/**
    * This file Copyright (c) 2003-2011 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.cms.gui.controlx.list;
  
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.NoSuchElementException;
  
  import org.apache.commons.lang.StringUtils;
  
  
  /**
   * @author Sameer Charles $Id:ListModelIteratorImpl.java 2492 2006-03-30 08:30:43Z scharles $
   */
  public class ListModelIteratorImpl implements ListModelIterator {
  
      private AbstractListModel model;
  
      /**
       * list holding all objects/records
       */
      private final List list;
  
      /**
       * next position
       */
      private int pos;
  
      /**
       * next content object (prefetched)
       */
      private Object next;
  
      /**
       * object on current pointer
       */
      private Object current;
  
      /**
       * key name on which provided list is grouped
       */
      private String groupKey;
  
      private ValueProvider valueProvider;
  
      public ListModelIteratorImpl(AbstractListModel model, List list) {
          this.model = model;
          this.list = new ArrayList(list);
          this.groupKey = model.getGroupBy();
          this.pos = 0;
          this.setValueProvider(model.getValueProvider());
  
          // prefetch next object
          prefetchNext();
      }
  
      /**
       * prefetch object for the list
       */
      private void prefetchNext() {
          this.next = null;
          while (this.next == null && this.pos < this.list.size()) {
              this.next = this.list.get(pos);
          }
      }
  
      /**
      * get named value
      * @param name its a key to which value is attached in this record
      */
     public Object getValue(String name) {
         return this.getValue(name, this.current);
     }
 
     /**
      * get value from a specified object
      * @param name its a key to which value is attached in this record
      * @param node
      */
     protected Object getValue(String name, Object node) {
         return this.getValueProvider().getValue(name, node);
     }
 
     /**
      * @see info.magnolia.cms.gui.controlx.list.ListModelIterator#getValueObject()
      */
     public Object getValueObject() {
         return this.current;
     }
 
     /**
      * get group name
      * @return name of the group of the current record
      */
     public String getGroupName() {
         if (StringUtils.isEmpty(this.groupKey)) {
             return StringUtils.EMPTY;
         }
         return (String) this.getValue(this.groupKey, this.current);
     }
 
     /**
      * move next
      */
     public Object next() {
         if (this.next == null) {
             throw new NoSuchElementException();
         }
         this.current = this.next;
         this.pos++;
         prefetchNext();
 
         return this.current;
     }
 
     /**
      * jump to next group
      */
     public Object nextGroup() {
         Object tmp = null;
         while (this.hasNextInGroup()) {
             tmp = this.next();
         }
         return tmp;
     }
 
     /**
      * checks if there is next record
      * @return true if not EOF
      */
     public boolean hasNext() {
         return this.next != null;
     }
 
     /**
      * checks if there are more records in the current group
      * @return true if not EOF
      */
     public boolean hasNextInGroup() {
         if (StringUtils.isEmpty(this.groupKey)) {
             return this.hasNext(); // no group key defined, its all one group
         }
         else if (this.hasNext()) {
             if (this.current != null) {
                 String currentValue = (String) this.getValue(this.groupKey, this.current);
                 String nextValue = (String) this.getValue(this.groupKey, this.next);
                 return StringUtils.equalsIgnoreCase(currentValue, nextValue);
             }
         }
         else {
             return false;
         }
         return true;
     }
 
     public String getId() {
         return this.model.resolveId(pos-1, this.getValueObject());
     }
 
     public void remove() {
         // not implemented
     }
 
     public void setValueProvider(ValueProvider valueProvider) {
         this.valueProvider = valueProvider;
     }
 
     public ValueProvider getValueProvider() {
         return valueProvider;
     }
 
 }