/**
    * Copyright 2005-2013 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.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  import java.util.ListIterator;
  
  import org.kuali.rice.krad.datadictionary.Copyable;
  
  /**
   * List implementation for internal use by a lifecycle element.
   *
   * <p>Mutability of the list will follow the semantics for the lifecycle element.</p>
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class LifecycleAwareList<E> implements List<E>, Copyable, UifCloneable, Serializable {
  
      private static final long serialVersionUID = -8971217230511446882L;
  
      /**
       * Delegating list iterator proxy.
       *
       * @author Kuali Rice Team (rice.collab@kuali.org)
       */
      private class ListIter implements ListIterator<E> {
  
          private final ListIterator<E> delegate;
  
          /**
           * @see LifecycleAwareList#listIterator()
           */
          private ListIter() {
              this.delegate = LifecycleAwareList.this.delegate.listIterator();
          }
  
          /**
           * @see LifecycleAwareList#listIterator(int)
           */
          private ListIter(int index) {
              this.delegate = LifecycleAwareList.this.delegate.listIterator(index);
          }
  
          @Override
          public boolean hasNext() {
              return this.delegate.hasNext();
          }
  
          @Override
          public E next() {
              return this.delegate.next();
          }
  
          @Override
          public boolean hasPrevious() {
              return this.delegate.hasPrevious();
          }
  
          @Override
          public E previous() {
              return this.delegate.previous();
          }
  
          @Override
          public int nextIndex() {
              return this.delegate.nextIndex();
          }
  
          @Override
          public int previousIndex() {
              return this.delegate.previousIndex();
          }
  
          @Override
          public void remove() {
              lifecycleElement.checkMutable(true);
              this.delegate.remove();
          }
  
          @Override
          public void set(E e) {
             lifecycleElement.checkMutable(true);
             this.delegate.set(e);
         }
 
         @Override
         public void add(E e) {
             lifecycleElement.checkMutable(true);
             this.delegate.add(e);
         }
 
     }
 
     /**
      * Delegating iterator proxy.
      *
      * @author Kuali Rice Team (rice.collab@kuali.org)
      */
     private class Iter implements Iterator<E> {
 
         private final Iterator<E> delegate;
 
         /**
          * @see LifecycleAwareList#iterator()
          */
         private Iter() {
             this.delegate = LifecycleAwareList.this.delegate.iterator();
         }
 
         @Override
         public boolean hasNext() {
             return this.delegate.hasNext();
         }
 
         @Override
         public E next() {
             return this.delegate.next();
         }
 
         @Override
         public void remove() {
             lifecycleElement.checkMutable(true);
             this.delegate.remove();
         }
     }
 
     /**
      * The component this list is related to.
      */
     private final LifecycleElement lifecycleElement;
 
     /**
      * Delegating list implementation.
      */
     private List<E> delegate;
 
     /**
      * Create a new list instance.
      *
      * @param lifecycleElement The lifecycle element to use for mutability checks.
      */
     public LifecycleAwareList(LifecycleElement lifecycleElement) {
         this.lifecycleElement = lifecycleElement;
         this.delegate = Collections.emptyList();
     }
 
     /**
      * 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 LifecycleAwareList(LifecycleElement lifecycleElement, List<E> delegate) {
         this.lifecycleElement = lifecycleElement;
         
         List<E> wrapped = delegate;
         while (wrapped instanceof LifecycleAwareList) {
             wrapped = ((LifecycleAwareList<E>) wrapped).delegate;
         }
         
         this.delegate = delegate;
     }
 
     /**
      * Ensure that the delegate list can be modified.
      */
     private void ensureMutable() {
         lifecycleElement.checkMutable(true);
 
         if (delegate == Collections.EMPTY_LIST) {
             delegate = new ArrayList<E>();
         }
     }
 
     @Override
     public int size() {
         return this.delegate.size();
     }
 
     @Override
     public boolean isEmpty() {
         return this.delegate.isEmpty();
     }
 
     @Override
     public boolean contains(Object o) {
         return this.delegate.contains(o);
     }
 
     @Override
     public Iterator<E> iterator() {
         return new Iter();
     }
 
     @Override
     public Object[] toArray() {
         return this.delegate.toArray();
     }
 
     @Override
     public <T> T[] toArray(T[] a) {
         return this.delegate.toArray(a);
     }
 
     @Override
     public boolean add(E e) {
         ensureMutable();
         return this.delegate.add(e);
     }
 
     @Override
     public boolean remove(Object o) {
         lifecycleElement.checkMutable(true);
         return delegate != Collections.EMPTY_LIST && delegate.remove(o);
     }
 
     @Override
     public boolean containsAll(Collection<?> c) {
         return this.delegate.containsAll(c);
     }
 
     @Override
     public boolean addAll(Collection<? extends E> c) {
         ensureMutable();
         return this.delegate.addAll(c);
     }
 
     @Override
     public boolean addAll(int index, Collection<? extends E> c) {
         ensureMutable();
         return this.delegate.addAll(index, c);
     }
 
     @Override
     public boolean removeAll(Collection<?> c) {
         lifecycleElement.checkMutable(true);
         return delegate != Collections.EMPTY_LIST && this.delegate.removeAll(c);
     }
 
     @Override
     public boolean retainAll(Collection<?> c) {
         lifecycleElement.checkMutable(true);
         return delegate != Collections.EMPTY_LIST && this.delegate.retainAll(c);
     }
 
     @Override
     public void clear() {
         if (this.delegate != Collections.EMPTY_LIST) {
             this.delegate.clear();
         }
     }
 
     @Override
     public boolean equals(Object o) {
         return this.delegate.equals(o);
     }
 
     @Override
     public int hashCode() {
         return this.delegate.hashCode();
     }
 
     @Override
     public E get(int index) {
         return this.delegate.get(index);
     }
 
     @Override
     public E set(int index, E element) {
         lifecycleElement.checkMutable(true);
         return this.delegate.set(index, element);
     }
 
     @Override
     public void add(int index, E element) {
         ensureMutable();
         this.delegate.add(index, element);
     }
 
     @Override
     public E remove(int index) {
         lifecycleElement.checkMutable(true);
         return this.delegate.remove(index);
     }
 
     @Override
     public int indexOf(Object o) {
         return this.delegate.indexOf(o);
     }
 
     @Override
     public int lastIndexOf(Object o) {
         return this.delegate.lastIndexOf(o);
     }
 
     @Override
     public ListIterator<E> listIterator() {
         ensureMutable();
         return new ListIter();
     }
 
     @Override
     public ListIterator<E> listIterator(int index) {
         ensureMutable();
         return new ListIter(index);
     }
 
     @Override
     public List<E> subList(int fromIndex, int toIndex) {
         return new LifecycleAwareList<E>(lifecycleElement, this.delegate.subList(fromIndex, toIndex));
     }
 
     /**
      * @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();
     }
 
 }