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

#ifndef ASSIMP_BUILD_NO_FINDINVALIDDATA_PROCESS

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

#include <assimp/Exceptional.h>
#include <assimp/qnan.h>

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
FindInvalidDataProcess::FindInvalidDataProcess() :
 configEpsilon(0.0), mIgnoreTexCoods(false) {
 // nothing to do here
}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
FindInvalidDataProcess::~FindInvalidDataProcess() = default;

// ------------------------------------------------------------------------------------------------
// 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));
 mIgnoreTexCoods = pImp->GetPropertyBool(AI_CONFIG_PP_FID_IGNORE_TEXTURECOORDS, false);
}

// ------------------------------------------------------------------------------------------------
// 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) {

 unsigned int ref = node->mMeshes[a];
 if (UINT_MAX != (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 ...
 node->mNumMeshes = out;
 if (0 == out) {
 delete[] node->mMeshes;
 node->mMeshes = nullptr;
 }
 }
 // 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) {
 ASSIMP_LOG_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 = ProcessMesh(pScene->mMeshes[a]);
 if (0 == result) {
 out = true;
 }
 if (2 == result) {
 // remove this mesh
 delete pScene->mMeshes[a];
 pScene->mMeshes[a] = nullptr;

 meshMapping[a] = UINT_MAX;
 out = true;
 continue;
 }

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

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

 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;
 }

 ASSIMP_LOG_INFO("FindInvalidDataProcess finished. Found issues ...");
 } else {
 ASSIMP_LOG_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 nullptr;
}

// ------------------------------------------------------------------------------------------------
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 nullptr;
}

// ------------------------------------------------------------------------------------------------
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) {
 ASSIMP_LOG_ERROR("FindInvalidDataProcess fails on mesh ", name, ": ", err);
 delete[] in;
 in = nullptr;
 return true;
 }
 return false;
}

// ------------------------------------------------------------------------------------------------
template <typename T>
AI_FORCE_INLINE bool EpsilonCompare(const T &n, const T &s, ai_real epsilon);

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

// ------------------------------------------------------------------------------------------------
template <>
bool EpsilonCompare<aiVectorKey>(const aiVectorKey &n, const aiVectorKey &s, ai_real 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, ai_real 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, ai_real epsilon) {
 if (num <= 1) {
 return true;
 }

 if (fabs(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) {
 ai_assert(nullptr != anim);
 if (anim->mNumPositionKeys == 0 && anim->mNumRotationKeys == 0 && anim->mNumScalingKeys == 0) {
 ai_assert_entry();
 return;
 }

 // Check whether all values in a tracks are identical - in this case
 // we can remove al keys except one.
 // POSITIONS
 int i = 0;
 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) {
 ASSIMP_LOG_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 != 0);

 // 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)) {
 ASSIMP_LOG_ERROR("Deleting mesh: Unable to continue without vertex positions");

 return 2;
 }

 // process texture coordinates
 if (!mIgnoreTexCoods) {
 for (unsigned int i = 0; i < AI_MAX_NUMBER_OF_TEXTURECOORDS && pMesh->mTextureCoords[i]; ++i) {
 if (ProcessArray(pMesh->mTextureCoords[i], pMesh->mNumVertices, "uvcoords", dirtyMask)) {
 pMesh->mNumUVComponents[i] = 0;

 // 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] = nullptr;
 pMesh->mNumUVComponents[a] = 0;
 }

 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 = nullptr;
 ret = true;
 }

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

#endif // !! ASSIMP_BUILD_NO_FINDINVALIDDATA_PROCESS