/*=========================================================================
 *
 *  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 itkNumericTraitsFixedArrayPixel_h
#define itkNumericTraitsFixedArrayPixel_h

#include "itkNumericTraits.h"
#include "itkFixedArray.h"

namespace itk
{
/**
 * \brief Define numeric traits for FixedArray.
 * \tparam T Component type of the FixedArray
 * \tparam D Dimension of the FixedArray
 *
 * We provide here a generic implementation based on creating types of
 * FixedArray whose components are the types of the NumericTraits from
 * the original FixedArray components. This implementation require
 * support for partial specializations, since it is based on the
 * concept that:
 *   NumericTraits<FixedArray< T, D > >  is defined piecewise by
 *   FixedArray< NumericTraits< T > >
 *
 * \sa NumericTraits
 * \ingroup DataRepresentation
 * \ingroup ITKCommon
 */
template <typename T, unsigned int D>
class NumericTraits<FixedArray<T, D>>
{
private:
  using ElementAbsType = typename NumericTraits<T>::AbsType;
  using ElementAccumulateType = typename NumericTraits<T>::AccumulateType;
  using ElementFloatType = typename NumericTraits<T>::FloatType;
  using ElementPrintType = typename NumericTraits<T>::PrintType;
  using ElementRealType = typename NumericTraits<T>::RealType;

public:
  /** Return the type of the native component type. */
  using ValueType = T;

  using Self = FixedArray<T, D>;

  /** Unsigned component type */
  using AbsType = FixedArray<ElementAbsType, D>;

  /** Accumulation of addition and multiplication. */
  using AccumulateType = FixedArray<ElementAccumulateType, D>;

  /** Typedef for operations that use floating point instead of real precision
   */
  using FloatType = FixedArray<ElementFloatType, D>;

  /** Return the type that can be printed. */
  using PrintType = FixedArray<ElementPrintType, D>;

  /** Type for real-valued scalar operations. */
  using RealType = FixedArray<ElementRealType, D>;

  /** Type for real-valued scalar operations. */
  using ScalarRealType = ElementRealType;

  /** Measurement vector type */
  using MeasurementVectorType = Self;

  /** Component wise defined element
   *
   * \note minimum value for floating pointer types is defined as
   * minimum positive normalize value.
   */
  static const Self
  max(const Self &)
  {
    return MakeFilled<Self>(NumericTraits<T>::max());
  }

  static const Self
  min(const Self &)
  {
    return MakeFilled<Self>(NumericTraits<T>::min());
  }

  static const Self
  max()
  {
    return MakeFilled<Self>(NumericTraits<T>::max());
  }

  static const Self
  min()
  {
    return MakeFilled<Self>(NumericTraits<T>::min());
  }

  static const Self
  NonpositiveMin()
  {
    return MakeFilled<Self>(NumericTraits<T>::NonpositiveMin());
  }

  static const Self
  ZeroValue()
  {
    return Self{};
  }

  static const Self
  OneValue()
  {
    return MakeFilled<Self>(NumericTraits<T>::OneValue());
  }

  static const Self
  NonpositiveMin(const Self &)
  {
    return NonpositiveMin();
  }

  static const Self
  ZeroValue(const Self &)
  {
    return ZeroValue();
  }

  static const Self
  OneValue(const Self &)
  {
    return OneValue();
  }

  /** Fixed length vectors cannot be resized, so an exception will
   *  be thrown if the input size is not valid.  If the size is valid
   *  the vector will be filled with zeros. */
  static void
  SetLength(FixedArray<T, D> & m, const unsigned int s)
  {
    if (s != D)
    {
      itkGenericExceptionMacro("Cannot set the size of a FixedArray of length " << D << " to " << s);
    }
    m.Fill(T{});
  }

  /** Return the length of the array. */
  static unsigned int
  GetLength(const FixedArray<T, D> &)
  {
    return D;
  }

  /** Return the length of the array. */
  static unsigned int
  GetLength()
  {
    return D;
  }

  static void
  AssignToArray(const Self & v, MeasurementVectorType & mv)
  {
    mv = v;
  }

  template <typename TArray>
  static void
  AssignToArray(const Self & v, TArray & mv)
  {
    for (unsigned int i = 0; i < D; ++i)
    {
      mv[i] = v[i];
    }
  }

  /** \note: the functions are preferred over the member variables as
   * they are defined for all partial specialization
   */
  static const Self ITKCommon_EXPORT Zero;
  static const Self ITKCommon_EXPORT One;
};

// a macro to define and initialize static member variables,
// NOTE: (T)(NumericTraits< T >::[Zero|One]) is needed to generate
//       a temporary variable that is initialized from the
//       constexpr [Zero|One] to be passed by const reference
//       to the GENERIC_ARRAY<T,D> constructor.
#define itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, D)                    \
  template <>                                                                           \
  ITKCommon_EXPORT const GENERIC_ARRAY<T, D> NumericTraits<GENERIC_ARRAY<T, D>>::Zero = \
    MakeFilled<GENERIC_ARRAY<T, D>>(NumericTraits<T>::Zero);                            \
  template <>                                                                           \
  ITKCommon_EXPORT const GENERIC_ARRAY<T, D> NumericTraits<GENERIC_ARRAY<T, D>>::One =  \
    MakeFilled<GENERIC_ARRAY<T, D>>(NumericTraits<T>::One);

//
// List here the array dimension specializations of these static
// Traits:
//
#define itkStaticNumericTraitsGenericArrayDimensionsMacro(GENERIC_ARRAY, T) \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 1);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 2);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 3);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 4);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 5);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 6);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 7);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 8);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 9);             \
  itkStaticNumericTraitsGenericArrayMacro(GENERIC_ARRAY, T, 10);
} // end namespace itk

#endif // itkNumericTraitsFixedArrayPixel_h