package org.argeo.maintenance.backup;
   
   import java.io.IOException;
   import java.io.InputStream;
   import java.io.Writer;
   import java.util.Base64;
   import java.util.Set;
   import java.util.TreeSet;
   
  import javax.jcr.Binary;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  
  import org.apache.commons.io.IOUtils;
  import org.xml.sax.Attributes;
  import org.xml.sax.SAXException;
  import org.xml.sax.helpers.DefaultHandler;
  
  public class BackupContentHandler extends DefaultHandler {
  	final static int MAX_DEPTH = 1024;
  	final static String SV_NAMESPACE_URI = "http://www.jcp.org/jcr/sv/1.0";
  	// elements
  	final static String NODE = "node";
  	final static String PROPERTY = "property";
  	final static String VALUE = "value";
  	// attributes
  	final static String NAME = "name";
  	final static String MULTIPLE = "multiple";
  	final static String TYPE = "type";
  
  	// values
  	final static String BINARY = "Binary";
  	final static String JCR_CONTENT = "jcr:content";
  
  	private Writer out;
  	private Session session;
  	private Set<String> contentPaths = new TreeSet<>();
  
  	public BackupContentHandler(Writer out, Session session) {
  		super();
  		this.out = out;
  		this.session = session;
  	}
  
  	private int currentDepth = -1;
  	private String[] currentPath = new String[MAX_DEPTH];
  
  	private boolean currentPropertyIsMultiple = false;
  	private String currentEncoded = null;
  	private Base64.Encoder base64encore = Base64.getEncoder();
  
  	@Override
  	public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
  		boolean isNode;
  		boolean isProperty;
  		switch (localName) {
  		case NODE:
  			isNode = true;
  			isProperty = false;
  			break;
  		case PROPERTY:
  			isNode = false;
  			isProperty = true;
  			break;
  		default:
  			isNode = false;
  			isProperty = false;
  		}
  
  		if (isNode) {
  			String nodeName = attributes.getValue(SV_NAMESPACE_URI, NAME);
  			currentDepth = currentDepth + 1;
  			if (currentDepth > 0)
  				currentPath[currentDepth - 1] = nodeName;
  //			System.out.println(getCurrentPath() + " , depth=" + currentDepth);
  		}
  
  		if (SV_NAMESPACE_URI.equals(uri))
  			try {
  				out.write("<");
  				out.write(localName);
  				if (isProperty)
  					currentPropertyIsMultiple = false; // always reset
  				for (int i = 0; i < attributes.getLength(); i++) {
  					String ns = attributes.getURI(i);
  					if (SV_NAMESPACE_URI.equals(ns)) {
  						String attrName = attributes.getLocalName(i);
  						String attrValue = attributes.getValue(i);
  						out.write(" ");
  						out.write(attrName);
  						out.write("=");
  						out.write("\"");
  						out.write(attrValue);
  						out.write("\"");
  						if (isProperty) {
  							if (MULTIPLE.equals(attrName))
  								currentPropertyIsMultiple = Boolean.parseBoolean(attrValue);
  							else if (TYPE.equals(attrName)) {
  								if (BINARY.equals(attrValue)) {
 									if (JCR_CONTENT.equals(getCurrentName())) {
 										contentPaths.add(getCurrentPath());
 									} else {
 										Binary binary = session.getNode(getCurrentPath()).getProperty(attrName)
 												.getBinary();
 										try (InputStream in = binary.getStream()) {
 											currentEncoded = base64encore.encodeToString(IOUtils.toByteArray(in));
 										} finally {
 
 										}
 									}
 								}
 							}
 						}
 					}
 				}
 				if (currentDepth == 0) {
 					out.write(" xmlns=\"" + SV_NAMESPACE_URI + "\"");
 				}
 				out.write(">");
 				if (isNode)
 					out.write("\n");
 				else if (isProperty && currentPropertyIsMultiple)
 					out.write("\n");
 			} catch (IOException | RepositoryException e) {
 				// TODO Auto-generated catch block
 				e.printStackTrace();
 			}
 	}
 
 	@Override
 	public void endElement(String uri, String localName, String qName) throws SAXException {
 		if (localName.equals(NODE)) {
 //			System.out.println("endElement " + getCurrentPath() + " , depth=" + currentDepth);
 			if (currentDepth > 0)
 				currentPath[currentDepth - 1] = null;
 			currentDepth = currentDepth - 1;
 		}
 		boolean isValue = localName.equals(VALUE);
 		if (SV_NAMESPACE_URI.equals(uri))
 			try {
 				if (isValue && currentEncoded != null) {
 					out.write(currentEncoded);
 				}
 				currentEncoded = null;
 				out.write("</");
 				out.write(localName);
 				out.write(">");
 				if (!isValue)
 					out.write("\n");
 				else {
 					if (currentPropertyIsMultiple)
 						out.write("\n");
 				}
 			} catch (IOException e) {
 				// TODO Auto-generated catch block
 				e.printStackTrace();
 			}
 	}
 
 	@Override
 	public void characters(char[] ch, int start, int length) throws SAXException {
 		try {
 			out.write(ch, start, length);
 		} catch (IOException e) {
 			// TODO Auto-generated catch block
 			e.printStackTrace();
 		}
 	}
 
 	protected String getCurrentName() {
 		assert currentDepth >= 0;
 		if (currentDepth == 0)
 			return "jcr:root";
 		return currentPath[currentDepth - 1];
 	}
 
 	protected String getCurrentPath() {
 		if (currentDepth == 0)
 			return "/";
 		StringBuilder sb = new StringBuilder("/");
 		for (int i = 0; i < currentDepth; i++) {
 			if (i != 0)
 				sb.append('/');
 			sb.append(currentPath[i]);
 		}
 		return sb.toString();
 	}
 
 	public Set<String> getContentPaths() {
 		return contentPaths;
 	}
 
 	
 	
 }