content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.asterix.external.input.record.reader.rss;
  
  import java.net.MalformedURLException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.asterix.common.dataflow.ICcApplicationContext;
  import org.apache.asterix.common.external.IExternalFilterEvaluatorFactory;
  import org.apache.asterix.external.api.IExternalDataRuntimeContext;
  import org.apache.asterix.external.api.IExternalDataSourceFactory;
  import org.apache.asterix.external.api.IRecordReader;
  import org.apache.asterix.external.api.IRecordReaderFactory;
  import org.apache.asterix.external.util.ExternalDataConstants;
  import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  import org.apache.hyracks.api.application.IServiceContext;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.api.exceptions.IWarningCollector;
  
  import com.rometools.rome.feed.synd.SyndEntry;
  
  public class RSSRecordReaderFactory implements IRecordReaderFactory<SyndEntry> {
  
      private static final long serialVersionUID = 1L;
      private final List<String> urls = new ArrayList<>();
      private transient AlgebricksAbsolutePartitionConstraint clusterLocations;
      private transient IServiceContext serviceContext;
      private static final List<String> recordReaderNames = Collections.unmodifiableList(Arrays.asList("rss_feed"));
  
      @Override
      public DataSourceType getDataSourceType() {
          return DataSourceType.RECORDS;
      }
  
      @Override
      public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AlgebricksException {
          int count = urls.size();
          clusterLocations = IExternalDataSourceFactory.getPartitionConstraints(
                  (ICcApplicationContext) serviceContext.getApplicationContext(), clusterLocations, count);
          return clusterLocations;
      }
  
      @Override
      public void configure(IServiceContext serviceContext, Map<String, String> configuration,
              IWarningCollector warningCollector, IExternalFilterEvaluatorFactory filterEvaluatorFactory) {
          this.serviceContext = serviceContext;
          String url = configuration.get(ExternalDataConstants.KEY_RSS_URL);
          if (url == null) {
              throw new IllegalArgumentException("no RSS URL provided");
          }
          initializeURLs(url);
      }
  
      private void initializeURLs(String url) {
          urls.clear();
          String[] rssURLs = url.split(",");
          for (String rssURL : rssURLs) {
              urls.add(rssURL);
          }
      }
  
      @Override
      public List<String> getRecordReaderNames() {
          return recordReaderNames;
      }
  
      @Override
      public IRecordReader<? extends SyndEntry> createRecordReader(IExternalDataRuntimeContext context)
              throws HyracksDataException {
          try {
              return new RSSRecordReader(urls.get(context.getPartition()));
          } catch (MalformedURLException e) {
              throw HyracksDataException.create(e);
          }
      }
  
      @Override
      public Class<? extends SyndEntry> getRecordClass() {
          return SyndEntry.class;
      }
  
  }
  