/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.runtime.config.spring.parsers.specific;

import org.mule.runtime.core.component.DefaultJavaComponent;
import org.mule.runtime.core.object.AbstractObjectFactory;
import org.mule.runtime.core.object.SingletonObjectFactory;

import java.util.HashMap;
import java.util.Map;

import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.GenericBeanDefinition;
import org.springframework.beans.factory.xml.ParserContext;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

/**
 * Used to parse shortcut elements for simple built-in components such as
 * {@link org.mule.runtime.core.component.simple.EchoComponent} and {@link org.mule.runtime.core.component.simple.LogComponent}.
 * This allows shortcuts like for example <i><mule:bridge-service/></i> to be used instead of having to use the
 * <i><mule:service/></i> element and specify the class name (and scope) for built-in components that don't require
 * configuration.
 * <p/>
 * <b>This DefinitionParser should only be used for state-less components.</b>
 * <p/>
 * In order to further customize components and use serviceFactory properties the <mule:service/> element should be used.
 */
public class SimpleComponentDefinitionParser extends ComponentDefinitionParser {

  private static Class OBJECT_FACTORY_TYPE = SingletonObjectFactory.class;
  private Class componentInstanceClass;
  private Map properties = new HashMap();

  public SimpleComponentDefinitionParser(Class component, Class componentInstanceClass) {
    super(DefaultJavaComponent.class);
    this.componentInstanceClass = componentInstanceClass;
  }

  @Override
  protected void preProcess(Element element) {
    super.preProcess(element);

    NamedNodeMap attrs = element.getAttributes();

    int numAttrs = attrs.getLength();
    Node attr;
    for (int i = numAttrs - 1; i >= 0; --i) {
      attr = attrs.item(i);
      if (attr.getNamespaceURI() == null) {
        properties.put(attr.getNodeName(), attr.getNodeValue());
        attrs.removeNamedItem(attr.getNodeName());
      }
    }
  }

  protected void parseChild(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) {
    // Create a BeanDefinition for the nested object factory and set it a
    // property value for the component
    builder.addPropertyValue("objectFactory", getObjectFactoryDefinition(element));

    super.parseChild(element, parserContext, builder);
  }

  protected AbstractBeanDefinition getObjectFactoryDefinition(Element element) {
    AbstractBeanDefinition objectFactoryBeanDefinition = new GenericBeanDefinition();
    objectFactoryBeanDefinition.setBeanClass(OBJECT_FACTORY_TYPE);
    objectFactoryBeanDefinition.getPropertyValues().addPropertyValue(AbstractObjectFactory.ATTRIBUTE_OBJECT_CLASS,
                                                                     componentInstanceClass);
    objectFactoryBeanDefinition.getPropertyValues().addPropertyValue("properties", properties);

    return objectFactoryBeanDefinition;
  }
}