// $HeadURL$
// $Id$
//
// Copyright © 2006, 2010, 2011, 2012 by the President and Fellows of Harvard College.
//
// Screensaver is an open-source project developed by the ICCB-L and NSRB labs
// at Harvard Medical School. This software is distributed under the terms of
// the GNU General Public License.

package edu.harvard.med.screensaver.model.libraries;

import java.util.Map;
import java.util.Set;

import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;

import edu.harvard.med.screensaver.model.VocabularyTerm;
import edu.harvard.med.screensaver.model.VocabularyUserType;

/**
 * The vocabulary of values for {@link Plate} status.
 * 
 * @author <a mailto="andrew_tolopko@hms.harvard.edu">Andrew Tolopko</a>
 */
public enum PlateStatus implements VocabularyTerm
{
  /**
   * Initial plate status of plates upon creation.
   */
  NOT_SPECIFIED("Not specified"),
  /**
   * {@link Plate} has not yet been created (any may never be created), and so is not available for use; implies that
   * plate is not stored at the facility and does not a {@link Plate#getLocation() location}.
   */
  NOT_CREATED("Not created"),
  /**
   * {@link Plate} has been created but is not available for use; implies that plate is stored at the facility at a
   * known {@link Plate#getLocation() location}. A plate that is "Not available" may become available at a later time.
   */
  NOT_AVAILABLE("Not available"),
  /**
   * {@link Plate} is available for use (where "use" is determined by the {@link Plate} {@link Copy}'s
   * {@link CopyUsageType}; implies that plate has been created by the facility and is stored at the facility at a known
   * {@link Plate#getLocation() location}. A plate that is "Available" may become "Not available" at a later time.
   */
  AVAILABLE("Available"),
  /**
   * {@link Plate} should no longer be used (where "use" is determined by the {@link Plate} {@link Copy}'s
   * {@link CopyUsageType}, but the plate is still stored at the facility at a known {@link Plate#getLocation()
   * location}.
   */
  RETIRED("Retired"),
  /**
   * {@link Plate} is no longer available for use as it is no longer stored at the facility; implies plate does not have
   * a {@link Plate#getLocation() location}.
   */
  GIVEN_AWAY("Given Away"),
  /**
   * {@link Plate} is no longer available for use as it has been discarded; implies plate does not have a
   * {@link Plate#getLocation() location}.
   */
  DISCARDED("Discarded"),
  /**
   * {@link Plate} is no longer available for use as it has been discarded, but its remaining reagent volume was first
   * transferred to another another {@link Plate}; implies plate does not have a {@link Plate#getLocation() location}
   */
  VOLUME_TRANSFERRED_AND_DISCARDED("Discarded (volume transferred)"),
  /**
   * The plate is no longer available for use, as its {@link Plate#getLocation() location} is no longer known.
   */
  LOST("Lost");

  private static Set<PlateStatus> allExcept(Set<PlateStatus> invalidPlateStatuses)
  {
    return Sets.difference(ImmutableSet.of(PlateStatus.values()), invalidPlateStatuses);
  }

  private static Map<PlateStatus,Set<PlateStatus>> Transitions = Maps.newHashMap();
  static {
    Transitions.put(NOT_SPECIFIED, ImmutableSet.of(PlateStatus.values()));
    Transitions.put(NOT_CREATED, allExcept(ImmutableSet.of(NOT_SPECIFIED)));
    Transitions.put(NOT_AVAILABLE, allExcept(ImmutableSet.of(NOT_SPECIFIED, NOT_CREATED)));
    Transitions.put(AVAILABLE, allExcept(ImmutableSet.of(NOT_SPECIFIED, NOT_CREATED)));
    Transitions.put(RETIRED, ImmutableSet.of(AVAILABLE, GIVEN_AWAY, DISCARDED, VOLUME_TRANSFERRED_AND_DISCARDED, LOST));
    Transitions.put(GIVEN_AWAY, ImmutableSet.<PlateStatus>of());
    Transitions.put(DISCARDED, ImmutableSet.<PlateStatus>of());
    Transitions.put(VOLUME_TRANSFERRED_AND_DISCARDED, ImmutableSet.<PlateStatus>of());
    Transitions.put(LOST, allExcept(ImmutableSet.of(NOT_SPECIFIED, NOT_CREATED)));
  }

  private static final Set<PlateStatus> InventoriedPlateStatuses = ImmutableSet.of(PlateStatus.NOT_AVAILABLE,
                                                                                  PlateStatus.AVAILABLE,
                                                                                  PlateStatus.RETIRED);

  /**
   * A Hibernate <code>UserType</code> to map the {@link PlateStatus} vocabulary.
   */
  public static class UserType extends VocabularyUserType<PlateStatus>
  {
    public UserType()
    {
      super(PlateStatus.values());
    }
  }


  private String _value;

  private PlateStatus(String value)
  {
    _value = value;
  }

  public String getValue()
  {
    return _value;
  }

  @Override
  public String toString()
  {
    return getValue();
  }
  
  public boolean canTransitionTo(PlateStatus newStatus)
  {
    return Transitions.get(this).contains(newStatus);
  }

  /**
   * @return true if this plate status implies that a plate is being inventoried (stored), otherwise false, implying
   *         that a plate has no location
   */
  public boolean isInventoried()
  {
    return InventoriedPlateStatuses.contains(this);
  }
}