/**
 *
 * 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.dci.restlet.server.api;

import org.qi4j.api.entity.EntityComposite;
import org.qi4j.api.unitofwork.NoSuchEntityException;
import org.qi4j.api.unitofwork.UnitOfWork;
import org.qi4j.spi.Qi4jSPI;
import org.qi4j.spi.entity.EntityState;
import org.restlet.Request;
import org.restlet.Response;
import org.restlet.data.Status;
import org.restlet.data.Tag;
import org.restlet.resource.ResourceException;

import java.util.Date;

/**
 * JAVADOC
 */
public class ResourceValidity
{
   EntityComposite entity;
   private final Qi4jSPI spi;

   public ResourceValidity( EntityComposite entity, Qi4jSPI spi)
   {
      this.entity = entity;
      this.spi = spi;
   }

   public void updateEntity(UnitOfWork current)
   {
      try
      {
         entity = current.get( entity );
      } catch (NoSuchEntityException e)
      {
         // Entity was deleted
         entity = null;
      }
   }

   public void updateResponse(Response response)
   {
      if (entity != null)
      {
         EntityState state = spi.getEntityState( entity );
         Date lastModified = new Date( state.lastModified() );
         Tag tag = new Tag( state.identity().identity() + "/" + state.version() );
         response.getEntity().setModificationDate( lastModified );
         response.getEntity().setTag( tag );
      }
   }

   public void checkRequest(Request request)
         throws ResourceException
   {
      // Check command rules
      Date modificationDate = request.getConditions().getUnmodifiedSince();
      if (modificationDate != null)
      {
         EntityState state = spi.getEntityState( entity );
         Date lastModified = new Date( (state.lastModified()/1000)*1000); // Cut off milliseconds
         if (lastModified.after( modificationDate ))
         {
            throw new ResourceException(Status.CLIENT_ERROR_CONFLICT);
         }
      }

      // Check query rules
      modificationDate = request.getConditions().getModifiedSince();
      if (modificationDate != null)
      {
         EntityState state = spi.getEntityState( entity );
         Date lastModified = new Date( (state.lastModified()/1000)*1000); // Cut off milliseconds
         if (!lastModified.after( modificationDate ))
         {
            throw new ResourceException(Status.REDIRECTION_NOT_MODIFIED);
         }
      }
   }
}