/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF 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.apache.commons.jxpath.ri.model.jdom;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import org.apache.commons.jxpath.ri.QName;
  import org.apache.commons.jxpath.ri.model.NodeIterator;
  import org.apache.commons.jxpath.ri.model.NodePointer;
  import org.jdom.Attribute;
  import org.jdom.Element;
  import org.jdom.Namespace;
  
  /**
   * An iterator of attributes of a DOM Node.
   */
  public class JDOMAttributeIterator implements NodeIterator {
  
      private NodePointer parent;
      private List<Attribute> attributes;
      private int position;
  
      /**
       * Constructs a new JDOMAttributeIterator.
       *
       * @param parent pointer
       * @param qName   test
       */
      public JDOMAttributeIterator(final NodePointer parent, final QName qName) {
          this.parent = parent;
          if (parent.getNode() instanceof Element) {
              final Element element = (Element) parent.getNode();
              final String prefix = qName.getPrefix();
              Namespace ns = null;
              if (prefix != null) {
                  if (prefix.equals("xml")) {
                      ns = Namespace.XML_NAMESPACE;
                  } else {
                      final String uri = parent.getNamespaceResolver().getNamespaceURI(prefix);
                      if (uri != null) {
                          ns = Namespace.getNamespace(prefix, uri);
                      }
                      if (ns == null) {
                          // TBD: no attributes
                          attributes = Collections.emptyList();
                          return;
                      }
                  }
              } else {
                  ns = Namespace.NO_NAMESPACE;
              }
              final String lname = qName.getName();
              if (!lname.equals("*")) {
                  attributes = new ArrayList<>();
                  final Attribute attr = element.getAttribute(lname, ns);
                  if (attr != null) {
                      attributes.add(attr);
                  }
              } else {
                  attributes = new ArrayList<>();
                  final List<Attribute> allAttributes = element.getAttributes();
                  for (int i = 0; i < allAttributes.size(); i++) {
                      final Attribute attr = allAttributes.get(i);
                      if (ns == Namespace.NO_NAMESPACE || attr.getNamespace().equals(ns)) {
                          attributes.add(attr);
                      }
                  }
              }
          }
      }
  
      @Override
      public NodePointer getNodePointer() {
          if (position == 0) {
              if (!setPosition(1)) {
                  return null;
              }
              position = 0;
          }
          int index = position - 1;
          if (index < 0) {
              index = 0;
         }
         return new JDOMAttributePointer(parent, attributes.get(index));
     }
 
     @Override
     public int getPosition() {
         return position;
     }
 
     @Override
     public boolean setPosition(final int position) {
         if (attributes == null) {
             return false;
         }
         this.position = position;
         return position >= 1 && position <= attributes.size();
     }
 }