package de.mpg.mpiwg.berlin.mpdl.cms.transform;

import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.net.URL;

import javax.xml.transform.stream.StreamSource;

import de.mpg.mpiwg.berlin.mpdl.exception.ApplicationException;

import net.sf.saxon.s9api.Processor;
import net.sf.saxon.s9api.QName;
import net.sf.saxon.s9api.SaxonApiException;
import net.sf.saxon.s9api.Serializer;
import net.sf.saxon.s9api.XdmAtomicValue;
import net.sf.saxon.s9api.XdmValue;
import net.sf.saxon.s9api.XsltCompiler;
import net.sf.saxon.s9api.XsltExecutable;
import net.sf.saxon.s9api.XsltTransformer;

public class TocTransformer {
  private Processor processor;
  private XsltCompiler xsltCompiler;
  private XsltTransformer tocTransformer;
  
  public TocTransformer() throws ApplicationException {
    init();
  }
  
  private void init() throws ApplicationException {
    try {
      processor = new Processor(false); 
      xsltCompiler = processor.newXsltCompiler();
      URL tocXslUrl = TocTransformer.class.getResource("tocOut.xsl");
      StreamSource xslStreamSource = new StreamSource(tocXslUrl.openStream());
      XsltExecutable xsltExecutable = xsltCompiler.compile(xslStreamSource);
      tocTransformer = xsltExecutable.load();
    } catch (SaxonApiException e) {
      throw new ApplicationException(e);
    } catch (IOException e) {
      throw new ApplicationException(e);
    }
  }
  
  public String transform(String inputStr, String type, String outputFormat) throws ApplicationException {
    String result = null;
    try {
      StringReader inputStrReader = new StringReader(inputStr);
      StreamSource xmlDoc = new StreamSource(inputStrReader);
      Serializer serializer = new Serializer();
      serializer.setOutputWriter(new StringWriter());
      serializer.setOutputProperty(Serializer.Property.SAXON_STYLESHEET_VERSION, "2.0");
      serializer.setOutputProperty(Serializer.Property.METHOD, "xhtml");
      serializer.setOutputProperty(Serializer.Property.INDENT, "no");
      serializer.setOutputProperty(Serializer.Property.OMIT_XML_DECLARATION, "yes");
      serializer.setOutputProperty(Serializer.Property.ENCODING, "utf-8");
      tocTransformer.setSource(xmlDoc);  
      tocTransformer.setDestination(serializer);
      QName typeQName = new QName("type");
      XdmValue typeXdmValue = new XdmAtomicValue(type);
      QName outputFormatQName = new QName("outputFormat");
      XdmValue outputFormatXdmValue = new XdmAtomicValue(outputFormat);
      tocTransformer.setParameter(typeQName, typeXdmValue);
      tocTransformer.setParameter(outputFormatQName, outputFormatXdmValue);
      tocTransformer.transform(); 
      result = serializer.getOutputDestination().toString();
    } catch (Exception e) {
      throw new ApplicationException(e);
    }
    return result;
  }

}