/*

 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.sun.org.apache.xpath.internal.functions;

import com.sun.org.apache.xalan.internal.res.XSLMessages;

import com.sun.org.apache.xml.internal.utils.QName;

import com.sun.org.apache.xpath.internal.Expression;

import com.sun.org.apache.xpath.internal.ExpressionOwner;

import com.sun.org.apache.xpath.internal.XPathVisitor;

import java.util.List;

/**

 * Base class for functions that accept one argument.

 * @xsl.usage advanced

 * @LastModified: Oct 2017

 */

public class FunctionOneArg extends Function implements ExpressionOwner

{

    static final long serialVersionUID = -5180174180765609758L;

  /** The first argument passed to the function (at index 0).

   *  @serial  */

  Expression m_arg0;

  /**

   * Return the first argument passed to the function (at index 0).

   *

   * @return An expression that represents the first argument passed to the

   *         function.

   */

  public Expression getArg0()

  {

    return m_arg0;

  }

  /**

   * Set an argument expression for a function.  This method is called by the

   * XPath compiler.

   *

   * @param arg non-null expression that represents the argument.

   * @param argNum The argument number index.

   *

   * @throws WrongNumberArgsException If the argNum parameter is greater than 0.

   */

  public void setArg(Expression arg, int argNum)

          throws WrongNumberArgsException

  {

    if (0 == argNum)

    {

      m_arg0 = arg;

      arg.exprSetParent(this);

    }

    else

      reportWrongNumberArgs();

  }

  /**

   * Check that the number of arguments passed to this function is correct.

   *

   *

   * @param argNum The number of arguments that is being passed to the function.

   *

   * @throws WrongNumberArgsException

   */

  public void checkNumberArgs(int argNum) throws WrongNumberArgsException

  {

    if (argNum != 1)

      reportWrongNumberArgs();

  }

  /**

   * Constructs and throws a WrongNumberArgException with the appropriate

   * message for this function object.

   *

   * @throws WrongNumberArgsException

   */

  protected void reportWrongNumberArgs() throws WrongNumberArgsException {

      throw new WrongNumberArgsException(XSLMessages.createXPATHMessage("one", null));

  }

  /**

   * Tell if this expression or it's subexpressions can traverse outside

   * the current subtree.

   *

   * @return true if traversal outside the context node's subtree can occur.

   */

   public boolean canTraverseOutsideSubtree()

   {

    return m_arg0.canTraverseOutsideSubtree();

   }

  /**

   * This function is used to fixup variables from QNames to stack frame

   * indexes at stylesheet build time.

   * @param vars List of QNames that correspond to variables.  This list

   * should be searched backwards for the first qualified name that

   * corresponds to the variable reference qname.  The position of the

   * QName in the vector from the start of the vector will be its position

   * in the stack frame (but variables above the globalsTop value will need

   * to be offset to the current stack frame).

   */

  public void fixupVariables(List<QName> vars, int globalsSize)

  {

    if(null != m_arg0)

      m_arg0.fixupVariables(vars, globalsSize);

  }

  /**

   * @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)

   */

  public void callArgVisitors(XPathVisitor visitor)

  {

        if(null != m_arg0)

                m_arg0.callVisitors(this, visitor);

  }

  /**

   * @see ExpressionOwner#getExpression()

   */

  public Expression getExpression()

  {

    return m_arg0;

  }

  /**

   * @see ExpressionOwner#setExpression(Expression)

   */

  public void setExpression(Expression exp)

  {

        exp.exprSetParent(this);

        m_arg0 = exp;

  }

  /**

   * @see Expression#deepEquals(Expression)

   */

  public boolean deepEquals(Expression expr)

  {

        if(!super.deepEquals(expr))

                return false;

        if(null != m_arg0)

        {

                if(null == ((FunctionOneArg)expr).m_arg0)

                        return false;

                if(!m_arg0.deepEquals(((FunctionOneArg)expr).m_arg0))

                        return false;

        }

        else if(null != ((FunctionOneArg)expr).m_arg0)

                return false;

        return true;

  }

}