/*
    * 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.content;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  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.impl.HttpSolrClient;
  import org.apache.solr.client.solrj.response.UpdateResponse;
  import org.apache.solr.common.SolrInputDocument;
  import org.mycore.common.content.MCRContent;
  import org.mycore.datamodel.metadata.MCRObjectID;
  import org.mycore.solr.MCRSolrClientFactory;
  import org.mycore.solr.index.MCRSolrIndexHandler;
  import org.mycore.solr.index.document.MCRSolrInputDocumentFactory;
  import org.mycore.solr.index.handlers.MCRSolrAbstractIndexHandler;
  import org.mycore.solr.index.handlers.document.MCRSolrInputDocumentHandler;
  import org.mycore.solr.index.statistic.MCRSolrIndexStatistic;
  import org.mycore.solr.index.statistic.MCRSolrIndexStatisticCollector;
  
  /**
   * @author Thomas Scheffler (yagee)
   *
   */
  public class MCRSolrMCRContentMapIndexHandler extends MCRSolrAbstractIndexHandler {
  
      private static final Logger LOGGER = LogManager.getLogger(MCRSolrMCRContentMapIndexHandler.class);
  
      private List<MCRSolrIndexHandler> subhandlers;
  
      private Map<MCRObjectID, MCRContent> contentMap;
  
      public MCRSolrMCRContentMapIndexHandler(Map<MCRObjectID, MCRContent> contentMap) {
          this(contentMap, MCRSolrClientFactory.getMainSolrClient());
      }
  
      public MCRSolrMCRContentMapIndexHandler(Map<MCRObjectID, MCRContent> contentMap, SolrClient solrClient) {
          super();
          this.contentMap = contentMap;
          this.subhandlers = new ArrayList<>(contentMap.size());
      }
  
      @Override
      public MCRSolrIndexStatistic getStatistic() {
          return MCRSolrIndexStatisticCollector.DOCUMENTS;
      }
  
      @Override
      public void index() throws IOException, SolrServerException {
          int totalCount = contentMap.size();
          LOGGER.info("Handling {} documents", totalCount);
          //multithread processing will result in too many http request
          UpdateResponse updateResponse;
          try {
              Iterator<SolrInputDocument> documents = MCRSolrInputDocumentFactory.getInstance().getDocuments(contentMap);
              SolrClient solrClient = getSolrClient();
              if (solrClient instanceof ConcurrentUpdateSolrClient) {
                  //split up to speed up processing
                  splitup(documents);
                  return;
              }
              if (LOGGER.isDebugEnabled()) {
                  ArrayList<SolrInputDocument> debugList = new ArrayList<>();
                  while (documents.hasNext()) {
                      debugList.add(documents.next());
                  }
                  LOGGER.debug("Sending these documents: {}", debugList);
                  //recreate documents interator;
                  documents = debugList.iterator();
              }
              if (solrClient instanceof HttpSolrClient) {
                  updateResponse = solrClient.add(documents);
              } else {
                  ArrayList<SolrInputDocument> docs = new ArrayList<>(totalCount);
                  while (documents.hasNext()) {
                     docs.add(documents.next());
                 }
                 updateResponse = solrClient.add(docs);
             }
         } catch (Throwable e) {
             LOGGER.warn("Error while indexing document collection. Split and retry.", e);
             splitup();
             return;
         }
         if (updateResponse.getStatus() != 0) {
             LOGGER.error("Error while indexing document collection. Split and retry: {}", updateResponse.getResponse());
             splitup();
         } else {
             LOGGER.info("Sending {} documents was successful in {} ms.", totalCount, updateResponse.getElapsedTime());
         }
 
     }
 
     private void splitup(Iterator<SolrInputDocument> documents) {
         while (documents.hasNext()) {
             MCRSolrInputDocumentHandler subhandler = new MCRSolrInputDocumentHandler(documents.next());
             subhandler.setCommitWithin(getCommitWithin());
             subhandlers.add(subhandler);
         }
         contentMap.clear();
     }
 
     private void splitup() {
         for (Map.Entry<MCRObjectID, MCRContent> entry : contentMap.entrySet()) {
             MCRSolrMCRContentIndexHandler subHandler = new MCRSolrMCRContentIndexHandler(entry.getKey(),
                 entry.getValue(), getSolrClient());
             subHandler.setCommitWithin(getCommitWithin());
             subhandlers.add(subHandler);
         }
         contentMap.clear();
     }
 
     @Override
     public List<MCRSolrIndexHandler> getSubHandlers() {
         return subhandlers;
     }
 
     @Override
     public int getDocuments() {
         return contentMap.size();
     }
 
     @Override
     public String toString() {
         return "bulk index " + contentMap.size() + " documents";
     }
 
 }