// Created on: 1991-04-19
// 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_Exponentiate.hxx>
#include <Expr_GeneralExpression.hxx>
#include <Expr_NamedUnknown.hxx>
#include <Expr_NotEvaluable.hxx>
#include <Expr_NumericValue.hxx>
#include <Expr_Operators.hxx>
#include <Expr_Product.hxx>
#include <Expr_SequenceOfGeneralExpression.hxx>
#include <Expr_Square.hxx>
#include <Expr_SquareRoot.hxx>
#include <Standard_NumericError.hxx>
#include <Standard_Type.hxx>
#include <TCollection_AsciiString.hxx>

IMPLEMENT_STANDARD_RTTIEXT(Expr_Square,Expr_UnaryExpression)

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

Handle(Expr_GeneralExpression) Expr_Square::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(Square(myNVexp->GetValue()));
  }
  if (myexp->IsKind(STANDARD_TYPE(Expr_SquareRoot))) {
    return myexp->SubExpression(1);
  }
  if (myexp->IsKind(STANDARD_TYPE(Expr_Square))) {
    Handle(Expr_GeneralExpression) op = myexp->SubExpression(1);
    Handle(Expr_NumericValue) val4 = new Expr_NumericValue(4.0);
    return new Expr_Exponentiate(op,val4);
  }
  if (myexp->IsKind(STANDARD_TYPE(Expr_Exponentiate))) {
    Handle(Expr_GeneralExpression) op = myexp->SubExpression(1);
    Handle(Expr_GeneralExpression) puis = myexp->SubExpression(2);
    Handle(Expr_Product) newpuis = 2.0 * puis;
    Handle(Expr_Exponentiate) res = new Expr_Exponentiate(op,newpuis->ShallowSimplified());
    return res->ShallowSimplified();
  }
  Handle(Expr_Square) me = this;
  return me;
}

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

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

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

Handle(Expr_GeneralExpression) Expr_Square::Derivative (const Handle(Expr_NamedUnknown)& X) const
{
  if (!Contains(X)) {
    return  new Expr_NumericValue(0.0);
  }
  Handle(Expr_GeneralExpression) myder = Operand();
  myder = myder->Derivative(X);
  Handle(Expr_NumericValue) coef = new Expr_NumericValue(2.0);
  Expr_SequenceOfGeneralExpression ops;
  ops.Append(coef);
  ops.Append(myder);
  Handle(Expr_GeneralExpression) usedop = Expr::CopyShare(Operand());
  ops.Append(usedop);
  Handle(Expr_Product) resu = new Expr_Product(ops);
  return resu->ShallowSimplified();
}

Standard_Real Expr_Square::Evaluate(const Expr_Array1OfNamedUnknown& vars, const TColStd_Array1OfReal& vals) const
{
  Standard_Real val = Operand()->Evaluate(vars,vals);
  return val*val;
}

TCollection_AsciiString Expr_Square::String() const
{
  TCollection_AsciiString str;
  Handle(Expr_GeneralExpression) op = Operand();
  if (op->NbSubExpressions() > 1) {
    str = "(";
    str += op->String();
    str += ")^2";
  }
  else {
    str = op->String();
    str += "^2";
  }
  return str;
}