// Created on: 1991-05-27
// Created by: Arnaud BOUZY
// Copyright (c) 1991-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#include <Expr.hxx>
#include <Expr_ArcCosine.hxx>
#include <Expr_Cosine.hxx>
#include <Expr_GeneralExpression.hxx>
#include <Expr_NamedUnknown.hxx>
#include <Expr_Operators.hxx>
#include <Expr_Product.hxx>
#include <Expr_Sine.hxx>
#include <Expr_UnaryMinus.hxx>
#include <Standard_Type.hxx>
#include <TCollection_AsciiString.hxx>

IMPLEMENT_STANDARD_RTTIEXT(Expr_Cosine, Expr_UnaryExpression)

Expr_Cosine::Expr_Cosine(const Handle(Expr_GeneralExpression)& exp)
{
  CreateOperand(exp);
}

Handle(Expr_GeneralExpression) Expr_Cosine::ShallowSimplified() const
{
  Handle(Expr_GeneralExpression) myexp = Operand();
  if (myexp->IsKind(STANDARD_TYPE(Expr_NumericValue)))
  {
    Handle(Expr_NumericValue) myNVexp = Handle(Expr_NumericValue)::DownCast(myexp);
    return new Expr_NumericValue(Cos(myNVexp->GetValue()));
  }
  if (myexp->IsKind(STANDARD_TYPE(Expr_ArcCosine)))
  {
    return myexp->SubExpression(1);
  }
  Handle(Expr_Cosine) me = this;
  return me;
}

Handle(Expr_GeneralExpression) Expr_Cosine::Copy() const
{
  return new Expr_Cosine(Expr::CopyShare(Operand()));
}

Standard_Boolean Expr_Cosine::IsIdentical(const Handle(Expr_GeneralExpression)& Other) const
{
  if (Other->IsKind(STANDARD_TYPE(Expr_Cosine)))
  {
    Handle(Expr_GeneralExpression) myexp = Operand();
    return myexp->IsIdentical(Other->SubExpression(1));
  }
  return Standard_False;
}

Standard_Boolean Expr_Cosine::IsLinear() const
{
  return !ContainsUnknowns();
}

Handle(Expr_GeneralExpression) Expr_Cosine::Derivative(const Handle(Expr_NamedUnknown)& X) const
{
  if (!Contains(X))
  {
    return new Expr_NumericValue(0.0);
  }
  Handle(Expr_GeneralExpression) myexp    = Operand();
  Handle(Expr_GeneralExpression) myder    = myexp->Derivative(X);
  Handle(Expr_Sine)              firstder = new Expr_Sine(Expr::CopyShare(myexp));
  Handle(Expr_UnaryMinus)        fder     = -(firstder->ShallowSimplified());
  Handle(Expr_Product)           resu     = fder->ShallowSimplified() * myder;
  return resu->ShallowSimplified();
}

Standard_Real Expr_Cosine::Evaluate(const Expr_Array1OfNamedUnknown& vars,
                                    const TColStd_Array1OfReal&      vals) const
{
  return ::Cos(Operand()->Evaluate(vars, vals));
}

TCollection_AsciiString Expr_Cosine::String() const
{
  TCollection_AsciiString str("Cos(");
  str += Operand()->String();
  str += ")";
  return str;
}
