/*
 * 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.
 */
/*
 * $Id: ExtensionNamespacesManager.java 1225575 2011-12-29 15:50:25Z mrglavas $
 */
package org.apache.xalan.extensions;

import java.util.Vector;

import org.apache.xalan.templates.Constants;

Used during assembly of a stylesheet to collect the information for each extension namespace that is required during the transformation process to generate an ExtensionHandler. /**
 * Used during assembly of a stylesheet to collect the information for each 
 * extension namespace that is required during the transformation process 
 * to generate an {@link ExtensionHandler}.
 * 
 */
public class ExtensionNamespacesManager
{
  
Vector of ExtensionNamespaceSupport objects to be used to generate ExtensionHandlers.
/**
   * Vector of ExtensionNamespaceSupport objects to be used to generate ExtensionHandlers.
   */
  private Vector m_extensions = new Vector();
  
Vector of ExtensionNamespaceSupport objects for predefined ExtensionNamespaces. Elements
from this vector are added to the m_extensions vector when encountered in the stylesheet.
/**
   * Vector of ExtensionNamespaceSupport objects for predefined ExtensionNamespaces. Elements
   * from this vector are added to the m_extensions vector when encountered in the stylesheet.
   */
  private Vector m_predefExtensions = new Vector(7);
  
Vector of extension namespaces for which sufficient information is not yet available to
complete the registration process.
/**
   * Vector of extension namespaces for which sufficient information is not yet available to
   * complete the registration process.
   */
  private Vector m_unregisteredExtensions = new Vector();
  
  
An ExtensionNamespacesManager is instantiated the first time an extension function or
element is found in the stylesheet. During initialization, a vector of ExtensionNamespaceSupport
objects is created, one for each predefined extension namespace.
/**
   * An ExtensionNamespacesManager is instantiated the first time an extension function or
   * element is found in the stylesheet. During initialization, a vector of ExtensionNamespaceSupport
   * objects is created, one for each predefined extension namespace.
   */
  public ExtensionNamespacesManager()
  {
    setPredefinedNamespaces();
  }
  
  
If necessary, register the extension namespace found compiling a function or 
creating an extension element. 
If it is a predefined namespace, create a
support object to simplify the instantiate of an appropriate ExtensionHandler
during transformation runtime. Otherwise, add the namespace, if necessary,
to a vector of undefined extension namespaces, to be defined later.
/**
   * If necessary, register the extension namespace found compiling a function or 
   * creating an extension element. 
   * 
   * If it is a predefined namespace, create a
   * support object to simplify the instantiate of an appropriate ExtensionHandler
   * during transformation runtime. Otherwise, add the namespace, if necessary,
   * to a vector of undefined extension namespaces, to be defined later.
   * 
   */
  public void registerExtension(String namespace)
  {
    if (namespaceIndex(namespace, m_extensions) == -1)
    {
      int predef = namespaceIndex(namespace, m_predefExtensions);
      if (predef !=-1)
        m_extensions.add(m_predefExtensions.get(predef));
      else if (!(m_unregisteredExtensions.contains(namespace)))
        m_unregisteredExtensions.add(namespace);       
    }
  }
  
  
Register the extension namespace for an ElemExtensionDecl or ElemFunction,
and prepare a support object to launch the appropriate ExtensionHandler at 
transformation runtime.
/**
   * Register the extension namespace for an ElemExtensionDecl or ElemFunction,
   * and prepare a support object to launch the appropriate ExtensionHandler at 
   * transformation runtime.
   */  
  public void registerExtension(ExtensionNamespaceSupport extNsSpt)
  {
    String namespace = extNsSpt.getNamespace();
    if (namespaceIndex(namespace, m_extensions) == -1)
    {
      m_extensions.add(extNsSpt);
      if (m_unregisteredExtensions.contains(namespace))
        m_unregisteredExtensions.remove(namespace);
    }
    
  }
  
  
Get the index for a namespace entry in the extension namespace Vector, -1 if
no such entry yet exists.
/**
   * Get the index for a namespace entry in the extension namespace Vector, -1 if
   * no such entry yet exists.
   */
  public int namespaceIndex(String namespace, Vector extensions)
  {
    for (int i = 0; i < extensions.size(); i++)
    {
      if (((ExtensionNamespaceSupport)extensions.get(i)).getNamespace().equals(namespace))
        return i;
    }
    return -1;
  }
  
    
  
Get the vector of extension namespaces. Used to provide
the extensions table access to a list of extension
namespaces encountered during composition of a stylesheet.
/**
   * Get the vector of extension namespaces. Used to provide
   * the extensions table access to a list of extension
   * namespaces encountered during composition of a stylesheet.
   */
  public Vector getExtensions()
  {
    return m_extensions;
  }
  
  
Attempt to register any unregistered extension namespaces.
/**
   * Attempt to register any unregistered extension namespaces.
   */
  public void registerUnregisteredNamespaces()
  {
    for (int i = 0; i < m_unregisteredExtensions.size(); i++)
    {
      String ns = (String)m_unregisteredExtensions.get(i);
      ExtensionNamespaceSupport extNsSpt = defineJavaNamespace(ns);
      if (extNsSpt != null)
        m_extensions.add(extNsSpt);
    }    
  }
  
    
For any extension namespace that is not either predefined or defined 
by a "component" declaration or exslt function declaration, attempt 
to create an ExtensionNamespaceSuport object for the appropriate 
Java class or Java package Extension Handler.
Called by StylesheetRoot.recompose(), after all ElemTemplate compose()
operations have taken place, in order to set up handlers for
the remaining extension namespaces.
Params:
ns – The extension namespace URI.
Throws:
TransformerException – 
Returns:
  An ExtensionNamespaceSupport object for this namespace
(which defines the ExtensionHandler to be used), or null if such 
an object cannot be created./**
   * For any extension namespace that is not either predefined or defined 
   * by a "component" declaration or exslt function declaration, attempt 
   * to create an ExtensionNamespaceSuport object for the appropriate 
   * Java class or Java package Extension Handler.
   * 
   * Called by StylesheetRoot.recompose(), after all ElemTemplate compose()
   * operations have taken place, in order to set up handlers for
   * the remaining extension namespaces.
   * 
   * @param ns The extension namespace URI.
   * @return   An ExtensionNamespaceSupport object for this namespace
   * (which defines the ExtensionHandler to be used), or null if such 
   * an object cannot be created. 
   *
   * @throws javax.xml.transform.TransformerException
   */
  public ExtensionNamespaceSupport defineJavaNamespace(String ns)
  {
    return defineJavaNamespace(ns, ns);
  }
  public ExtensionNamespaceSupport defineJavaNamespace(String ns, String classOrPackage)
  {
    if(null == ns || ns.trim().length() == 0) // defensive. I don't think it's needed.  -sb
      return null;

    // Prepare the name of the actual class or package, stripping
    // out any leading "class:".  Next, see if there is a /.  If so,
    // only look at the text to the right of the rightmost /.
    String className = classOrPackage;
    if (className.startsWith("class:"))
      className = className.substring(6);

    int lastSlash = className.lastIndexOf('/');
    if (-1 != lastSlash)
      className = className.substring(lastSlash + 1);
      
    // The className can be null here, and can cause an error in getClassForName
    // in JDK 1.8.
    if(null == className || className.trim().length() == 0) 
      return null;
    
    try
    {
      ExtensionHandler.getClassForName(className);
      return new ExtensionNamespaceSupport(
                           ns, 
                           "org.apache.xalan.extensions.ExtensionHandlerJavaClass",                                         
                           new Object[]{ns, "javaclass", className});
    }
    catch (ClassNotFoundException e)
    {
      return new ExtensionNamespaceSupport(
                            ns, 
                            "org.apache.xalan.extensions.ExtensionHandlerJavaPackage",
                            new Object[]{ns, "javapackage", className + "."});
    }
  }
  
/*
  public ExtensionNamespaceSupport getSupport(int index, Vector extensions)
  {
    return (ExtensionNamespaceSupport)extensions.elementAt(index);
  }
*/
  
  
  
Set up a Vector for predefined extension namespaces.
/**
   * Set up a Vector for predefined extension namespaces.
   */
  private void setPredefinedNamespaces()
  {    
    String uri = Constants.S_EXTENSIONS_JAVA_URL;
    String handlerClassName = "org.apache.xalan.extensions.ExtensionHandlerJavaPackage";
    String lang = "javapackage";
    String lib = "";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
   
    uri = Constants.S_EXTENSIONS_OLD_JAVA_URL;
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
    
    uri = Constants.S_EXTENSIONS_LOTUSXSL_JAVA_URL;
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
    
    uri = Constants.S_BUILTIN_EXTENSIONS_URL;
    handlerClassName = "org.apache.xalan.extensions.ExtensionHandlerJavaClass";
    lang = "javaclass"; // for remaining predefined extension namespaces.    
    lib = "org.apache.xalan.lib.Extensions";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
    
    uri = Constants.S_BUILTIN_OLD_EXTENSIONS_URL;
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
    
    // Xalan extension namespaces (redirect, pipe and SQL).
    uri = Constants.S_EXTENSIONS_REDIRECT_URL;
    lib = "org.apache.xalan.lib.Redirect";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
 
    uri = Constants.S_EXTENSIONS_PIPE_URL;
    lib = "org.apache.xalan.lib.PipeDocument";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
 
    uri = Constants.S_EXTENSIONS_SQL_URL;
    lib = "org.apache.xalan.lib.sql.XConnection";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
 
    
    //EXSLT namespaces (not including EXSLT function namespaces which are
    // registered by the associated ElemFunction.
    uri = Constants.S_EXSLT_COMMON_URL;
    lib = "org.apache.xalan.lib.ExsltCommon";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));

    uri = Constants.S_EXSLT_MATH_URL;
    lib = "org.apache.xalan.lib.ExsltMath";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
    
    uri = Constants.S_EXSLT_SETS_URL;
    lib = "org.apache.xalan.lib.ExsltSets";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
    
    uri = Constants.S_EXSLT_DATETIME_URL;
    lib = "org.apache.xalan.lib.ExsltDatetime";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));
                                             
    uri = Constants.S_EXSLT_DYNAMIC_URL;
    lib = "org.apache.xalan.lib.ExsltDynamic";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));

    uri = Constants.S_EXSLT_STRINGS_URL;
    lib = "org.apache.xalan.lib.ExsltStrings";
    m_predefExtensions.add(new ExtensionNamespaceSupport(uri, handlerClassName,
                                             new Object[]{uri, lang, lib}));                                             
  }    
  
}