/*******************************************************************************
* Copyright (c) 2012 Michael Kutschke.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Michael Kutschke - initial API and implementation
******************************************************************************/
package org.eclipse.recommenders.jayes.io.xdsl;
import static com.google.common.collect.Lists.newArrayList;
import static org.eclipse.recommenders.jayes.io.xdsl.Constants.*;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.StringTokenizer;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.eclipse.recommenders.internal.jayes.io.util.XMLUtil;
import org.eclipse.recommenders.jayes.BayesNet;
import org.eclipse.recommenders.jayes.BayesNode;
import org.eclipse.recommenders.jayes.io.IBayesNetReader;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import com.google.common.base.CharMatcher;
import com.google.common.base.Splitter;
import com.google.common.collect.Iterables;
import com.google.common.primitives.Doubles;
public class XDSLReader implements IBayesNetReader {
private final InputStream str;
public XDSLReader(InputStream str) {
this.str = str;
}
@Override
public BayesNet read() throws IOException {
Document doc = obtainDocument(str);
return readFromDocument(doc);
}
public BayesNet readFromString(String xdslString) throws IOException {
Document doc = obtainDocument(new ByteArrayInputStream(xdslString.getBytes()));
return readFromDocument(doc);
}
private Document obtainDocument(InputStream xdslStream) throws IOException {
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder docBldr = docBuilderFactory.newDocumentBuilder();
Document doc = docBldr.parse(xdslStream);
doc.normalize();
return doc;
} catch (ParserConfigurationException e) {
throw new IOException("Bad parser configuration, probably missing dependency", e);
} catch (SAXException e) {
throw new IOException("Parse failed", e);
}
}
private BayesNet readFromDocument(Document doc) {
BayesNet net = new BayesNet();
Node smileNode = doc.getElementsByTagName("smile").item(0);
String networkName = getId(smileNode);
net.setName(XMLUtil.unescape(networkName));
intializeNodes(doc, net);
initializeNodeOutcomes(doc, net);
setParents(doc, net);
parseProbabilities(doc, net);
return net;
}
private void intializeNodes(Document doc, BayesNet net) {
NodeList nodelist = doc.getElementsByTagName(CPT);
for (int i = 0; i < nodelist.getLength(); i++) {
net.createNode(getId(nodelist.item(i)));
}
}
private String getId(Node node) {
return XMLUtil.unescape(node.getAttributes().getNamedItem(ID).getTextContent());
}
private void initializeNodeOutcomes(Document doc, BayesNet net) {
NodeList nodelist = doc.getElementsByTagName(STATE);
for (int i = 0; i < nodelist.getLength(); i++) {
Node node = nodelist.item(i);
BayesNode bNode = net.getNode(getId(node.getParentNode()));
bNode.addOutcome(getId(node));
}
}
private void setParents(Document doc, BayesNet net) {
NodeList nodelist = doc.getElementsByTagName(PARENTS);
for (int i = 0; i < nodelist.getLength(); i++) {
Node node = nodelist.item(i);
BayesNode bNode = net.getNode(getId(node.getParentNode()));
List<String> parentNames = newArrayList();
Iterables.addAll(parentNames,
Splitter.on(CharMatcher.WHITESPACE).omitEmptyStrings().split(node.getTextContent()));
List<BayesNode> parents = newArrayList();
for (String parentname : parentNames) {
parents.add(net.getNode(XMLUtil.unescape(parentname)));
}
bNode.setParents(parents);
}
}
private void parseProbabilities(Document doc, BayesNet net) {
NodeList nodelist = doc.getElementsByTagName(PROBABILITIES);
for (int i = 0; i < nodelist.getLength(); i++) {
Node node = nodelist.item(i);
BayesNode bNode = net.getNode(getId(node.getParentNode()));
String table = node.getTextContent();
List<Double> probabilities = newArrayList();
StringTokenizer tok = new StringTokenizer(table);
while (tok.hasMoreTokens()) {
probabilities.add(Double.valueOf(tok.nextToken()));
}
bNode.setProbabilities(Doubles.toArray(probabilities));
}
}
@Override
public void close() throws IOException {
str.close();
}
}