/*

 * 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.xalan.internal.res.XSLTErrorResources;

import com.sun.org.apache.xml.internal.dtm.DTM;

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

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

import com.sun.org.apache.xpath.internal.axes.LocPathIterator;

import com.sun.org.apache.xpath.internal.axes.PredicatedNodeTest;

import com.sun.org.apache.xpath.internal.axes.SubContextList;

import com.sun.org.apache.xpath.internal.objects.XNodeSet;

import com.sun.org.apache.xpath.internal.objects.XObject;

import com.sun.org.apache.xpath.internal.patterns.StepPattern;

import java.util.List;

/**

 * Execute the current() function.

 * @xsl.usage advanced

 * @LastModified: Oct 2017

 */

public class FuncCurrent extends Function

{

    static final long serialVersionUID = 5715316804877715008L;

  /**

   * Execute the function.  The function must return

   * a valid object.

   * @param xctxt The current execution context.

   * @return A valid XObject.

   *

   * @throws javax.xml.transform.TransformerException

   */

  public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException

  {

    SubContextList subContextList = xctxt.getCurrentNodeList();

    int currentNode = DTM.NULL;

    if (null != subContextList) {

        if (subContextList instanceof PredicatedNodeTest) {

            LocPathIterator iter = ((PredicatedNodeTest)subContextList)

                                                          .getLocPathIterator();

            currentNode = iter.getCurrentContextNode();

         } else if(subContextList instanceof StepPattern) {

           throw new RuntimeException(XSLMessages.createMessage(

              XSLTErrorResources.ER_PROCESSOR_ERROR,null));

         }

    } else {

        // not predicate => ContextNode == CurrentNode

        currentNode = xctxt.getContextNode();

    }

    return new XNodeSet(currentNode, xctxt.getDTMManager());

  }

  /**

   * No arguments to process, so this does nothing.

   */

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

  {

    // no-op

  }

}