/**
 *
 */
package it.univr.di.cstnu.graph;

import it.univr.di.labeledvalue.Constants;
import org.junit.Assert;
import org.junit.Test;
import org.xml.sax.SAXException;

import javax.xml.parsers.ParserConfigurationException;
import java.io.File;
import java.io.IOException;
import java.util.Objects;

/**
 * Allows to read a DenseTCGraph from a file written in GraphML format.<br> GraphML format allows the definition of different attributes for the tNGraph, vertices
 * and edges.<br> All attributes are defined in the first part of a GraphML file. Examples of GraphML file that can read by this class are given in the
 * Instances directory under CstnuTool one.
 *
 * @author posenato
 * @version $Id: $Id
 */
public class STNUGraphMLReaderTest {

	/**
	 *
	 */
	static final File fileSTNU = new File("src/test/resources/testGraphML.stnu");
	/**
	 *
	 */
	TCGraphMLReader<STNUEdge> readerSTNU;

	/**
	 *
	 */
	DenseTCGraph<STNUEdge> stnu;

	/**
	 * @throws Exception if the file cannot read.
	 */
	@Test
	public void testGraphAttribute() throws Exception {
		this.readerSTNU = new TCGraphMLReader<>();
		this.stnu = this.readerSTNU.readGraph(fileSTNU, STNUEdgeInt.class);
		Assert.assertEquals("testGraphML", this.stnu.getName());
	}

	/**
	 * @throws IOException                  none
	 * @throws ParserConfigurationException none
	 * @throws SAXException                 none
	 */
	@Test
	public void testSTNU() throws Exception {
		this.readerSTNU = new TCGraphMLReader<>();
		this.stnu = this.readerSTNU.readGraph(fileSTNU, STNUEdgeInt.class);
		Assert.assertEquals(-5, Objects.requireNonNull(this.stnu.getEdge("YX")).getLabeledValue());
		Assert.assertEquals(2, Objects.requireNonNull(this.stnu.getEdge("XY")).getLabeledValue());
		final TCGraphMLWriter writer = new TCGraphMLWriter();
		final String graphXML = writer.save(this.stnu);
		this.readerSTNU = new TCGraphMLReader<>();
		this.stnu = this.readerSTNU.readGraph(graphXML, STNUEdgeInt.class);
		Assert.assertEquals(-5, Objects.requireNonNull(this.stnu.getEdge("YX")).getLabeledValue());
		Assert.assertEquals(2, Objects.requireNonNull(this.stnu.getEdge("XY")).getLabeledValue());
	}

	/**
	 * @throws IOException                  none
	 * @throws ParserConfigurationException none
	 * @throws SAXException                 none
	 */
	@Test
	public void testSTNU1() throws Exception {
		this.readerSTNU = new TCGraphMLReader<>();
		this.stnu = this.readerSTNU.readGraph(fileSTNU, STNUEdgeInt.class);
		Assert.assertEquals(2, this.stnu.getEdgeCount());
	}

	/**
	 * @throws IOException                  none
	 * @throws ParserConfigurationException none
	 * @throws SAXException                 none
	 */
	@Test
	public void testSTNU33() throws Exception {
		this.readerSTNU = new TCGraphMLReader<>();
		this.stnu = this.readerSTNU.readGraph(fileSTNU, STNUEdgeInt.class);
		Assert.assertEquals(Constants.INT_NULL, Objects.requireNonNull(this.stnu.getEdge("YX")).getValue());
		Assert.assertEquals(Constants.INT_NULL, Objects.requireNonNull(this.stnu.getEdge("XY")).getValue());
	}

	/** The GraphML reader must populate the requested backend directly, without a dense conversion.
	 * @throws Exception*/
	@Test
	public void testSTNUSparseBackend() throws Exception {
		this.readerSTNU = new TCGraphMLReader<>();
		final TemporalConstraintGraph<STNUEdge> sparse = this.readerSTNU.readGraph(
			fileSTNU, STNUEdgeInt.class, new SparseTCGraph<>("prototype", STNUEdgeInt.class));
		Assert.assertTrue(sparse instanceof SparseTCGraph<?>);
		Assert.assertEquals(2, sparse.getEdgeCount());
		Assert.assertEquals(-5, Objects.requireNonNull(sparse.getEdge("YX")).getLabeledValue());
		Assert.assertEquals(2, Objects.requireNonNull(sparse.getEdge("XY")).getLabeledValue());
		Assert.assertEquals(fileSTNU, sparse.getInputFile());
	}

	/** Sparse graphs can be serialized and read again without using the dense/JUNG backend.
	 * @throws Exception*/
	@Test
	public void testSparseRoundTrip() throws Exception {
		this.readerSTNU = new TCGraphMLReader<>();
		final TemporalConstraintGraph<STNUEdge> sparse = this.readerSTNU.readGraph(
			fileSTNU, STNUEdgeInt.class, new SparseTCGraph<>("prototype", STNUEdgeInt.class));
		final String serialized = new TCGraphMLWriter().save(sparse);
		final TemporalConstraintGraph<STNUEdge> reloaded = this.readerSTNU.readGraph(
			serialized, STNUEdgeInt.class, sparse);
		Assert.assertTrue(reloaded instanceof SparseTCGraph<?>);
		Assert.assertEquals(2, reloaded.getEdgeCount());
		Assert.assertEquals(-5, Objects.requireNonNull(reloaded.getEdge("YX")).getLabeledValue());
		Assert.assertEquals(2, Objects.requireNonNull(reloaded.getEdge("XY")).getLabeledValue());
	}
}