/*
    * 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.chain.web.servlet;
  
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Enumeration;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import javax.servlet.ServletContext;
  import org.apache.commons.chain.web.MapEntry;
  
  
  /**
   * <p>Private implementation of <code>Map</code> for servlet context
   * attributes.</p>
   *
   * @author Craig R. McClanahan
   * @version $Revision: 661007 $ $Date: 2008-05-28 17:28:49 +0100 (Wed, 28 May 2008) $
   */
  
  final class ServletApplicationScopeMap implements Map {
  
  
      public ServletApplicationScopeMap(ServletContext context) {
          this.context = context;
      }
  
  
      private ServletContext context = null;
  
  
      public void clear() {
          Iterator keys = keySet().iterator();
          while (keys.hasNext()) {
              context.removeAttribute((String) keys.next());
          }
      }
  
  
      public boolean containsKey(Object key) {
          return (context.getAttribute(key(key)) != null);
      }
  
  
      public boolean containsValue(Object value) {
          if (value == null) {
              return (false);
          }
          Enumeration keys = context.getAttributeNames();
          while (keys.hasMoreElements()) {
              Object next = context.getAttribute((String) keys.nextElement());
              if (value.equals(next)) {
                  return (true);
              }
          }
          return (false);
      }
  
  
      public Set entrySet() {
          Set set = new HashSet();
          Enumeration keys = context.getAttributeNames();
          String key;
          while (keys.hasMoreElements()) {
              key = (String)keys.nextElement();
              set.add(new MapEntry(key, context.getAttribute(key), true));
          }
          return (set);
      }
  
  
      public boolean equals(Object o) {
          return (context.equals(o));
      }
  
  
      public Object get(Object key) {
          return (context.getAttribute(key(key)));
      }
  
 
     public int hashCode() {
         return (context.hashCode());
     }
 
 
     public boolean isEmpty() {
         return (size() < 1);
     }
 
 
     public Set keySet() {
         Set set = new HashSet();
         Enumeration keys = context.getAttributeNames();
         while (keys.hasMoreElements()) {
             set.add(keys.nextElement());
         }
         return (set);
     }
 
 
     public Object put(Object key, Object value) {
         if (value == null) {
             return (remove(key));
         }
         String skey = key(key);
         Object previous = context.getAttribute(skey);
         context.setAttribute(skey, value);
         return (previous);
     }
 
 
     public void putAll(Map map) {
         Iterator entries = map.entrySet().iterator();
         while (entries.hasNext()) {
             Map.Entry entry = (Map.Entry)entries.next();
             put(entry.getKey(), entry.getValue());
         }
     }
 
 
     public Object remove(Object key) {
         String skey = key(key);
         Object previous = context.getAttribute(skey);
         context.removeAttribute(skey);
         return (previous);
     }
 
 
     public int size() {
         int n = 0;
         Enumeration keys = context.getAttributeNames();
         while (keys.hasMoreElements()) {
             keys.nextElement();
             n++;
         }
         return (n);
     }
 
 
     public Collection values() {
         List list = new ArrayList();
         Enumeration keys = context.getAttributeNames();
         while (keys.hasMoreElements()) {
             list.add(context.getAttribute((String) keys.nextElement()));
         }
         return (list);
     }
 
 
     private String key(Object key) {
         if (key == null) {
             throw new IllegalArgumentException();
         } else if (key instanceof String) {
             return ((String) key);
         } else {
             return (key.toString());
         }
     }
 
 
 }