/*
    * #%L
    * Bitrepository Integrity Service
    * %%
    * 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.integrityservice.workflow;
  
  import java.io.IOException;
  
  import org.bitrepository.common.utils.ChecksumUtils;
  import org.bitrepository.integrityservice.IntegrityServiceManager;
  import org.bitrepository.integrityservice.reports.BasicIntegrityReporter;
  import org.bitrepository.integrityservice.reports.IntegrityReporter;
  import org.bitrepository.integrityservice.workflow.step.CreateStatisticsEntryStep;
  import org.bitrepository.integrityservice.workflow.step.HandleChecksumValidationStep;
  import org.bitrepository.integrityservice.workflow.step.HandleDeletedFilesStep;
  import org.bitrepository.integrityservice.workflow.step.HandleMissingChecksumsStep;
  import org.bitrepository.integrityservice.workflow.step.HandleMissingFilesStep;
  import org.bitrepository.integrityservice.workflow.step.HandleObsoleteChecksumsStep;
  import org.bitrepository.integrityservice.workflow.step.UpdateChecksumsStep;
  import org.bitrepository.integrityservice.workflow.step.UpdateFileIDsStep;
  import org.bitrepository.service.workflow.JobID;
  import org.bitrepository.service.workflow.Workflow;
  import org.bitrepository.service.workflow.WorkflowContext;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Simple workflow for performing integrity checks of the system. 
   * Starts by updating the file ids in the integrity model, followed by updating the checksums in the integrity model.
   * Then the data is validated for integrity issues.
   * And finally it is verified whether any missing or obsolete checksums can be found.
   */
  public abstract class IntegrityCheckWorkflow extends Workflow {
      private final Logger log = LoggerFactory.getLogger(getClass());
      /** The context for the workflow.*/
      protected IntegrityWorkflowContext context;
      protected String collectionID;
      protected IntegrityReporter latestReport = null;
      /**
       * Remember to call the initialise method needs to be called before the start method.
       */
      public IntegrityCheckWorkflow() {}
  
      @Override
      public void initialise(WorkflowContext context, String collectionID) {
          this.context = (IntegrityWorkflowContext)context;
          this.collectionID = collectionID;
          jobID = new JobID(getClass().getSimpleName(), collectionID);
      }
      
      protected abstract UpdateFileIDsStep getUpdateFileIDsStep();
      
      public IntegrityReporter getLatestIntegrityReport() {
          return latestReport;
      }
      
      @Override
      public void start() {
  
          if (context == null) {
              throw new IllegalStateException("The workflow can not be started before the initialise method has been " +
                      "called.");
          }
          IntegrityReporter reporter = new BasicIntegrityReporter(jobID.getCollectionID(), jobID.getWorkflowName(),
                  IntegrityServiceManager.getIntegrityReportStorageDir());
          
          super.start();
          try {
              UpdateFileIDsStep updateFileIDsStep = getUpdateFileIDsStep();
              performStep(updateFileIDsStep);
              
              UpdateChecksumsStep updateChecksumStep = new UpdateChecksumsStep(
                      context.getCollector(), context.getStore(), context.getAlerter(),
                      ChecksumUtils.getDefault(context.getSettings()), context.getSettings(), collectionID);
              performStep(updateChecksumStep);
  
              HandleDeletedFilesStep handleDeletedFilesStep = new HandleDeletedFilesStep(context.getStore(), reporter);
              performStep(handleDeletedFilesStep);
              
              HandleMissingFilesStep handleMissingFilesStep = new HandleMissingFilesStep(context.getStore(),reporter);
              performStep(handleMissingFilesStep);
              
             HandleChecksumValidationStep handleChecksumValidationStep 
                     = new HandleChecksumValidationStep(context.getStore(), context.getAuditManager(), reporter);
             performStep(handleChecksumValidationStep);
             
             HandleMissingChecksumsStep handleMissingChecksumsStep 
                     = new HandleMissingChecksumsStep(context.getStore(), reporter);
             performStep(handleMissingChecksumsStep);
             
             HandleObsoleteChecksumsStep handleObsoleteChecksumsStep 
                     = new HandleObsoleteChecksumsStep(context.getSettings(), context.getStore(), reporter);
             performStep(handleObsoleteChecksumsStep);
             
             CreateStatisticsEntryStep createStatistics = new CreateStatisticsEntryStep(
                     context.getStore(), collectionID);
             performStep(createStatistics);
 
             if(reporter.hasIntegrityIssues()) {
                 context.getAlerter().integrityFailed(reporter.generateSummaryOfReport(), collectionID);
             }
             try {
                 reporter.generateReport();
             } catch (IOException e) {
                 log.error("Failed to generate integrity report", e);
             }
             
             latestReport = reporter;
             
         } finally {
             finish();
         }
     }
 }