/*
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Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2008, ASSIMP Development Team

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* Redistributions of source code must retain the above
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  following disclaimer.

* Redistributions in binary form must reproduce the above
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  derived from this software without specific prior
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*/

/** @file Defines a post processing step to search an importer's output
    for data that is obviously invalid  */

#include "AssimpPCH.h"

#ifndef AI_BUILD_NO_FINDINVALIDDATA_PROCESS

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

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
FindInvalidDataProcess::FindInvalidDataProcess()
{
	// nothing to do here
}

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

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

// ------------------------------------------------------------------------------------------------
// Update mesh references in the node graph
void UpdateMeshReferences(aiNode* node, const std::vector<unsigned int>& meshMapping)
{
	if (node->mNumMeshes)
	{
		unsigned int out = 0;
		for (unsigned int a = 0; a < node->mNumMeshes;++a)
		{
			register unsigned int ref = node->mMeshes[a];
			if (0xffffffff != (ref = meshMapping[ref]))
			{
				node->mMeshes[out++] = ref;
			}
		}
		// just let the members that are unused, that's much cheaper
		// than a full array realloc'n'copy party ...
		if(!(node->mNumMeshes = out))
		{
			delete[] node->mMeshes;
			node->mMeshes = NULL;
		}
	}
	// recursively update all children
	for (unsigned int i = 0; i < node->mNumChildren;++i)
		UpdateMeshReferences(node->mChildren[i],meshMapping);
}

// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void FindInvalidDataProcess::Execute( aiScene* pScene)
{
	DefaultLogger::get()->debug("FindInvalidDataProcess begin");

	bool out = false;
	std::vector<unsigned int> meshMapping(pScene->mNumMeshes);
	unsigned int real = 0, realAnimations = 0;	

	// Process meshes
	for( unsigned int a = 0; a < pScene->mNumMeshes; a++)
	{
		int result;
		if ((result = ProcessMesh( pScene->mMeshes[a])))
		{
			out = true;
			if (2 == result)
			{
				// remove this mesh
				delete pScene->mMeshes[a];
				AI_DEBUG_INVALIDATE_PTR(pScene->mMeshes[a]);

				meshMapping[a] = 0xffffffff;
				continue;
			}
		}
		pScene->mMeshes[real] = pScene->mMeshes[a];
		meshMapping[a] = real++;
	}

	// Process animations
	for (unsigned int a = 0; a < pScene->mNumAnimations;++a)
		ProcessAnimation( pScene->mAnimations[a]);


	if (out)
	{
		if ( real != pScene->mNumMeshes)
		{
			if (!real)
				throw new ImportErrorException("No meshes remaining");

			
			// we need to remove some meshes.
			// therefore we'll also need to remove all references
			// to them from the scenegraph 
			UpdateMeshReferences(pScene->mRootNode,meshMapping);
			pScene->mNumMeshes = real;
		}

		DefaultLogger::get()->info("FindInvalidDataProcess finished. Found issues ...");
	}
	else DefaultLogger::get()->debug("FindInvalidDataProcess finished. Everything seems to be OK.");
}

// ------------------------------------------------------------------------------------------------
template <typename T>
inline const char* ValidateArrayContents(const T* arr, unsigned int size,
	const std::vector<bool>& dirtyMask, bool mayBeIdentical = false, bool mayBeZero = true)
{
	return NULL;
}

// ------------------------------------------------------------------------------------------------
template <>
inline const char* ValidateArrayContents<aiVector3D>(const aiVector3D* arr, unsigned int size,
	const std::vector<bool>& dirtyMask, bool mayBeIdentical , bool mayBeZero )
{
	bool b = false;
	for (unsigned int i = 0; i < size;++i)
	{
		if (dirtyMask.size() && dirtyMask[i])continue;

		const aiVector3D& v = arr[i];
		if (is_special_float(v.x) || is_special_float(v.y) || is_special_float(v.z))
		{
			return "INF/NAN was found in a vector component";
		}
		if (!mayBeZero && !v.x && !v.y && !v.z )
		{
			return "Found zero-length vector";
		}
		if (i && v != arr[i-1])b = true;
	}
	if (!b && !mayBeIdentical)
		return "All vectors are identical";
	return NULL;
}

// ------------------------------------------------------------------------------------------------
template <typename T>
inline bool ProcessArray(T*& in, unsigned int num,const char* name,
	const std::vector<bool>& dirtyMask, bool mayBeIdentical = false, bool mayBeZero = true)
{
	const char* err = ValidateArrayContents(in,num,dirtyMask,
		mayBeIdentical,mayBeZero);
	if (err)
	{
		DefaultLogger::get()->error(std::string("FindInvalidDataProcess fails on mesh ") + name + ": " + err);
		
		delete[] in;
		in = NULL;
		return true;
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
template <typename T>
inline bool AllIdentical(T* in, unsigned int num)
{
	if (num <= 1)return true;
	for (unsigned int i = 0; i < num-1;++i)
	{
		if (in[i] != in[i+1])return false;
	}
	return true;
}

// ------------------------------------------------------------------------------------------------
// Search an animation for invalid content
void FindInvalidDataProcess::ProcessAnimation (aiAnimation* anim)
{
	// Process all animation channels
	for (unsigned int a = 0; a < anim->mNumChannels;++a)
		ProcessAnimationChannel( anim->mChannels[a]);
}

// ------------------------------------------------------------------------------------------------
void FindInvalidDataProcess::ProcessAnimationChannel (aiNodeAnim* anim)
{
	int i = 0;

	// ScenePreprocessor's work ...
	ai_assert((0 != anim->mPositionKeys && 0 != anim->mRotationKeys && 0 != anim->mScalingKeys));

	// Check whether all values in a tracks are identical - in this case
	// we can remove al keys except one.
	// POSITIONS
	if (anim->mNumPositionKeys > 1 && AllIdentical(anim->mPositionKeys,anim->mNumPositionKeys))
	{
		aiVectorKey v = anim->mPositionKeys[0];

		// Reallocate ... we need just ONE element, it makes no sense to reuse the array
		delete[] anim->mPositionKeys;
		anim->mPositionKeys = new aiVectorKey[anim->mNumPositionKeys = 1];
		anim->mPositionKeys[0] = v;
		i = 1;
	}

	// ROTATIONS
	if (anim->mNumRotationKeys > 1 && AllIdentical(anim->mRotationKeys,anim->mNumRotationKeys))
	{
		aiQuatKey v = anim->mRotationKeys[0];

		// Reallocate ... we need just ONE element, it makes no sense to reuse the array
		delete[] anim->mRotationKeys;
		anim->mRotationKeys = new aiQuatKey[anim->mNumRotationKeys = 1];
		anim->mRotationKeys[0] = v;
		i = 1;
	}

	// SCALINGS
	if (anim->mNumScalingKeys > 1 && AllIdentical(anim->mScalingKeys,anim->mNumScalingKeys))
	{
		aiVectorKey v = anim->mScalingKeys[0];

		// Reallocate ... we need just ONE element, it makes no sense to reuse the array
		delete[] anim->mScalingKeys;
		anim->mScalingKeys = new aiVectorKey[anim->mNumScalingKeys = 1];
		anim->mScalingKeys[0] = v;
		i = 1;
	}
	if (1 == i)
		DefaultLogger::get()->warn("Simplified dummy tracks with just one key");
}

// ------------------------------------------------------------------------------------------------
// Search a mesh for invalid contents
int FindInvalidDataProcess::ProcessMesh (aiMesh* pMesh)
{
	bool ret = false;
	std::vector<bool> dirtyMask;

	// process vertex positions
	if(pMesh->mVertices && ProcessArray(pMesh->mVertices,pMesh->mNumVertices,"positions",dirtyMask))
	{
		DefaultLogger::get()->error("Deleting mesh: Unable to continue without vertex positions");
		return 2;
	}

	// process texture coordinates
	for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS;++i)
	{
		if (!pMesh->mTextureCoords[i])break;
		if (ProcessArray(pMesh->mTextureCoords[i],pMesh->mNumVertices,"uvcoords",dirtyMask))
		{
			// delete all subsequent texture coordinate sets.
			for (unsigned int a = i+1; a < AI_MAX_NUMBER_OF_TEXTURECOORDS;++a)
			{
				delete[] pMesh->mTextureCoords[a]; pMesh->mTextureCoords[a] = NULL;
			}
			ret = true;
		}
	}

	// -- we don't validate vertex colors, it's difficult to say whether
	// they are invalid or not.

	// normals and tangents are undefined for point and line faces.
	// we generate a small lookup table in which we mark all
	// indices into the normals/tangents array that MAY be invalid
	if (pMesh->mNormals || pMesh->mTangents)
	{
		if (aiPrimitiveType_POINT & pMesh->mPrimitiveTypes ||
			aiPrimitiveType_LINE  & pMesh->mPrimitiveTypes)
		{
			if (aiPrimitiveType_TRIANGLE & pMesh->mPrimitiveTypes ||
				aiPrimitiveType_POLYGON  & pMesh->mPrimitiveTypes)
			{
				// we need the lookup table
				dirtyMask.resize(pMesh->mNumVertices,false);
				for (unsigned int m = 0; m < pMesh->mNumFaces;++m)
				{
					const aiFace& f = pMesh->mFaces[m];
					if (2 == f.mNumIndices)
					{
						dirtyMask[f.mIndices[0]] = dirtyMask[f.mIndices[1]] = true;
					}
					else if (1 == f.mNumIndices)dirtyMask[f.mIndices[0]] = true;
				}
			}
			else return ret;
		}

		// process mesh normals
		if (pMesh->mNormals && ProcessArray(pMesh->mNormals,pMesh->mNumVertices,
			"normals",dirtyMask,true,false))
			ret = true;

		// process mesh tangents
		if (pMesh->mTangents && ProcessArray(pMesh->mTangents,pMesh->mNumVertices,
			"tangents",dirtyMask))
		{
			delete[] pMesh->mBitangents; pMesh->mBitangents = NULL;
			ret = true;
		}

		// process mesh bitangents
		if (pMesh->mBitangents && ProcessArray(pMesh->mBitangents,pMesh->mNumVertices,
			"bitangents",dirtyMask))
		{
			delete[] pMesh->mTangents; pMesh->mTangents = NULL;
			ret = true;
		}
	}
	return ret ? 1 : 0;
}


#endif // !! AI_BUILD_NO_FINDINVALIDDATA_PROCESS