/**
    * Copyright 2005-2014 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.krad.uif.util;
  
  import java.io.Serializable;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  
  import org.kuali.rice.krad.datadictionary.Copyable;
  
  /**
   * Map implementation for internal use by a lifecycle element.
   *
   * <p>Mutability of the map will follow the semantics for the lifecycle element.</p>
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   * @param <K> map key type
   * @param <V> map value type
   */
  public class LifecycleAwareMap<K, V> implements Map<K, V>, UifCloneable, Copyable, Serializable {
      private static final long serialVersionUID = -2872079344892779899L;
  
      /**
       * The lifecycle element this map is related to.
       */
      private final LifecycleElement lifecycleElement;
  
      /**
       * Delegating map implementation.
       */
      private Map<K, V> delegate;
  
      /**
       * Create a new map instance for use with a lifecycle element.
       *
       * @param lifecycleElement The lifecycle element to use for mutability checks.
       */
      public LifecycleAwareMap(LifecycleElement lifecycleElement) {
          this.lifecycleElement = lifecycleElement;
          this.delegate = Collections.emptyMap();
      }
  
      /**
       * Create a new list instance, based on another list.
       *
       * @param lifecycleElement The lifecycle element to use for mutability checks.
       * @param delegate The list to wrap.
       */
      public LifecycleAwareMap(LifecycleElement lifecycleElement, Map<K, V> delegate) {
          this.lifecycleElement = lifecycleElement;
          this.delegate = delegate;
      }
  
      /**
       * Ensure that the delegate list can be modified.
       */
      private void ensureMutable() {
          lifecycleElement.checkMutable(true);
  
          if (delegate == Collections.EMPTY_MAP) {
              delegate = new HashMap<K, V>();
          }
      }
  
      @Override
      public int size() {
          return this.delegate.size();
      }
  
      @Override
      public boolean isEmpty() {
          return this.delegate.isEmpty();
      }
  
      @Override
      public boolean containsKey(Object key) {
          return this.delegate.containsKey(key);
      }
  
      @Override
      public boolean containsValue(Object value) {
          return this.delegate.containsValue(value);
      }
 
     @Override
     public V get(Object key) {
         return this.delegate.get(key);
     }
 
     @Override
     public V put(K key, V value) {
         ensureMutable();
         return this.delegate.put(key, value);
     }
 
     @Override
     public V remove(Object key) {
         lifecycleElement.checkMutable(true);
         return delegate == Collections.EMPTY_MAP ? null : this.delegate.remove(key);
     }
 
     @Override
     public void putAll(Map<? extends K, ? extends V> m) {
         ensureMutable();
         this.delegate.putAll(m);
     }
 
     @Override
     public void clear() {
         if (delegate != Collections.EMPTY_MAP) {
             this.delegate.clear();
         }
     }
 
     @Override
     public Set<K> keySet() {
         return this.delegate.keySet();
     }
 
     @Override
     public Collection<V> values() {
         return this.delegate.values();
     }
 
     @Override
     public Set<java.util.Map.Entry<K, V>> entrySet() {
         // TODO: Return entrySet wrapper
         return this.delegate.entrySet();
     }
 
     @Override
     public boolean equals(Object o) {
         return this.delegate.equals(o);
     }
 
     @Override
     public int hashCode() {
         return this.delegate.hashCode();
     }
 
     /**
      * @see org.kuali.rice.krad.datadictionary.Copyable#copy()
      */
     @SuppressWarnings("unchecked")
     @Override
     public <T> T copy() {
         try {
             return (T) clone();
         } catch (CloneNotSupportedException e) {
             throw new IllegalStateException("Unexpected error in clone()", e);
         }
     }
 
     /**
      * Modification is not controlled at this level.
      * 
      * @see Copyable#preventModification()
      */
     @Override
     public void preventModification() {}
 
     /**
      * @see java.lang.Object#clone()
      */
     @Override
     public Object clone() throws CloneNotSupportedException {
         return super.clone();
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Copyable unwrap() {
         return this;
     }
 
 }