numPolyVerts += pFirstFace-> mNumIndices;
			}
		}

		VertexWeightTable* avw = ComputeVertexBoneWeightTable(mesh);
		for (unsigned int real = 0; real < 4; ++real,++meshIdx)
		{
			if ( !aiNumPerPType[real] || configRemoveMeshes & (1u << real))
			{
				continue;
			}

			*meshIdx = (unsigned int) outMeshes.size();
			outMeshes.push_back(new aiMesh());
			aiMesh* out = outMeshes.back();

			// the name carries the adjacency information between the meshes
			out->mName = mesh->mName;

			// copy data members
			out->mPrimitiveTypes = 1u << real;
			out->mMaterialIndex = mesh->mMaterialIndex;

			// allocate output storage
			out->mNumFaces = aiNumPerPType[real];
			aiFace* outFaces = out->mFaces = new aiFace[out->mNumFaces];

			out->mNumVertices = (3 == real ? numPolyVerts : out->mNumFaces * (real+1));

			aiVector3D *vert(NULL), *nor(NULL), *tan(NULL), *bit(NULL);
			aiVector3D *uv   [AI_MAX_NUMBER_OF_TEXTURECOORDS];
			aiColor4D  *cols [AI_MAX_NUMBER_OF_COLOR_SETS];
		
			if (mesh->mVertices)
				vert = out->mVertices = new aiVector3D[out->mNumVertices];

			if (mesh->mNormals)
				nor  = out->mNormals  = new aiVector3D[out->mNumVertices];

			if (mesh->mTangents)
			{
				tan = out->mTangents   = new aiVector3D[out->mNumVertices];
				bit = out->mBitangents = new aiVector3D[out->mNumVertices];
			}

			for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS;++i)
			{
				if (mesh->mTextureCoords[i])
					uv[i] = out->mTextureCoords[i] = new aiVector3D[out->mNumVertices];
				else uv[i] = NULL;

				out->mNumUVComponents[i] = mesh->mNumUVComponents[i];
			}

			for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_COLOR_SETS;++i)
			{
				if (mesh->mColors[i])
					cols[i] = out->mColors[i] = new aiColor4D[out->mNumVertices];
				else cols[i] = NULL;
			}

			typedef std::vector< aiVertexWeight > TempBoneInfo;
			std::vector< TempBoneInfo > tempBones(mesh->mNumBones);

			// try to guess how much storage we'll need
			for (unsigned int q = 0; q < mesh->mNumBones;++q)
			{
				tempBones[q].reserve(mesh->mBones[q]->mNumWeights / (num-1));
			}

			unsigned int outIdx = 0;
			for (unsigned int m = 0; m < mesh->mNumFaces; ++m)
			{
				aiFace& in = mesh->mFaces[m];
				if ((real == 3  && in.mNumIndices <= 3) || (real != 3 && in.mNumIndices != real+1))
				{
					continue;
				}
				
				outFaces->mNumIndices = in.mNumIndices;
				outFaces->mIndices    = in.mIndices;

				for (unsigned int q = 0; q < in.mNumIndices; ++q)
				{
					unsigned int idx = in.mIndices[q];

					// process all bones of this index
					if (avw)
					{
						VertexWeightTable& tbl = avw[idx];
						for (VertexWeightTable::const_iterator it = tbl.begin(), end = tbl.end();
							 it != end; ++it)
						{
							tempBones[ (*it).first ].push_back( aiVertexWeight(outIdx, (*it).second) );
						}
					}

					if (vert)
					{
						*vert++ = mesh->mVertices[idx];
						//mesh->mVertices[idx].x = get_qnan();
					}
					if (nor )*nor++  = mesh->mNormals[idx];
					if (tan )
					{
						*tan++  = mesh->mTangents[idx];
						*bit++  = mesh->mBitangents[idx];
					}

					for (unsigned int pp = 0; pp < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++pp)
					{
						if (!uv[pp])break;
						*uv[pp]++ = mesh->mTextureCoords[pp][idx];
					}

					for (unsigned int pp = 0; pp < AI_MAX_NUMBER_OF_COLOR_SETS; ++pp)
					{
						if (!cols[pp])break;
						*cols[pp]++ = mesh->mColors[pp][idx];
					}

					in.mIndices[q] = outIdx++;
				}

				in.mIndices = NULL;
				++outFaces;
			}
			ai_assert(outFaces == out->mFaces + out->mNumFaces);

			// now generate output bones
			for (unsigned int q = 0; q < mesh->mNumBones;++q)
				if (!tempBones[q].empty())++out->mNumBones;

			if (out->mNumBones)
			{
				out->mBones = new aiBone*[out->mNumBones];
				for (unsigned int q = 0, real = 0; q < mesh->mNumBones;++q)
				{
					TempBoneInfo& in = tempBones[q];
					if (in.empty())continue;

					aiBone* srcBone = mesh->mBones[q];
					aiBone* bone = out->mBones[real] = new aiBone();

					bone->mName = srcBone->mName;
					bone->mOffsetMatrix = srcBone->mOffsetMatrix;

					bone->mNumWeights = (unsigned int)in.size();
					bone->mWeights = new aiVertexWeight[bone->mNumWeights];

					::memcpy(bone->mWeights,&in[0],bone->mNumWeights*sizeof(aiVertexWeight));

					++real;
				}
			}
		}

		// delete the per-vertex bone weights table
		delete[] avw;

		// delete the input mesh
		delete mesh;

        // avoid invalid pointer
        pScene->mMeshes[i] = NULL;
	}

	if (outMeshes.empty())
	{
		// This should not occur
		throw DeadlyImportError("No meshes remaining");
	}

	// If we added at least one mesh process all nodes in the node
	// graph and update their respective mesh indices.
	if (bAnyChanges)
	{
		UpdateNodes(replaceMeshIndex,pScene->mRootNode);
	}

	if (outMeshes.size() != pScene->mNumMeshes)
	{
		delete[] pScene->mMeshes;
		pScene->mNumMeshes = (unsigned int)outMeshes.size();
		pScene->mMeshes = new aiMesh*[pScene->mNumMeshes];
	}
	::memcpy(pScene->mMeshes,&outMeshes[0],pScene->mNumMeshes*sizeof(void*));

	if (!DefaultLogger::isNullLogger())
	{
		char buffer[1024];
		::sprintf(buffer,"Points: %i%s, Lines: %i%s, Triangles: %i%s, Polygons: %i%s (Meshes, X = removed)",
			aiNumMeshesPerPType[0], (configRemoveMeshes & aiPrimitiveType_POINT     ? "X" : ""),
			aiNumMeshesPerPType[1], (configRemoveMeshes & aiPrimitiveType_LINE      ? "X" : ""),
			aiNumMeshesPerPType[2], (configRemoveMeshes & aiPrimitiveType_TRIANGLE  ? "X" : ""),
			aiNumMeshesPerPType[3], (configRemoveMeshes & aiPrimitiveType_POLYGON   ? "X" : ""));
		DefaultLogger::get()->info(buffer);
		DefaultLogger::get()->debug("SortByPTypeProcess finished");
	}
}

