/*
    * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
    *
    * This software is open source.
    * See the bottom of this file for the licence.
    */
   
   package org.dom4j.io;
   
  import java.io.File;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.io.OutputStream;
  import java.io.StringWriter;
  import java.io.Writer;
  import java.util.Iterator;
  
  import javax.xml.namespace.QName;
  import javax.xml.stream.XMLEventFactory;
  import javax.xml.stream.XMLOutputFactory;
  import javax.xml.stream.XMLStreamException;
  import javax.xml.stream.events.Characters;
  import javax.xml.stream.events.DTD;
  import javax.xml.stream.events.EndDocument;
  import javax.xml.stream.events.EndElement;
  import javax.xml.stream.events.EntityReference;
  import javax.xml.stream.events.ProcessingInstruction;
  import javax.xml.stream.events.StartDocument;
  import javax.xml.stream.events.StartElement;
  import javax.xml.stream.util.XMLEventConsumer;
  
  import org.dom4j.Attribute;
  import org.dom4j.Branch;
  import org.dom4j.CDATA;
  import org.dom4j.Comment;
  import org.dom4j.Document;
  import org.dom4j.DocumentType;
  import org.dom4j.Element;
  import org.dom4j.Entity;
  import org.dom4j.Namespace;
  import org.dom4j.Node;
  import org.dom4j.Text;
  
  /***
   * Writes DOM4J {@link Node}s to a StAX event stream. In addition the
   * <code>createXXX</code> methods are provided to directly create STAX events
   * from DOM4J nodes.
   * 
   * @author Christian Niles
   */
  public class STAXEventWriter {
      /*** The event stream to which events are written. */
      private XMLEventConsumer consumer;
  
      /*** The event factory used to construct events. */
      private XMLEventFactory factory = XMLEventFactory.newInstance();
  
      private XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();
  
      public STAXEventWriter() {
      }
  
      /***
       * Constructs a <code>STAXEventWriter</code> that writes events to the
       * provided file.
       * 
       * @param file
       *            The file to which events will be written.
       * 
       * @throws XMLStreamException
       *             If an error occurs creating an event writer from the file.
       * @throws IOException
       *             If an error occurs openin the file for writing.
       */
      public STAXEventWriter(File file) throws XMLStreamException, IOException {
          consumer = outputFactory.createXMLEventWriter(new FileWriter(file));
      }
  
      /***
       * Constructs a <code>STAXEventWriter</code> that writes events to the
       * provided character stream.
       * 
       * @param writer
       *            The character stream to which events will be written.
       * 
       * @throws XMLStreamException
       *             If an error occurs constructing an event writer from the
       *             character stream.
       */
      public STAXEventWriter(Writer writer) throws XMLStreamException {
          consumer = outputFactory.createXMLEventWriter(writer);
      }
  
      /***
       * Constructs a <code>STAXEventWriter</code> that writes events to the
       * provided stream.
       * 
       * @param stream
       *            The output stream to which events will be written.
      * 
      * @throws XMLStreamException
      *             If an error occurs constructing an event writer from the
      *             stream.
      */
     public STAXEventWriter(OutputStream stream) throws XMLStreamException {
         consumer = outputFactory.createXMLEventWriter(stream);
     }
 
     /***
      * Constructs a <code>STAXEventWriter</code> that writes events to the
      * provided event stream.
      * 
      * @param consumer
      *            The event stream to which events will be written.
      */
     public STAXEventWriter(XMLEventConsumer consumer) {
         this.consumer = consumer;
     }
 
     /***
      * Returns a reference to the underlying event consumer to which events are
      * written.
      * 
      * @return The underlying event consumer to which events are written.
      */
     public XMLEventConsumer getConsumer() {
         return consumer;
     }
 
     /***
      * Sets the underlying event consumer to which events are written.
      * 
      * @param consumer
      *            The event consumer to which events should be written.
      */
     public void setConsumer(XMLEventConsumer consumer) {
         this.consumer = consumer;
     }
 
     /***
      * Returns a reference to the event factory used to construct STAX events.
      * 
      * @return The event factory used to construct STAX events.
      */
     public XMLEventFactory getEventFactory() {
         return factory;
     }
 
     /***
      * Sets the event factory used to construct STAX events.
      * 
      * @param eventFactory
      *            The new event factory.
      */
     public void setEventFactory(XMLEventFactory eventFactory) {
         this.factory = eventFactory;
     }
 
     /***
      * Writes a DOM4J {@link Node}to the stream. This method is simply a
      * gateway to the overloaded methods such as {@link#writeElement(Element)}.
      * 
      * @param n
      *            The DOM4J {@link Node}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeNode(Node n) throws XMLStreamException {
         switch (n.getNodeType()) {
             case Node.ELEMENT_NODE:
                 writeElement((Element) n);
 
                 break;
 
             case Node.TEXT_NODE:
                 writeText((Text) n);
 
                 break;
 
             case Node.ATTRIBUTE_NODE:
                 writeAttribute((Attribute) n);
 
                 break;
 
             case Node.NAMESPACE_NODE:
                 writeNamespace((Namespace) n);
 
                 break;
 
             case Node.COMMENT_NODE:
                 writeComment((Comment) n);
 
                 break;
 
             case Node.CDATA_SECTION_NODE:
                 writeCDATA((CDATA) n);
 
                 break;
 
             case Node.PROCESSING_INSTRUCTION_NODE:
                 writeProcessingInstruction((org.dom4j.ProcessingInstruction) n);
 
                 break;
 
             case Node.ENTITY_REFERENCE_NODE:
                 writeEntity((Entity) n);
 
                 break;
 
             case Node.DOCUMENT_NODE:
                 writeDocument((Document) n);
 
                 break;
 
             case Node.DOCUMENT_TYPE_NODE:
                 writeDocumentType((DocumentType) n);
 
                 break;
 
             default:
                 throw new XMLStreamException("Unsupported DOM4J Node: " + n);
         }
     }
 
     /***
      * Writes each child node within the provided {@link Branch}instance. This
      * method simply iterates through the {@link Branch}'s nodes and calls
      * {@link #writeNode(Node)}.
      * 
      * @param branch
      *            The node whose children will be written to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeChildNodes(Branch branch) throws XMLStreamException {
         for (int i = 0, s = branch.nodeCount(); i < s; i++) {
             Node n = branch.node(i);
             writeNode(n);
         }
     }
 
     /***
      * Writes a DOM4J {@link Element}node and its children to the stream.
      * 
      * @param elem
      *            The {@link Element}node to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeElement(Element elem) throws XMLStreamException {
         consumer.add(createStartElement(elem));
         writeChildNodes(elem);
         consumer.add(createEndElement(elem));
     }
 
     /***
      * Constructs a STAX {@link StartElement}event from a DOM4J {@link
      * Element}.
      * 
      * @param elem
      *            The {@link Element}from which to construct the event.
      * 
      * @return The newly constructed {@link StartElement}event.
      */
     public StartElement createStartElement(Element elem) {
         // create name
         QName tagName = createQName(elem.getQName());
 
         // create attribute & namespace iterators
         Iterator attrIter = new AttributeIterator(elem.attributeIterator());
         Iterator nsIter = new NamespaceIterator(elem.declaredNamespaces()
                 .iterator());
 
         // create start event
         return factory.createStartElement(tagName, attrIter, nsIter);
     }
 
     /***
      * Constructs a STAX {@link EndElement}event from a DOM4J {@link Element}.
      * 
      * @param elem
      *            The {@link Element}from which to construct the event.
      * 
      * @return The newly constructed {@link EndElement}event.
      */
     public EndElement createEndElement(Element elem) {
         QName tagName = createQName(elem.getQName());
         Iterator nsIter = new NamespaceIterator(elem.declaredNamespaces()
                 .iterator());
 
         return factory.createEndElement(tagName, nsIter);
     }
 
     /***
      * Writes a DOM4J {@link Attribute}to the stream.
      * 
      * @param attr
      *            The {@link Attribute}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeAttribute(Attribute attr) throws XMLStreamException {
         consumer.add(createAttribute(attr));
     }
 
     /***
      * Constructs a STAX {@link javax.xml.stream.events.Attribute}event from a
      * DOM4J {@link Attribute}.
      * 
      * @param attr
      *            The {@link Attribute}from which to construct the event.
      * 
      * @return The newly constructed {@link javax.xml.stream.events.Attribute}
      *         event.
      */
     public javax.xml.stream.events.Attribute createAttribute(Attribute attr) {
         QName attrName = createQName(attr.getQName());
         String value = attr.getValue();
 
         return factory.createAttribute(attrName, value);
     }
 
     /***
      * Writes a DOM4J {@link Namespace}to the stream.
      * 
      * @param ns
      *            The {@link Namespace}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeNamespace(Namespace ns) throws XMLStreamException {
         consumer.add(createNamespace(ns));
     }
 
     /***
      * Constructs a STAX {@link javax.xml.stream.events.Namespace}event from a
      * DOM4J {@link Namespace}.
      * 
      * @param ns
      *            The {@link Namespace}from which to construct the event.
      * 
      * @return The constructed {@link javax.xml.stream.events.Namespace}event.
      */
     public javax.xml.stream.events.Namespace createNamespace(Namespace ns) {
         String prefix = ns.getPrefix();
         String uri = ns.getURI();
 
         return factory.createNamespace(prefix, uri);
     }
 
     /***
      * Writes a DOM4J {@link Text}to the stream.
      * 
      * @param text
      *            The {@link Text}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeText(Text text) throws XMLStreamException {
         consumer.add(createCharacters(text));
     }
 
     /***
      * Constructs a STAX {@link Characters}event from a DOM4J {@link Text}.
      * 
      * @param text
      *            The {@link Text}from which to construct the event.
      * 
      * @return The constructed {@link Characters}event.
      */
     public Characters createCharacters(Text text) {
         return factory.createCharacters(text.getText());
     }
 
     /***
      * Writes a DOM4J {@link CDATA}to the event stream.
      * 
      * @param cdata
      *            The {@link CDATA}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeCDATA(CDATA cdata) throws XMLStreamException {
         consumer.add(createCharacters(cdata));
     }
 
     /***
      * Constructs a STAX {@link Characters}event from a DOM4J {@link CDATA}.
      * 
      * @param cdata
      *            The {@link CDATA}from which to construct the event.
      * 
      * @return The newly constructed {@link Characters}event.
      */
     public Characters createCharacters(CDATA cdata) {
         return factory.createCData(cdata.getText());
     }
 
     /***
      * Writes a DOM4J {@link Comment}to the stream.
      * 
      * @param comment
      *            The {@link Comment}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeComment(Comment comment) throws XMLStreamException {
         consumer.add(createComment(comment));
     }
 
     /***
      * Constructs a STAX {@link javax.xml.stream.events.Comment}event from a
      * DOM4J {@link Comment}.
      * 
      * @param comment
      *            The {@link Comment}from which to construct the event.
      * 
      * @return The constructed {@link javax.xml.stream.events.Comment}event.
      */
     public javax.xml.stream.events.Comment createComment(Comment comment) {
         return factory.createComment(comment.getText());
     }
 
     /***
      * Writes a DOM4J {@link ProcessingInstruction}to the stream.
      * 
      * @param pi
      *            The {@link ProcessingInstruction}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeProcessingInstruction(org.dom4j.ProcessingInstruction pi)
             throws XMLStreamException {
         consumer.add(createProcessingInstruction(pi));
     }
 
     /***
      * Constructs a STAX {@link javax.xml.stream.events.ProcessingInstruction}
      * event from a DOM4J {@link ProcessingInstruction}.
      * 
      * @param pi
      *            The {@link ProcessingInstruction}from which to construct the
      *            event.
      * 
      * @return The constructed {@link
      *         javax.xml.stream.events.ProcessingInstruction} event.
      */
     public ProcessingInstruction createProcessingInstruction(
             org.dom4j.ProcessingInstruction pi) {
         String target = pi.getTarget();
         String data = pi.getText();
 
         return factory.createProcessingInstruction(target, data);
     }
 
     /***
      * Writes a DOM4J {@link Entity}to the stream.
      * 
      * @param entity
      *            The {@link Entity}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeEntity(Entity entity) throws XMLStreamException {
         consumer.add(createEntityReference(entity));
     }
 
     /***
      * Constructs a STAX {@link EntityReference}event from a DOM4J {@link
      * Entity}.
      * 
      * @param entity
      *            The {@link Entity}from which to construct the event.
      * 
      * @return The constructed {@link EntityReference}event.
      */
     private EntityReference createEntityReference(Entity entity) {
         return factory.createEntityReference(entity.getName(), null);
     }
 
     /***
      * Writes a DOM4J {@link DocumentType}to the stream.
      * 
      * @param docType
      *            The {@link DocumentType}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeDocumentType(DocumentType docType)
             throws XMLStreamException {
         consumer.add(createDTD(docType));
     }
 
     /***
      * Constructs a STAX {@link DTD}event from a DOM4J {@link DocumentType}.
      * 
      * @param docType
      *            The {@link DocumentType}from which to construct the event.
      * 
      * @return The constructed {@link DTD}event.
      * 
      * @throws RuntimeException
      *             DOCUMENT ME!
      */
     public DTD createDTD(DocumentType docType) {
         StringWriter decl = new StringWriter();
 
         try {
             docType.write(decl);
         } catch (IOException e) {
             throw new RuntimeException("Error writing DTD", e);
         }
 
         return factory.createDTD(decl.toString());
     }
 
     /***
      * Writes a DOM4J {@link Document}node, and all its contents, to the
      * stream.
      * 
      * @param doc
      *            The {@link Document}to write to the stream.
      * 
      * @throws XMLStreamException
      *             If an error occurs writing to the stream.
      */
     public void writeDocument(Document doc) throws XMLStreamException {
         consumer.add(createStartDocument(doc));
 
         writeChildNodes(doc);
 
         consumer.add(createEndDocument(doc));
     }
 
     /***
      * Constructs a STAX {@link StartDocument}event from a DOM4J {@link
      * Document}.
      * 
      * @param doc
      *            The {@link Document}from which to construct the event.
      * 
      * @return The constructed {@link StartDocument}event.
      */
     public StartDocument createStartDocument(Document doc) {
         String encoding = doc.getXMLEncoding();
 
         if (encoding != null) {
             return factory.createStartDocument(encoding);
         } else {
             return factory.createStartDocument();
         }
     }
 
     /***
      * Constructs a STAX {@link EndDocument}event from a DOM4J {@link
      * Document}.
      * 
      * @param doc
      *            The {@link Document}from which to construct the event.
      * 
      * @return The constructed {@link EndDocument}event.
      */
     public EndDocument createEndDocument(Document doc) {
         return factory.createEndDocument();
     }
 
     /***
      * Constructs a STAX {@link QName}from a DOM4J {@link org.dom4j.QName}.
      * 
      * @param qname
      *            The {@link org.dom4j.QName}from which to construct the STAX
      *            {@link QName}.
      * 
      * @return The constructed {@link QName}.
      */
     public QName createQName(org.dom4j.QName qname) {
         return new QName(qname.getNamespaceURI(), qname.getName(), qname
                 .getNamespacePrefix());
     }
 
     /***
      * Internal {@link Iterator}implementation used to pass DOM4J {@link
      * Attribute}s to the stream.
      */
     private class AttributeIterator implements Iterator {
         /*** The underlying DOm4J attribute iterator. */
         private Iterator iter;
 
         public AttributeIterator(Iterator iter) {
             this.iter = iter;
         }
 
         public boolean hasNext() {
             return iter.hasNext();
         }
 
         public Object next() {
             Attribute attr = (Attribute) iter.next();
             QName attrName = createQName(attr.getQName());
             String value = attr.getValue();
 
             return factory.createAttribute(attrName, value);
         }
 
         public void remove() {
             throw new UnsupportedOperationException();
         }
     }
 
     /***
      * Internal {@link Iterator}implementation used to pass DOM4J {@link
      * Namespace}s to the stream.
      */
     private class NamespaceIterator implements Iterator {
         private Iterator iter;
 
         public NamespaceIterator(Iterator iter) {
             this.iter = iter;
         }
 
         public boolean hasNext() {
             return iter.hasNext();
         }
 
         public Object next() {
             Namespace ns = (Namespace) iter.next();
             String prefix = ns.getPrefix();
             String nsURI = ns.getURI();
 
             return factory.createNamespace(prefix, nsURI);
         }
 
         public void remove() {
             throw new UnsupportedOperationException();
         }
     }
 }
 
 /*
  * Redistribution and use of this software and associated documentation
  * ("Software"), with or without modification, are permitted provided that the
  * following conditions are met:
  * 
  * 1. Redistributions of source code must retain copyright statements and
  * notices. Redistributions must also contain a copy of this document.
  * 
  * 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 name "DOM4J" must not be used to endorse or promote products derived
  * from this Software without prior written permission of MetaStuff, Ltd. For
  * written permission, please contact dom4j-info@metastuff.com.
  * 
  * 4. Products derived from this Software may not be called "DOM4J" nor may
  * "DOM4J" appear in their names without prior written permission of MetaStuff,
  * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
  * 
  * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
  * 
  * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``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 METASTUFF, LTD. 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.
  * 
  * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
  */