/*
    * #%L
    * Bitrepository Reference Pillar
    * %%
    * Copyright (C) 2010 - 2012 The State and University Library, The Royal Library and The State Archives, Denmark
    * %%
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as 
    * published by the Free Software Foundation, either version 2.1 of the 
   * License, or (at your option) any later version.
   * 
   * This program 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 Lesser Public License for more details.
   * 
   * You should have received a copy of the GNU General Lesser Public 
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/lgpl-2.1.html>.
   * #L%
   */
  package org.bitrepository.pillar.cache;
  
  import java.util.Date;
  
  import javax.xml.datatype.XMLGregorianCalendar;
  
  import org.bitrepository.common.ArgumentValidator;
  import org.bitrepository.common.settings.Settings;
  import org.bitrepository.pillar.cache.database.ChecksumExtractor;
  import org.bitrepository.pillar.cache.database.ChecksumIngestor;
  import org.bitrepository.pillar.cache.database.ExtractedChecksumResultSet;
  import org.bitrepository.pillar.cache.database.ExtractedFileIDsResultSet;
  import org.bitrepository.service.database.DBConnector;
  import org.bitrepository.service.database.DatabaseManager;
  
  /**
   * The checksum store backed by a database.
   * This contains one ingestor and one extractor for each collec
   */
  public class ChecksumDAO implements ChecksumStore {
      /** The ingestors for the database.*/
      private final ChecksumIngestor ingestor;
      /** The extractor for the database.*/
      private final ChecksumExtractor extractor;
      /** The connector for the database.*/
      private final DBConnector connector;
      
      /**
       * Constructor.
       * @param settings The settings.
       */
      public ChecksumDAO(DatabaseManager databaseManager) {
          synchronized(this) {
              connector = databaseManager.getConnector();
              this.ingestor = new ChecksumIngestor(connector);
              this.extractor = new ChecksumExtractor(connector);
          }
      }
      
      @Override
      public void insertChecksumCalculation(String fileId, String collectionId, String checksum, Date calculationDate) {
          ArgumentValidator.checkNotNull(fileId, "String fileId");
          ArgumentValidator.checkNotNull(collectionId, "String collectionId");
          
          if(extractor.hasFile(fileId, collectionId)) {
              ingestor.updateEntry(fileId, collectionId, checksum, calculationDate);
          } else {
              ingestor.insertNewEntry(fileId, collectionId, checksum, calculationDate);
          }
      }
  
      @Override
      public void deleteEntry(String fileId, String collectionId) {
          ArgumentValidator.checkNotNull(fileId, "String fileId");
          ArgumentValidator.checkNotNull(collectionId, "String collectionId");
  
          if(!extractor.hasFile(fileId, collectionId)) {
              throw new IllegalStateException("No entry for file '" + fileId + "' to delete.");
          }
          ingestor.removeEntry(fileId, collectionId);
      }
  
      @Override
      public ChecksumEntry getEntry(String fileId, String collectionId) {
          ArgumentValidator.checkNotNull(fileId, "String fileId");
          ArgumentValidator.checkNotNull(collectionId, "String collectionId");
          
          return extractor.extractSingleEntry(fileId, collectionId);
      }
      
      @Override
      public ExtractedChecksumResultSet getEntries(XMLGregorianCalendar minTimeStamp, XMLGregorianCalendar maxTimeStamp, 
              Long maxNumberOfResults, String collectionId) {
          ArgumentValidator.checkNotNull(collectionId, "String collectionId");
          return extractor.extractEntries(minTimeStamp, maxTimeStamp, maxNumberOfResults, collectionId);
      }
      
      @Override
     public Date getCalculationDate(String fileId, String collectionId) {
         ArgumentValidator.checkNotNull(fileId, "String fileId");
         ArgumentValidator.checkNotNull(collectionId, "String collectionId");
 
         Date res = extractor.extractDateForFile(fileId, collectionId);
         if(res == null) {
             throw new IllegalStateException("No entry for file '" + fileId + "' to delete.");
         }
         return res;
         
     }
     
     @Override
     public ExtractedFileIDsResultSet getFileIDs(XMLGregorianCalendar minTimeStamp, XMLGregorianCalendar maxTimeStamp, 
             Long maxNumberOfResults, String collectionId) {
         ArgumentValidator.checkNotNull(collectionId, "String collectionId");
         return extractor.getFileIDs(minTimeStamp, maxTimeStamp, maxNumberOfResults, collectionId);
     }
 
     @Override
     public boolean hasFile(String fileId, String collectionId) {
         ArgumentValidator.checkNotNull(fileId, "String fileId");
         ArgumentValidator.checkNotNull(collectionId, "String collectionId");
 
         return extractor.hasFile(fileId, collectionId);
     }
 
     @Override
     public String getChecksum(String fileId, String collectionId) {
         ArgumentValidator.checkNotNull(fileId, "String fileId");
         ArgumentValidator.checkNotNull(collectionId, "String collectionId");
 
         String res = extractor.extractChecksumForFile(fileId, collectionId);
         if(res == null) {
             throw new IllegalStateException("No entry for file '" + fileId + "' to delete.");
         }
         return res;
     }
 
     @Override
     public java.util.Collection<String> getAllFileIDs(String collectionId) {
         ArgumentValidator.checkNotNull(collectionId, "String collectionId");
         return extractor.extractAllFileIDs(collectionId);
     }
 
     @Override
     public void close() {
         connector.destroy();
     }
 }