package fr.in2p3.jsaga.impl.resource.task;
   
   import org.ogf.saga.context.Context;
   import org.ogf.saga.error.*;
   import org.ogf.saga.monitoring.Callback;
   import org.ogf.saga.monitoring.Metric;
   import org.ogf.saga.monitoring.Monitorable;
   import org.ogf.saga.resource.instance.Resource;
   import org.ogf.saga.resource.task.ResourceTask;
  import org.ogf.saga.resource.task.State;
  import org.ogf.saga.session.Session;
  
  import fr.in2p3.jsaga.adaptor.resource.ResourceAdaptor;
  import fr.in2p3.jsaga.helpers.SAGAId;
  import fr.in2p3.jsaga.impl.resource.instance.ResourceAttributes;
  
  /* ***************************************************
   * *** Centre de Calcul de l'IN2P3 - Lyon (France) ***
   * ***             http://cc.in2p3.fr/             ***
   * ***************************************************/
  public class AbstractResourceTaskImpl<R extends Resource>
          extends AbstractMonitorableWithAsyncAttributes<R>
          implements ResourceTask, ResourceMonitorCallback
  {
      protected ResourceAdaptor m_adaptor;
      protected ResourceAttributes m_attributes;
      private StateListener m_listener;
      private ResourceMetrics m_metrics;
      private State m_state = State.NEW;
      private long m_stateLastUpdate = 0;
  
      // TODO: make this a parameter
      private long m_stateLifetimeMillis = 30000;
      
      /** common to all constructors */
      public AbstractResourceTaskImpl(Session session, StateListener listener, ResourceAdaptor adaptor) {
          super(session);
          m_adaptor = adaptor;
          m_listener = listener;
          m_metrics = new ResourceMetrics(this);
      }
  
      @Override
      public String getId() {
          return m_attributes.m_ResourceID.getObject();
      }
  
      public State getState() throws NotImplementedException, TimeoutException, NoSuccessException {
          // either take status from cache or ask the adaptor
          if (m_state != null && m_stateLastUpdate != 0 
                  && (System.currentTimeMillis() < m_stateLastUpdate + m_stateLifetimeMillis)) {
              return m_state;
          } else {
              try {
                  return m_adaptor.getResourceStatus(SAGAId.idFromSagaId(getId())).getSagaState();
              } catch (DoesNotExistException e) {
                  throw new NoSuccessException(e);
              } catch (BadParameterException e) {
                  throw new NoSuccessException(e);
              }
          }
      }
      
      public void waitFor() throws NotImplementedException, IncorrectStateException, TimeoutException, NoSuccessException {
          this.waitFor(WAIT_FOREVER, State.FINAL);
      }
      public void waitFor(float timeoutInSeconds) throws NotImplementedException, IncorrectStateException, TimeoutException, NoSuccessException {
          this.waitFor(timeoutInSeconds, State.FINAL);
      }
      public void waitFor(State state) throws NotImplementedException, IncorrectStateException, TimeoutException, NoSuccessException {
          this.waitFor(WAIT_FOREVER, state);
      }
      public void waitFor(float timeoutInSeconds, State state) throws NotImplementedException, IncorrectStateException, TimeoutException, NoSuccessException {
          try {
              // start listening
              int cookie = m_metrics.m_State.addCallback(new Callback() {
                  public boolean cb(Monitorable mt, Metric metric, Context ctx) throws NotImplementedException, AuthorizationFailedException {
                      AbstractResourceTaskImpl resource = (AbstractResourceTaskImpl) mt;
                      try {
                          String value = metric.getAttribute(Metric.VALUE);
                          State current = State.valueOf(value);
                          resource.setState(current, null);
                      }
                      catch (NotImplementedException e) {throw e;}
                      catch (AuthorizationFailedException e) {throw e;}
                      catch (Exception e) {e.printStackTrace();}
                      // callback must stay registered
                      return true;
                  }
              });
  
              // wait for specified state
              long endTime;
              if (timeoutInSeconds == WAIT_FOREVER) {
                  endTime = -1;
              } else {
                  endTime = System.currentTimeMillis() + (long) (timeoutInSeconds*1000f);
              }
              int mask = state.getValue();
             State current;
             do {
                 try {
                     Thread.sleep(500);
                 } catch (InterruptedException e) {
                     throw new NoSuccessException(e);
                 }
                 current = this.m_state;
                 if (System.currentTimeMillis()>=endTime) {
                     throw new TimeoutException();
                 }
             } while ((current.getValue() & mask) == 0);
 
             // stop listening
             m_metrics.m_State.removeCallback(cookie);
         } catch (AuthenticationFailedException e) {
             throw new NoSuccessException(e);
         } catch (AuthorizationFailedException e) {
             throw new NoSuccessException(e);
         } catch (PermissionDeniedException e) {
             throw new NoSuccessException(e);
         } catch (BadParameterException e) {
             throw new NoSuccessException(e);
         }
     }
 
     ////////////////////////////////////////// internal methods //////////////////////////////////////////
 
     public void startListening() throws NotImplementedException, IncorrectStateException, TimeoutException, NoSuccessException {
         // forward to manager
         try {
             m_listener.startListening(SAGAId.idFromSagaId(getId()), this);
         } catch (BadParameterException e) {
             throw new NoSuccessException(e);
         }
     }
     public void stopListening() throws NotImplementedException, TimeoutException, NoSuccessException {
         // forward to manager
         try {
             m_listener.stopListening(SAGAId.idFromSagaId(getId()));
         } catch (BadParameterException e) {
             throw new NoSuccessException(e);
         }
     }
     
     @Override
     public void setState(State state, String stateDetail) {
         // save the notified state
         m_state = state;
         m_metrics.m_StateDetail.setValue(stateDetail);
         m_stateLastUpdate = System.currentTimeMillis();
     }
 
 }