/*
GanttProject is an opensource project management tool. License: GPL3
Copyright (C) 2011 Dmitry Barashev
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 3
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package net.sourceforge.ganttproject.client;
import net.sourceforge.ganttproject.GPVersion;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.util.DateParser;
import org.w3c.util.InvalidDateException;
import org.xml.sax.InputSource;
import com.google.common.base.Strings;
import javax.xml.namespace.NamespaceContext;
import javax.xml.xpath.*;
import java.io.*;
import java.util.Date;
import java.util.Iterator;
class RssParser {
private final XPathFactory myXPathFactory = XPathFactory.newInstance();
private XPathExpression getXPath(String expression) throws XPathExpressionException {
XPath xpath = myXPathFactory.newXPath();
xpath.setNamespaceContext(new NamespaceContext() {
@Override
public String getNamespaceURI(String s) {
if ("atom".equals(s)) {
return "http://www.w3.org/2005/Atom";
}
throw new IllegalArgumentException(s);
}
@Override
public String getPrefix(String s) {
throw new UnsupportedOperationException();
}
@Override
public Iterator<?> getPrefixes(String s) {
throw new UnsupportedOperationException();
}
});
return xpath.compile(expression);
}
public RssFeed parse(InputStream inputStream, Date lastCheckDate) {
RssFeed result = new RssFeed();
try {
XPathExpression xpath = getXPath("//atom:entry");
NodeList items = (NodeList) xpath.evaluate(new InputSource(new InputStreamReader(inputStream)),
XPathConstants.NODESET);
final String currentVersion = GPVersion.getCurrentVersionNumber();
final String currentBuild = GPVersion.getCurrentBuildNumber();
for (int i = 0; i < items.getLength(); i++) {
if (isApplicableToVersion(items.item(i), currentVersion, currentBuild)) {
addItem(result, items.item(i), lastCheckDate);
}
}
} catch (XPathExpressionException e) {
e.printStackTrace();
}
return result;
}
private boolean isApplicableToVersion(Node item, String version, String build) throws XPathExpressionException {
boolean hasRestriction = false;
NodeList categories = (NodeList) getXPath("atom:category").evaluate(item, XPathConstants.NODESET);
for (int i = 0; i < categories.getLength(); i++) {
Element elCategory = (Element) categories.item(i);
String category = elCategory.getAttribute("term");
if (!Strings.isNullOrEmpty(category)) {
if (category.startsWith("__version")) {
hasRestriction = true;
if (compareCategory(category, "version", version)) {
return true;
}
}
if (category.startsWith("__build")) {
hasRestriction = true;
if (compareCategory(category, "build", build)) {
return true;
}
}
}
}
return !hasRestriction;
}
private boolean compareCategory(String category, String type, String value) {
if (category.startsWith("__" + type + "_lt_")) {
String valueRequired = category.substring(("__" + type + "_lt_").length());
if (value.compareTo(valueRequired) < 0) {
return true;
}
} else if (category.startsWith("__" + type + "_gt_")) {
String valueRequired = category.substring(("__" + type + "_gt_").length());
if (value.compareTo(valueRequired) > 0) {
return true;
}
} else if (category.startsWith("__" + type + "_eq_")) {
String valueRequired = category.substring(("__" + type + "_eq_").length());
if (value.equals(valueRequired)) {
return true;
}
}
return false;
}
private void addItem(RssFeed result, Node item, Date lastCheckDate) throws XPathExpressionException {
if (lastCheckDate != null) {
String updateString = getXPath("atom:updated/text()").evaluate(item);
try {
Date updateDate = DateParser.parse(updateString);
if (updateDate.before(lastCheckDate)) {
return;
}
} catch (InvalidDateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
String title = getXPath("atom:title/text()").evaluate(item);
String body = getXPath("atom:content/text()").evaluate(item);
result.addItem(title, body);
}
}