/*
    * #%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.service.workflow;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Abstract interface for running a SchedulableJob based on WorkflowSteps.
   * @see SchedulableJob {@link SchedulableJob}
   * @see WorkflowStep {@link WorkflowStep} 
   */
  public abstract class Workflow implements SchedulableJob {
      /** The jobID */
      protected JobID jobID;
      /** The log.*/
      private Logger log = LoggerFactory.getLogger(getClass());
  
      /** The current step running.*/
      private WorkflowStep currentStep = null;
      private WorkflowStatistic statistics;
  
      @Override
      public synchronized void start() {
          statistics = new WorkflowStatistic(getClass().getSimpleName());
          statistics.start();
      }
  
      /**
       * Initiates the given step and sets it to the current running step.
       * @param step The step to start.
       */
      protected void performStep(WorkflowStep step) {
          this.currentStep = step;
          log.info("Starting step: '" + step.getName() + "'");
          try {
              statistics.startSubStatistic(step.getName());
              step.performStep();
              statistics.finishSubStatistic();
              log.info(statistics.getCurrentSubStatistic().toString());
  
          } catch (Exception e) {
              log.error("Failure in step: '" + step.getName() + "'.", e);
              throw new RuntimeException("Failed to run step " + step.getName(), e);
          }
      }
      
      /**
       * For telling that the workflow has finished its task.
       */
      protected void finish() {
          statistics.finish();
          this.currentStep = null;
          log.info(statistics.getFullStatistics());
      }
      
      @Override
      public String currentState() {
          if(currentStep == null) {
              return NOT_RUNNING;
          } else {
              return currentStep.getName();
          }
      }
  
      /**
       * @return The statistics for this workflow.
       */
      public synchronized WorkflowStatistic getWorkflowStatistics() {
          if(statistics == null) {
              statistics = new WorkflowStatistic(getClass().getSimpleName());
          }
          return statistics;
      }
  
      @Override
      public JobID getJobID() {
          return jobID;
      }
  
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
         Workflow that = (Workflow) o;
 
         if (!jobID.equals(that.jobID)) return false;
 
         return true;
     }
 
     @Override
     public int hashCode() {
         return jobID.hashCode();
     }
 }