/*
---------------------------------------------------------------------------
Open Asset Import Library (ASSIMP)
---------------------------------------------------------------------------

Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

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with or without modification, are permitted provided that the following 
conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the ASSIMP team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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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);
}

// ------------------------------------------------------------------------------------------------
// Setup import configuration
void FindInvalidDataProcess::SetupProperties(const Importer* pImp)
{
	// Get the current value of AI_CONFIG_PP_FID_ANIM_ACCURACY
	configEpsilon = (0 != pImp->GetPropertyFloat(AI_CONFIG_PP_FID_ANIM_ACCURACY,0.f));
}

// ------------------------------------------------------------------------------------------------
// 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;	

	// 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 DeadlyImportError("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;
	unsigned int cnt = 0;
	for (unsigned int i = 0; i < size;++i)	{

		if (dirtyMask.size() && dirtyMask[i]) {
			continue;
		}
		++cnt;

		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 (cnt > 1 && !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>
AI_FORCE_INLINE bool EpsilonCompare(const T& n, const T& s, float epsilon);

// ------------------------------------------------------------------------------------------------
AI_FORCE_INLINE bool EpsilonCompare(float n, float s, float epsilon) {
	return fabs(n-s)>epsilon;
}

// ------------------------------------------------------------------------------------------------
template <>
bool EpsilonCompare<aiVectorKey>(const aiVectorKey& n, const aiVectorKey& s, float epsilon)	{
	return 
		EpsilonCompare(n.mValue.x,s.mValue.x,epsilon) &&
		EpsilonCompare(n.mValue.y,s.mValue.y,epsilon) &&
		EpsilonCompare(n.mValue.z,s.mValue.z,epsilon);
}

// ------------------------------------------------------------------------------------------------
template <>
bool EpsilonCompare<aiQuatKey>(const aiQuatKey& n, const aiQuatKey& s, float epsilon)	{
	return 
		EpsilonCompare(n.mValue.x,s.mValue.x,epsilon) &&
		EpsilonCompare(n.mValue.y,s.mValue.y,epsilon) &&
		EpsilonCompare(n.mValue.z,s.mValue.z,epsilon) &&
		EpsilonCompare(n.mValue.w,s.mValue.w,epsilon);
}

// ------------------------------------------------------------------------------------------------
template <typename T>
inline bool AllIdentical(T* in, unsigned int num, float epsilon)
{
	if (num <= 1) {
		return true;
	}

	if (epsilon > 0.f) {
		for (unsigned int i = 0; i < num-1;++i) {

			if (!EpsilonCompare(in[i],in[i+1],epsilon)) {
				return false;
			}
		}
	}
	else {
		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,configEpsilon))
	{
		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,configEpsilon))
	{
		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,configEpsilon))
	{
		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(pMesh->mNumVertices,(pMesh->mNumFaces ? true : false));

	// Ignore elements that are not referenced by vertices.
	// (they are, for example, caused by the FindDegenerates step)
	for (unsigned int m = 0; m < pMesh->mNumFaces;++m)	{
		const aiFace& f = pMesh->mFaces[m];
		
		for (unsigned int i = 0; i < f.mNumIndices;++i) {
			dirtyMask[f.mIndices[i]] = false;
		}
	}

	// 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 && pMesh->mTextureCoords[i];++i)	{
		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.
	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 to update the lookup-table
				for (unsigned int m = 0; m < pMesh->mNumFaces;++m)
				{
					const aiFace& f = pMesh->mFaces[m];

					if (f.mNumIndices < 3)	{
						dirtyMask[f.mIndices[0]] = true;

						if (f.mNumIndices == 2) {
							dirtyMask[f.mIndices[1]] = true;
						}
					}
				}
			}
			// Normals, tangents and bitangents are undefined for
			// the whole mesh (and should not even be there)
			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