/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe 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.
    *
   * MyCoRe 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 MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.solr.index.handlers.document;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.apache.solr.client.solrj.SolrClient;
  import org.apache.solr.client.solrj.SolrServerException;
  import org.apache.solr.client.solrj.impl.ConcurrentUpdateSolrClient;
  import org.apache.solr.client.solrj.request.UpdateRequest;
  import org.apache.solr.client.solrj.response.UpdateResponse;
  import org.apache.solr.common.SolrInputDocument;
  import org.mycore.solr.MCRSolrClientFactory;
  import org.mycore.solr.MCRSolrConstants;
  import org.mycore.solr.index.MCRSolrIndexHandler;
  import org.mycore.solr.index.handlers.MCRSolrAbstractIndexHandler;
  import org.mycore.solr.index.statistic.MCRSolrIndexStatistic;
  import org.mycore.solr.index.statistic.MCRSolrIndexStatisticCollector;
  
  /**
   * @author Thomas Scheffler (yagee)
   *
   */
  public class MCRSolrInputDocumentsHandler extends MCRSolrAbstractIndexHandler {
      Collection<SolrInputDocument> documents;
  
      List<MCRSolrIndexHandler> subHandlerList;
  
      private static Logger LOGGER = LogManager.getLogger(MCRSolrInputDocumentsHandler.class);
  
      public MCRSolrInputDocumentsHandler(Collection<SolrInputDocument> documents) {
          this(documents, MCRSolrClientFactory.getMainSolrClient());
      }
  
      public MCRSolrInputDocumentsHandler(Collection<SolrInputDocument> documents, SolrClient solrClient) {
          super(solrClient);
          this.documents = documents;
      }
  
      /* (non-Javadoc)
       * @see org.mycore.solr.index.MCRSolrIndexHandler#getStatistic()
       */
      @Override
      public MCRSolrIndexStatistic getStatistic() {
          return MCRSolrIndexStatisticCollector.DOCUMENTS;
      }
  
      /* (non-Javadoc)
       * @see org.mycore.solr.index.handlers.MCRSolrAbstractIndexHandler#index()
       */
      @Override
      public void index() throws IOException, SolrServerException {
          if (documents == null || documents.isEmpty()) {
              LOGGER.warn("No input documents to index.");
              return;
          }
          int totalCount = documents.size();
          LOGGER.info("Handling {} documents", totalCount);
          SolrClient solrClient = getSolrClient();
          if (solrClient instanceof ConcurrentUpdateSolrClient) {
              LOGGER.info("Detected ConcurrentUpdateSolrClient. Split up batch update.");
              splitDocuments();
              //for statistics:
              documents.clear();
              return;
          }
          UpdateResponse updateResponse;
          try {
              UpdateRequest updateRequest = getUpdateRequest(MCRSolrConstants.SOLR_UPDATE_PATH);
              updateRequest.add(documents);
              updateResponse = updateRequest.process(getSolrClient());
          } catch (Throwable e) {
              LOGGER.warn("Error while indexing document collection. Split and retry.");
              splitDocuments();
              return;
          }
          if (updateResponse.getStatus() != 0) {
              LOGGER.error("Error while indexing document collection. Split and retry: {}", updateResponse.getResponse());
             splitDocuments();
         } else {
             LOGGER.info("Sending {} documents was successful in {} ms.", totalCount, updateResponse.getElapsedTime());
         }
     }
 
     private void splitDocuments() {
         subHandlerList = new ArrayList<>(documents.size());
         for (SolrInputDocument document : documents) {
             MCRSolrInputDocumentHandler subHandler = new MCRSolrInputDocumentHandler(document, getSolrClient());
             subHandler.setCommitWithin(getCommitWithin());
             this.subHandlerList.add(subHandler);
         }
     }
 
     @Override
     public List<MCRSolrIndexHandler> getSubHandlers() {
         return subHandlerList == null ? super.getSubHandlers() : subHandlerList;
     }
 
     @Override
     public int getDocuments() {
         return documents.size();
     }
 
     @Override
     public String toString() {
         return "index " + this.documents.size() + " mycore documents";
     }
 
 }