core/src/main/java/org/jclouds/location/predicates/LocationPredicates.java

/**
 * Licensed to jclouds, Inc. (jclouds) under one or more
 * contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  jclouds licenses this file
 * to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
 *
 * 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 org.jclouds.location.predicates;

import static com.google.common.base.Preconditions.checkNotNull;

import javax.inject.Singleton;

import org.jclouds.domain.Location;
import org.jclouds.domain.LocationScope;

import com.google.common.base.Predicate;

/**
 * 
 * @author Adrian Cole
 */
public class LocationPredicates {

   public static Predicate<Location> isZone() {
      return IsZone.INSTANCE;
   }

   @Singleton
   static enum IsZone implements Predicate<Location> {
      INSTANCE;
      @Override
      public boolean apply(Location input) {
         return input.getScope() == LocationScope.ZONE;
      }

      @Override
      public String toString() {
         return "isZone()";
      }
   }

   public static Predicate<Location> isRegion() {
      return IsRegion.INSTANCE;
   }

   static enum IsRegion implements Predicate<Location> {
      INSTANCE;
      @Override
      public boolean apply(Location input) {
         return input.getScope() == LocationScope.REGION;
      }

      @Override
      public String toString() {
         return "isRegion()";
      }
   }

   public static Predicate<Location> isZoneOrRegionWhereRegionIdEquals(String region) {
      return new IsZoneOrRegionWhereRegionIdEquals(region);
   }

   static class IsZoneOrRegionWhereRegionIdEquals implements Predicate<Location> {

      private final String region;

      IsZoneOrRegionWhereRegionIdEquals(String region) {
         this.region = checkNotNull(region, "region");
      }

      @Override
      public boolean apply(Location input) {
         switch (input.getScope()) {
         case ZONE:
            return input.getParent().getId().equals(region);
         case REGION:
            return input.getId().equals(region);
         default:
            return false;
         }
      }

      @Override
      public String toString() {
         return "isRegionAndIdEqualsOrIsZoneParentIdEquals(" + region + ")";
      }
   }

}