#include <poincare/hyperbolic_arc_tangent.h>
#include <poincare/simplification_engine.h>
#include <poincare/trigonometry.h>
extern "C" {
#include <assert.h>
}
#include <cmath>

namespace Poincare {

Expression::Type HyperbolicArcTangent::type() const {
  return Type::HyperbolicArcTangent;
}

Expression * HyperbolicArcTangent::clone() const {
  HyperbolicArcTangent * a = new HyperbolicArcTangent(m_operands, true);
  return a;
}

Expression * HyperbolicArcTangent::shallowReduce(Context& context, AngleUnit angleUnit) {
  Expression * e = Expression::shallowReduce(context, angleUnit);
  if (e != this) {
    return e;
  }
#if MATRIX_EXACT_REDUCING
  Expression * op = editableOperand(0);
  if (op->type() == Type::Matrix) {
    return SimplificationEngine::map(this, context, angleUnit);
  }
#endif
  return this;
}

template<typename T>
std::complex<T> HyperbolicArcTangent::computeOnComplex(const std::complex<T> c, 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 Trigonometry::RoundToMeaningfulDigits(result);
}

}