/*************************************************************************
 * Copyright 2009-2014 Eucalyptus Systems, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3 of the License.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/.
 *
 * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
 * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
 * additional information or have any questions.
 ************************************************************************/
package com.eucalyptus.compute.policy;

import static com.eucalyptus.auth.PolicyResourceContext.PolicyResourceInfo;
import static com.eucalyptus.compute.policy.ComputePolicyContext.ComputePolicyContextResource;
import static com.eucalyptus.auth.PolicyResourceContext.PolicyResourceInterceptor;
import java.util.Set;
import com.eucalyptus.auth.PolicyResourceContext.PolicyResourceIdentity;
import com.eucalyptus.compute.common.CloudMetadata;
import com.eucalyptus.compute.common.CloudMetadata.NetworkGroupMetadata;
import com.eucalyptus.records.Logs;
import com.eucalyptus.auth.type.RestrictedType;
import com.eucalyptus.util.TypeMappers;
import com.google.common.base.Strings;
import com.google.common.collect.Sets;

/**
 *
 */
public class ComputePolicyResourceInterceptor implements PolicyResourceInterceptor {
  private static final Set<Class<? extends RestrictedType>> accepted = Sets.newCopyOnWriteArraySet( );
  private static final Set<Class<? extends RestrictedType>> rejected = Sets.newCopyOnWriteArraySet( );

  @SuppressWarnings( "unchecked" )
	@Override
  public void onResource( final PolicyResourceInfo resource, final String action ) {
    ComputePolicyContext.clearContext( );

    if ( resource != null && CloudMetadata.class.isAssignableFrom( resource.getResourceClass( ) ) ) {
      final String resourceAccountNumber = resource.getResourceAccountNumber( );
      final Class<? extends CloudMetadata> resourceClass = (Class<? extends CloudMetadata>)resource.getResourceClass( );
      final String resourceId = Strings.emptyToNull( resource.getResourceObject() == null ?
          null :
          NetworkGroupMetadata.class.isAssignableFrom( resource.getResourceClass( ) ) ?
              ((NetworkGroupMetadata)resource.getResourceObject( )).getGroupId( ):
              ((CloudMetadata)resource.getResourceObject( )).getDisplayName( ) );

      if ( accepted.contains( resource.getResourceClass( ) ) ||
          (!rejected.contains( resource.getResourceClass( ) ) ) ) try {
        ComputePolicyContext.setComputePolicyContextResource(
            resourceAccountNumber,
            resourceClass,
            resourceId,
            resource.getResourceObject() == null ?
                null :
                TypeMappers.transform( resource.getResourceObject( ), ComputePolicyContextResource.class )
         );
        accepted.add( (Class<? extends RestrictedType>) resource.getResourceClass( ) );
      } catch ( IllegalArgumentException e ) {
        rejected.add( (Class<? extends RestrictedType>) resource.getResourceClass( ) );
        Logs.exhaust( ).info(
            "Policy context not set for resource type: " + resource.getResourceClass().getSimpleName( ) );
      }
      if ( rejected.contains( resource.getResourceClass( ) ) )  {
        ComputePolicyContext.setComputePolicyContextResource( resourceAccountNumber, resourceClass, resourceId, null );
      }
    }
  }

  @Override
  public void pushResource( final PolicyResourceIdentity resourceIdentity ) {
    resourceIdentity.setIdentity(
        ComputePolicyContext.getPolicyResourceType( ),
        ComputePolicyContext.getResourceId( )
    );
  }
}