/*
    * Copyright 2005-2012 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.soap.axiom;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import javax.xml.namespace.QName;
  import javax.xml.stream.XMLStreamConstants;
  
  import org.springframework.util.Assert;
  import org.springframework.xml.namespace.QNameUtils;
  
  import org.apache.axiom.om.OMAttribute;
  import org.apache.axiom.om.OMContainer;
  import org.apache.axiom.om.OMElement;
  import org.apache.axiom.om.OMFactory;
  import org.apache.axiom.om.OMNamespace;
  import org.xml.sax.Attributes;
  import org.xml.sax.ContentHandler;
  import org.xml.sax.Locator;
  import org.xml.sax.SAXException;
  import org.xml.sax.ext.LexicalHandler;
  
  /**
   * Specific SAX {@link ContentHandler} and {@link LexicalHandler} that adds the resulting AXIOM OMElement to a specified
   * parent element when <code>endDocument</code> is called. Used for returing <code>SAXResult</code>s from Axiom
   * elements.
   *
   * @author Arjen Poutsma
   * @since 1.0.0
   */
  class AxiomHandler implements ContentHandler, LexicalHandler {
  
      private final OMFactory factory;
  
      private final List<OMContainer> elements = new ArrayList<OMContainer>();
  
      private Map<String, String> namespaces = new HashMap<String, String>();
  
      private final OMContainer container;
  
      private int charactersType = XMLStreamConstants.CHARACTERS;
  
      AxiomHandler(OMContainer container, OMFactory factory) {
          Assert.notNull(container, "'container' must not be null");
          Assert.notNull(factory, "'factory' must not be null");
          this.factory = factory;
          this.container = container;
      }
  
      private OMContainer getParent() {
          if (!elements.isEmpty()) {
              return elements.get(elements.size() - 1);
          }
          else {
              return container;
          }
      }
  
      public void startPrefixMapping(String prefix, String uri) throws SAXException {
          namespaces.put(prefix, uri);
      }
  
      public void endPrefixMapping(String prefix) throws SAXException {
          namespaces.remove(prefix);
      }
  
      public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
          OMContainer parent = getParent();
          OMNamespace ns = factory.createOMNamespace(uri, QNameUtils.toQName(uri, qName).getPrefix());
          OMElement element = factory.createOMElement(localName, ns, parent);
          for (Map.Entry<String, String> entry : namespaces.entrySet()) {
              String prefix = entry.getKey();
              if (prefix.length() == 0) {
                  element.declareDefaultNamespace((String) entry.getValue());
              }
              else {
                  element.declareNamespace((String) entry.getValue(), prefix);
              }
          }
          for (int i = 0; i < atts.getLength(); i++) {
              QName attrName = QNameUtils.toQName(atts.getURI(i), atts.getQName(i));
              String value = atts.getValue(i);
             if (!atts.getQName(i).startsWith("xmlns")) {
                 OMNamespace namespace = factory.createOMNamespace(attrName.getNamespaceURI(), attrName.getPrefix());
                 OMAttribute attribute = factory.createOMAttribute(attrName.getLocalPart(), namespace, value);
                 element.addAttribute(attribute);
             }
         }
 
         elements.add(element);
     }
 
     public void endElement(String uri, String localName, String qName) throws SAXException {
         elements.remove(elements.size() - 1);
     }
 
     public void characters(char ch[], int start, int length) throws SAXException {
         String data = new String(ch, start, length);
         OMContainer parent = getParent();
         factory.createOMText(parent, data, charactersType);
     }
 
     public void ignorableWhitespace(char ch[], int start, int length) throws SAXException {
         charactersType = XMLStreamConstants.SPACE;
         characters(ch, start, length);
         charactersType = XMLStreamConstants.CHARACTERS;
     }
 
     public void processingInstruction(String target, String data) throws SAXException {
         OMContainer parent = getParent();
         factory.createOMProcessingInstruction(parent, target, data);
     }
 
     public void comment(char ch[], int start, int length) throws SAXException {
         String content = new String(ch, start, length);
         OMContainer parent = getParent();
         factory.createOMComment(parent, content);
     }
 
     public void startCDATA() throws SAXException {
         charactersType = XMLStreamConstants.CDATA;
     }
 
     public void endCDATA() throws SAXException {
         charactersType = XMLStreamConstants.CHARACTERS;
     }
 
     public void startEntity(String name) throws SAXException {
         if (!isPredefinedEntityReference(name)) {
             charactersType = XMLStreamConstants.ENTITY_REFERENCE;
         }
     }
 
     public void endEntity(String name) throws SAXException {
         charactersType = XMLStreamConstants.CHARACTERS;
     }
 
     private boolean isPredefinedEntityReference(String name) {
         return "lt".equals(name) || "gt".equals(name) || "amp".equals(name) || "quot".equals(name) ||
                 "apos".equals(name);
     }
 
     /*
     * Unsupported
     */
 
     public void setDocumentLocator(Locator locator) {
     }
 
     public void startDocument() throws SAXException {
     }
 
     public void endDocument() throws SAXException {
     }
 
     public void skippedEntity(String name) throws SAXException {
     }
 
     public void startDTD(String name, String publicId, String systemId) throws SAXException {
     }
 
     public void endDTD() throws SAXException {
     }
 }