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	/*
	* 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.operations;

	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.XPathContext;
	import com.sun.org.apache.xpath.internal.XPathVisitor;
	import com.sun.org.apache.xpath.internal.axes.PathComponent;
	import com.sun.org.apache.xpath.internal.axes.WalkerFactory;
	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.res.XPATHErrorResources;
	import java.util.List;
	import javax.xml.transform.TransformerException;


	/**
	* The variable reference expression executer.
	*
	* @LastModified: Oct 2017
	*/
	public class Variable extends Expression implements PathComponent
	{
	static final long serialVersionUID = -4334975375609297049L;
	/** Tell if fixupVariables was called.
	* @serial */
	private boolean m_fixUpWasCalled = false;

	/** The qualified name of the variable.
	* @serial */
	protected QName m_qname;

	/**
	* The index of the variable, which is either an absolute index to a
	* global, or, if higher than the globals area, must be adjusted by adding
	* the offset to the current stack frame.
	*/
	protected int m_index;

	/**
	* Set the index for the variable into the stack. For advanced use only. You
	* must know what you are doing to use this.
	*
	* @param index a global or local index.
	*/
	public void setIndex(int index)
	{
	m_index = index;
	}

	/**
	* Set the index for the variable into the stack. For advanced use only.
	*
	* @return index a global or local index.
	*/
	public int getIndex()
	{
	return m_index;
	}

	/**
	* Set whether or not this is a global reference. For advanced use only.
	*
	* @param isGlobal true if this should be a global variable reference.
	*/
	public void setIsGlobal(boolean isGlobal)
	{
	m_isGlobal = isGlobal;
	}

	/**
	* Set the index for the variable into the stack. For advanced use only.
	*
	* @return true if this should be a global variable reference.
	*/
	public boolean getGlobal()
	{
	return m_isGlobal;
	}





	protected boolean m_isGlobal = false;

	/**
	* 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)
	{
	m_fixUpWasCalled = true;
	int sz = vars.size();

	for (int i = vars.size()-1; i >= 0; i--)
	{
	QName qn = vars.get(i);
	// System.out.println("qn: "+qn);
	if(qn.equals(m_qname))
	{

	if(i < globalsSize)
	{
	m_isGlobal = true;
	m_index = i;
	}
	else
	{
	m_index = i-globalsSize;
	}

	return;
	}
	}

	java.lang.String msg = XSLMessages.createXPATHMessage(XPATHErrorResources.ER_COULD_NOT_FIND_VAR,
	new Object[]{m_qname.toString()});

	TransformerException te = new TransformerException(msg, this);

	throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(te);

	}


	/**
	* Set the qualified name of the variable.
	*
	* @param qname Must be a non-null reference to a qualified name.
	*/
	public void setQName(QName qname)
	{
	m_qname = qname;
	}

	/**
	* Get the qualified name of the variable.
	*
	* @return A non-null reference to a qualified name.
	*/
	public QName getQName()
	{
	return m_qname;
	}

	/**
	* Execute an expression in the XPath runtime context, and return the
	* result of the expression.
	*
	*
	* @param xctxt The XPath runtime context.
	*
	* @return The result of the expression in the form of a <code>XObject</code>.
	*
	* @throws javax.xml.transform.TransformerException if a runtime exception
	* occurs.
	*/
	public XObject execute(XPathContext xctxt)
	throws javax.xml.transform.TransformerException
	{
	return execute(xctxt, false);
	}


	/**
	* Dereference the variable, and return the reference value. Note that lazy
	* evaluation will occur. If a variable within scope is not found, a warning
	* will be sent to the error listener, and an empty nodeset will be returned.
	*
	*
	* @param xctxt The runtime execution context.
	*
	* @return The evaluated variable, or an empty nodeset if not found.
	*
	* @throws javax.xml.transform.TransformerException
	*/
	public XObject execute(XPathContext xctxt, boolean destructiveOK) throws javax.xml.transform.TransformerException
	{
	com.sun.org.apache.xml.internal.utils.PrefixResolver xprefixResolver = xctxt.getNamespaceContext();

	XObject result;
	// Is the variable fetched always the same?
	// XObject result = xctxt.getVariable(m_qname);
	if(m_fixUpWasCalled)
	{
	if(m_isGlobal)
	result = xctxt.getVarStack().getGlobalVariable(xctxt, m_index, destructiveOK);
	else
	result = xctxt.getVarStack().getLocalVariable(xctxt, m_index, destructiveOK);
	}
	else {
	result = xctxt.getVarStack().getVariableOrParam(xctxt,m_qname);
	}

	if (null == result)
	{
	// This should now never happen...
	warn(xctxt, XPATHErrorResources.WG_ILLEGAL_VARIABLE_REFERENCE,
	new Object[]{ m_qname.getLocalPart() }); //"VariableReference given for variable out "+
	// (new RuntimeException()).printStackTrace();
	// error(xctxt, XPATHErrorResources.ER_COULDNOT_GET_VAR_NAMED,
	// new Object[]{ m_qname.getLocalPart() }); //"Could not get variable named "+varName);

	result = new XNodeSet(xctxt.getDTMManager());
	}

	return result;
	// }
	// else
	// {
	// // Hack city... big time. This is needed to evaluate xpaths from extensions,
	// // pending some bright light going off in my head. Some sort of callback?
	// synchronized(this)
	// {
	// com.sun.org.apache.xalan.internal.templates.ElemVariable vvar= getElemVariable();
	// if(null != vvar)
	// {
	// m_index = vvar.getIndex();
	// m_isGlobal = vvar.getIsTopLevel();
	// m_fixUpWasCalled = true;
	// return execute(xctxt);
	// }
	// }
	// throw new javax.xml.transform.TransformerException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_VAR_NOT_RESOLVABLE, new Object[]{m_qname.toString()})); //"Variable not resolvable: "+m_qname);
	// }
	}

	/**
	* Get the XSLT ElemVariable that this sub-expression references. In order for
	* this to work, the SourceLocator must be the owning ElemTemplateElement.
	* @return The dereference to the ElemVariable, or null if not found.
	*/
	// J2SE does not support Xalan interpretive
	/*
	public com.sun.org.apache.xalan.internal.templates.ElemVariable getElemVariable()
	{

	// Get the current ElemTemplateElement, and then walk backwards in
	// document order, searching
	// for an xsl:param element or xsl:variable element that matches our
	// qname. If we reach the top level, use the StylesheetRoot's composed
	// list of top level variables and parameters.

	com.sun.org.apache.xalan.internal.templates.ElemVariable vvar = null;
	com.sun.org.apache.xpath.internal.ExpressionNode owner = getExpressionOwner();

	if (null != owner && owner instanceof com.sun.org.apache.xalan.internal.templates.ElemTemplateElement)
	{

	com.sun.org.apache.xalan.internal.templates.ElemTemplateElement prev =
	(com.sun.org.apache.xalan.internal.templates.ElemTemplateElement) owner;

	if (!(prev instanceof com.sun.org.apache.xalan.internal.templates.Stylesheet))
	{
	while ( prev != null && !(prev.getParentNode() instanceof com.sun.org.apache.xalan.internal.templates.Stylesheet) )
	{
	com.sun.org.apache.xalan.internal.templates.ElemTemplateElement savedprev = prev;

	while (null != (prev = prev.getPreviousSiblingElem()))
	{
	if(prev instanceof com.sun.org.apache.xalan.internal.templates.ElemVariable)
	{
	vvar = (com.sun.org.apache.xalan.internal.templates.ElemVariable) prev;

	if (vvar.getName().equals(m_qname))
	{
	return vvar;
	}
	vvar = null;
	}
	}
	prev = savedprev.getParentElem();
	}
	}
	if (prev != null)
	vvar = prev.getStylesheetRoot().getVariableOrParamComposed(m_qname);
	}
	return vvar;

	}
	*/
	/**
	* Tell if this expression returns a stable number that will not change during
	* iterations within the expression. This is used to determine if a proximity
	* position predicate can indicate that no more searching has to occur.
	*
	*
	* @return true if the expression represents a stable number.
	*/
	public boolean isStableNumber()
	{
	return true;
	}

	/**
	* Get the analysis bits for this walker, as defined in the WalkerFactory.
	* @return One of WalkerFactory#BIT_DESCENDANT, etc.
	*/
	public int getAnalysisBits()
	{

	// J2SE does not support Xalan interpretive
	/*
	com.sun.org.apache.xalan.internal.templates.ElemVariable vvar = getElemVariable();
	if(null != vvar)
	{
	XPath xpath = vvar.getSelect();
	if(null != xpath)
	{
	Expression expr = xpath.getExpression();
	if(null != expr && expr instanceof PathComponent)
	{
	return ((PathComponent)expr).getAnalysisBits();
	}
	}
	}
	*/

	return WalkerFactory.BIT_FILTER;
	}


	/**
	* @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
	*/
	public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
	{
	visitor.visitVariableRef(owner, this);
	}
	/**
	* @see Expression#deepEquals(Expression)
	*/
	public boolean deepEquals(Expression expr)
	{
	if(!isSameClass(expr))
	return false;

	if(!m_qname.equals(((Variable)expr).m_qname))
	return false;

	// J2SE does not support Xalan interpretive
	/*
	// We have to make sure that the qname really references
	// the same variable element.
	if(getElemVariable() != ((Variable)expr).getElemVariable())
	return false;
	*/

	return true;
	}

	static final java.lang.String PSUEDOVARNAMESPACE = "http://xml.apache.org/xalan/psuedovar";

	/**
	* Tell if this is a psuedo variable reference, declared by Xalan instead
	* of by the user.
	*/
	public boolean isPsuedoVarRef()
	{
	java.lang.String ns = m_qname.getNamespaceURI();
	if((null != ns) && ns.equals(PSUEDOVARNAMESPACE))
	{
	if(m_qname.getLocalName().startsWith("#"))
	return true;
	}
	return false;
	}


	}

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