/*=========================================================================
 *
 *  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 itkSimilarity2DTransform_hxx
#define itkSimilarity2DTransform_hxx

#include "itkMath.h"

namespace itk
{

template <typename TParametersValueType>
Similarity2DTransform<TParametersValueType>::Similarity2DTransform()
  : Superclass(ParametersDimension)
{
  m_Scale = 1.0f;
}


template <typename TParametersValueType>
Similarity2DTransform<TParametersValueType>::Similarity2DTransform(unsigned int parametersDimension)
  : Superclass(parametersDimension)
{
  m_Scale = 1.0f;
}


template <typename TParametersValueType>
Similarity2DTransform<TParametersValueType>::Similarity2DTransform(unsigned int, unsigned int parametersDimension)
  : Superclass(parametersDimension)
{
  m_Scale = 1.0f;
}


template <typename TParametersValueType>
void
Similarity2DTransform<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 scale
  const TParametersValueType scale = parameters[0];
  this->SetVarScale(scale);

  // Set angle
  const TParametersValueType angle = parameters[1];
  this->SetVarAngle(angle);

  // Set translation
  OffsetType translation;
  for (unsigned int i = 0; i < SpaceDimension; ++i)
  {
    translation[i] = parameters[i + 2];
  }
  this->SetVarTranslation(translation);

  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
Similarity2DTransform<TParametersValueType>::GetParameters() const -> const ParametersType &
{
  itkDebugMacro("Getting parameters ");

  this->m_Parameters[0] = this->GetScale();
  this->m_Parameters[1] = this->GetAngle();

  // Get the translation
  OffsetType translation = this->GetTranslation();
  for (unsigned int i = 0; i < SpaceDimension; ++i)
  {
    this->m_Parameters[i + 2] = translation[i];
  }

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

  return this->m_Parameters;
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::SetScale(ScaleType scale)
{
  m_Scale = scale;
  this->ComputeMatrix();
  this->ComputeOffset();
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::ComputeMatrix()
{
  const double angle = this->GetAngle();

  const double cc = std::cos(angle);
  const double ss = std::sin(angle);

  const MatrixValueType ca = cc * m_Scale;
  const MatrixValueType sa = ss * m_Scale;

  MatrixType matrix;

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

  this->SetVarMatrix(matrix);
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::ComputeMatrixParameters()
{
  m_Scale = std::sqrt(itk::Math::sqr(this->GetMatrix()[0][0]) + itk::Math::sqr(this->GetMatrix()[0][1]));

  // Throw if m_Scale is zero, or a denormal floating point number (close to zero)".
  // https://bitbashing.io/comparing-floats.html
  // https://en.cppreference.com/w/cpp/types/numeric_limits/epsilon
  if (m_Scale < std::numeric_limits<TParametersValueType>::min())
  {
    itkExceptionMacro("Bad Rotation Matrix. Scale cannot be zero.\n"
                      << "m_Scale : " << m_Scale);
  }

  this->SetVarAngle(std::acos(this->GetMatrix()[0][0] / m_Scale));

  if (this->GetMatrix()[1][0] < 0.0)
  {
    this->SetVarAngle(-this->GetAngle());
  }

  if ((this->GetMatrix()[1][0] / m_Scale) - std::sin(this->GetAngle()) > 0.000001)
  {
    itkExceptionMacro("Bad Rotation Matrix");
  }
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::ComputeJacobianWithRespectToParameters(const InputPointType & p,
                                                                                    JacobianType & jacobian) const
{
  const double angle = this->GetAngle();
  const double ca = std::cos(angle);
  const double sa = std::sin(angle);

  jacobian.SetSize(2, this->GetNumberOfLocalParameters());
  jacobian.Fill(0.0);

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

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

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

  // compute derivatives with respect to the translation part
  // first with respect to tx
  jacobian[0][2] = 1.0;
  jacobian[1][2] = 0.0;
  // first with respect to ty
  jacobian[0][3] = 0.0;
  jacobian[1][3] = 1.0;
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::SetIdentity()
{
  this->Superclass::SetIdentity();
  m_Scale = static_cast<TParametersValueType>(1.0f);
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::PrintSelf(std::ostream & os, Indent indent) const
{
  Superclass::PrintSelf(os, indent);

  os << indent << "Scale: " << static_cast<typename NumericTraits<ScaleType>::PrintType>(m_Scale) << std::endl;
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::CloneInverseTo(Pointer & result) const
{
  result = New();
  this->GetInverse(result);
}


template <typename TParametersValueType>
bool
Similarity2DTransform<TParametersValueType>::GetInverse(Self * inverse) const
{
  if (!inverse)
  {
    return false;
  }

  inverse->SetFixedParameters(this->GetFixedParameters());
  const auto & inverseMatrix = this->GetInverseMatrix();
  if (this->GetSingular())
  {
    return false;
  }
  inverse->SetCenter(this->GetCenter()); // inverse have the same center
  inverse->SetScale(1.0 / this->GetScale());
  inverse->SetAngle(-this->GetAngle());
  inverse->SetTranslation(-(inverseMatrix * this->GetTranslation()));

  return true;
}


template <typename TParametersValueType>
auto
Similarity2DTransform<TParametersValueType>::GetInverseTransform() const -> InverseTransformBasePointer
{
  return Superclass::InvertTransform(*this);
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::CloneTo(Pointer & result) const
{
  result = New();
  result->SetCenter(this->GetCenter());
  result->SetScale(this->GetScale());
  result->SetAngle(this->GetAngle());
  result->SetTranslation(this->GetTranslation());
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::SetMatrix(const MatrixType & matrix)
{
  const TParametersValueType tolerance = MatrixOrthogonalityTolerance<TParametersValueType>::GetTolerance();
  this->SetMatrix(matrix, tolerance);
}


template <typename TParametersValueType>
void
Similarity2DTransform<TParametersValueType>::SetMatrix(const MatrixType & matrix, const TParametersValueType tolerance)
{
  itkDebugMacro("setting  m_Matrix  to " << matrix);

  typename MatrixType::InternalMatrixType test = matrix.GetVnlMatrix() * matrix.GetTranspose();

  test /= test[0][0]; // factor out the scale

  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();
}

} // end namespace itk

#endif