/*
    * Copyright 2005-2010 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.ws.wsdl.wsdl11.provider;
  
  import java.util.Iterator;
  import javax.wsdl.Definition;
  import javax.wsdl.Message;
  import javax.wsdl.Part;
  import javax.wsdl.Types;
  import javax.wsdl.WSDLException;
  import javax.wsdl.extensions.ExtensibilityElement;
  import javax.wsdl.extensions.schema.Schema;
  import javax.xml.namespace.QName;
  
  import org.springframework.util.Assert;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.w3c.dom.Element;
  import org.w3c.dom.Node;
  import org.w3c.dom.NodeList;
  
  /**
   * Default implementation of the {@link MessagesProvider}.
   * <p/>
   * Simply adds all elements contained in the schema(s) as messages.
   *
   * @author Arjen Poutsma
   * @since 1.5.0
   */
  public class DefaultMessagesProvider implements MessagesProvider {
  
      private static final Log logger = LogFactory.getLog(DefaultMessagesProvider.class);
  
      public void addMessages(Definition definition) throws WSDLException {
          Types types = definition.getTypes();
          Assert.notNull(types, "No types element present in definition");
          for (Iterator<?> iterator = types.getExtensibilityElements().iterator(); iterator.hasNext();) {
              ExtensibilityElement extensibilityElement = (ExtensibilityElement) iterator.next();
              if (extensibilityElement instanceof Schema) {
                  Schema schema = (Schema) extensibilityElement;
                  if (schema.getElement() != null) {
                      createMessages(definition, schema.getElement());
                  }
              }
          }
          if (definition.getMessages().isEmpty() && logger.isWarnEnabled()) {
              logger.warn("No messages were created, make sure the referenced schema(s) contain elements");
          }
      }
  
      private void createMessages(Definition definition, Element schemaElement) throws WSDLException {
          String schemaTargetNamespace = schemaElement.getAttribute("targetNamespace");
          Assert.hasText(schemaTargetNamespace, "No targetNamespace defined on schema");
          if (logger.isDebugEnabled()) {
              logger.debug("Looking for elements in schema with target namespace [" + schemaTargetNamespace + "]");
          }
          NodeList children = schemaElement.getChildNodes();
          for (int i = 0; i < children.getLength(); i++) {
              Node child = children.item(i);
              if (child.getNodeType() == Node.ELEMENT_NODE) {
                  Element childElement = (Element) child;
                  if (isMessageElement(childElement)) {
                      QName elementName = new QName(schemaTargetNamespace, getElementName(childElement));
                      Message message = definition.createMessage();
                      populateMessage(definition, message, elementName);
                      Part part = definition.createPart();
                      populatePart(definition, part, elementName);
                      message.addPart(part);
                      message.setUndefined(false);
                      definition.addMessage(message);
                  }
              }
          }
      }
  
      /**
       * Returns the name attribute of the given element.
       *
       * @param element the element whose name to return
       * @return the name of the element
       */
      protected String getElementName(Element element) {
          return element.getAttribute("name");
      }
 
     /**
      * Indicates whether the given element should be includes as {@link Message} in the definition.
      * <p/>
      * Default implementation checks whether the element has the XML Schema namespace, and if it has the local name
      * "element".
      *
      * @param element the element elligable for being a message
      * @return <code>true</code> if to be included as message; <code>false</code> otherwise
      */
     protected boolean isMessageElement(Element element) {
         return "element".equals(element.getLocalName()) &&
                 "http://www.w3.org/2001/XMLSchema".equals(element.getNamespaceURI());
     }
 
     /**
      * Called after the {@link Message} has been created.
      * <p/>
      * Default implementation sets the name of the message to the element name.
      *
      * @param definition  the WSDL4J <code>Definition</code>
      * @param message     the WSDL4J <code>Message</code>
      * @param elementName the element name
      * @throws WSDLException in case of errors
      */
     protected void populateMessage(Definition definition, Message message, QName elementName) throws WSDLException {
         QName messageName = new QName(definition.getTargetNamespace(), elementName.getLocalPart());
         if (logger.isDebugEnabled()) {
             logger.debug("Creating message [" + messageName + "]");
         }
         message.setQName(messageName);
     }
 
     /**
      * Called after the {@link Part} has been created.
      * <p/>
      * Default implementation sets the element name of the part.
      *
      * @param definition  the WSDL4J <code>Definition</code>
      * @param part        the WSDL4J <code>Part</code>
      * @param elementName the elementName @throws WSDLException in case of errors
      * @see Part#setElementName(javax.xml.namespace.QName)
      */
     protected void populatePart(Definition definition, Part part, QName elementName) throws WSDLException {
         part.setElementName(elementName);
         part.setName(elementName.getLocalPart());
     }
 
 }