package org.ossim.planet.message;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

/**
 * <b><code>DOMSerializer</code></b> will take a DOM
 *   tree and serialize that tree.
 */
public class DOMSerializer 
{
   
   private boolean addHeaderFlag;
   /** Indentation to use */
   private String indent;
   
   /** Line separator to use */
   private String lineSeparator;
   
   /**
    * <p> This initializes the needed settings. </p>
    */
   public DOMSerializer() {
      addHeaderFlag = true;
      indent = "";
      lineSeparator = "\n";
   }
   
   /**
    * <p> This sets the indentation to use. </p>
    *
    * @param indent the indentation <code>String</code> to use.
    */
   public void setAddHeaderFlag(boolean flag)
   {
      addHeaderFlag = flag;
   }
   public void setIndent(String indent) {
      this.indent = indent;
   }
   /**
    * <p> This sets the line separator to use. </p>
    *
    * @param lineSeparator line separator to use.
    */
   public void setLineSeparator(String lineSeparator) {
      this.lineSeparator = lineSeparator;
   }
   
   /**
    * <p> This serializes a DOM tree to the supplied
    *  <code>OutputStream</code>.</p>
    *
    * @param doc DOM tree to serialize.
    * @param out <code>OutputStream</code> to write to.
    */
   public void serialize(Document doc, OutputStream out)
		throws IOException {
			
			Writer writer = new OutputStreamWriter(out);
			serialize(doc, writer);
		}
   public void serializeElement(Element el, OutputStream out)
		throws IOException {
			
			Writer writer = new OutputStreamWriter(out);
			serializeNode(el, writer, "");
			writer.flush();
		}
   
   /**
    * <p> This serializes a DOM tree to the supplied
    *  <code>OutputStream</code>.</p>
    *
    * @param doc DOM tree to serialize.
    * @param file <code>File</code> to write to.
    */
   public void serialize(Document doc, File file)
   throws IOException {
      
      Writer writer = new FileWriter(file);
      serialize(doc, writer);
   }
   
   /**
    * <p> This serializes a DOM tree to the supplied
    *  <code>OutputStream</code>.</p>
    *
    * @param doc DOM tree to serialize.
    * @param writer <code>Writer</code> to write to.
    */
   public void serialize(Document doc, Writer writer)
   throws IOException {
      
      // Start serialization recursion with no indenting
      serializeNode(doc, writer, "");
      writer.flush();
   }
   
   /**
    * <p> This will serialize a DOM <code>Node</code> to
    *   the supplied <code>Writer</code>. </p>
    *
    * @param node DOM <code>Node</code> to serialize.
    * @param writer <code>Writer</code> to write to.
    * @param indentLevel current indentation.
    */
   public void serializeNode(Node node, Writer writer,
                             String indentLevel)
   throws IOException {
      
      // Determine action based on node type
      switch (node.getNodeType()) {
         case Node.DOCUMENT_NODE:
            if(addHeaderFlag == true)
            {
               writer.write("<?xml version=\"1.0\"?>");
               writer.write(lineSeparator);
            }
            
            // recurse on each child
            NodeList nodes = node.getChildNodes();
            if (nodes != null) {
               for (int i=0; i<nodes.getLength(); i++) {
                  serializeNode(nodes.item(i), writer, "");
               }
            }
            /*
             Document doc = (Document)node;
             serializeNode(doc.getDocumentElement(), writer, "");
             */
            break;
            
            case Node.ELEMENT_NODE:
            String name = node.getNodeName();
            writer.write(indentLevel + "<" + name);
            NamedNodeMap attributes = node.getAttributes();
            for (int i=0; i<attributes.getLength(); i++) {
               Node current = attributes.item(i);
               writer.write(" " + current.getNodeName() +
                            "=\"" + current.getNodeValue() +
                            "\"");
            }
            writer.write(">");
            
            // recurse on each child
            NodeList children = node.getChildNodes();
            if (children != null) {
               if ((children.item(0) != null) &&
                   (children.item(0).getNodeType() ==
                    Node.ELEMENT_NODE)) {
                  
                  writer.write(lineSeparator);
               }
               for (int i=0; i<children.getLength(); i++) {
                  serializeNode(children.item(i), writer,
                                indentLevel + indent);
               }
               if ((children.item(0) != null) &&
                   (children.item(children.getLength()-1)
                    .getNodeType() ==
                    Node.ELEMENT_NODE)) {
                  
                  writer.write(indentLevel);
               }
            }
            
            writer.write("</" + name + ">");
            writer.write(lineSeparator);
            break;
            
            case Node.TEXT_NODE:
            writer.write(node.getNodeValue());
            break;
            
            case Node.CDATA_SECTION_NODE:
            writer.write("<![CDATA[" +
                         node.getNodeValue() + "]]>");
            break;
            
            case Node.COMMENT_NODE:
            writer.write(indentLevel + "<!-- " +
                         node.getNodeValue() + " -->");
            writer.write(lineSeparator);
            break;
            
            case Node.PROCESSING_INSTRUCTION_NODE:
            writer.write("<?" + node.getNodeName() +
                         " " + node.getNodeValue() +
                         "?>");
            writer.write(lineSeparator);
            break;
            
            case Node.ENTITY_REFERENCE_NODE:
            writer.write("&" + node.getNodeName() + ";");
            break;
            
            case Node.DOCUMENT_TYPE_NODE:
            DocumentType docType = (DocumentType)node;
            writer.write("<!DOCTYPE " + docType.getName());
            if (docType.getPublicId() != null)  {
               System.out.print(" PUBLIC \"" +
                                docType.getPublicId() + "\" ");
            } else {
               writer.write(" SYSTEM ");
            }
            writer.write("\"" + docType.getSystemId() + "\">");
            writer.write(lineSeparator);
            break;
      }
   }
}
/*   Java and XML, Second Edition
 *   Solutions to Real-World Problems
 *   By Brett McLaughlin
 *   Second Edition August 2001
 *   ISBN: 0-596-00197-5
 *   http://www.oreilly.com/catalog/javaxml2/
 */