package won.cryptography.utils;

import org.apache.jena.query.Dataset;
import org.apache.jena.query.DatasetFactory;
import org.apache.jena.rdf.model.Model;
import org.apache.jena.rdf.model.Property;
import org.apache.jena.rdf.model.ResIterator;
import org.apache.jena.rdf.model.Resource;
import org.apache.jena.riot.RDFDataMgr;
import org.apache.jena.riot.RDFFormat;
import org.junit.Assert;
import org.junit.Test;

import java.io.*;

/**
 * User: ypanchenko
 * Date: 15.07.2014
 */
public class JenaBnodeInDatasetTest
{
  private static final String RESOURCE_FILE = "/test_2graphs.trig";

  @Test
  public void testReadWriteDatasetWithTwoGraphs() throws Exception {

    InputStream is = this.getClass().getResourceAsStream(RESOURCE_FILE);
    Dataset dataset = DatasetFactory.createGeneral();
    RDFDataMgr.read(dataset, is, RDFFormat.TRIG.getLang());
    is.close();
    assertSameSubjBnode(dataset, "http://www.example.com#", "G1", "G2", "pred1", "pred2");


    File outFile = File.createTempFile("won", ".trig");
    System.out.println(outFile);
    OutputStream os = new FileOutputStream(outFile);
    // Writing in TRIG results in loosing info about shared between graphs blank node.
    // I wrote to Jena mailing list and they opened https://issues.apache.org/jira/browse/JENA-745
    // Solution for the moment is to use TRIG_BLOCKS when writing
    //RDFDataMgr.write(os, dataset, RDFFormat.TRIG);
    RDFDataMgr.write(os, dataset, RDFFormat.TRIG_BLOCKS);
    os.close();

    InputStream is2 = new FileInputStream(outFile);;
    Dataset dataset2 = DatasetFactory.createGeneral();
    RDFDataMgr.read(dataset2, is2, RDFFormat.TRIG.getLang());
    is2.close();
    assertSameSubjBnode(dataset2, "http://www.example.com#", "G1", "G2", "pred1", "pred2");

  }

  private void assertSameSubjBnode(Dataset dataset, final String ns,
                                   final String g1,
                                   final String g2,
                                   final String pred1,
                                   final String pred2) {
    Model model1 = dataset.getNamedModel(ns + g1);
    Model model2 = dataset.getNamedModel(ns + g2);
    Property prop1 = model1.createProperty(ns, pred1);
    ResIterator iter1 = model1.listResourcesWithProperty(prop1, null);
    Property prop2 = model2.createProperty(ns, pred2);
    ResIterator iter2 = model2.listResourcesWithProperty(prop2, null);
    Resource r1 = iter1.next();
    Resource r2 = iter2.next();
    Assert.assertTrue(r1 != null && r1.equals(r2));
  }

}