/*
 * 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.
 */
/*
 * $Id$
 */

package org.apache.xml.dtm.ref.dom2dtm;

import org.apache.xml.dtm.DTMException;

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.TypeInfo;
import org.w3c.dom.UserDataHandler;
import org.w3c.dom.DOMException;

/** This is a kluge to let us shove a declaration for xml: into the
 * DOM2DTM model.  Basically, it creates a proxy node in DOM space to
 * carry the additional information. This is _NOT_ a full DOM
 * implementation, and shouldn't be one since it sits alongside the
 * DOM rather than becoming part of the DOM model.
 * 
 * (This used to be an internal class within DOM2DTM. Moved out because
 * I need to perform an instanceof operation on it to support a temporary
 * workaround in DTMManagerDefault.)
 * 
 * %REVIEW% What if the DOM2DTM was built around a DocumentFragment and
 * there isn't a single root element? I think this fails that case...
 * 
 * %REVIEW% An alternative solution would be to create the node _only_
 * in DTM space, but given how DOM2DTM is currently written I think
 * this is simplest.
 * */
public class DOM2DTMdefaultNamespaceDeclarationNode implements Attr,TypeInfo
{
  final String NOT_SUPPORTED_ERR="Unsupported operation on pseudonode";
  
  Element pseudoparent;
  String prefix,uri,nodename;
  int handle;
  DOM2DTMdefaultNamespaceDeclarationNode(Element pseudoparent,String prefix,String uri,int handle)
  {
    this.pseudoparent=pseudoparent;
    this.prefix=prefix;
    this.uri=uri;
    this.handle=handle;
    this.nodename="xmlns:"+prefix;
  }
  public String getNodeName() {return nodename;}
  public String getName() {return nodename;}
  public String getNamespaceURI() {return "http://www.w3.org/2000/xmlns/";}
  public String getPrefix() {return prefix;}
  public String getLocalName() {return prefix;}
  public String getNodeValue() {return uri;}
  public String getValue() {return uri;}
  public Element getOwnerElement() {return pseudoparent;}
  
  public boolean isSupported(String feature, String version) {return false;}
  public boolean hasChildNodes() {return false;}
  public boolean hasAttributes() {return false;}
  public Node getParentNode() {return null;}
  public Node getFirstChild() {return null;}
  public Node getLastChild() {return null;}
  public Node getPreviousSibling() {return null;}
  public Node getNextSibling() {return null;}
  public boolean getSpecified() {return false;}
  public void normalize() {return;}
  public NodeList getChildNodes() {return null;}
  public NamedNodeMap getAttributes() {return null;}
  public short getNodeType() {return Node.ATTRIBUTE_NODE;}
  public void setNodeValue(String value) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public void setValue(String value) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public void setPrefix(String value) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Node insertBefore(Node a, Node b) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Node replaceChild(Node a, Node b) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Node appendChild(Node a) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Node removeChild(Node a) {throw new DTMException(NOT_SUPPORTED_ERR);}
  public Document getOwnerDocument() {return pseudoparent.getOwnerDocument();}
  public Node cloneNode(boolean deep) {throw new DTMException(NOT_SUPPORTED_ERR);}
	
    /** Non-DOM method, part of the temporary kluge
     * %REVIEW% This would be a pruning problem, but since it will always be
     * added to the root element and we prune on elements, we shouldn't have 
     * to worry.
     */
    public int getHandleOfNode()		
    {
        return handle;
    }

    //RAMESH: PENDING=> Add proper implementation for the below DOM L3 additions

    /**
     * @see org.w3c.dom.TypeInfo#getTypeName()
     */
    public String getTypeName() {return null; }
     
    /**
     * @see org.w3c.dom.TypeInfo#getTypeNamespace()
     */
    public String getTypeNamespace() { return null;}
    
    /**
     * @see or.gw3c.dom.TypeInfo#isDerivedFrom(String,String,int)
     */
    public boolean isDerivedFrom( String ns, String localName, int derivationMethod ) {
        return false;
    }

    public TypeInfo getSchemaTypeInfo() { return this; }
    
    public boolean isId( ) { return false; }

    /**
     * Associate an object to a key on this node. The object can later be
     * retrieved from this node by calling <code>getUserData</code> with the
     * same key.
     * @param key The key to associate the object to.
     * @param data The object to associate to the given key, or
     *   <code>null</code> to remove any existing association to that key.
     * @param handler The handler to associate to that key, or
     *   <code>null</code>.
     * @return Returns the <code>DOMObject</code> previously associated to
     *   the given key on this node, or <code>null</code> if there was none.
     * @since DOM Level 3
     */
    public Object setUserData(String key,
                              Object data,
                              UserDataHandler handler) {
        return getOwnerDocument().setUserData( key, data, handler);
    }

    /**
     * Retrieves the object associated to a key on a this node. The object
     * must first have been set to this node by calling
     * <code>setUserData</code> with the same key.
     * @param key The key the object is associated to.
     * @return Returns the <code>DOMObject</code> associated to the given key
     *   on this node, or <code>null</code> if there was none.
     * @since DOM Level 3
     */
    public Object getUserData(String key) {
        return getOwnerDocument().getUserData( key);
    } 

    /**
     *  This method returns a specialized object which implements the
     * specialized APIs of the specified feature and version. The
     * specialized object may also be obtained by using binding-specific
     * casting methods but is not necessarily expected to, as discussed in Mixed DOM implementations.
     * @param feature The name of the feature requested (case-insensitive).
     * @param version  This is the version number of the feature to test. If
     *   the version is <code>null</code> or the empty string, supporting
     *   any version of the feature will cause the method to return an
     *   object that supports at least one version of the feature.
     * @return  Returns an object which implements the specialized APIs of
     *   the specified feature and version, if any, or <code>null</code> if
     *   there is no object which implements interfaces associated with that
     *   feature. If the <code>DOMObject</code> returned by this method
     *   implements the <code>Node</code> interface, it must delegate to the
     *   primary core <code>Node</code> and not return results inconsistent
     *   with the primary core <code>Node</code> such as attributes,
     *   childNodes, etc.
     * @since DOM Level 3
     */
    public Object getFeature(String feature, String version) {
        // we don't have any alternate node, either this node does the job
        // or we don't have anything that does
        return isSupported(feature, version) ? this : null;
    }

    /**
     * Tests whether two nodes are equal.
     * <br>This method tests for equality of nodes, not sameness (i.e.,
     * whether the two nodes are references to the same object) which can be
     * tested with <code>Node.isSameNode</code>. All nodes that are the same
     * will also be equal, though the reverse may not be true.
     * <br>Two nodes are equal if and only if the following conditions are
     * satisfied: The two nodes are of the same type.The following string
     * attributes are equal: <code>nodeName</code>, <code>localName</code>,
     * <code>namespaceURI</code>, <code>prefix</code>, <code>nodeValue</code>
     * , <code>baseURI</code>. This is: they are both <code>null</code>, or
     * they have the same length and are character for character identical.
     * The <code>attributes</code> <code>NamedNodeMaps</code> are equal.
     * This is: they are both <code>null</code>, or they have the same
     * length and for each node that exists in one map there is a node that
     * exists in the other map and is equal, although not necessarily at the
     * same index.The <code>childNodes</code> <code>NodeLists</code> are
     * equal. This is: they are both <code>null</code>, or they have the
     * same length and contain equal nodes at the same index. This is true
     * for <code>Attr</code> nodes as for any other type of node. Note that
     * normalization can affect equality; to avoid this, nodes should be
     * normalized before being compared.
     * <br>For two <code>DocumentType</code> nodes to be equal, the following
     * conditions must also be satisfied: The following string attributes
     * are equal: <code>publicId</code>, <code>systemId</code>,
     * <code>internalSubset</code>.The <code>entities</code>
     * <code>NamedNodeMaps</code> are equal.The <code>notations</code>
     * <code>NamedNodeMaps</code> are equal.
     * <br>On the other hand, the following do not affect equality: the
     * <code>ownerDocument</code> attribute, the <code>specified</code>
     * attribute for <code>Attr</code> nodes, the
     * <code>isWhitespaceInElementContent</code> attribute for
     * <code>Text</code> nodes, as well as any user data or event listeners
     * registered on the nodes.
     * @param arg The node to compare equality with.
     * @param deep If <code>true</code>, recursively compare the subtrees; if
     *   <code>false</code>, compare only the nodes themselves (and its
     *   attributes, if it is an <code>Element</code>).
     * @return If the nodes, and possibly subtrees are equal,
     *   <code>true</code> otherwise <code>false</code>.
     * @since DOM Level 3
     */
    public boolean isEqualNode(Node arg) {
        if (arg == this) {
            return true;
        }
        if (arg.getNodeType() != getNodeType()) {
            return false;
        }
        // in theory nodeName can't be null but better be careful
        // who knows what other implementations may be doing?...
        if (getNodeName() == null) {
            if (arg.getNodeName() != null) {
                return false;
            }
        }
        else if (!getNodeName().equals(arg.getNodeName())) {
            return false;
        }

        if (getLocalName() == null) {
            if (arg.getLocalName() != null) {
                return false;
            }
        }
        else if (!getLocalName().equals(arg.getLocalName())) {
            return false;
        }

        if (getNamespaceURI() == null) {
            if (arg.getNamespaceURI() != null) {
                return false;
            }
        }
        else if (!getNamespaceURI().equals(arg.getNamespaceURI())) {
            return false;
        }

        if (getPrefix() == null) {
            if (arg.getPrefix() != null) {
                return false;
            }
        }
        else if (!getPrefix().equals(arg.getPrefix())) {
            return false;
        }

        if (getNodeValue() == null) {
            if (arg.getNodeValue() != null) {
                return false;
            }
        }
        else if (!getNodeValue().equals(arg.getNodeValue())) {
            return false;
        }
    /*
        if (getBaseURI() == null) {
            if (((NodeImpl) arg).getBaseURI() != null) {
                return false;
            }
        }
        else if (!getBaseURI().equals(((NodeImpl) arg).getBaseURI())) {
            return false;
        }
*/

             return true;
    }

    /**
     * DOM Level 3 - Experimental:
     * Look up the namespace URI associated to the given prefix, starting from this node.
     * Use lookupNamespaceURI(null) to lookup the default namespace
     *
     * @param namespaceURI
     * @return th URI for the namespace
     * @since DOM Level 3
     */
    public String lookupNamespaceURI(String specifiedPrefix) {
        short type = this.getNodeType();
        switch (type) {
        case Node.ELEMENT_NODE : {

                String namespace = this.getNamespaceURI();
                String prefix = this.getPrefix();
                if (namespace !=null) {
                    // REVISIT: is it possible that prefix is empty string?
                    if (specifiedPrefix== null && prefix==specifiedPrefix) {
                        // looking for default namespace
                        return namespace;
                    } else if (prefix != null && prefix.equals(specifiedPrefix)) {
                        // non default namespace
                        return namespace;
                    }
                }
                if (this.hasAttributes()) {
                    NamedNodeMap map = this.getAttributes();
                    int length = map.getLength();
                    for (int i=0;i<length;i++) {
                        Node attr = map.item(i);
                        String attrPrefix = attr.getPrefix();
                        String value = attr.getNodeValue();
                        namespace = attr.getNamespaceURI();
                        if (namespace !=null && namespace.equals("http://www.w3.org/2000/xmlns/")) {
                            // at this point we are dealing with DOM Level 2 nodes only
                            if (specifiedPrefix == null &&
                                attr.getNodeName().equals("xmlns")) {
                                // default namespace
                                return value;
                            } else if (attrPrefix !=null &&
                                       attrPrefix.equals("xmlns") &&
                                       attr.getLocalName().equals(specifiedPrefix)) {
                 // non default namespace
                                return value;
                            }
                        }
                    }
                }
		/*
                NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                if (ancestor != null) {
                    return ancestor.lookupNamespaceURI(specifiedPrefix);
                }
		*/

                return null;


            }
/*
        case Node.DOCUMENT_NODE : {
                return((NodeImpl)((Document)this).getDocumentElement()).lookupNamespaceURI(specifiedPrefix) ;
            }
*/
        case Node.ENTITY_NODE :
        case Node.NOTATION_NODE:
        case Node.DOCUMENT_FRAGMENT_NODE:
        case Node.DOCUMENT_TYPE_NODE:
            // type is unknown
            return null;
        case Node.ATTRIBUTE_NODE:{
                if (this.getOwnerElement().getNodeType() == Node.ELEMENT_NODE) {
                    return getOwnerElement().lookupNamespaceURI(specifiedPrefix);

                }
                return null;
            }
        default:{
	   /*
                NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                if (ancestor != null) {
                    return ancestor.lookupNamespaceURI(specifiedPrefix);
                }
             */
                return null;
            }

        }
    }
    
    /**
     *  DOM Level 3: Experimental
     *  This method checks if the specified <code>namespaceURI</code> is the
     *  default namespace or not.
     *  @param namespaceURI The namespace URI to look for.
     *  @return  <code>true</code> if the specified <code>namespaceURI</code>
     *   is the default namespace, <code>false</code> otherwise.
     * @since DOM Level 3
     */
    public boolean isDefaultNamespace(String namespaceURI){
       /*
        // REVISIT: remove casts when DOM L3 becomes REC.
        short type = this.getNodeType();
        switch (type) {
        case Node.ELEMENT_NODE: {
            String namespace = this.getNamespaceURI();
            String prefix = this.getPrefix();

            // REVISIT: is it possible that prefix is empty string?
            if (prefix == null || prefix.length() == 0) {
                if (namespaceURI == null) {
                    return (namespace == namespaceURI);
                }
                return namespaceURI.equals(namespace);
            }
            if (this.hasAttributes()) {
                ElementImpl elem = (ElementImpl)this;
                NodeImpl attr = (NodeImpl)elem.getAttributeNodeNS("http://www.w3.org/2000/xmlns/", "xmlns");
                if (attr != null) {
                    String value = attr.getNodeValue();
                    if (namespaceURI == null) {
                        return (namespace == value);
                    }
                    return namespaceURI.equals(value);
                }
            }

            NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
            if (ancestor != null) {
                return ancestor.isDefaultNamespace(namespaceURI);
            }
            return false;
        }
        case Node.DOCUMENT_NODE:{
                return((NodeImpl)((Document)this).getDocumentElement()).isDefaultNamespace(namespaceURI);
            }

        case Node.ENTITY_NODE :
          case Node.NOTATION_NODE:
        case Node.DOCUMENT_FRAGMENT_NODE:
        case Node.DOCUMENT_TYPE_NODE:
            // type is unknown
            return false;
        case Node.ATTRIBUTE_NODE:{
                if (this.ownerNode.getNodeType() == Node.ELEMENT_NODE) {
                    return ownerNode.isDefaultNamespace(namespaceURI);

                }
                return false;
            }
        default:{  
                NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                if (ancestor != null) {
                    return ancestor.isDefaultNamespace(namespaceURI);
                }
                return false;
            }

        }
*/
        return false;


    }

    /**
     *
     * DOM Level 3 - Experimental:
     * Look up the prefix associated to the given namespace URI, starting from this node.
     *
     * @param namespaceURI
     * @return the prefix for the namespace
     */
    public String lookupPrefix(String namespaceURI){

        // REVISIT: When Namespaces 1.1 comes out this may not be true
        // Prefix can't be bound to null namespace
        if (namespaceURI == null) {
            return null;
        }

        short type = this.getNodeType();

        switch (type) {
/*
        case Node.ELEMENT_NODE: {

                String namespace = this.getNamespaceURI(); // to flip out children
                return lookupNamespacePrefix(namespaceURI, (ElementImpl)this);
            }

        case Node.DOCUMENT_NODE:{
                return((NodeImpl)((Document)this).getDocumentElement()).lookupPrefix(namespaceURI);
            }
*/
        case Node.ENTITY_NODE :
        case Node.NOTATION_NODE:
        case Node.DOCUMENT_FRAGMENT_NODE:
        case Node.DOCUMENT_TYPE_NODE:
            // type is unknown
            return null;
        case Node.ATTRIBUTE_NODE:{
                if (this.getOwnerElement().getNodeType() == Node.ELEMENT_NODE) {
                    return getOwnerElement().lookupPrefix(namespaceURI);

                }
                return null;
            }
        default:{ 
/*
                NodeImpl ancestor = (NodeImpl)getElementAncestor(this);
                if (ancestor != null) {
                    return ancestor.lookupPrefix(namespaceURI);
                }
*/
                return null;
            }
         }
    }

    /**
     * Returns whether this node is the same node as the given one.
     * <br>This method provides a way to determine whether two
     * <code>Node</code> references returned by the implementation reference
     * the same object. When two <code>Node</code> references are references
     * to the same object, even if through a proxy, the references may be
     * used completely interchangably, such that all attributes have the
     * same values and calling the same DOM method on either reference
     * always has exactly the same effect.
     * @param other The node to test against.
     * @return Returns <code>true</code> if the nodes are the same,
     *   <code>false</code> otherwise.
     * @since DOM Level 3
     */
    public boolean isSameNode(Node other) {
        // we do not use any wrapper so the answer is obvious
        return this == other;
    }

    /**
     * This attribute returns the text content of this node and its
     * descendants. When it is defined to be null, setting it has no effect.
     * When set, any possible children this node may have are removed and
     * replaced by a single <code>Text</code> node containing the string
     * this attribute is set to. On getting, no serialization is performed,
     * the returned string does not contain any markup. No whitespace
     * normalization is performed, the returned string does not contain the
     * element content whitespaces . Similarly, on setting, no parsing is
     * performed either, the input string is taken as pure textual content.
     * <br>The string returned is made of the text content of this node
     * depending on its type, as defined below:
     * <table border='1'>
     * <tr>
     * <th>Node type</th>
     * <th>Content</th>
     * </tr>
     * <tr>
     * <td valign='top' rowspan='1' colspan='1'>
     * ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE,
     * DOCUMENT_FRAGMENT_NODE</td>
     * <td valign='top' rowspan='1' colspan='1'>concatenation of the <code>textContent</code>
     * attribute value of every child node, excluding COMMENT_NODE and
     * PROCESSING_INSTRUCTION_NODE nodes</td>
     * </tr>
     * <tr>
     * <td valign='top' rowspan='1' colspan='1'>ATTRIBUTE_NODE, TEXT_NODE,
     * CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE</td>
     * <td valign='top' rowspan='1' colspan='1'>
     * <code>nodeValue</code></td>
     * </tr>
     * <tr>
     * <td valign='top' rowspan='1' colspan='1'>DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE</td>
     * <td valign='top' rowspan='1' colspan='1'>
     * null</td>
     * </tr>
     * </table>
     * @exception DOMException
     *   NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
     * @exception DOMException
     *   DOMSTRING_SIZE_ERR: Raised when it would return more characters than
     *   fit in a <code>DOMString</code> variable on the implementation
     *   platform.
     * @since DOM Level 3
     */
    public void setTextContent(String textContent)
        throws DOMException {
        setNodeValue(textContent);
    }
    
    /**
     * This attribute returns the text content of this node and its
     * descendants. When it is defined to be null, setting it has no effect.
     * When set, any possible children this node may have are removed and
     * replaced by a single <code>Text</code> node containing the string
     * this attribute is set to. On getting, no serialization is performed,
     * the returned string does not contain any markup. No whitespace
     * normalization is performed, the returned string does not contain the
     * element content whitespaces . Similarly, on setting, no parsing is
     * performed either, the input string is taken as pure textual content.
     * <br>The string returned is made of the text content of this node
     * depending on its type, as defined below:
     * <table border='1'>
     * <tr>
     * <th>Node type</th>
     * <th>Content</th>
     * </tr>
     * <tr>
     * <td valign='top' rowspan='1' colspan='1'>
     * ELEMENT_NODE, ENTITY_NODE, ENTITY_REFERENCE_NODE,
     * DOCUMENT_FRAGMENT_NODE</td>
     * <td valign='top' rowspan='1' colspan='1'>concatenation of the <code>textContent</code>
     * attribute value of every child node, excluding COMMENT_NODE and
     * PROCESSING_INSTRUCTION_NODE nodes</td>
     * </tr>
     * <tr>
     * <td valign='top' rowspan='1' colspan='1'>ATTRIBUTE_NODE, TEXT_NODE,
     * CDATA_SECTION_NODE, COMMENT_NODE, PROCESSING_INSTRUCTION_NODE</td>
     * <td valign='top' rowspan='1' colspan='1'>
     * <code>nodeValue</code></td>
     * </tr>
     * <tr>
     * <td valign='top' rowspan='1' colspan='1'>DOCUMENT_NODE, DOCUMENT_TYPE_NODE, NOTATION_NODE</td>
     * <td valign='top' rowspan='1' colspan='1'>
     * null</td>
     * </tr>
     * </table>
     * @exception DOMException
     *   NO_MODIFICATION_ALLOWED_ERR: Raised when the node is readonly.
     * @exception DOMException
     *   DOMSTRING_SIZE_ERR: Raised when it would return more characters than
     *   fit in a <code>DOMString</code> variable on the implementation
     *   platform.
     * @since DOM Level 3
     */
    public String getTextContent() throws DOMException {
        return getNodeValue();  // overriden in some subclasses
    }

    /**
     * Compares a node with this node with regard to their position in the
     * document.
     * @param other The node to compare against this node.
     * @return Returns how the given node is positioned relatively to this
     *   node.
     * @since DOM Level 3
     */
    public short compareDocumentPosition(Node other) throws DOMException {
        return 0;
    }

    /**
     * The absolute base URI of this node or <code>null</code> if undefined.
     * This value is computed according to . However, when the
     * <code>Document</code> supports the feature "HTML" , the base URI is
     * computed using first the value of the href attribute of the HTML BASE
     * element if any, and the value of the <code>documentURI</code>
     * attribute from the <code>Document</code> interface otherwise.
     * <br> When the node is an <code>Element</code>, a <code>Document</code>
     * or a a <code>ProcessingInstruction</code>, this attribute represents
     * the properties [base URI] defined in . When the node is a
     * <code>Notation</code>, an <code>Entity</code>, or an
     * <code>EntityReference</code>, this attribute represents the
     * properties [declaration base URI] in the . How will this be affected
     * by resolution of relative namespace URIs issue?It's not.Should this
     * only be on Document, Element, ProcessingInstruction, Entity, and
     * Notation nodes, according to the infoset? If not, what is it equal to
     * on other nodes? Null? An empty string? I think it should be the
     * parent's.No.Should this be read-only and computed or and actual
     * read-write attribute?Read-only and computed (F2F 19 Jun 2000 and
     * teleconference 30 May 2001).If the base HTML element is not yet
     * attached to a document, does the insert change the Document.baseURI?
     * Yes. (F2F 26 Sep 2001)
     * @since DOM Level 3
     */
    public String getBaseURI() {
        return null;
    }
}