/*
 * 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 org.apache.xalan.templates;

import java.util.Vector;

import javax.xml.transform.SourceLocator;
import javax.xml.transform.TransformerException;

import org.apache.xalan.res.XSLTErrorResources;
import org.apache.xalan.transformer.TransformerImpl;
import org.apache.xalan.xslt.util.XslTransformEvaluationHelper;
import org.apache.xml.utils.XML11Char;
import org.apache.xpath.XPath;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XObject;
import org.w3c.dom.DOMException;

/**
 * Implement xsl:processing-instruction.
 * <pre>
 * <!ELEMENT xsl:processing-instruction %char-template;>
 * <!ATTLIST xsl:processing-instruction
 *   name %avt; #REQUIRED
 *   %space-att;
 * >
 * </pre>
 * @see <a href="http://www.w3.org/TR/xslt#section-Creating-Processing-Instructions">section-Creating-Processing-Instructions in XSLT Specification</a>
 * @xsl.usage advanced
 */
public class ElemPI extends ElemTemplateElement
{
  static final long serialVersionUID = 5621976448020889825L;

  /**
   * The xsl:processing-instruction element has a required name
   * attribute that specifies the name of the processing instruction node.
   * The value of the name attribute is interpreted as an
   * attribute value template.
   */
  private AVT m_name_atv = null;

  /**
   * Set the value of "name" attribute.
   *
   * @param v Value for the name attribute
   */
  public void setName(AVT v)
  {
    m_name_atv = v;
  }

  /**
   * Get the value of "name" attribute.
   *
   * @return The value of the "name" attribute 
   */
  public AVT getName()
  {
    return m_name_atv;
  }
  
  /**
   * Class field to, represent the value of "xpath-default-namespace" 
   * attribute.
   */
  private String m_xpath_default_namespace = null;
  
  /**
   * Set the value of "xpath-default-namespace" attribute.
   *
   * @param v   Value of the "xpath-default-namespace" attribute
   */
  public void setXpathDefaultNamespace(String v)
  {
	  m_xpath_default_namespace = v; 
  }

  /**
   * Get the value of "xpath-default-namespace" attribute.
   *  
   * @return		  The value of "xpath-default-namespace" attribute 
   */
  public String getXpathDefaultNamespace() {
	  return m_xpath_default_namespace;
  }
  
  /**
   * Variable to indicate whether, an attribute 'expand-text'
   * is declared on xsl:processing-instruction instruction.
   */
  private boolean m_expand_text_declared;
  
  /**
   * Class field, that represents the value of "expand-text" 
   * attribute.
   */
  private boolean m_expand_text;

  /**
   * Set the value of "expand-text" attribute.
   *
   * @param v   Value of the "expand-text" attribute
   */
  public void setExpandText(boolean v)
  {
	  m_expand_text = v;
	  m_expand_text_declared = true;
  }

  /**
   * Get the value of "expand-text" attribute.
   *  
   * @return		  The value of "expand-text" attribute 
   */
  public boolean getExpandText() {
	  return m_expand_text;
  }

  /**
   * Get a boolean value indicating whether, an "expand-text" 
   * attribute has been declared. 
   */
  public boolean getExpandTextDeclared() {
	  return m_expand_text_declared;
  }
  
  /**
   * The optional select attribute contains an expression.
   */
  public XPath m_selectExpression = null;

  /**
   * Set the "select" attribute.
   *
   * @param expr Expression for select attribute 
   */
  public void setSelect(XPath expr)
  {      
	  m_selectExpression = expr;
  }

  /**
   * Get the "select" attribute.
   *
   * @return Expression for select attribute 
   */
  public XPath getSelect()
  {
	  return m_selectExpression;
  }
  
  private String m_pi_name = null;
  
  public String getPiName() {
	  return m_pi_name; 
  }
  
  public void setPiName(String piName) {
	  m_pi_name = piName; 
  }
  
  private String m_pi_value = null;
  
  public String getPiValue() {
	  return m_pi_value; 
  }
  
  public void setPiValue(String piValue) {
	  m_pi_value = piValue; 
  }
  
  /**
   * Class field to refer to the fact that, whether to 
   * serialize an XML pi node to XSL transform's output.
   */
  private boolean m_is_serialize = true;
  
  public boolean getIsSerialize() {
	  return m_is_serialize;
  }
  
  public void setIsSerialize(boolean serialize) {
	  m_is_serialize = serialize;  
  }
  
  private Vector m_vars;
  
  private int m_globals_size;
  
  /**
   * This function is called after everything else has been
   * recomposed, and allows the template to set remaining
   * values that may be based on some other property that
   * depends on recomposition.
   */
  public void compose(StylesheetRoot sroot) throws TransformerException
  {
	  super.compose(sroot);
	  
	  java.util.Vector vnames = sroot.getComposeState().getVariableNames();
	  if (m_name_atv != null)
		  m_name_atv.fixupVariables(vnames, sroot.getComposeState().getGlobalsSize());

	  StylesheetRoot.ComposeState cstate = sroot.getComposeState();

	  m_vars = (Vector)vnames.clone();
	  m_globals_size = cstate.getGlobalsSize();
  }

  /**
   * Get an int constant identifying the type of element.
   * @see org.apache.xalan.templates.Constants
   *
   * @return The token id for the element
   */
  public int getXSLToken()
  {
    return Constants.ELEMNAME_PI;
  }

  /**
   * Return the node name.
   *
   * @return The element's name
   */
  public String getNodeName()
  {
    return Constants.ELEMNAME_PI_STRING;
  }

  /**
   * Create a processing instruction in the result tree.
   * The content of the xsl:processing-instruction element is a
   * template for the string-value of the processing instruction node.
   * @see <a href="http://www.w3.org/TR/xslt#section-Creating-Processing-Instructions">section-Creating-Processing-Instructions in XSLT Specification</a>
   *
   * @param transformer non-null reference to the the current transform-time state.
   *
   * @throws TransformerException
   */
  public void execute(
          TransformerImpl transformer)
            throws TransformerException
  {

	  if (transformer.getDebug())
		  transformer.getTraceManager().emitTraceEvent(this);

	  XPathContext xctxt = transformer.getXPathContext();
	  
	  final int contextNode = xctxt.getCurrentNode();
	  
	  SourceLocator srcLocator = xctxt.getSAXLocator();
	  
	  if ((m_selectExpression != null) && (m_xpath_default_namespace != null)) {    		
    	  m_selectExpression = new XPath(m_selectExpression.getPatternString(), srcLocator, xctxt.getNamespaceContext(), XPath.SELECT, null);
      }	
	  
	  if ((m_selectExpression != null) && (getFirstChildElem() != null)) {
		 throw new TransformerException("XTSE0940 : An XSL processing instruction cannot have, "
		 		                                                          + "both 'select' attribute and non-empty content.", srcLocator); 
	  }

	  String piName = m_name_atv == null ? null : m_name_atv.evaluate(xctxt, contextNode, this);

	  // Ignore processing instruction if name is null
	  if (piName == null) return;

	  if (piName.equalsIgnoreCase("xml"))
	  {
		  transformer.getMsgMgr().warn(
				  this, XSLTErrorResources.WG_PROCESSINGINSTRUCTION_NAME_CANT_BE_XML,
				  new Object[]{ Constants.ATTRNAME_NAME, piName });
		  return;
	  }

	  // Only check if an avt was used (ie. this wasn't checked at compose time.)
	  // Ignore processing instruction, if invalid
	  else if ((!m_name_atv.isSimple()) && (!XML11Char.isXML11ValidNCName(piName)))
	  {
		  transformer.getMsgMgr().warn(
				  this, XSLTErrorResources.WG_PROCESSINGINSTRUCTION_NOTVALID_NCNAME,
				  new Object[]{ Constants.ATTRNAME_NAME, piName });
		  return;    	
	  }

	  String data = null;		  
	  if (m_selectExpression != null) {
		  XObject xObj = m_selectExpression.execute(xctxt, contextNode, xctxt.getNamespaceContext());			  
		  data = XslTransformEvaluationHelper.getStrVal(xObj);
	  }
	  else {
		  data = transformer.transformToString(this);
	  }

	  boolean isExpandText = false;
	  if (m_expand_text_declared) {
		  isExpandText = m_expand_text;  
	  }
	  else {
		  ElemTemplateElement elemTemplateElem = getParentElem();      
		  isExpandText = getExpandTextValue(elemTemplateElem);
	  }

	  if (isExpandText) {
		  data = getStrValueAfterExpandTextProcessing(data, transformer, m_vars, m_globals_size);
	  }

	  if (m_is_serialize) {
		  try
		  {
			  transformer.getResultTreeHandler().processingInstruction(piName, data);
		  }
		  catch(org.xml.sax.SAXException se)
		  {
			  throw new TransformerException(se);
		  }
	  }
	  else {
		  m_pi_name = piName;
		  m_pi_value = data; 
	  }

	  if (transformer.getDebug())
		  transformer.getTraceManager().emitTraceEndEvent(this);
  }

  /**
   * Add a child to the child list.
   *
   * @param newChild Child to add to child list
   *
   * @return The child just added to the child list
   *
   * @throws DOMException
   */
  public ElemTemplateElement appendChild(ElemTemplateElement newChild)
  {

    int type = ((ElemTemplateElement) newChild).getXSLToken();

    switch (type)
    {

    // char-instructions 
    case Constants.ELEMNAME_TEXTLITERALRESULT :
    case Constants.ELEMNAME_APPLY_TEMPLATES :
    case Constants.ELEMNAME_APPLY_IMPORTS :
    case Constants.ELEMNAME_CALLTEMPLATE :
    case Constants.ELEMNAME_FOREACH :
    case Constants.ELEMNAME_VALUEOF :
    case Constants.ELEMNAME_COPY_OF :
    case Constants.ELEMNAME_NUMBER :
    case Constants.ELEMNAME_CHOOSE :
    case Constants.ELEMNAME_IF :
    case Constants.ELEMNAME_TEXT :
    case Constants.ELEMNAME_COPY :
    case Constants.ELEMNAME_VARIABLE :
    case Constants.ELEMNAME_MESSAGE :

      // instructions 
      // case Constants.ELEMNAME_PI:
      // case Constants.ELEMNAME_COMMENT:
      // case Constants.ELEMNAME_ELEMENT:
      // case Constants.ELEMNAME_ATTRIBUTE:
      break;
    default :
      String lineNo = String.valueOf(newChild.getLineNumber());
  	  String columnNo = String.valueOf(newChild.getColumnNumber());

  	  error(XSLTErrorResources.ER_CANNOT_ADD,
  										   new Object[]{ newChild.getNodeName(),
  												    this.getNodeName(), lineNo, columnNo });
    }

    return super.appendChild(newChild);
  }
  
  /**
   * This after the template's children have been composed.
   */
  public void endCompose(StylesheetRoot sroot) throws TransformerException
  {
     super.endCompose(sroot);
  }
}
