/**
 * Copyright 2010 JBoss Inc
 *
 * 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.drools.container.spring.namespace;

import static org.drools.container.spring.namespace.DefinitionParserHelper.emptyAttributeCheck;

import org.drools.container.spring.beans.KnowledgeAgentBeanFactory;
import org.drools.container.spring.beans.StatelessKnowledgeSessionBeanFactory;
import org.springframework.beans.PropertyValue;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.RuntimeBeanReference;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.ManagedList;
import org.springframework.beans.factory.xml.AbstractBeanDefinitionParser;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.util.StringUtils;
import org.w3c.dom.Element;

/**
 * 
 * @author Lucas Amador
 *
 */
public class KnowledgeAgentDefinitionParser extends AbstractBeanDefinitionParser {

    @Override
    protected AbstractBeanDefinition parseInternal(Element element,
                                                   ParserContext parserContext) {

        BeanDefinitionBuilder factory = BeanDefinitionBuilder.rootBeanDefinition( KnowledgeAgentBeanFactory.class );

        String id = element.getAttribute( "id" );
        emptyAttributeCheck( element.getLocalName(),
                             "id",
                             id );
        factory.addPropertyValue( "id",
                                  id );

        String kbase = element.getAttribute( "kbase" );
        if ( StringUtils.hasText( kbase ) ) {
            factory.addPropertyReference( "kbase",
                                          kbase );
        }

        String newInstance = element.getAttribute( "new-instance" );
        if ( StringUtils.hasText( newInstance ) ) {
            factory.addPropertyValue( "newInstance",
                                      newInstance );
        }

        ManagedList resources = KnowledgeBaseDefinitionParser.getResources( element,
                                                                            parserContext,
                                                                            factory );

        if ( resources != null ) {
            factory.addPropertyValue( "resources",
                                      resources );
        }

        // inject the kagent into any stateless sessions
        for ( String beanName : parserContext.getRegistry().getBeanDefinitionNames() ) {
            BeanDefinition def = parserContext.getRegistry().getBeanDefinition( beanName );
            if ( def.getBeanClassName().equals( StatelessKnowledgeSessionBeanFactory.class.getName() ) ) {
                PropertyValue pvalue = def.getPropertyValues().getPropertyValue( "kbase" );
                RuntimeBeanReference tbf = (RuntimeBeanReference) pvalue.getValue();
                if ( kbase.equals( tbf.getBeanName() ) ) {
                    def.getPropertyValues().addPropertyValue( "knowledgeAgent",
                                                              new RuntimeBeanReference( id ) );
                }
            }
        }

        return factory.getBeanDefinition();
    }
}