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

 *

 *  Copyright Insight Software Consortium

 *

 *  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.

 *

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

#ifndef itkPyVnl_hxx

#define itkPyVnl_hxx

#include "itkPyVnl.h"

#include <stdexcept>

namespace itk

{

template<class TElement>

PyObject *

PyVnl<TElement>

::_GetArrayViewFromVnlVector( VectorType * vector)

{

  PyObject *                  memoryView    = NULL;

  Py_buffer                   pyBuffer;

  memset(&pyBuffer, 0, sizeof(Py_buffer));

  size_t                      elementSize   = sizeof(DataType);

  int                         res           = 0;

  if( !vector )

    {

    throw std::runtime_error("Input vector is null");

    }

  DataType *buffer = vector->data_block();

  void * vectorBuffer = (void *)( buffer );

  // Computing the length of data

  Py_ssize_t len = vector->size();

  len *= elementSize;

  res = PyBuffer_FillInfo(&pyBuffer, NULL, (void*)vectorBuffer, len, 0, PyBUF_CONTIG);

  memoryView = PyMemoryView_FromBuffer(&pyBuffer);

  PyBuffer_Release(&pyBuffer);

  return memoryView;

}

template<class TElement>

const typename PyVnl<TElement>::VectorType

PyVnl<TElement>

::_GetVnlVectorViewFromArray( PyObject *arr, PyObject *shape)

{

  PyObject *                  obj           = NULL;

  PyObject *                  shapeseq      = NULL;

  PyObject *                  item          = NULL;

  Py_ssize_t                  bufferLength;

  Py_buffer                   pyBuffer;

  memset(&pyBuffer, 0, sizeof(Py_buffer));

  size_t numberOfElements = 1;

  const void *                buffer;

  unsigned int                dimension     = 0;

  size_t                      elementSize   = sizeof(DataType);

  size_t                      len           = 1;

  if(PyObject_GetBuffer(arr, &pyBuffer, PyBUF_CONTIG) == -1)

    {

    PyErr_SetString( PyExc_RuntimeError, "Cannot get an instance of NumPy array." );

    PyBuffer_Release(&pyBuffer);

    return VectorType();

    }

  else

    {

    bufferLength = pyBuffer.len;

    buffer = pyBuffer.buf;

    }

  obj        = shape;

  shapeseq   = PySequence_Fast(obj, "expected sequence");

  dimension  = PySequence_Size(obj);

  item = PySequence_Fast_GET_ITEM(shapeseq,0);// Only one dimension

  numberOfElements = (size_t)PyLong_AsLong(item);

  len = numberOfElements*elementSize;

  if ( bufferLength != len )

    {

    PyErr_SetString( PyExc_RuntimeError, "Size mismatch of vector and Buffer." );

    PyBuffer_Release(&pyBuffer);

    return VectorType();

    }

  DataType * data = (DataType *)buffer;

  VectorType output(data, numberOfElements);

  PyBuffer_Release(&pyBuffer);

  return output;

}

template<class TElement>

PyObject *

PyVnl<TElement>

::_GetArrayViewFromVnlMatrix( MatrixType * matrix)

{

  PyObject *                  memoryView    = NULL;

  Py_buffer                   pyBuffer;

  memset(&pyBuffer, 0, sizeof(Py_buffer));

  size_t                      elementSize   = sizeof(DataType);

  int                         res           = 0;

  if( !matrix )

    {

    throw std::runtime_error("Input matrix is null");

    }

  DataType *buffer =  matrix->data_block();

  //ComponentType *buffer =  const_cast < ComponentType *> (reinterpret_cast< const ComponentType* > ( image->GetBufferPointer() ) );

  void * matrixBuffer = (void *)( buffer );

  // Computing the length of data

  Py_ssize_t len = matrix->size();

  len *= elementSize;

  res = PyBuffer_FillInfo(&pyBuffer, NULL, (void*)matrixBuffer, len, 0, PyBUF_CONTIG);

  memoryView = PyMemoryView_FromBuffer(&pyBuffer);

  PyBuffer_Release(&pyBuffer);

  return memoryView;

}

template<class TElement>

const typename PyVnl<TElement>::MatrixType

PyVnl<TElement>

::_GetVnlMatrixViewFromArray( PyObject *arr, PyObject *shape)

{

  PyObject *                  obj           = NULL;

  PyObject *                  shapeseq      = NULL;

  PyObject *                  item          = NULL;

  Py_ssize_t                  bufferLength;

  Py_buffer                   pyBuffer;

  memset(&pyBuffer, 0, sizeof(Py_buffer));

  size_t numberOfElements = 1;

  const void *                buffer;

  unsigned int                dimension     = 0;

  size_t                      elementSize   = sizeof(DataType);

  size_t                      len           = 1;

  unsigned int                size[2];

  if(PyObject_GetBuffer(arr, &pyBuffer, PyBUF_CONTIG) == -1)

    {

    PyErr_SetString( PyExc_RuntimeError, "Cannot get an instance of NumPy array." );

    PyBuffer_Release(&pyBuffer);

    return MatrixType();

    }

  else

    {

    bufferLength = pyBuffer.len;

    buffer = pyBuffer.buf;

    }

  obj        = shape;

  shapeseq   = PySequence_Fast(obj, "expected sequence");

  dimension  = PySequence_Size(obj);

  for( unsigned int i = 0; i < 2; ++i )

    {

    item = PySequence_Fast_GET_ITEM(shapeseq,i);

    size[i] = (unsigned int)PyLong_AsLong(item);

    numberOfElements *= size[i];

    }

  len = numberOfElements*elementSize;

  if ( bufferLength != len )

    {

    PyErr_SetString( PyExc_RuntimeError, "Size mismatch of matrix and Buffer." );

    PyBuffer_Release(&pyBuffer);

    return MatrixType();

    }

  DataType * data = (DataType *)buffer;

  MatrixType output(data, size[0], size[1]);

  PyBuffer_Release(&pyBuffer);

  return output;

}

} // namespace itk

#endif