/*=========================================================================

   Library: iMSTK

   Copyright (c) Kitware, Inc. & Center for Modeling, Simulation,
   & Imaging in Medicine, Rensselaer Polytechnic Institute.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0.txt

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

=========================================================================*/

#include "imstkMeshIO.h"
#include "imstkAssimpMeshIO.h"
#include "imstkLogger.h"
#include "imstkMSHMeshIO.h"
#include "imstkSurfaceMesh.h"
#include "imstkTetrahedralMesh.h"
#include "imstkVegaMeshIO.h"
#include "imstkVTKMeshIO.h"

#include <cctype>
#include <sys/stat.h>
#include <unordered_map>

namespace imstk
{
static std::unordered_map<std::string, MeshFileType> extToType =
{
    { "vtk", MeshFileType::VTK },
    { "vtp", MeshFileType::VTP },
    { "vtu", MeshFileType::VTU },
    { "obj", MeshFileType::OBJ },
    { "stl", MeshFileType::STL },
    { "ply", MeshFileType::PLY },
    { "dae", MeshFileType::DAE },
    { "fbx", MeshFileType::FBX },
    { "3ds", MeshFileType::_3DS },
    { "veg", MeshFileType::VEG },
    { "msh", MeshFileType::MSH },
    { "dcm", MeshFileType::DCM },
    { "nrrd", MeshFileType::NRRD },
    { "nii", MeshFileType::NII },
    { "mhd", MeshFileType::MHD },
    { "jpg", MeshFileType::JPG },
    { "jpeg", MeshFileType::JPG },
    { "png", MeshFileType::PNG },
    { "bmp", MeshFileType::BMP },
};

std::shared_ptr<PointSet>
MeshIO::read(const std::string& filePath)
{
    bool isDirectory = false;
    bool exists = fileExists(filePath, isDirectory);

    CHECK(exists && !isDirectory) << "File " << filePath << " doesn't exist or is a directory.";

    MeshFileType meshType = MeshIO::getFileType(filePath);
    switch (meshType)
    {
    case MeshFileType::VTK:
    case MeshFileType::VTU:
    case MeshFileType::VTP:
    case MeshFileType::STL:
    case MeshFileType::PLY:
    case MeshFileType::NRRD:
    case MeshFileType::NII:
    case MeshFileType::DCM:
    case MeshFileType::MHD:
    case MeshFileType::JPG:
    case MeshFileType::PNG:
    case MeshFileType::BMP:
        return VTKMeshIO::read(filePath, meshType);
        break;
    case MeshFileType::OBJ:
    case MeshFileType::DAE:
    case MeshFileType::FBX:
    case MeshFileType::_3DS:
        return AssimpMeshIO::read(filePath, meshType);
        break;
    case MeshFileType::VEG:
        return VegaMeshIO::read(filePath, meshType);
        break;
    case MeshFileType::MSH:
        return MSHMeshIO::read(filePath, meshType);
        break;
    case MeshFileType::UNKNOWN:
    default:
        break;
    }
    LOG(FATAL) << "Error: file type not supported for input " << filePath;
    return nullptr;
}

bool
MeshIO::fileExists(const std::string& file, bool& isDirectory)
{
    struct stat buf;
    if (stat(file.c_str(), &buf) == 0)
    {
        if (buf.st_mode & S_IFDIR)
        {
            isDirectory = true;
        }
        else
        {
            isDirectory = false;
        }
        return true;
    }
    else
    {
        return false;
    }
}

const MeshFileType
MeshIO::getFileType(const std::string& filePath)
{
    std::string extString = filePath.substr(filePath.find_last_of(".") + 1);

    CHECK(!extString.empty()) << "Error: invalid file name " << filePath;

    // To lowercase
    std::transform(extString.begin(), extString.end(), extString.begin(),
        [](unsigned char c) { return static_cast<unsigned char>(std::tolower(c)); });

    if (extToType.count(extString) == 0)
    {
        LOG(FATAL) << "Error: unknown file extension " << extString;
    }

    return extToType[extString];
}

bool
MeshIO::write(const std::shared_ptr<imstk::PointSet> imstkMesh, const std::string& filePath)
{
    if (imstkMesh == nullptr)
    {
        LOG(WARNING) << "Error: Mesh object supplied is not valid!";
        return false;
    }

    MeshFileType meshType = MeshIO::getFileType(filePath);
    switch (meshType)
    {
    case MeshFileType::VEG:
        return VegaMeshIO::write(imstkMesh, filePath, meshType);
        break;
    case MeshFileType::NII:
    case MeshFileType::NRRD:
    case MeshFileType::VTU:
    case MeshFileType::VTK:
    case MeshFileType::VTP:
    case MeshFileType::STL:
    case MeshFileType::PLY:
    case MeshFileType::MHD:
    case MeshFileType::BMP:
    case MeshFileType::PNG:
    case MeshFileType::JPG:
        return VTKMeshIO::write(imstkMesh, filePath, meshType);
        break;
    case MeshFileType::UNKNOWN:
    default:
        break;
    }

    LOG(FATAL) << "Error: file type not supported for input " << filePath;
    return false;
}
} // imstk
