// Copyright 2008-2014 severally by the contributors

 //

 // 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 net.sf.practicalxml.builder;

 import java.io.IOException;

 import java.io.OutputStream;

 import java.util.ArrayList;

 import java.util.List;

 import org.w3c.dom.Document;

 import org.w3c.dom.Element;

 import org.xml.sax.Attributes;

 import org.xml.sax.ContentHandler;

 import org.xml.sax.InputSource;

 import org.xml.sax.SAXException;

 import org.xml.sax.helpers.AttributesImpl;

 import org.xml.sax.helpers.XMLFilterImpl;

 import net.sf.practicalxml.DomUtil;

 import net.sf.practicalxml.OutputUtil;

 /**

  *  The primary class for building XML trees and converting them to different

  *  JAXP-centric forms. Callers should not create instances of this class

  *  directly; instead use the static factory methods in {@link XmlBuilder}.

  */

 public final class ElementNode

 extends Node

 {

     private static final long serialVersionUID = 2L;

     private String _nsUri;

     private String _qname;

     private String _lclName;

     private List<AttributeNode> _attribs = new ArrayList<AttributeNode>();

     private List<Node> _children = new ArrayList<Node>();

     ElementNode(String nsUri, String qname, Node... children)

     {

         _nsUri = nsUri;

         _qname = qname;

         _lclName = getLocalName(qname);

         for (Node child : children)

             addChild(child);

     }

     /**

      *  Adds a child node -- of any type -- to this element. Returns this as

      *  a convenience to caller, allowing calls to be chained.

      */

     public ElementNode addChild(Node child)

     {

         if (child instanceof AttributeNode)

             _attribs.add((AttributeNode)child);

         else if (child != null)

             _children.add(child);

         return this;

     }

     /**

      *  Generates a new DOM document with this element as the root.

      */

     public Document toDOM()

     {

         Element root = DomUtil.newDocument(_nsUri, _qname);

         appendChildren(root);

         return root.getOwnerDocument();

     }

     /**

      *  Invokes the passed <code>ContentHandler</code> for this element and

      *  its children. Note that the implementation class must also implement

      *  <code>LexicalHandler</code> to receive events from all nodes in the

      *  tree (particularly comments).

      */

     @Override

     protected void toSAX(ContentHandler handler)

     throws SAXException

     {

         handler.startElement(_nsUri, _lclName, _qname, getAttributes());

         for (Node child : _children)

         {

             child.toSAX(handler);

         }

         handler.endElement(_nsUri, _lclName, _qname);

     }

     /**

      *  Generates an XML string, where this node is the root element. Does

      *  not insert whitespace between elements. Note that you <em>must</em>

      *  use UTF-8 encoding or add a prologue that specifies encoding when

      *  writing this string to a stream.

      */

     @Override

     public String toString()

     {

         return OutputUtil.compactString(new SerializationHelper());

     }

     /**

      *  Generates an XML string, where this node is the root element. Inserts

      *  whitespace between nodes, along with newlines and the specified indent

      *  between elements.

      *  <p>

      *  This is the best choice for writing log output. If you write this string

      *  to a stream, you <em>must</em> use UTF-8 encoding or attach a prologue

      *  that specifies the encoding used.

      */

     public String toString(int indentSize)

     {

         return OutputUtil.indentedString(new SerializationHelper(), indentSize);

     }

     /**

      *  Writes the tree rooted at this element to an <code>OutputStream</code>,

      *  using UTF-8 encoding, without a prologue or whitepspace between nodes.

      *  <p>

      *  This is the best choice for writing XML that will be read by another

      *  party.

      */

     public void toStream(OutputStream out)

     {

         OutputUtil.compactStream(new SerializationHelper(), out);

     }

     /**

      *  Writes the tree rooted at this element to an <code>OutputStream</code>,

      *  using a specified encoding, without a prologue or whitepspace between

      *  nodes.

      */

     public void toStream(OutputStream out, String encoding)

     {

         OutputUtil.compactStream(toDOM(), out, encoding);

     }

 //----------------------------------------------------------------------------

 //  Internals

 //----------------------------------------------------------------------------

     @Override

     protected void appendToElement(Element parent)

     {

         appendChildren(DomUtil.appendChild(parent, _nsUri, _qname));

     }

     private void appendChildren(Element elem)

     {

         for (Node child : _attribs)

         {

             child.appendToElement(elem);

         }

         for (Node child : _children)

         {

             child.appendToElement(elem);

         }

     }

     private Attributes getAttributes()

     {

         AttributesImpl result = new AttributesImpl();

         for (AttributeNode attr : _attribs)

         {

             attr.appendToAttributes(result);

         }

         return result;

     }

     private class SerializationHelper

     extends XMLFilterImpl

     {

         @Override

         public void parse(InputSource input)

         throws SAXException, IOException

         {

             startDocument();

             toSAX(getContentHandler());

             endDocument();

         }

     }

 }