/*

 * 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.patterns;

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

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

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.XPathContext;

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

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

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

import java.util.List;

/**

 * Match pattern step that contains a function.

 * @xsl.usage advanced

 * @LastModified: Oct 2017

 */

public class FunctionPattern extends StepPattern

{

    static final long serialVersionUID = -5426793413091209944L;

  /**

   * Construct a FunctionPattern from a

   * {@link com.sun.org.apache.xpath.internal.functions.Function expression}.

   *

   * NEEDSDOC @param expr

   */

  public FunctionPattern(Expression expr, int axis, int predaxis)

  {

    super(0, null, null, axis, predaxis);

    m_functionExpr = expr;

  }

  /**

   * Static calc of match score.

   */

  public final void calcScore()

  {

    m_score = SCORE_OTHER;

    if (null == m_targetString)

      calcTargetString();

  }

  /**

   * Should be a {@link com.sun.org.apache.xpath.internal.functions.Function expression}.

   *  @serial

   */

  Expression m_functionExpr;

  /**

   * 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)

  {

    super.fixupVariables(vars, globalsSize);

    m_functionExpr.fixupVariables(vars, globalsSize);

  }

  /**

   * Test a node to see if it matches the given node test.

   *

   * @param xctxt XPath runtime context.

   *

   * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.

   *

   * @throws javax.xml.transform.TransformerException

   */

  public XObject execute(XPathContext xctxt, int context)

          throws javax.xml.transform.TransformerException

  {

    DTMIterator nl = m_functionExpr.asIterator(xctxt, context);

    XNumber score = SCORE_NONE;

    if (null != nl)

    {

      int n;

      while (DTM.NULL != (n = nl.nextNode()))

      {

        score = (n == context) ? SCORE_OTHER : SCORE_NONE;

        if (score == SCORE_OTHER)

        {

          context = n;

          break;

        }

      }

      // nl.detach();

    }

    nl.detach();

    return score;

  }

  /**

   * Test a node to see if it matches the given node test.

   *

   * @param xctxt XPath runtime context.

   *

   * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.

   *

   * @throws javax.xml.transform.TransformerException

   */

  public XObject execute(XPathContext xctxt, int context,

                         DTM dtm, int expType)

          throws javax.xml.transform.TransformerException

  {

    DTMIterator nl = m_functionExpr.asIterator(xctxt, context);

    XNumber score = SCORE_NONE;

    if (null != nl)

    {

      int n;

      while (DTM.NULL != (n = nl.nextNode()))

      {

        score = (n == context) ? SCORE_OTHER : SCORE_NONE;

        if (score == SCORE_OTHER)

        {

          context = n;

          break;

        }

      }

      nl.detach();

    }

    return score;

  }

  /**

   * Test a node to see if it matches the given node test.

   *

   * @param xctxt XPath runtime context.

   *

   * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or

   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.

   *

   * @throws javax.xml.transform.TransformerException

   */

  public XObject execute(XPathContext xctxt)

          throws javax.xml.transform.TransformerException

  {

    int context = xctxt.getCurrentNode();

    DTMIterator nl = m_functionExpr.asIterator(xctxt, context);

    XNumber score = SCORE_NONE;

    if (null != nl)

    {

      int n;

      while (DTM.NULL != (n = nl.nextNode()))

      {

        score = (n == context) ? SCORE_OTHER : SCORE_NONE;

        if (score == SCORE_OTHER)

        {

          context = n;

          break;

        }

      }

      nl.detach();

    }

    return score;

  }

  class FunctionOwner implements ExpressionOwner

  {

    /**

     * @see ExpressionOwner#getExpression()

     */

    public Expression getExpression()

    {

      return m_functionExpr;

    }

    /**

     * @see ExpressionOwner#setExpression(Expression)

     */

    public void setExpression(Expression exp)

    {

        exp.exprSetParent(FunctionPattern.this);

        m_functionExpr = exp;

    }

  }

  /**

   * Call the visitor for the function.

   */

  protected void callSubtreeVisitors(XPathVisitor visitor)

  {

    m_functionExpr.callVisitors(new FunctionOwner(), visitor);

    super.callSubtreeVisitors(visitor);

  }

}