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//
// Helper namespace field_utils inline implementation

// Author: Dmitry Sorokin (CERN, Google Summer of Code 2017), 13.10.2017
// Supervision: John Apostolakis (CERN)
// --------------------------------------------------------------------

namespace field_utils {

namespace internal
{
  template<class T>
  std::size_t getFirstIndex(const T& value)
  {
    return static_cast<std::size_t>(value);
  }
}

template <typename ArrayType>
inline G4double getValue(const ArrayType& array, Value1D value)
{
  const auto begin = internal::getFirstIndex(value);
  return array[begin];
}

template <typename ArrayType>
G4double getValue2(const ArrayType& array, Value1D value)
{
  return sqr(getValue(array, value));
}

template <typename ArrayType>
G4double getValue(const ArrayType& array, Value3D value)
{
  return std::sqrt(getValue2(array, value));
}

template <typename ArrayType>
G4double getValue2(const ArrayType& array, const Value3D value)
{
  const auto begin = internal::getFirstIndex(value);
  return sqr(array[begin]) + sqr(array[begin+1]) + sqr(array[begin+2]);
}

template <typename ArrayType>
G4ThreeVector makeVector(const ArrayType& array, Value3D value)
{
    const auto begin = internal::getFirstIndex(value);
    return G4ThreeVector(array[begin], array[begin + 1], array[begin + 2]);
}

template <typename SourceArray, typename TargetArray>
void setValue(const SourceArray& src, Value1D value, TargetArray& trg)
{
  const auto begin = internal::getFirstIndex(value);
  trg[begin] = src[begin];
}

template <typename SourceArray, typename TargetArray, typename ...TargetArrays>
void setValue(const SourceArray& src, Value1D value,
              TargetArray& trg, TargetArrays&... trgs)
{
  const auto begin = internal::getFirstIndex(value);
  trg[begin] = src[begin];
  setValue(src, value, trgs...);
}

template <typename T>
T clamp(T value, T lo, T hi)
{
  return std::min(std::max(lo, value), hi);
}

} // field_utils