/*
 *                  BioJava development code
 *
 * This code may be freely distributed and modified under the
 * terms of the GNU Lesser General Public Licence.  This should
 * be distributed with the code.  If you do not have a copy,
 * see:
 *
 *      http://www.gnu.org/copyleft/lesser.html
 *
 * Copyright for this code is held jointly by the individual
 * authors.  These should be listed in @author doc comments.
 *
 * For more information on the BioJava project and its aims,
 * or to join the biojava-l mailing list, visit the home page
 * at:
 *
 *      http://www.biojava.org/
 *
 * Created on Feb 24, 2006
 *
 */
package jalview.biojava.dasobert.das2.io;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;


import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

//import jalview.biojava.dasobert.das.AlignmentThread;
import jalview.biojava.dasobert.das.DAS_FeatureRetrieve;
import jalview.biojava.dasobert.dasregistry.DasSource;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.XMLReader;

public class DasSourceReaderImpl implements DasSourceReader {

    Exception loggedException;

    public DasSourceReaderImpl() {
        super();
        loggedException = null;

        // open the stream to a server and then parse the result ...
    }

    private InputStream open(URL url)
    throws java.io.IOException, java.net.ConnectException
    {
        InputStream inStream = null;


        HttpURLConnection huc = DAS_FeatureRetrieve.openHttpURLConnection(url);

        inStream = huc.getInputStream();

        return inStream;

    }


    public DasSource[] readDasSource(URL url){
        DasSource[] sources = new DasSource[0];

        try {
            InputStream stream = open(url);

            sources = readDasSource(stream);
        } catch (Exception e){
            e.printStackTrace();
            loggedException = e;
        }
        return sources;
    }

    /** read a DAS2 sources response and return a list of DAS sources.
     *
     */
    public DasSource[] readDasSource(InputStream stream)  {

        DasSource[] sources = new DasSource[0];

        try {
        SAXParserFactory spfactory =
            SAXParserFactory.newInstance();

        spfactory.setValidating(false);

        SAXParser saxParser = null ;

        try{
            saxParser =
                spfactory.newSAXParser();
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
            loggedException = e;
        }

        String vali = System.getProperty("XMLVALIDATION");

        boolean validation = false ;
        if ( vali != null )
            if ( vali.equals("true") )
                validation = true ;


        XMLReader xmlreader = saxParser.getXMLReader();

        //XMLReader xmlreader = XMLReaderFactory.createXMLReader();
        try {
            xmlreader.setFeature("http://xml.org/sax/features/validation", validation);
        } catch (SAXException e) {
            //logger.log(Level.FINE,"Cannot set validation " + validation);
        }

        try {
            xmlreader.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd",validation);
        } catch (SAXNotRecognizedException e){
            e.printStackTrace();
            //logger.log(Level.FINE,"Cannot set load-external-dtd "+validation);

        }

        DAS2SourceHandler cont_handle = new DAS2SourceHandler() ;

        xmlreader.setContentHandler(cont_handle);
        xmlreader.setErrorHandler(new org.xml.sax.helpers.DefaultHandler());
        InputSource insource = new InputSource() ;
        insource.setByteStream(stream);


        xmlreader.parse(insource);
        sources = cont_handle.getSources();



        } catch (Exception e) {
            e.printStackTrace();
            loggedException = e;
        }
        return sources;
    }

    public Exception getLoggedException(){
        return loggedException;
    }

    public static void main (String[] args){
        String url = "http://www.spice-3d.org/dasregistry/das2/sources/";
        DasSourceReaderImpl reader = new DasSourceReaderImpl();
        try {
            URL u = new URL(url);
            DasSource[] sources = reader.readDasSource(u);
            for (int i=0; i< sources.length;i++){
                DasSource ds = sources[i];
                System.out.println(ds.toString());
            }

        } catch (Exception e){
            e.printStackTrace();
        }

    }



}