/**
    * Licensed to jclouds, Inc. (jclouds) under one or more
    * contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  jclouds licenses this file
    * to you 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.jclouds.s3.xml;
  
  import static org.jclouds.util.SaxUtils.currentOrNull;
  
  import java.net.URI;
  
  import org.jclouds.http.functions.ParseSax;
  import org.jclouds.s3.domain.AccessControlList;
  import org.jclouds.s3.domain.CanonicalUser;
  import org.jclouds.s3.domain.AccessControlList.CanonicalUserGrantee;
  import org.jclouds.s3.domain.AccessControlList.EmailAddressGrantee;
  import org.jclouds.s3.domain.AccessControlList.Grantee;
  import org.jclouds.s3.domain.AccessControlList.GroupGrantee;
  import org.xml.sax.Attributes;
  
  /**
   * Parses the following XML document:
   * <p/>
   * AccessControlPolicy xmlns="http://s3.amazonaws.com/doc/2006-03-01/"
   * 
   * @author James Murty
   * @see <a href="http://docs.amazonwebservices.com/AmazonS3/2006-03-01/RESTAccessPolicy.html"/>
   */
  public class AccessControlListHandler extends ParseSax.HandlerWithResult<AccessControlList> {
     private AccessControlList acl = new AccessControlList();
     private StringBuilder currentText = new StringBuilder();
  
     public AccessControlListHandler() {
     }
  
     public AccessControlList getResult() {
        return acl;
     }
  
     private String currentId;
     private String currentDisplayName;
     private String currentGranteeType;
     private String currentPermission;
     private Grantee currentGrantee;
  
     public void startElement(String uri, String name, String qName, Attributes attrs) {
        if (qName.equals("Grantee")) {
           currentGranteeType = attrs.getValue("xsi:type");
        }
     }
  
     public void endElement(String uri, String name, String qName) {
        if (qName.equals("Owner")) {
           CanonicalUser owner = new CanonicalUser(currentId);
           owner.setDisplayName(currentDisplayName);
           acl.setOwner(owner);
        } else if (qName.equals("Grantee")) {
           if ("AmazonCustomerByEmail".equals(currentGranteeType)) {
              currentGrantee = new EmailAddressGrantee(currentId);
           } else if ("CanonicalUser".equals(currentGranteeType)) {
              currentGrantee = new CanonicalUserGrantee(currentId, currentDisplayName);
           } else if ("Group".equals(currentGranteeType)) {
              currentGrantee = new GroupGrantee(URI.create(currentId));
           }
        } else if (qName.equals("Grant")) {
           acl.addPermission(currentGrantee, currentPermission);
        }
  
        else if (qName.equals("ID") || qName.equals("EmailAddress") || qName.equals("URI")) {
           currentId = currentOrNull(currentText);
        } else if (qName.equals("DisplayName")) {
           currentDisplayName = currentOrNull(currentText);
        } else if (qName.equals("Permission")) {
           currentPermission = currentOrNull(currentText);
        }
        currentText = new StringBuilder();
     }
  
     public void characters(char ch[], int start, int length) {
        currentText.append(ch, start, length);
     }
  }