/*
    * Copyright 2015 the original author or authors.
    *
    * Licensed 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.springframework.batch.admin.configuration;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  
  import org.springframework.batch.core.configuration.support.ApplicationContextFactory;
  import org.springframework.beans.factory.FactoryBean;
  import org.springframework.beans.factory.InitializingBean;
  import org.springframework.util.Assert;
  import org.springframework.util.CollectionUtils;
  
  /**
   * @author Michael Minella
   */
  public class CompositeApplicationContextFactory implements FactoryBean<ApplicationContextFactory[]>, InitializingBean {
  
  	private List<FactoryBean<ApplicationContextFactory[]>> factoryBeans;
  
  	private List<ApplicationContextFactory> delegateFactories;
  
  	public void setFactoryBeans(List<FactoryBean<ApplicationContextFactory[]>> factoryBeans) {
  		this.factoryBeans = factoryBeans;
  	}
  
  	public void setFactories(List<ApplicationContextFactory> delegateFactories) {
  		this.delegateFactories = delegateFactories;
  	}
  
  	@Override
  	public ApplicationContextFactory[] getObject() throws Exception {
  		List<ApplicationContextFactory> factories = new ArrayList<ApplicationContextFactory>();
  
  		if(factoryBeans != null) {
  			for (FactoryBean<ApplicationContextFactory[]> factory : factoryBeans) {
  				factories.addAll(Arrays.asList(factory.getObject()));
  			}
  		}
  
  		if(delegateFactories != null) {
  			factories.addAll(delegateFactories);
  		}
  
  		return factories.toArray(new ApplicationContextFactory[factories.size()]);
  	}
  
  	@Override
  	public Class<?> getObjectType() {
  		return ApplicationContextFactory[].class;
  	}
  
  	@Override
  	public boolean isSingleton() {
  		return true;
  	}
  
  	@Override
  	public void afterPropertiesSet() throws Exception {
  		Assert.state(!CollectionUtils.isEmpty(factoryBeans) || !CollectionUtils.isEmpty(delegateFactories),
  				"A factory or factoryBean is required");
  	}
  }