/*
 * Data Hub Service (DHuS) - For Space data distribution.
 * Copyright (C) 2013,2014,2015,2016 GAEL Systems
 *
 * This file is part of DHuS software sources.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package fr.gael.dhus.olingo.v1;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.apache.olingo.odata2.api.edm.Edm;
import org.apache.olingo.odata2.api.edm.EdmAssociation;
import org.apache.olingo.odata2.api.edm.EdmComplexType;
import org.apache.olingo.odata2.api.edm.EdmEntityContainer;
import org.apache.olingo.odata2.api.edm.EdmEntitySet;
import org.apache.olingo.odata2.api.edm.EdmEntitySetInfo;
import org.apache.olingo.odata2.api.edm.EdmEntityType;
import org.apache.olingo.odata2.api.edm.EdmException;
import org.apache.olingo.odata2.api.edm.EdmFunctionImport;
import org.apache.olingo.odata2.api.edm.EdmServiceMetadata;
import org.apache.olingo.odata2.api.exception.ODataException;

/**
 * Decorates an EDM to remove non top-level Entity Sets.
 * This is needed to remove these Entity Sets from the service document.
 */
public class EdmWrapper implements Edm
{
   /** EDM to decorate. */
   private final Edm edm;

   /**
    * Decorate the given EDM to hide non top-level ES in the service document.
    * @param edm to decorate.
    */
   public EdmWrapper(Edm edm)
   {
      this.edm = edm;
   }

   @Override
   public List<EdmEntitySet> getEntitySets() throws EdmException
   {
      List<EdmEntitySet> eesl = new ArrayList<>();

      for (EdmEntitySet ees: edm.getEntitySets())
      {
         if (Model.getEntitySet(ees.getName()).isTopLevel())
         {
            eesl.add(ees);
         }
      }

      return eesl;
   }

   @Override
   public EdmServiceMetadata getServiceMetadata()
   {
      return new EdmServiceMetadata()
      {
         @Override
         public List<EdmEntitySetInfo> getEntitySetInfos() throws ODataException
         {
            List<EdmEntitySetInfo> eesil = new ArrayList<>();

            for (EdmEntitySetInfo ees: edm.getServiceMetadata().getEntitySetInfos())
            {
               String eesName = ees.getEntitySetName();
               if (Model.getEntitySet(eesName).isTopLevel())
               {
                  eesil.add(ees);
               }
            }
            return eesil;
         }

         @Override
         public InputStream getMetadata() throws ODataException
         {
            return edm.getServiceMetadata().getMetadata();
         }

         @Override
         public String getDataServiceVersion() throws ODataException
         {
            return edm.getServiceMetadata().getDataServiceVersion();
         }
      };
   }

   @Override
   public EdmEntityContainer getEntityContainer(String name) throws EdmException
   {
      return edm.getEntityContainer(name);
   }

   @Override
   public EdmEntityType getEntityType(String namespace, String name) throws EdmException
   {
      return edm.getEntityType(namespace, name);
   }

   @Override
   public EdmComplexType getComplexType(String namespace, String name) throws EdmException
   {
      return edm.getComplexType(namespace, name);
   }

   @Override
   public EdmAssociation getAssociation(String namespace, String name) throws EdmException
   {
      return edm.getAssociation(namespace, name);
   }

   @Override
   public EdmEntityContainer getDefaultEntityContainer() throws EdmException
   {
      return edm.getDefaultEntityContainer();
   }

   @Override
   public List<EdmFunctionImport> getFunctionImports() throws EdmException
   {
      return edm.getFunctionImports();
   }
}