/**
 *
 * Copyright
 * 2009-2015 Jayway Products AB
 * 2016-2017 Föreningen Sambruk
 *
 * Licensed under AGPL, Version 3.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.gnu.org/licenses/agpl.txt
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package se.streamsource.streamflow.web.domain.structure.label;

import java.util.ArrayList;
import java.util.List;

import org.qi4j.api.common.Optional;
import org.qi4j.api.entity.association.ManyAssociation;
import org.qi4j.api.injection.scope.This;
import org.qi4j.api.mixin.Mixins;

import se.streamsource.streamflow.infrastructure.event.domain.DomainEvent;

/**
 * JAVADOC
 */
@Mixins(Labelable.Mixin.class)
public interface Labelable
{
   void addLabel( Label label );

   void removeLabel( Label label );

   void retainLabels( @Optional SelectedLabels currentSelection, @Optional SelectedLabels nextSelection );

   interface Data
   {
      ManyAssociation<Label> labels();

      void addedLabel( @Optional DomainEvent event, Label label );

      void removedLabel( @Optional DomainEvent event, Label label );
   }

   abstract class Mixin
         implements Labelable, Data
   {
      @This
      Data data;

      public void addLabel( Label label )
      {
         data.addedLabel( null, label );
      }

      public void removeLabel( Label label )
      {
         if (data.labels().contains( label ))
         {
            data.removedLabel( null, label );
         }
      }

      public void retainLabels( SelectedLabels currentSelection, SelectedLabels nextSelection )
      {
         List<Label> removedLabels = new ArrayList<Label>();
         if (nextSelection == null)
         {
            for (Label labelEntity : labels())
            {
               if (currentSelection.hasSelectedLabel( labelEntity ))
                  removedLabels.add( labelEntity );
            }
         } else if (currentSelection == null)
         {
            // Do nothing
         } else
         {
            for (Label labelEntity : labels())
            {
               if (currentSelection.hasSelectedLabel( labelEntity ) && !nextSelection.hasSelectedLabel( labelEntity ))
                  removedLabels.add( labelEntity );
            }
         }

         // Remove any labels that should not be retained
         for (Label removedLabel : removedLabels)
         {
            removeLabel( removedLabel );
         }
      }

      public void addedLabel( @Optional DomainEvent event, Label label )
      {
         for (int i = 0; i < data.labels().count(); i++)
         {
            if (data.labels().get( i ).getDescription().compareTo( label.getDescription() ) > 0)
            {
               data.labels().add( i, label );
               return;
            }
         }

         data.labels().add( label );
      }

      public void removedLabel( @Optional DomainEvent event, Label label )
      {
         data.labels().remove( label );
      }
   }
}