/*
    * 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.collections.map;
  
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.io.Serializable;
  import java.util.Collection;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.commons.collections.OrderedMap;
  import org.apache.commons.collections.OrderedMapIterator;
  import org.apache.commons.collections.Unmodifiable;
  import org.apache.commons.collections.collection.UnmodifiableCollection;
  import org.apache.commons.collections.iterators.UnmodifiableOrderedMapIterator;
  import org.apache.commons.collections.set.UnmodifiableSet;
  
  /**
   * Decorates another <code>OrderedMap</code> to ensure it can't be altered.
   * <p>
   * This class is Serializable from Commons Collections 3.1.
   * <p>
   * Attempts to modify it will result in an UnsupportedOperationException. 
   *
   * @since 3.0
   * @version $Id: UnmodifiableOrderedMap.java 1429905 2013-01-07 17:15:14Z ggregory $
   */
  public final class UnmodifiableOrderedMap<K, V> extends AbstractOrderedMapDecorator<K, V> implements
          Unmodifiable, Serializable {
  
      /** Serialization version */
      private static final long serialVersionUID = 8136428161720526266L;
  
      /**
       * Factory method to create an unmodifiable sorted map.
       * 
       * @param <K>  the key type
       * @param <V>  the value type
       * @param map  the map to decorate, must not be null
       * @return a new ordered map
       * @throws IllegalArgumentException if map is null
       */
      public static <K, V> OrderedMap<K, V> unmodifiableOrderedMap(final OrderedMap<K, V> map) {
          if (map instanceof Unmodifiable) {
              return map;
          }
          return new UnmodifiableOrderedMap<K, V>(map);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Constructor that wraps (not copies).
       * 
       * @param map  the map to decorate, must not be null
       * @throws IllegalArgumentException if map is null
       */
      private UnmodifiableOrderedMap(final OrderedMap<K, V> map) {
          super(map);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Write the map out using a custom routine.
       * 
       * @param out  the output stream
       * @throws IOException
       * @since 3.1
       */
      private void writeObject(final ObjectOutputStream out) throws IOException {
          out.defaultWriteObject();
          out.writeObject(map);
      }
  
      /**
       * Read the map in using a custom routine.
       * 
       * @param in  the input stream
       * @throws IOException
       * @throws ClassNotFoundException
       * @since 3.1
       */
      @SuppressWarnings("unchecked") // (1) should only fail if input stream is incorrect 
      private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
         in.defaultReadObject();
         map = (Map<K, V>) in.readObject(); // (1)
     }
 
     //-----------------------------------------------------------------------
     @Override
     public OrderedMapIterator<K, V> mapIterator() {
         final OrderedMapIterator<K, V> it = decorated().mapIterator();
         return UnmodifiableOrderedMapIterator.unmodifiableOrderedMapIterator(it);
     }
 
     @Override
     public void clear() {
         throw new UnsupportedOperationException();
     }
 
     @Override
     public V put(final K key, final V value) {
         throw new UnsupportedOperationException();
     }
 
     @Override
     public void putAll(final Map<? extends K, ? extends V> mapToCopy) {
         throw new UnsupportedOperationException();
     }
 
     @Override
     public V remove(final Object key) {
         throw new UnsupportedOperationException();
     }
 
     @Override
     public Set<Map.Entry<K, V>> entrySet() {
         final Set<Map.Entry<K, V>> set = super.entrySet();
         return UnmodifiableEntrySet.unmodifiableEntrySet(set);
     }
 
     @Override
     public Set<K> keySet() {
         final Set<K> set = super.keySet();
         return UnmodifiableSet.unmodifiableSet(set);
     }
 
     @Override
     public Collection<V> values() {
         final Collection<V> coll = super.values();
         return UnmodifiableCollection.unmodifiableCollection(coll);
     }
 
 }