/*
 * Copyright 2002-2005 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.springmodules.workflow.jbpm31.definition;

import org.jbpm.graph.def.ProcessDefinition;
import org.springframework.beans.FatalBeanException;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.io.Resource;

import java.io.InputStream;

/**
 * Process Definition Factory Bean. It acts as a simple utility for loading ProcessDefinitions
 * using Spring own resource.
 * 
 * <strong>Note:</strong> Jbpm does not support parsing subprocesses - use LocalJbpmConfigurationFactoryBean#setProcessDefinitionsResources in this case.
 * See <a href="http://opensource.atlassian.com/projects/spring/browse/MOD-193">MOD-193</a> for more details.
 * 
 * @see org.springmodules.workflow.jbpm31.LocalJbpmConfigurationFactoryBean#setProcessDefinitionsResources(Resource[])
 * 
 * @author Rob Harrop
 * @author Costin Leau
 */
public class ProcessDefinitionFactoryBean implements FactoryBean, InitializingBean {

	private ProcessDefinition processDefinition;

	private Resource definitionLocation;

	public void setDefinitionLocation(Resource definitionLocation) {
		this.definitionLocation = definitionLocation;
	}

	public void afterPropertiesSet() throws Exception {
		if (this.definitionLocation == null) {
			throw new FatalBeanException("Property [definitionLocation] of class ["
					+ ProcessDefinitionFactoryBean.class.getName()
					+ "] is required.");
		}

		InputStream inputStream = null;
		try {
			inputStream = this.definitionLocation.getInputStream();
			this.processDefinition = ProcessDefinition.parseXmlInputStream(inputStream);

		}
		finally {
			if (inputStream != null) {
				inputStream.close();
			}
		}
	}

	public Object getObject() throws Exception {
		return this.processDefinition;
	}

	public Class getObjectType() {
		return (processDefinition == null) ? ProcessDefinition.class : processDefinition.getClass();
	}

	public boolean isSingleton() {
		return true;
	}
}