#include <poincare/hyperbolic_arc_tangent.h>
#include <poincare/complex.h>
#include <poincare/layout_helper.h>
#include <poincare/serialization_helper.h>
#include <cmath>

namespace Poincare {

constexpr Expression::FunctionHelper HyperbolicArcTangent::s_functionHelper;

Layout HyperbolicArcTangentNode::createLayout(Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const {
  return LayoutHelper::Prefix(HyperbolicArcTangent(this), floatDisplayMode, numberOfSignificantDigits, HyperbolicArcTangent::s_functionHelper.name());
}

int HyperbolicArcTangentNode::serialize(char * buffer, int bufferSize, Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const {
  return SerializationHelper::Prefix(this, buffer, bufferSize, floatDisplayMode, numberOfSignificantDigits, HyperbolicArcTangent::s_functionHelper.name());
}

template<typename T>
Complex<T> HyperbolicArcTangentNode::computeOnComplex(const std::complex<T> c, Preferences::ComplexFormat, Preferences::AngleUnit angleUnit) {
  std::complex<T> result = std::atanh(c);
  /* atanh has a branch cut on ]-inf, -1[U]1, +inf[: it is then multivalued on
   * this cut. We followed the convention chosen by the lib c++ of llvm on
   * ]-inf+0i, -1+0i[ (warning: atanh takes the other side of the cut values on
   * ]-inf-0i, -1-0i[) and choose the values on ]1+0i, +inf+0i[ to comply with
   * atanh(-x) = -atanh(x) and sin(artanh(x)) = x/sqrt(1-x^2). */
  if (c.imag() == 0 && c.real() > 1) {
    result.imag(-result.imag()); // other side of the cut
  }
  return Complex<T>::Builder(Trigonometry::RoundToMeaningfulDigits(result, c));
}


template Complex<float> Poincare::HyperbolicArcTangentNode::computeOnComplex<float>(std::complex<float>, Preferences::ComplexFormat, Preferences::AngleUnit);
template Complex<double> Poincare::HyperbolicArcTangentNode::computeOnComplex<double>(std::complex<double>, Preferences::ComplexFormat complexFormat, Preferences::AngleUnit);

}
