content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF 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.apache.ambari.server.controller.predicate;
  
  import java.util.Arrays;
  import java.util.LinkedList;
  import java.util.List;
  
  import javax.annotation.Nonnull;
  
  import org.apache.ambari.server.controller.spi.Predicate;
  import org.apache.ambari.server.controller.spi.Resource;
  
  /**
   * Predicate which evaluates to true if any of the predicates in a predicate
   * array evaluate to true.
   */
  public class OrPredicate extends ArrayPredicate {
  
    public OrPredicate(Predicate... predicates) {
      super(predicates);
    }
  
    @Override
    public Predicate create(Predicate... predicates) {
      return instance(predicates);
    }
  
    public static Predicate instance(Predicate... predicates) {
      return of(Arrays.asList(predicates));
    }
  
    public static Predicate of(@Nonnull Iterable<? extends Predicate> predicates) {
      List<Predicate> predicateList = new LinkedList<>();
  
      // Simplify the predicate array
      for (Predicate predicate : predicates) {
        if (predicate instanceof AlwaysPredicate) {
          return predicate;
        }
        else if (predicate instanceof OrPredicate) {
          predicateList.addAll(Arrays.asList(((OrPredicate) predicate).getPredicates()));
        }
        else {
          predicateList.add(predicate);
        }
      }
      return predicateList.size() == 1 ?
          predicateList.get(0) :
          new OrPredicate(predicateList.toArray(new Predicate[predicateList.size()]));
    }
  
    @Override
    public boolean evaluate(Resource resource) {
      Predicate[] predicates = getPredicates();
      for (Predicate predicate : predicates) {
        if (predicate.evaluate(resource)) {
          return true;
        }
      }
      return false;
    }
  
    @Override
    public String getOperator() {
      return "OR";
    }
  }
  