/*

  * Copyright 1999,2004 The Apache Software Foundation.

  * 

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  * 

  *      http://www.apache.org/licenses/LICENSE-2.0

  * 

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.commons.feedparser.locate.blogservice;

 import java.net.*;

 import java.util.regex.Matcher;

 import java.util.regex.Pattern;

 import org.apache.commons.feedparser.FeedParserException;

 import org.apache.commons.feedparser.locate.*;

 /**

  * Models the Xanga blog service, encapsulating whether a given weblog

  * is this type of service and where it usually keeps its feeds.

  * 

  * @author Brad Neuberg, bkn3@columbia.edu

  */

 public class Xanga extends BlogService {

     /**

      * A regex to extract the user from a Xanga URL

      */

     private static Pattern xangaURLPattern = Pattern.compile(".*user=(\\w*)");

     /** Returns whether we can trust the results of this blog service's 

      *  autodiscovery links.  For example, TextAmerica returns invalid 

      *  autodiscovery results.

      */

     public boolean hasValidAutoDiscovery() {

         return true;

     }

     /** Returns whether we should follow HTTP redirects for this blog service.

      *  Some services don't implement HTTP redirects correctly, while others,

      *  like Xanga, require it.

      */

     public boolean followRedirects() {

         return true;

     }

     /** Determines if the weblog at the given resource and with the given

      *  content is this blog service.

      * @param resource A full URI to this resource, such as 

      * "http://www.codinginparadise.org".

      * @param content The full HTML content at the resource's URL.

      * @throws FeedParserException Thrown if an error occurs while 

      * determining the type of this weblog.

      */

     public boolean isThisService(String resource, String content)

                                                 throws FeedParserException {

         boolean results = false;

         results = containsDomain(resource, "xanga.com");

         return results;

     }

     /**

      * Returns an array of FeedReferences that contains information on the

      * usual locations this blog service contains its feed.  The feeds should

      * be ordered by quality, so that higher quality feeds come before lower

      * quality ones (i.e. you would want to have an Atom FeedReference

      * object come before an RSS 0.91 FeedReference object in this list).

      * @param resource A URL to the given weblog that might be used to build

      * up where feeds are usually located.

      * @param content The full content of the resource URL, which might

      * be useful to determine where feeds are usually located.  This can be

      * null.

      * @throws FeedParserException Thrown if an error occurs while trying

      * to determine the usual locations of feeds for this service.

      */

     public FeedReference[] getFeedLocations(String resource,

                                             String content)

                                                 throws FeedParserException {

         // Xanga feeds have to be handled specially since they put their

         // feeds at the location: http://www.xanga.com/rss.aspx?user=username

         String user = getXangaUser(resource);

         FeedReference xangaLocations[] =

             { new FeedReference("rss.aspx?user=" + user, 

                                 FeedReference.RSS_MEDIA_TYPE) };

         return xangaLocations;

     }

     /** Xanga's feed locations are dependent on the 'user' attribute in a

      *  Xanga URI.  This method helps extract the user element from an 

      *  existing URI, such as http://www.xanga.com/home.aspx?user=wdfphillz.

      */

     protected String getXangaUser(String resource) {

         Matcher xangaMatcher = xangaURLPattern.matcher(resource);

         xangaMatcher.matches();

         return xangaMatcher.group(1);

     }

 }