/*
    * 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.file;
  
  import java.io.IOException;
  import java.nio.file.Path;
  import java.nio.file.ProviderMismatchException;
  import java.nio.file.attribute.BasicFileAttributes;
  import java.util.Collection;
  import java.util.Date;
  import java.util.HashSet;
  import java.util.concurrent.TimeUnit;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.apache.solr.common.SolrInputDocument;
  import org.mycore.common.MCRCache;
  import org.mycore.datamodel.classifications2.MCRCategLinkReference;
  import org.mycore.datamodel.classifications2.MCRCategLinkServiceFactory;
  import org.mycore.datamodel.classifications2.MCRCategory;
  import org.mycore.datamodel.classifications2.MCRCategoryDAO;
  import org.mycore.datamodel.classifications2.MCRCategoryDAOFactory;
  import org.mycore.datamodel.classifications2.MCRCategoryID;
  import org.mycore.datamodel.common.MCRISO8601Date;
  import org.mycore.datamodel.common.MCRXMLMetadataManager;
  import org.mycore.datamodel.metadata.MCRMetadataManager;
  import org.mycore.datamodel.metadata.MCRObjectID;
  import org.mycore.datamodel.niofs.MCRContentTypes;
  import org.mycore.datamodel.niofs.MCRPath;
  
  import com.google.common.io.Files;
  
  public class MCRSolrFileIndexBaseAccumulator implements MCRSolrFileIndexAccumulator {
  
      private static Logger LOGGER = LogManager.getLogger(MCRSolrFileIndexBaseAccumulator.class);
  
      private static MCRXMLMetadataManager XML_MANAGER = MCRXMLMetadataManager.instance();
  
      private static final MCRCategoryDAO CATEGORY_DAO = MCRCategoryDAOFactory.getInstance();
  
      private static final MCRCache<String, String> DERIVATE_MODIFIED_CACHE = new MCRCache<>(10000,
          "derivateID ISODateString cache");
  
      @Override
      public void accumulate(SolrInputDocument doc, Path input, BasicFileAttributes attr) throws IOException {
          doc.setField("id", input.toUri().toString());
          String absolutePath = '/' + input.subpath(0, input.getNameCount()).toString();
          try {
              MCRPath mcrPath = MCRPath.toMCRPath(input); //check if this is an MCRPath -> more metadata
              MCRObjectID mcrObjID = MCRMetadataManager.getObjectId(MCRObjectID.getInstance(mcrPath.getOwner()), 10,
                  TimeUnit.SECONDS);
              if (mcrObjID == null) {
                  LOGGER.warn("Could not determine MCRObject for file {}", absolutePath);
                  doc.setField("returnId", mcrPath.getOwner());
              } else {
                  doc.setField("returnId", mcrObjID.toString());
                  doc.setField("objectProject", mcrObjID.getProjectId());
              }
              String ownerID = mcrPath.getOwner();
              doc.setField("derivateID", ownerID);
              doc.setField("derivateModified", getDerivateModified(ownerID));
              Collection<MCRCategoryID> linksFromReference = MCRCategLinkServiceFactory.getInstance()
                  .getLinksFromReference(new MCRCategLinkReference(mcrPath));
              HashSet<MCRCategoryID> linkedCategories = new HashSet<>(linksFromReference);
              for (MCRCategoryID category : linksFromReference) {
                  for (MCRCategory parent : CATEGORY_DAO.getParents(category)) {
                      linkedCategories.add(parent.getId());
                  }
              }
              for (MCRCategoryID category : linkedCategories) {
                  doc.addField("fileCategory", category.toString());
              }
          } catch (ProviderMismatchException e) {
              LOGGER.warn("Cannot build all fields as input is not an instance of MCRPath: {}", input);
          }
          doc.setField("objectType", "data_file");
          doc.setField("fileName", input.getFileName().toString());
          doc.setField("filePath", absolutePath);
          doc.setField("stream_size", attr.size());
          doc.setField("stream_name", absolutePath);
          doc.setField("stream_source_info", input.toString());
          doc.setField("stream_content_type", MCRContentTypes.probeContentType(input));
          doc.setField("extension", Files.getFileExtension(input.getFileName().toString()));
         MCRISO8601Date iDate = new MCRISO8601Date();
         iDate.setDate(new Date(attr.lastModifiedTime().toMillis()));
         doc.setField("modified", iDate.getISOString());
     }
 
     /**
      * returns ISO8601 formated string of when derivate was last modified
      *
      * @param derivateID
      * @throws IOException
      *             thrown by {@link MCRCache.ModifiedHandle#getLastModified()}
      */
     private static String getDerivateModified(final String derivateID) throws IOException {
         MCRObjectID derID = MCRObjectID.getInstance(derivateID);
         MCRCache.ModifiedHandle modifiedHandle = XML_MANAGER.getLastModifiedHandle(derID, 30, TimeUnit.SECONDS);
         String modified = DERIVATE_MODIFIED_CACHE.getIfUpToDate(derivateID, modifiedHandle);
         if (modified == null) {
             Date date = new Date(modifiedHandle.getLastModified());
             MCRISO8601Date date2 = new MCRISO8601Date();
             date2.setDate(date);
             modified = date2.getISOString();
             DERIVATE_MODIFIED_CACHE.put(derivateID, modified);
         }
         return modified;
     }
 }