/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <math.h>

#include "mozilla/FloatingPoint.h"
#include "txExpr.h"
#include "txIXPathContext.h"

nsresult txNumberExpr::evaluate(txIEvalContext* aContext,
                                txAExprResult** aResult) {
  *aResult = nullptr;

  RefPtr<txAExprResult> exprRes;
  nsresult rv = mRightExpr->evaluate(aContext, getter_AddRefs(exprRes));
  NS_ENSURE_SUCCESS(rv, rv);

  double rightDbl = exprRes->numberValue();

  rv = mLeftExpr->evaluate(aContext, getter_AddRefs(exprRes));
  NS_ENSURE_SUCCESS(rv, rv);

  double leftDbl = exprRes->numberValue();
  double result = 0;

  switch (mOp) {
    case ADD:
      result = leftDbl + rightDbl;
      break;

    case SUBTRACT:
      result = leftDbl - rightDbl;
      break;

    case DIVIDE:
      if (rightDbl == 0) {
#if defined(XP_WIN)
        /* XXX MSVC miscompiles such that (NaN == 0) */
        if (std::isnan(rightDbl))
          result = mozilla::UnspecifiedNaN<double>();
        else
#endif
            if (leftDbl == 0 || std::isnan(leftDbl))
          result = mozilla::UnspecifiedNaN<double>();
        else if (mozilla::IsNegative(leftDbl) != mozilla::IsNegative(rightDbl))
          result = mozilla::NegativeInfinity<double>();
        else
          result = mozilla::PositiveInfinity<double>();
      } else
        result = leftDbl / rightDbl;
      break;

    case MODULUS:
      if (rightDbl == 0) {
        result = mozilla::UnspecifiedNaN<double>();
      } else {
#if defined(XP_WIN)
        /* Workaround MS fmod bug where 42 % (1/0) => NaN, not 42. */
        if (!std::isinf(leftDbl) && std::isinf(rightDbl))
          result = leftDbl;
        else
#endif
          result = fmod(leftDbl, rightDbl);
      }
      break;

    case MULTIPLY:
      result = leftDbl * rightDbl;
      break;
  }

  return aContext->recycler()->getNumberResult(result, aResult);
}  //-- evaluate

TX_IMPL_EXPR_STUBS_2(txNumberExpr, NUMBER_RESULT, mLeftExpr, mRightExpr)

bool txNumberExpr::isSensitiveTo(ContextSensitivity aContext) {
  return mLeftExpr->isSensitiveTo(aContext) ||
         mRightExpr->isSensitiveTo(aContext);
}

#ifdef TX_TO_STRING
void txNumberExpr::toString(nsAString& str) {
  mLeftExpr->toString(str);

  switch (mOp) {
    case ADD:
      str.AppendLiteral(" + ");
      break;
    case SUBTRACT:
      str.AppendLiteral(" - ");
      break;
    case DIVIDE:
      str.AppendLiteral(" div ");
      break;
    case MODULUS:
      str.AppendLiteral(" mod ");
      break;
    case MULTIPLY:
      str.AppendLiteral(" * ");
      break;
  }

  mRightExpr->toString(str);
}
#endif