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/** @file  CSMLoader.cpp

 *  Implementation of the CSM importer class.

 */

#ifndef ASSIMP_BUILD_NO_CSM_IMPORTER

#include "CSMLoader.h"

#include <assimp/SkeletonMeshBuilder.h>

#include <assimp/ParsingUtils.h>

#include <assimp/fast_atof.h>

#include <assimp/Importer.hpp>

#include <memory>

#include <assimp/IOSystem.hpp>

#include <assimp/anim.h>

#include <assimp/DefaultLogger.hpp>

#include <assimp/scene.h>

#include <assimp/importerdesc.h>

using namespace Assimp;

static constexpr aiImporterDesc desc = {

    "CharacterStudio Motion Importer (MoCap)",

    "",

    "",

    "",

    aiImporterFlags_SupportTextFlavour,

    0,

    0,

    0,

    0,

    "csm"

};

// ------------------------------------------------------------------------------------------------

// Constructor to be privately used by Importer

CSMImporter::CSMImporter() : noSkeletonMesh(){

    // empty

}

// ------------------------------------------------------------------------------------------------

// Returns whether the class can handle the format of the given file.

bool CSMImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool /*checkSig*/) const {

    static const char* tokens[] = {"$Filename"};

    return SearchFileHeaderForToken(pIOHandler,pFile,tokens,AI_COUNT_OF(tokens));

}

// ------------------------------------------------------------------------------------------------

// Build a string of all file extensions supported

const aiImporterDesc* CSMImporter::GetInfo () const {

    return &desc;

}

// ------------------------------------------------------------------------------------------------

// Setup configuration properties for the loader

void CSMImporter::SetupProperties(const Importer* pImp) {

    noSkeletonMesh = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_NO_SKELETON_MESHES,0) != 0;

}

// ------------------------------------------------------------------------------------------------

// Imports the given file into the given scene structure.

void CSMImporter::InternReadFile( const std::string& pFile,

    aiScene* pScene, IOSystem* pIOHandler)

{

    std::unique_ptr<IOStream> file( pIOHandler->Open( pFile, "rb"));

    // Check whether we can read from the file

    if (file == nullptr) {

        throw DeadlyImportError( "Failed to open CSM file ", pFile, ".");

    }

    // allocate storage and copy the contents of the file to a memory buffer

    std::vector<char> mBuffer2;

    TextFileToBuffer(file.get(),mBuffer2);

    const char* buffer = &mBuffer2[0];

    const char *end = &mBuffer2[mBuffer2.size() - 1] + 1;

    std::unique_ptr<aiAnimation> anim(new aiAnimation());

    int first = 0, last = 0x00ffffff;

    // now process the file and look out for '$' sections

    while (true) {

        SkipSpaces(&buffer, end);

        if ('\0' == *buffer)

            break;

        if ('$'  == *buffer)    {

            ++buffer;

            if (TokenMatchI(buffer,"firstframe",10))    {

                SkipSpaces(&buffer, end);

                first = strtol10(buffer,&buffer);

            }

            else if (TokenMatchI(buffer,"lastframe",9))     {

                SkipSpaces(&buffer, end);

                last = strtol10(buffer,&buffer);

            }

            else if (TokenMatchI(buffer,"rate",4))  {

                SkipSpaces(&buffer, end);

                float d = { 0.0f };

                buffer = fast_atoreal_move<float>(buffer,d);

                anim->mTicksPerSecond = d;

            }

            else if (TokenMatchI(buffer,"order",5)) {

                std::vector< aiNodeAnim* > anims_temp;

                anims_temp.reserve(30);

                while (true) {

                    SkipSpaces(&buffer, end);

                    if (IsLineEnd(*buffer) && SkipSpacesAndLineEnd(&buffer, end) && *buffer == '$')

                        break; // next section

                    // Construct a new node animation channel and setup its name

                    anims_temp.push_back(new aiNodeAnim());

                    aiNodeAnim* nda = anims_temp.back();

                    char* ot = nda->mNodeName.data;

                    while (!IsSpaceOrNewLine(*buffer)) {

                        *ot++ = *buffer++;

                    }

                    *ot = '\0';

                    nda->mNodeName.length = static_cast<ai_uint32>(ot-nda->mNodeName.data);

                }

                anim->mNumChannels = static_cast<unsigned int>(anims_temp.size());

                if (!anim->mNumChannels) {

                    throw DeadlyImportError("CSM: Empty $order section");

                }

                // copy over to the output animation

                anim->mChannels = new aiNodeAnim*[anim->mNumChannels];

                ::memcpy(anim->mChannels,&anims_temp[0],sizeof(aiNodeAnim*)*anim->mNumChannels);

            } else if (TokenMatchI(buffer,"points",6)) {

                if (!anim->mNumChannels) {

                    throw DeadlyImportError("CSM: \'$order\' section is required to appear prior to \'$points\'");

                }

                // If we know how many frames we'll read, we can preallocate some storage

                unsigned int alloc = 100;

                if (last != 0x00ffffff) {

                    alloc = last-first;

                    alloc += alloc>>2u; // + 25%

                    for (unsigned int i = 0; i < anim->mNumChannels; ++i) {

                        anim->mChannels[i]->mPositionKeys = new aiVectorKey[alloc];

                    }

                }

                unsigned int filled = 0;

                // Now read all point data.

                while (true) {

                    SkipSpaces(&buffer, end);

                    if (IsLineEnd(*buffer) && (!SkipSpacesAndLineEnd(&buffer, end) || *buffer == '$'))   {

                        break; // next section

                    }

                    // read frame

                    const int frame = ::strtoul10(buffer,&buffer);

                    last  = std::max(frame,last);

                    first = std::min(frame,last);

                    for (unsigned int i = 0; i < anim->mNumChannels;++i)    {

                        aiNodeAnim* s = anim->mChannels[i];

                        if (s->mNumPositionKeys == alloc)   {

                            // need to reallocate?

                            aiVectorKey* old = s->mPositionKeys;

                            s->mPositionKeys = new aiVectorKey[s->mNumPositionKeys = alloc*2];

                            ::memcpy(s->mPositionKeys,old,sizeof(aiVectorKey)*alloc);

                            delete[] old;

                        }

                        // read x,y,z

                        if (!SkipSpacesAndLineEnd(&buffer, end)) {

                            throw DeadlyImportError("CSM: Unexpected EOF occurred reading sample x coord");

                        }

                        if (TokenMatchI(buffer, "DROPOUT", 7))  {

                            // seems this is invalid marker data; at least the doc says it's possible

                            ASSIMP_LOG_WARN("CSM: Encountered invalid marker data (DROPOUT)");

                        } else {

                            aiVectorKey* sub = s->mPositionKeys + s->mNumPositionKeys;

                            sub->mTime = (double)frame;

                            buffer = fast_atoreal_move<float>(buffer, (float&)sub->mValue.x);

                            if (!SkipSpacesAndLineEnd(&buffer, end)) {

                                throw DeadlyImportError("CSM: Unexpected EOF occurred reading sample y coord");

                            }

                            buffer = fast_atoreal_move<float>(buffer, (float&)sub->mValue.y);

                            if (!SkipSpacesAndLineEnd(&buffer, end)) {

                                throw DeadlyImportError("CSM: Unexpected EOF occurred reading sample z coord");

                            }

                            buffer = fast_atoreal_move<float>(buffer, (float&)sub->mValue.z);

                            ++s->mNumPositionKeys;

                        }

                    }

                    // update allocation granularity

                    if (filled == alloc) {

                        alloc *= 2;

                    }

                    ++filled;

                }

                // all channels must be complete in order to continue safely.

                for (unsigned int i = 0; i < anim->mNumChannels;++i)    {

                    if (!anim->mChannels[i]->mNumPositionKeys) {

                        throw DeadlyImportError("CSM: Invalid marker track");

                    }

                }

            }

        } else {

            // advance to the next line

            SkipLine(&buffer, end);

        }

    }

    // Setup a proper animation duration

    anim->mDuration = last - std::min( first, 0 );

    // build a dummy root node with the tiny markers as children

    pScene->mRootNode = new aiNode();

    pScene->mRootNode->mName.Set("$CSM_DummyRoot");

    pScene->mRootNode->mNumChildren = anim->mNumChannels;

    pScene->mRootNode->mChildren = new aiNode* [anim->mNumChannels];

    for (unsigned int i = 0; i < anim->mNumChannels;++i) {

        aiNodeAnim* na = anim->mChannels[i];

        aiNode* nd  = pScene->mRootNode->mChildren[i] = new aiNode();

        nd->mName   = anim->mChannels[i]->mNodeName;

        nd->mParent = pScene->mRootNode;

        aiMatrix4x4::Translation(na->mPositionKeys[0].mValue, nd->mTransformation);

    }

    // Store the one and only animation in the scene

    pScene->mAnimations    = new aiAnimation*[pScene->mNumAnimations=1];

    anim->mName.Set("$CSM_MasterAnim");

    pScene->mAnimations[0] = anim.release();

    // mark the scene as incomplete and run SkeletonMeshBuilder on it

    pScene->mFlags |= AI_SCENE_FLAGS_INCOMPLETE;

    if (!noSkeletonMesh) {

        SkeletonMeshBuilder maker(pScene,pScene->mRootNode,true);

    }

}

#endif // !! ASSIMP_BUILD_NO_CSM_IMPORTER