/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  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
 *
 *         https://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 itkRigid2DTransform_hxx
#define itkRigid2DTransform_hxx

#include "vnl/algo/vnl_svd.h"

namespace itk
{

template <typename TParametersValueType>
Rigid2DTransform<TParametersValueType>::Rigid2DTransform()
  : Superclass(ParametersDimension)
  , m_Angle(TParametersValueType{})
{}


template <typename TParametersValueType>
Rigid2DTransform<TParametersValueType>::Rigid2DTransform(unsigned int parametersDimension)
  : Superclass(parametersDimension)
  , m_Angle(TParametersValueType{})
{}


template <typename TParametersValueType>
Rigid2DTransform<TParametersValueType>::Rigid2DTransform(unsigned int, unsigned int parametersDimension)
  : Superclass(parametersDimension)
  , m_Angle(TParametersValueType{})
{}

template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);

  os << indent << "Angle: " << static_cast<typename NumericTraits<TParametersValueType>::PrintType>(m_Angle)
     << std::endl;
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::SetMatrix(const MatrixType & matrix)
{
  const TParametersValueType tolerance = MatrixOrthogonalityTolerance<TParametersValueType>::GetTolerance();
  this->SetMatrix(matrix, tolerance);
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::SetMatrix(const MatrixType & matrix, const TParametersValueType tolerance)
{
  itkDebugMacro("setting  m_Matrix  to " << matrix);
  // The matrix must be orthogonal otherwise it is not
  // representing a valid rotation in 2D space
  const typename MatrixType::InternalMatrixType test = matrix.GetVnlMatrix() * matrix.GetTranspose();

  if (!test.is_identity(tolerance))
  {
    itk::ExceptionObject ex(__FILE__, __LINE__, "Attempt to set a Non-Orthogonal matrix", ITK_LOCATION);
    throw ex;
  }

  this->SetVarMatrix(matrix);
  this->ComputeOffset();
  this->ComputeMatrixParameters();
  this->Modified();
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::ComputeMatrixParameters()
{
  // Extract the orthogonal part of the matrix
  //
  MatrixType                       p{ this->GetMatrix().GetVnlMatrix() };
  vnl_svd<TParametersValueType>    svd{ (p.GetVnlMatrix()).as_ref() };
  vnl_matrix<TParametersValueType> r{ svd.U() * svd.V().transpose() };

  m_Angle = std::acos(r[0][0]);
  if (r[1][0] < 0.0)
  {
    m_Angle *= -1;
  }

  if (r[1][0] - std::sin(m_Angle) > 0.000001)
  {
    itkWarningMacro("Bad Rotation Matrix " << this->GetMatrix());
  }
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::Translate(const OffsetType & offset, bool)
{
  OutputVectorType newOffset = this->GetOffset();

  newOffset += offset;
  this->SetOffset(newOffset);
  this->ComputeTranslation();
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::CloneInverseTo(Pointer & result) const
{
  result = New();
  this->GetInverse(result);
}


template <typename TParametersValueType>
bool
Rigid2DTransform<TParametersValueType>::GetInverse(Self * inverse) const
{
  if (!inverse)
  {
    return false;
  }

  inverse->SetFixedParameters(this->GetFixedParameters());
  inverse->SetCenter(this->GetCenter()); // inverse have the same center
  inverse->SetAngle(-this->GetAngle());
  inverse->SetTranslation(-(this->GetInverseMatrix() * this->GetTranslation()));

  return true;
}


template <typename TParametersValueType>
auto
Rigid2DTransform<TParametersValueType>::GetInverseTransform() const -> InverseTransformBasePointer
{
  return Superclass::InvertTransform(*this);
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::CloneTo(Pointer & result) const
{
  result = New();
  result->SetCenter(this->GetCenter());
  result->SetAngle(this->GetAngle());
  result->SetTranslation(this->GetTranslation());
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::SetIdentity()
{
  this->Superclass::SetIdentity();
  m_Angle = TParametersValueType{};
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::SetAngle(TParametersValueType angle)
{
  m_Angle = angle;
  this->ComputeMatrix();
  this->ComputeOffset();
  this->Modified();
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::SetAngleInDegrees(TParametersValueType angle)
{
  const TParametersValueType angleInRadians = angle * std::atan(1.0) / 45.0;

  this->SetAngle(angleInRadians);
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::ComputeMatrix()
{
  const MatrixValueType ca = std::cos(m_Angle);
  const MatrixValueType sa = std::sin(m_Angle);

  MatrixType rotationMatrix;

  rotationMatrix[0][0] = ca;
  rotationMatrix[0][1] = -sa;
  rotationMatrix[1][0] = sa;
  rotationMatrix[1][1] = ca;

  this->SetVarMatrix(rotationMatrix);
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::SetParameters(const ParametersType & parameters)
{
  itkDebugMacro("Setting parameters " << parameters);

  // Save parameters. Needed for proper operation of TransformUpdateParameters.
  if (&parameters != &(this->m_Parameters))
  {
    this->m_Parameters = parameters;
  }

  // Set angle
  const TParametersValueType angle = parameters[0];
  this->SetVarAngle(angle);

  // Set translation
  OutputVectorType translation;
  for (unsigned int i = 0; i < OutputSpaceDimension; ++i)
  {
    translation[i] = parameters[i + 1];
  }
  this->SetVarTranslation(translation);

  // Update matrix and offset
  this->ComputeMatrix();
  this->ComputeOffset();

  // Modified is always called since we just have a pointer to the
  // parameters and cannot know if the parameters have changed.
  this->Modified();

  itkDebugMacro("After setting parameters ");
}


template <typename TParametersValueType>
auto
Rigid2DTransform<TParametersValueType>::GetParameters() const -> const ParametersType &
{
  itkDebugMacro("Getting parameters ");

  // Get the angle
  this->m_Parameters[0] = this->GetAngle();
  // Get the translation
  for (unsigned int i = 0; i < OutputSpaceDimension; ++i)
  {
    this->m_Parameters[i + 1] = this->GetTranslation()[i];
  }

  itkDebugMacro("After getting parameters " << this->m_Parameters);

  return this->m_Parameters;
}


template <typename TParametersValueType>
void
Rigid2DTransform<TParametersValueType>::ComputeJacobianWithRespectToParameters(const InputPointType & p,
                                                                               JacobianType &         j) const
{
  j.SetSize(OutputSpaceDimension, this->GetNumberOfLocalParameters());
  j.Fill(0.0);

  const double ca = std::cos(this->GetAngle());
  const double sa = std::sin(this->GetAngle());

  const double cx = this->GetCenter()[0];
  const double cy = this->GetCenter()[1];

  // derivatives with respect to the angle
  j[0][0] = -sa * (p[0] - cx) - ca * (p[1] - cy);
  j[1][0] = ca * (p[0] - cx) - sa * (p[1] - cy);

  // compute derivatives for the translation part
  constexpr unsigned int blockOffset{ 1 };
  for (unsigned int dim = 0; dim < OutputSpaceDimension; ++dim)
  {
    j[dim][blockOffset + dim] = 1.0;
  }
}

} // namespace itk

#endif
