
/*
 * Copyright  1999-2004 The Apache Software Foundation.
 *
 *  Licensed 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.xml.security.utils;



import java.io.IOException;
import java.io.OutputStream;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import org.apache.xml.security.c14n.CanonicalizationException;
import org.apache.xml.security.c14n.Canonicalizer;
import org.apache.xml.security.c14n.InvalidCanonicalizerException;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;



/**
 * DOM and XML accessibility and comfort functions.
 *
 * @author Christian Geuer-Pollmann
 */
public class XMLUtils {

   private static boolean ignoreLineBreaks = ((Boolean)
      AccessController.doPrivileged(new PrivilegedAction() {
         public Object run() {
            return Boolean.valueOf(Boolean.getBoolean
	       ("org.apache.xml.security.ignoreLineBreaks"));
         }
      })).booleanValue();
	
   /**
    * Constructor XMLUtils
    *
    */
   private XMLUtils() {

      // we don't allow instantiation
   }
   public static Element getNextElement(Node el) {
	   while ((el!=null) && (el.getNodeType()!=Node.ELEMENT_NODE)) {
		   el=el.getNextSibling();
	   }
	   return (Element)el;
	   
   }
   
   /**
    * @param rootNode
    * @param result
    * @param exclude
    * @param com wheather comments or not
    */   
   public static void getSet(Node rootNode,Set result,Node exclude ,boolean com) {
   	  if ((exclude!=null) && isDescendantOrSelf(exclude,rootNode)){
   	  	return;
      }
      getSetRec(rootNode,result,exclude,com);
   }
   static final void getSetRec(final Node rootNode,final Set result,
        final Node exclude ,final boolean com) {
   	   //Set result = new HashSet();
       if (rootNode==exclude) {
          return;
       }
   	   switch (rootNode.getNodeType()) {   	   		   	   			
   	   	case Node.ELEMENT_NODE:
   	   			result.add(rootNode);
   	   	        Element el=(Element)rootNode;
                if (el.hasAttributes()) {
   	   		        NamedNodeMap nl = ((Element)rootNode).getAttributes();
   	   		        for (int i=0;i<nl.getLength();i++) {
   	   		        	result.add(nl.item(i));
   	   		        }
                }
                //no return keep working
   	   	case Node.DOCUMENT_NODE:   	   			
   	   			for (Node r=rootNode.getFirstChild();r!=null;r=r.getNextSibling()){                                    
   	   				if (r.getNodeType()==Node.TEXT_NODE) {
   	   					result.add(r); 
   	   					while ((r!=null) && (r.getNodeType()==Node.TEXT_NODE)) {
   	   						r=r.getNextSibling();
   	   					}
   	   					if (r==null)
   	   						return;
   	   				}  
   	   				getSetRec(r,result,exclude,com);                
   	   			}
   	   			return;
   	   		case Node.COMMENT_NODE:
   	   			if (com) {
   	   				result.add(rootNode);
   	   			}
   	   		    return;
   	   		case Node.DOCUMENT_TYPE_NODE:
   	   			return;
   	   		default:
   	   			result.add(rootNode);
   	   }
   	   return;
   }


   /**
    * Outputs a DOM tree to an {@link OutputStream}.
    *
    * @param contextNode root node of the DOM tree
    * @param os the {@link OutputStream}
    */
   public static void outputDOM(Node contextNode, OutputStream os) {
      XMLUtils.outputDOM(contextNode, os, false);
   }

   /**
    * Outputs a DOM tree to an {@link OutputStream}. <I>If an Exception is
    * thrown during execution, it's StackTrace is output to System.out, but the
    * Exception is not re-thrown.</I>
    *
    * @param contextNode root node of the DOM tree
    * @param os the {@link OutputStream}
    * @param addPreamble
    */
   public static void outputDOM(Node contextNode, OutputStream os,
                                boolean addPreamble) {

      try {
         if (addPreamble) {
            os.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n".getBytes());
         }

         os.write(
            Canonicalizer.getInstance(
               Canonicalizer.ALGO_ID_C14N_WITH_COMMENTS).canonicalizeSubtree(
               contextNode));
      } catch (IOException ex) {}
      catch (InvalidCanonicalizerException ex) {
         ex.printStackTrace();
      } catch (CanonicalizationException ex) {
         ex.printStackTrace();
      }
   }

   /**
    * Serializes the <CODE>contextNode</CODE> into the OutputStream, <I>but
    * supresses all Exceptions</I>.
    * <BR />
    * NOTE: <I>This should only be used for debugging purposes,
    * NOT in a production environment; this method ignores all exceptions,
    * so you won't notice if something goes wrong. If you're asking what is to
    * be used in a production environment, simply use the code inside the
    * <code>try{}</code> statement, but handle the Exceptions appropriately.</I>
    *
    * @param contextNode
    * @param os
    */
   public static void outputDOMc14nWithComments(Node contextNode,
           OutputStream os) {

      try {
         os.write(
            Canonicalizer.getInstance(
               Canonicalizer.ALGO_ID_C14N_WITH_COMMENTS).canonicalizeSubtree(
               contextNode));
      } catch (IOException ex) {

         // throw new RuntimeException(ex.getMessage());
      } catch (InvalidCanonicalizerException ex) {

         // throw new RuntimeException(ex.getMessage());
      } catch (CanonicalizationException ex) {

         // throw new RuntimeException(ex.getMessage());
      }
   }

 
   /**
    * Method getFullTextChildrenFromElement
    *
    * @param element
    * @return the string of chi;ds
    */
   public static String getFullTextChildrenFromElement(Element element) {

      StringBuffer sb = new StringBuffer();
      NodeList children = element.getChildNodes();
      int iMax = children.getLength();

      for (int i = 0; i < iMax; i++) {
         Node curr = children.item(i);

         if (curr.getNodeType() == Node.TEXT_NODE) {
            sb.append(((Text) curr).getData());
         }
      }

      return sb.toString();
   }


   static  String dsPrefix=null;
   static Map namePrefixes=new HashMap();
   /**
    * Creates an Element in the XML Signature specification namespace.
    *
    * @param doc the factory Document
    * @param elementName the local name of the Element
    * @return the Element
    */
   public static Element createElementInSignatureSpace(Document doc,
           String elementName) {

      if (doc == null) {
         throw new RuntimeException("Document is null");
      }
     
      if ((dsPrefix == null) || (dsPrefix.length() == 0)) {
         return doc.createElementNS(Constants.SignatureSpecNS, elementName);
      } 
      String namePrefix=(String) namePrefixes.get(elementName);
      if (namePrefix==null) {
    	  StringBuffer tag=new StringBuffer(dsPrefix);
    	  tag.append(':');
    	  tag.append(elementName);
    	  namePrefix=tag.toString();
    	  namePrefixes.put(elementName,namePrefix);
      }
      return doc.createElementNS(Constants.SignatureSpecNS, namePrefix);
   }

   static  String xencPrefix=null;
   /**
    * Creates an Element in the XML Encryption specification namespace.
    *
    * @param doc the factory Document
    * @param elementName the local name of the Element
    * @return the Element
    */
   public static Element createElementInEncryptionSpace(Document doc,
           String elementName) {

      if (doc == null) {
         throw new RuntimeException("Document is null");
      }
     
      if ((xencPrefix == null) || (xencPrefix.length() == 0)) {
         return doc.createElementNS(EncryptionConstants.EncryptionSpecNS, elementName);
      } 
      String namePrefix=(String) namePrefixes.get(elementName);
      if (namePrefix==null) {
    	  StringBuffer tag=new StringBuffer(xencPrefix);
    	  tag.append(':');
    	  tag.append(elementName);
    	  namePrefix=tag.toString();
    	  namePrefixes.put(elementName,namePrefix);
      }
      return doc.createElementNS(EncryptionConstants.EncryptionSpecNS, namePrefix);
   }

   /**
    * Returns true if the element is in XML Signature namespace and the local
    * name equals the supplied one.
    *
    * @param element
    * @param localName
    * @return true if the element is in XML Signature namespace and the local name equals the supplied one
    */
   public static boolean elementIsInSignatureSpace(Element element,
           String localName) {
      return ElementProxy.checker.isNamespaceElement(element, localName, Constants.SignatureSpecNS);
   }

   /**
    * Returns true if the element is in XML Encryption namespace and the local
    * name equals the supplied one.
    *
    * @param element
    * @param localName
    * @return true if the element is in XML Encryption namespace and the local name equals the supplied one
    */
   public static boolean elementIsInEncryptionSpace(Element element,
           String localName) {
	   return ElementProxy.checker.isNamespaceElement(element, localName, EncryptionConstants.EncryptionSpecNS);
   }

   /**
    * This method returns the owner document of a particular node.
    * This method is necessary because it <I>always</I> returns a
    * {@link Document}. {@link Node#getOwnerDocument} returns <CODE>null</CODE>
    * if the {@link Node} is a {@link Document}.
    *
    * @param node
    * @return the owner document of the node
    */
   public static Document getOwnerDocument(Node node) {

      if (node.getNodeType() == Node.DOCUMENT_NODE) {
         return (Document) node;
      } 
         try {
            return node.getOwnerDocument();
         } catch (NullPointerException npe) {
            throw new NullPointerException(I18n.translate("endorsed.jdk1.4.0")
                                           + " Original message was \""
                                           + npe.getMessage() + "\"");
         }
      
   }

    /**
     * This method returns the first non-null owner document of the Node's in this Set.
     * This method is necessary because it <I>always</I> returns a
     * {@link Document}. {@link Node#getOwnerDocument} returns <CODE>null</CODE>
     * if the {@link Node} is a {@link Document}.
     *
     * @param xpathNodeSet
     * @return the owner document 
     */
    public static Document getOwnerDocument(Set xpathNodeSet) {
       NullPointerException npe = null;
       Iterator iterator = xpathNodeSet.iterator();
       while(iterator.hasNext()) {
           Node node = (Node) iterator.next();
           int nodeType =node.getNodeType();
           if (nodeType == Node.DOCUMENT_NODE) {
              return (Document) node;
           } 
              try {
                 if (nodeType==Node.ATTRIBUTE_NODE) {
                    return ((Attr)node).getOwnerElement().getOwnerDocument();  
                 }
                 return node.getOwnerDocument();
              } catch (NullPointerException e) {
                  npe = e;
              }
           
       }
       throw new NullPointerException(I18n.translate("endorsed.jdk1.4.0")
                                       + " Original message was \""
                                       + (npe == null ? "" : npe.getMessage()) + "\"");
    }
    
    /**
     * Method createDSctx
     *
     * @param doc
     * @param prefix
     * @param namespace
     * @return the element.
     */
    public static Element createDSctx(Document doc, String prefix,
                                      String namespace) {

       if ((prefix == null) || (prefix.trim().length() == 0)) {
          throw new IllegalArgumentException("You must supply a prefix");
       }

       Element ctx = doc.createElementNS(null, "namespaceContext");

       ctx.setAttributeNS(Constants.NamespaceSpecNS, "xmlns:" + prefix.trim(),
                          namespace);

       return ctx;
    }

   /**
    * Method addReturnToElement
    *
    * @param e
    */
   public static void addReturnToElement(Element e) {

      if (!ignoreLineBreaks) {
         Document doc = e.getOwnerDocument();
         e.appendChild(doc.createTextNode("\n"));
      }
   }

   public static void addReturnToElement(Document doc, HelperNodeList nl) {
      if (!ignoreLineBreaks) {
         nl.appendChild(doc.createTextNode("\n"));
      }
   }

   public static void addReturnBeforeChild(Element e, Node child) {
      if (!ignoreLineBreaks) {
         Document doc = e.getOwnerDocument();
         e.insertBefore(doc.createTextNode("\n"), child);
      }
   }

   /**
    * Method convertNodelistToSet
    *
    * @param xpathNodeSet
    * @return the set with the nodelist
    */
   public static Set convertNodelistToSet(NodeList xpathNodeSet) {

      if (xpathNodeSet == null) {
         return new HashSet();
      }

      int length = xpathNodeSet.getLength();
      Set set = new HashSet(length);

      for (int i = 0; i < length; i++) {
         set.add(xpathNodeSet.item(i));
      }

      return set;
   }


   /**
    * This method spreads all namespace attributes in a DOM document to their
    * children. This is needed because the XML Signature XPath transform
    * must evaluate the XPath against all nodes in the input, even against
    * XPath namespace nodes. Through a bug in XalanJ2, the namespace nodes are
    * not fully visible in the Xalan XPath model, so we have to do this by
    * hand in DOM spaces so that the nodes become visible in XPath space.
    *
    * @param doc
    * @see <A HREF="http://nagoya.apache.org/bugzilla/show_bug.cgi?id=2650">Namespace axis resolution is not XPath compliant </A>
    */
   public static void circumventBug2650(Document doc) {

      Element documentElement = doc.getDocumentElement();

      // if the document element has no xmlns definition, we add xmlns=""
      Attr xmlnsAttr =
         documentElement.getAttributeNodeNS(Constants.NamespaceSpecNS, "xmlns");

      if (xmlnsAttr == null) {
         documentElement.setAttributeNS(Constants.NamespaceSpecNS, "xmlns", "");
      }

      XMLUtils.circumventBug2650internal(doc);
   }

   /**
    * This is the work horse for {@link #circumventBug2650}.
    *
    * @param node
    * @see <A HREF="http://nagoya.apache.org/bugzilla/show_bug.cgi?id=2650">Namespace axis resolution is not XPath compliant </A>
    */
   private static void circumventBug2650internal(Node node) {
	   Node parent=null;
	   Node sibling=null;
	   final String namespaceNs=Constants.NamespaceSpecNS;
	   do {
         switch (node.getNodeType()) {
         case Node.ELEMENT_NODE :
        	 Element element = (Element) node;
             if (!element.hasChildNodes())
            	 break;
             if (element.hasAttributes()) {            	 
             NamedNodeMap attributes = element.getAttributes();         	
             int attributesLength = attributes.getLength();    
             
             for (Node child = element.getFirstChild(); child!=null; 
             	child=child.getNextSibling()) {            

             	if (child.getNodeType() != Node.ELEMENT_NODE) {
             		continue;
             	}
             	Element childElement = (Element) child;

             	for (int i = 0; i < attributesLength; i++) {
             		Attr currentAttr = (Attr) attributes.item(i); 
             		if (namespaceNs!=currentAttr.getNamespaceURI())
             			continue;
             		if (childElement.hasAttributeNS(namespaceNs,
    							currentAttr.getLocalName())) {
             				continue;
             		}
             		childElement.setAttributeNS(namespaceNs,
                                                currentAttr.getName(),
                                                currentAttr.getNodeValue());         					
             				
             			
             	}
             }            
             }
         case Node.ENTITY_REFERENCE_NODE :
         case Node.DOCUMENT_NODE :
        	 parent=node;
        	 sibling=node.getFirstChild();
             break;
         }
         while ((sibling==null) && (parent!=null)) {
        		 sibling=parent.getNextSibling();
        		 parent=parent.getParentNode();
        	 };
       if (sibling==null) {
        		 return;
        	 }
       	
         node=sibling;
         sibling=node.getNextSibling();
	   } while (true);
   }

   /**
    * @param sibling
    * @param nodeName
    * @param number
    * @return nodes with the constrain
    */
   public static Element selectDsNode(Node sibling, String nodeName, int number) {
	while (sibling!=null) {
		if (ElementProxy.checker.isNamespaceElement(sibling, nodeName, Constants.SignatureSpecNS )) {
			if (number==0){
				return (Element)sibling;
			}
			number--;
		}
		sibling=sibling.getNextSibling();
	}
	return null;
   }
   
   /**
    * @param sibling
    * @param nodeName
    * @param number
    * @return nodes with the constrain
    */

   public static Element selectXencNode(Node sibling, String nodeName, int number) {
	while (sibling!=null) {
		if (ElementProxy.checker.isNamespaceElement(sibling, nodeName, EncryptionConstants.EncryptionSpecNS )) {
			if (number==0){
				return (Element)sibling;
			}
			number--;
		}
		sibling=sibling.getNextSibling();
	}
	return null;
   }
   

   /**
    * @param sibling
    * @param nodeName
    * @param number
    * @return nodes with the constrain
    */
   public static Text selectDsNodeText(Node sibling, String nodeName, int number) {
   	    Node n=selectDsNode(sibling,nodeName,number);
        if (n==null) {
        	return null;
        }
        n=n.getFirstChild();
        while (n!=null && n.getNodeType()!=Node.TEXT_NODE) {
        	n=n.getNextSibling();
        }
        return (Text)n;
   }
   
   /**
    * @param sibling
    * @param uri
    * @param nodeName
    * @param number
    * @return nodes with the constrain
    */
   public static Text selectNodeText(Node sibling, String uri, String nodeName, int number) {
        Node n=selectNode(sibling,uri,nodeName,number);
    if (n==null) {
        return null;
    }
    n=n.getFirstChild();
    while (n!=null && n.getNodeType()!=Node.TEXT_NODE) {
        n=n.getNextSibling();
    }
    return (Text)n;
   }
   
   /**
    * @param sibling
    * @param uri
    * @param nodeName
    * @param number
    * @return nodes with the constrain
    */
   public static Element selectNode(Node sibling, String uri,String nodeName, int number) {
	while (sibling!=null) {
		if (ElementProxy.checker.isNamespaceElement(sibling, nodeName, uri)) {
			if (number==0){
				return (Element)sibling;
			}
			number--;
		}
		sibling=sibling.getNextSibling();
	}
	return null;
   }
   
   /**
    * @param sibling
    * @param nodeName    
    * @return nodes with the constrain
    */
   public static Element[] selectDsNodes(Node sibling,String nodeName) {
     return selectNodes(sibling,Constants.SignatureSpecNS,nodeName);
   }
   /**
    * @param sibling
    * @param uri
    * @param nodeName
    * @return nodes with the constrain
    */
    public static Element[] selectNodes(Node sibling,String uri,String nodeName) {
    	int size=20;
    	Element[] a= new Element[size];
    	int curr=0;
    	//List list=new ArrayList();
    	while (sibling!=null) {
    		if (ElementProxy.checker.isNamespaceElement(sibling, nodeName, uri)) {
    			a[curr++]=(Element)sibling;
    			if (size<=curr) {
    				int cursize= size<<2;
    				Element []cp=new Element[cursize];
    				System.arraycopy(a,0,cp,0,size);
    				a=cp;
    				size=cursize;
    			}   
    		}
    		sibling=sibling.getNextSibling();
    	}
    	Element []af=new Element[curr];
    	System.arraycopy(a,0,af,0,curr);
    	return af;
   }

   /**
    * @param signatureElement
    * @param inputSet
    * @return nodes with the constrain
    */
    public static Set excludeNodeFromSet(Node signatureElement, Set inputSet) {
	  Set resultSet = new HashSet();
	  Iterator iterator = inputSet.iterator();

	  while (iterator.hasNext()) {
	    Node inputNode = (Node) iterator.next();

	    if (!XMLUtils
	            .isDescendantOrSelf(signatureElement, inputNode)) {
	       resultSet.add(inputNode);
	    }
	 }
	 return resultSet;
     }

   /**
    * Returns true if the descendantOrSelf is on the descendant-or-self axis
    * of the context node.
    *
    * @param ctx
    * @param descendantOrSelf
    * @return true if the node is descendant
    */
   static public boolean isDescendantOrSelf(Node ctx, Node descendantOrSelf) {

      if (ctx == descendantOrSelf) {
         return true;
      }

      Node parent = descendantOrSelf;

      while (true) {
         if (parent == null) {
            return false;
         }

         if (parent == ctx) {
            return true;
         }

         if (parent.getNodeType() == Node.ATTRIBUTE_NODE) {
            parent = ((Attr) parent).getOwnerElement();
         } else {
            parent = parent.getParentNode();
         }
      }
   }

    public static boolean ignoreLineBreaks() {
        return ignoreLineBreaks;
    }
}
