/*
    * 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.
   */
  package org.apache.maven.internal.xml;
  
  import javax.xml.stream.XMLOutputFactory;
  import javax.xml.stream.XMLStreamException;
  import javax.xml.stream.XMLStreamWriter;
  
  import java.io.Writer;
  import java.util.Map;
  
  import org.apache.maven.api.xml.XmlNode;
  import org.codehaus.stax2.util.StreamWriterDelegate;
  
  /**
   *
   */
  public class XmlNodeWriter {
      public static void write(Writer writer, XmlNode dom) throws XMLStreamException {
          XMLOutputFactory factory = new com.ctc.wstx.stax.WstxOutputFactory();
          factory.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, false);
          factory.setProperty(com.ctc.wstx.api.WstxOutputProperties.P_USE_DOUBLE_QUOTES_IN_XML_DECL, true);
          factory.setProperty(com.ctc.wstx.api.WstxOutputProperties.P_ADD_SPACE_AFTER_EMPTY_ELEM, true);
          XMLStreamWriter serializer = new IndentingXMLStreamWriter(factory.createXMLStreamWriter(writer));
          write(serializer, dom);
          serializer.close();
      }
  
      public static void write(XMLStreamWriter xmlWriter, XmlNode dom) throws XMLStreamException {
          xmlWriter.writeStartElement(dom.getPrefix(), dom.getName(), dom.getNamespaceUri());
          for (Map.Entry<String, String> attr : dom.getAttributes().entrySet()) {
              xmlWriter.writeAttribute(attr.getKey(), attr.getValue());
          }
          for (XmlNode aChildren : dom.getChildren()) {
              write(xmlWriter, aChildren);
          }
          String value = dom.getValue();
          if (value != null) {
              xmlWriter.writeCharacters(value);
          }
          xmlWriter.writeEndElement();
      }
  
      static class IndentingXMLStreamWriter extends StreamWriterDelegate {
  
          int depth = 0;
          boolean hasChildren = false;
          boolean anew = true;
  
          IndentingXMLStreamWriter(XMLStreamWriter parent) {
              super(parent);
          }
  
          @Override
          public void writeStartDocument() throws XMLStreamException {
              super.writeStartDocument();
              anew = false;
          }
  
          @Override
          public void writeStartDocument(String version) throws XMLStreamException {
              super.writeStartDocument(version);
              anew = false;
          }
  
          @Override
          public void writeStartDocument(String encoding, String version) throws XMLStreamException {
              super.writeStartDocument(encoding, version);
              anew = false;
          }
  
          @Override
          public void writeEmptyElement(String localName) throws XMLStreamException {
              indent();
              super.writeEmptyElement(localName);
              hasChildren = true;
              anew = false;
          }
  
          @Override
          public void writeEmptyElement(String namespaceURI, String localName) throws XMLStreamException {
              indent();
              super.writeEmptyElement(namespaceURI, localName);
             hasChildren = true;
             anew = false;
         }
 
         @Override
         public void writeEmptyElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
             indent();
             super.writeEmptyElement(prefix, localName, namespaceURI);
             hasChildren = true;
             anew = false;
         }
 
         @Override
         public void writeStartElement(String localName) throws XMLStreamException {
             indent();
             super.writeStartElement(localName);
             depth++;
             hasChildren = false;
             anew = false;
         }
 
         @Override
         public void writeStartElement(String namespaceURI, String localName) throws XMLStreamException {
             indent();
             super.writeStartElement(namespaceURI, localName);
             depth++;
             hasChildren = false;
             anew = false;
         }
 
         @Override
         public void writeStartElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
             indent();
             super.writeStartElement(prefix, localName, namespaceURI);
             depth++;
             hasChildren = false;
             anew = false;
         }
 
         @Override
         public void writeEndElement() throws XMLStreamException {
             depth--;
             if (hasChildren) {
                 indent();
             }
             super.writeEndElement();
             hasChildren = true;
             anew = false;
         }
 
         private void indent() throws XMLStreamException {
             if (!anew) {
                 super.writeCharacters("\n");
             }
             for (int i = 0; i < depth; i++) {
                 super.writeCharacters("  ");
             }
         }
     }
 }