/*

---------------------------------------------------------------------------

Open Asset Import Library (assimp)

---------------------------------------------------------------------------

Copyright (c) 2006-2025, assimp team

All rights reserved.

Redistribution and use of this software in source and binary forms,

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 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,

SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

---------------------------------------------------------------------------

*/

/** @file  OFFLoader.cpp

 *  @brief Implementation of the OFF importer class

 */

#ifndef ASSIMP_BUILD_NO_OFF_IMPORTER

// internal headers

#include "OFFLoader.h"

#include <assimp/ParsingUtils.h>

#include <assimp/fast_atof.h>

#include <memory>

#include <assimp/IOSystem.hpp>

#include <assimp/scene.h>

#include <assimp/DefaultLogger.hpp>

#include <assimp/importerdesc.h>

namespace Assimp {

static constexpr aiImporterDesc desc = {

    "OFF Importer",

    "",

    "",

    "",

    aiImporterFlags_SupportBinaryFlavour,

    0,

    0,

    0,

    0,

    "off"

};

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

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

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

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

    return SearchFileHeaderForToken(pIOHandler, pFile, tokens, AI_COUNT_OF(tokens), 3);

}

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

const aiImporterDesc *OFFImporter::GetInfo() const {

    return &desc;

}

// skip blank space, lines and comments

static void NextToken(const char **car, const char *end) {

    SkipSpacesAndLineEnd(car, end);

    while (*car < end && (**car == '#' || **car == '\n' || **car == '\r')) {

        SkipLine(car, end);

        SkipSpacesAndLineEnd(car, end);

    }

}

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

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

void OFFImporter::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 OFF 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];

    // Proper OFF header parser. We only implement normal loading for now.

    bool hasTexCoord = false, hasNormals = false, hasColors = false;

    bool hasHomogenous = false, hasDimension = false;

    unsigned int dimensions = 3;

    const char *car = buffer;

    const char *end = buffer + mBuffer2.size();

    NextToken(&car, end);

    if (car < end - 2 && car[0] == 'S' && car[1] == 'T') {

        hasTexCoord = true;

        car += 2;

    }

    if (car < end - 1 && car[0] == 'C') {

        hasColors = true;

        car++;

    }

    if (car < end - 1 && car[0] == 'N') {

        hasNormals = true;

        car++;

    }

    if (car < end - 1 && car[0] == '4') {

        hasHomogenous = true;

        car++;

    }

    if (car < end - 1 && car[0] == 'n') {

        hasDimension = true;

        car++;

    }

    if (car < end - 3 && car[0] == 'O' && car[1] == 'F' && car[2] == 'F') {

        car += 3;

        NextToken(&car, end);

    } else {

        // in case there is no OFF header (which is allowed by the

        // specification...), then we might have unintentionally read an

        // additional dimension from the primitive count fields

        dimensions = 3;

        hasHomogenous = false;

        NextToken(&car, end);

        // at this point the next token should be an integer number

        if (car >= end - 1 || *car < '0' || *car > '9') {

            throw DeadlyImportError("OFF: Header is invalid");

        }

    }

    if (hasDimension) {

        dimensions = strtoul10(car, &car);

        NextToken(&car, end);

    }

    if (dimensions > 3) {

        throw DeadlyImportError("OFF: Number of vertex coordinates higher than 3 unsupported");

    }

    NextToken(&car, end);

    const unsigned int numVertices = strtoul10(car, &car);

    NextToken(&car, end);

    const unsigned int numFaces = strtoul10(car, &car);

    NextToken(&car, end);

    strtoul10(car, &car); // skip edge count

    NextToken(&car, end);

    if (!numVertices) {

        throw DeadlyImportError("OFF: There are no valid vertices");

    }

    if (!numFaces) {

        throw DeadlyImportError("OFF: There are no valid faces");

    }

    pScene->mNumMeshes = 1;

    pScene->mMeshes = new aiMesh *[pScene->mNumMeshes];

    aiMesh *mesh = new aiMesh();

    pScene->mMeshes[0] = mesh;

    mesh->mNumFaces = numFaces;

    aiFace *faces = new aiFace[mesh->mNumFaces];

    mesh->mFaces = faces;

    mesh->mNumVertices = numVertices;

    mesh->mVertices = new aiVector3D[numVertices];

    mesh->mNormals = hasNormals ? new aiVector3D[numVertices] : nullptr;

    mesh->mColors[0] = hasColors ? new aiColor4D[numVertices] : nullptr;

    if (hasTexCoord) {

        mesh->mNumUVComponents[0] = 2;

        mesh->mTextureCoords[0] = new aiVector3D[numVertices];

    }

    char line[4096];

    buffer = car;

    const char *sz = car;

    const char *lineEnd = &line[4096];

    // now read all vertex lines

    for (unsigned int i = 0; i < numVertices; ++i) {

        if (!GetNextLine(buffer, line)) {

            ASSIMP_LOG_ERROR("OFF: The number of verts in the header is incorrect");

            break;

        }

        aiVector3D &v = mesh->mVertices[i];

        sz = line;

        // helper array to write a for loop over possible dimension values

        ai_real *vec[3] = { &v.x, &v.y, &v.z };

        // stop at dimensions: this allows loading 1D or 2D coordinate vertices

        for (unsigned int dim = 0; dim < dimensions; ++dim) {

            SkipSpaces(&sz, lineEnd);

            sz = fast_atoreal_move(sz, *vec[dim]);

        }

        // if has homogeneous coordinate, divide others by this one

        if (hasHomogenous) {

            SkipSpaces(&sz, lineEnd);

            ai_real w = 1.;

            sz = fast_atoreal_move(sz, w);

            for (unsigned int dim = 0; dim < dimensions; ++dim) {

                *(vec[dim]) /= w;

            }

        }

        // read optional normals

        if (hasNormals) {

            aiVector3D &n = mesh->mNormals[i];

            SkipSpaces(&sz, lineEnd);

            sz = fast_atoreal_move(sz, n.x);

            SkipSpaces(&sz, lineEnd);

            sz = fast_atoreal_move(sz, n.y);

            SkipSpaces(&sz, lineEnd);

            fast_atoreal_move(sz, n.z);

        }

        // reading colors is a pain because the specification says it can be

        // integers or floats, and any number of them between 1 and 4 included,

        // until the next comment or end of line

        // in theory should be testing type !

        if (hasColors) {

            aiColor4D &c = mesh->mColors[0][i];

            SkipSpaces(&sz, lineEnd);

            sz = fast_atoreal_move(sz, c.r);

            if (*sz != '#' && *sz != '\n' && *sz != '\r') {

                SkipSpaces(&sz, lineEnd);

                sz = fast_atoreal_move(sz, c.g);

            } else {

                c.g = 0.;

            }

            if (*sz != '#' && *sz != '\n' && *sz != '\r') {

                SkipSpaces(&sz, lineEnd);

                sz = fast_atoreal_move(sz, c.b);

            } else {

                c.b = 0.;

            }

            if (*sz != '#' && *sz != '\n' && *sz != '\r') {

                SkipSpaces(&sz, lineEnd);

                sz = fast_atoreal_move(sz, c.a);

            } else {

                c.a = 1.;

            }

        }

        if (hasTexCoord) {

            aiVector3D &t = mesh->mTextureCoords[0][i];

            SkipSpaces(&sz, lineEnd);

            sz = fast_atoreal_move(sz, t.x);

            SkipSpaces(&sz, lineEnd);

            fast_atoreal_move(sz, t.y);

        }

    }

    // load faces with their indices

    faces = mesh->mFaces;

    for (unsigned int i = 0; i < numFaces;) {

        if (!GetNextLine(buffer, line)) {

            ASSIMP_LOG_ERROR("OFF: The number of faces in the header is incorrect");

            throw DeadlyImportError("OFF: The number of faces in the header is incorrect");

        }

        unsigned int idx;

        sz = line;

        SkipSpaces(&sz, lineEnd);

        idx = strtoul10(sz, &sz);

        if (!idx || idx > 9) {

            ASSIMP_LOG_ERROR("OFF: Faces with zero indices aren't allowed");

            --mesh->mNumFaces;

            ++i;

            continue;

        }

        faces->mNumIndices = idx;

        faces->mIndices = new unsigned int[faces->mNumIndices];

        for (unsigned int m = 0; m < faces->mNumIndices; ++m) {

            SkipSpaces(&sz, lineEnd);

            idx = strtoul10(sz, &sz);

            if (idx >= numVertices) {

                ASSIMP_LOG_ERROR("OFF: Vertex index is out of range");

                idx = numVertices - 1;

            }

            faces->mIndices[m] = idx;

        }

        ++i;

        ++faces;

    }

    // generate the output node graph

    pScene->mRootNode = new aiNode();

    pScene->mRootNode->mName.Set("<OFFRoot>");

    pScene->mRootNode->mNumMeshes = 1;

    pScene->mRootNode->mMeshes = new unsigned int[pScene->mRootNode->mNumMeshes];

    pScene->mRootNode->mMeshes[0] = 0;

    // generate a default material

    pScene->mNumMaterials = 1;

    pScene->mMaterials = new aiMaterial *[pScene->mNumMaterials];

    aiMaterial *pcMat = new aiMaterial();

    aiColor4D clr(0.6f, 0.6f, 0.6f, 1.0f);

    pcMat->AddProperty(&clr, 1, AI_MATKEY_COLOR_DIFFUSE);

    pScene->mMaterials[0] = pcMat;

    const int twosided = 1;

    pcMat->AddProperty(&twosided, 1, AI_MATKEY_TWOSIDED);

}

} // namespace Assimp

#endif // !! ASSIMP_BUILD_NO_OFF_IMPORTER