/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xalan.templates;

import java.util.Vector;

import org.w3c.dom.*;

import org.xml.sax.*;

import org.apache.xpath.*;
import org.apache.xml.utils.QName;
import org.apache.xalan.res.XSLTErrorResources;
import org.apache.xpath.VariableStack;
import org.apache.xalan.transformer.TransformerImpl;
import javax.xml.transform.SourceLocator;
import javax.xml.transform.TransformerException;
import org.apache.xpath.objects.XObject;

/**
 * <meta name="usage" content="advanced"/>
 * Implement xsl:call-template.
 * <pre>
 * &amp;!ELEMENT xsl:call-template (xsl:with-param)*>
 * &amp;!ATTLIST xsl:call-template
 *   name %qname; #REQUIRED
 * &amp;
 * </pre>
 * @see <a href="http://www.w3.org/TR/xslt#named-templates">named-templates in XSLT Specification</a>
 */
public class ElemCallTemplate extends ElemForEach
{

  /**
   * An xsl:call-template element invokes a template by name;
   * it has a required name attribute that identifies the template to be invoked.
   * @serial
   */
  public QName m_templateName = null;

  /**
   * Set the "name" attribute.
   * An xsl:call-template element invokes a template by name;
   * it has a required name attribute that identifies the template to be invoked.
   *
   * @param name Name attribute to set
   */
  public void setName(QName name)
  {
    m_templateName = name;
  }

  /**
   * Get the "name" attribute.
   * An xsl:call-template element invokes a template by name;
   * it has a required name attribute that identifies the template to be invoked.
   *
   * @return Name attribute of this element
   */
  public QName getName()
  {
    return m_templateName;
  }

  /**
   * The template which is named by QName.
   * @serial
   */
  private ElemTemplate m_template = null;

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

  /**
   * Return the node name.
   *
   * @return The name of this element
   */
  public String getNodeName()
  {
    return Constants.ELEMNAME_CALLTEMPLATE_STRING;
  }
  
  /**
   * 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);
    
    // Call compose on each param no matter if this is apply-templates 
    // or call templates.
    int length = getParamElemCount();
    for (int i = 0; i < length; i++) 
    {
      ElemWithParam ewp = getParamElem(i);
      ewp.compose(sroot);
    }
    
    if ((null != m_templateName) && (null == m_template))
    {
      m_template =
        this.getStylesheetRoot().getTemplateComposed(m_templateName);
        
      if(null == m_template)
        return; // %REVIEW% error?
    
      length = getParamElemCount();
      for (int i = 0; i < length; i++) 
      {
        ElemWithParam ewp = getParamElem(i);
        ewp.m_index = -1;
        // Find the position of the param in the template being called, 
        // and set the index of the param slot.
        int etePos = 0;
        for (ElemTemplateElement ete = m_template.getFirstChildElem(); 
             null != ete; ete = ete.getNextSiblingElem()) 
        {
          if(ete.getXSLToken() == Constants.ELEMNAME_PARAMVARIABLE)
          {
            ElemParam ep = (ElemParam)ete;
            if(ep.getName().equals(ewp.getName()))
            {
              ewp.m_index = etePos;
            }
          }
          else
            break;
          etePos++;
        }
        
      }
    }
  }
  
  /**
   * This after the template's children have been composed.
   */
  public void endCompose(StylesheetRoot sroot) throws TransformerException
  {
    int length = getParamElemCount();
    for (int i = 0; i < length; i++) 
    {
      ElemWithParam ewp = getParamElem(i);
      ewp.endCompose(sroot);
    }    
    
    super.endCompose(sroot);
  }

  /**
   * Invoke a named template.
   * @see <a href="http://www.w3.org/TR/xslt#named-templates">named-templates in XSLT Specification</a>
   *
   * @param transformer non-null reference to the the current transform-time state.
   * @param sourceNode non-null reference to the <a href="http://www.w3.org/TR/xslt#dt-current-node">current source node</a>.
   * @param mode reference, which may be null, to the <a href="http://www.w3.org/TR/xslt#modes">current mode</a>.
   *
   * @throws TransformerException
   */
  public void execute(
          TransformerImpl transformer)
            throws TransformerException
  {

    if (TransformerImpl.S_DEBUG)
      transformer.getTraceManager().fireTraceEvent(this);

    if (null != m_template)
    {
      XPathContext xctxt = transformer.getXPathContext();
      VariableStack vars = xctxt.getVarStack();

      int thisframe = vars.getStackFrame();
      int nextFrame = vars.link(m_template.m_frameSize);
      
      // We have to clear the section of the stack frame that has params 
      // so that the default param evaluation will work correctly.
      if(m_template.m_inArgsSize > 0)
      {
        vars.clearLocalSlots(0, m_template.m_inArgsSize);
      
        if(null != m_paramElems)
        {
          int currentNode = xctxt.getCurrentNode();
          vars.setStackFrame(thisframe);
          int size = m_paramElems.length;
          
          for (int i = 0; i < size; i++) 
          {
            ElemWithParam ewp = m_paramElems[i];
            if(ewp.m_index >= 0)
            {
              XObject obj = ewp.getValue(transformer, currentNode);
              
              // Note here that the index for ElemWithParam must have been 
              // statically made relative to the xsl:template being called, 
              // NOT this xsl:template.
              vars.setLocalVariable(ewp.m_index, obj, nextFrame);
            }
          }
          vars.setStackFrame(nextFrame);
        }
      }
      
      SourceLocator savedLocator = xctxt.getSAXLocator();

      try
      {
        xctxt.setSAXLocator(m_template);

        // template.executeChildTemplates(transformer, sourceNode, mode, true);
        transformer.pushElemTemplateElement(m_template);
        m_template.execute(transformer);
      }
      finally
      {
        transformer.popElemTemplateElement();
        xctxt.setSAXLocator(savedLocator);
        vars.unlink();
      }
    }
    else
    {
      transformer.getMsgMgr().error(this, XSLTErrorResources.ER_TEMPLATE_NOT_FOUND,
                                    new Object[]{ m_templateName });  //"Could not find template named: '"+templateName+"'");
    }
  }
  
  /** Vector of xsl:param elements associated with this element. 
   *  @serial */
  protected ElemWithParam[] m_paramElems = null;

  /**
   * Get the count xsl:param elements associated with this element.
   * @return The number of xsl:param elements.
   */
  public int getParamElemCount()
  {
    return (m_paramElems == null) ? 0 : m_paramElems.length;
  }

  /**
   * Get a xsl:param element associated with this element.
   *
   * @param i Index of element to find
   *
   * @return xsl:param element at given index
   */
  public ElemWithParam getParamElem(int i)
  {
    return m_paramElems[i];
  }

  /**
   * Set a xsl:param element associated with this element.
   *
   * @param ParamElem xsl:param element to set. 
   */
  public void setParamElem(ElemWithParam ParamElem)
  {
    if (null == m_paramElems)
    {
      m_paramElems = new ElemWithParam[1];
      m_paramElems[0] = ParamElem;
    }
    else
    {
      // Expensive 1 at a time growth, but this is done at build time, so 
      // I think it's OK.
      int length = m_paramElems.length;
      ElemWithParam[] ewp = new ElemWithParam[length + 1];
      System.arraycopy(m_paramElems, 0, ewp, 0, length);
      m_paramElems = ewp;
      ewp[length] = ParamElem;
    }
  }

  /**
   * Add a child to the child list.
   * <!ELEMENT xsl:apply-templates (xsl:sort|xsl:with-param)*>
   * <!ATTLIST xsl:apply-templates
   *   select %expr; "node()"
   *   mode %qname; #IMPLIED
   * >
   *
   * @param newChild Child to add to this node's children list
   *
   * @return The child that was just added the children list 
   *
   * @throws DOMException
   */
  public ElemTemplateElement appendChild(ElemTemplateElement newChild)
  {

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

    if (Constants.ELEMNAME_WITHPARAM == type)
    {
      setParamElem((ElemWithParam) newChild);
    }

    // You still have to append, because this element can
    // contain a for-each, and other elements.
    return super.appendChild(newChild);
  }
}