/*
    * 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.myfaces.trinidad.component;
  
  import java.io.Externalizable;
  import java.io.IOException;
  import java.io.ObjectInput;
  import java.io.ObjectOutput;
  import java.io.Serializable;
  
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import javax.faces.component.EditableValueHolder;
  import javax.faces.component.UIComponent;
  import javax.faces.component.UIPanel;
  import javax.faces.context.FacesContext;
  
  import org.apache.myfaces.trinidad.bean.FacesBean;
  import org.apache.myfaces.trinidad.logging.TrinidadLogger;
  
  
  /**
   * This class saves the state of stamp components.
   */
  final class StampState implements Externalizable
  {
    public StampState()
    {
      _rows = Collections.emptyMap();
    }
  
    /**
     * Clears all state except for the state associated with the
     * give currencyObj
     * @param skipCurrencyObj
     */
    public void clear(Object skipCurrencyObj)
    {
      if (!_rows.isEmpty())
      {
        Iterator<DualKey> iter = _rows.keySet().iterator();
        while(iter.hasNext())
        {
          DualKey dk = iter.next();
          if (_eq(dk._key1, skipCurrencyObj))
            continue;
          iter.remove();
        }
      }
    }
  
    public void put(Object currencyObj, String key, Object value)
    {
      Map<DualKey, Object> comparant = Collections.emptyMap();
      if (_rows == comparant)
      {
        if (value == null)
          return;
  
        // =-=AEW Better default sizes
        _rows = new HashMap<DualKey, Object>(109);
      }
  
      DualKey dk = new DualKey(currencyObj, key);
      // Make sure that if we're applying a null value, that we
      // don't hold on to the key and retain the entry - just nuke
      // the entry
      if (value == null)
        _rows.remove(dk);
      else
        _rows.put(dk, value);
    }
  
    public int size()
    {
      return _rows.size();
    }
  
    public Object get(Object currencyObj, String key)
   {
     DualKey dk = new DualKey(currencyObj, key);
     return _rows.get(dk);
   }
 
   /**
    * Save the per-row state of a given stamp.
    */
   public static Object saveStampState(FacesContext context, UIComponent stamp)
   {
     RowState state = _createState(stamp);
     return state;
   }
 
   /**
    * Restore the per-row state of a given stamp.
    */
   public static void restoreStampState(FacesContext context, UIComponent stamp,
                                        Object stampState)
   {
     if (stampState != null)
     {
       RowState state = (RowState) stampState;
       state.restoreRowState(stamp);
     }
   }
 
   /**
    * save the stamp state of just the children of the given component
    * in the given table.
    */
   @SuppressWarnings("unchecked")
   public static Object saveChildStampState(
     FacesContext context,
     UIComponent   stamp,
     UIXCollection table)
   {
     int childCount = stamp.getChildCount();
     // If we have any children, iterate through the array,
     // saving state
     if (childCount == 0)
       return null;
 
     Object[] childStateArray = null;
     List<UIComponent> children = stamp.getChildren();
     boolean childStateIsEmpty = true;
     for(int i=0; i < childCount; i++)
     {
       UIComponent child = children.get(i);
       Object childState = table.saveStampState(context, child);
 
       // Until we have one non-null entry, don't allocate the array.
       // Unlike facets, we *do* care about stashing Transient.TRUE,
       // because we have to keep track of them relative to any
       // later components, BUT if it's all null and transient, we
       // can discard the array.  This does mean that putting
       // transient components into a stamp is a bit inefficient
 
       // So: allocate the array if we encounter our first
       // non-null childState (even if it's transient)
       if (childStateArray == null)
       {
         if (childState == null)
           continue;
 
         childStateArray = new Object[childCount];
       }
 
       // But remember the moment we've encountered a non-null
       // *and* non-transient component, because that means we'll
       // really need to keep this array
       if ((childState != UIXCollection.Transient.TRUE) && (childState != null))
         childStateIsEmpty = false;
 
       // Store a value into the array
       assert(childStateArray != null);
       childStateArray[i] = childState;
     }
 
     // Even if we bothered to allocate an array, if all we
     // had were transient + null, don't bother with the array at all
     if (childStateIsEmpty)
       return null;
 
     return childStateArray;
   }
 
   /**
    * Restore the stamp state of just the children of the given component
    * in the given table.
    */
   @SuppressWarnings("unchecked")
   public static void restoreChildStampState(
     FacesContext context,
     UIComponent stamp,
     UIXCollection table,
     Object stampState)
   {
     if (stampState == null)
       return;
 
     List<UIComponent> kids = stamp.getChildren();
     Object[] state = (Object[]) stampState;
 
     int childIndex = 0;
     for(int i=0; i<state.length; i++)
     {
       Object childState = state[i];
       // Skip over any saved state that corresponds to transient
       // components
       if (childState != UIXCollection.Transient.TRUE)
       {
         while (childIndex < kids.size())
         {
           UIComponent kid = kids.get(childIndex);
           childIndex++;
           // Skip over any transient components before restoring state
           if (!kid.isTransient())
           {
             table.restoreStampState(context, kid, childState);
             break;
           }
         }
       }
       // The component may or may not still be there;  if it
       // is, then we'd better skip over it
       else
       {
         if (childIndex < kids.size())
         {
           UIComponent child = kids.get(childIndex);
           // If the child isn't transient, then it must be
           // something that we want to look at on the next
           // iteration.
           if (child.isTransient())
             childIndex++;
         }
       }
     }
   }
 
   /**
    * @todo can do better...
    */
   public void writeExternal(ObjectOutput out) throws IOException
   {
     out.writeInt(_rows.size());
 
     if (_rows.isEmpty())
       return;
 
     HashMap<DualKey, Object> map = new HashMap<DualKey, Object>(_rows.size());
     map.putAll(_rows);
 
     if (_LOG.isFinest())
     {
       for(Map.Entry<DualKey, Object> entry : map.entrySet())
       {
         _LOG.finest("Saving " + entry.getKey() + ", " + entry.getValue());
       }
     }
 
     out.writeObject(map);
   }
 
   @SuppressWarnings("unchecked")
   public void readExternal(ObjectInput in)
     throws IOException, ClassNotFoundException
   {
     int size = in.readInt();
 
     if (size > 0)
     _rows = (Map<DualKey, Object>) in.readObject();
 
     if (_LOG.isFinest())
     {
       for(Map.Entry<DualKey, Object> entry : _rows.entrySet())
       {
         _LOG.finest("Restoring " + entry.getKey() + ", " + entry.getValue());
       }
     }
   }
 
   private static RowState _createState(UIComponent child)
   {
     RowState state;
     if (child instanceof EditableValueHolder)
     {
       state = new EVHState();
       state.saveRowState(child);
     }
     else if (child instanceof UIXCollection)
     {
       state = new TableState();
       state.saveRowState(child);
     }
     else if (child instanceof UIXShowDetail)
     {
       state = SDState.getState((UIXShowDetail) child);
     }
     else
     {
       state = null;
     }
 
     return state;
   }
 
   private static boolean _eq(Object k1, Object k2)
   {
     if (k1 == null)
       return k2 == null;
     return k1.equals(k2);
   }
 
   // State for a single row
   static private abstract class RowState implements Serializable
   {
 
     public RowState()
     {
     }
 
     abstract public void saveRowState(UIComponent child);
 
     abstract public void restoreRowState(UIComponent child);
 
     abstract public boolean isNull();
     
     private static final long serialVersionUID = 1L;
   }
 
   static private final class SDState extends RowState
   {
     /**
      * Return cached, shared instances of SDState.
      */
     static public RowState getState(UIXShowDetail child)
     {
       FacesBean bean = child.getFacesBean();
       Boolean disclosed = (Boolean)bean.getLocalProperty(UIXShowDetail.DISCLOSED_KEY);
       if (disclosed == null)
         return _NULL;
       else if (disclosed)
         return _TRUE;
       else
         return _FALSE;
     }
 
     public SDState()
     {
     }
 
     private SDState(Boolean disclosed)
     {
       _disclosed = disclosed;
     }
 
     @Override
     public void saveRowState(UIComponent child)
     {
       FacesBean bean = ((UIXShowDetail)child).getFacesBean();
       _disclosed = (Boolean)bean.getLocalProperty(UIXShowDetail.DISCLOSED_KEY);
     }
 
     @Override
     public void restoreRowState(UIComponent child)
     {
       FacesBean bean = ((UIXShowDetail)child).getFacesBean();
       bean.setProperty(UIXShowDetail.DISCLOSED_KEY, _disclosed);
     }
 
     @Override
     public boolean isNull()
     {
       return _disclosed == null;
     }
 
     @Override
     public String toString()
     {
       return "SDState[disclosed=" + _disclosed + "]";
     }
 
     // Reusable instances of SDState. TODO: use readResolve/writeReplace
     // so that we only send across and restore instances of these
     static private final SDState _TRUE = new SDState(true);
     static private final SDState _FALSE = new SDState(false);
     static private final SDState _NULL = new SDState(null);
 
     /**
      *
      */
     private static final long serialVersionUID = -8605916495935317932L;
 
     private Boolean _disclosed;
   }
 
   static private final class TableState extends RowState
   {
     public TableState()
     {
     }
 
     @Override
     public void saveRowState(UIComponent child)
     {
       _state = ((UIXCollection) child).__getMyStampState();
     }
 
     @Override
     public void restoreRowState(UIComponent child)
     {
       //There is a bug in the RI where, on a PPR request, an UIPanel will sometimes be
       //added to a facet that contains only one child in facelets.  This, of course,
       //changes the structure of the saved data.  If we get a UIPanel here, then this
       //but is the cause.  It means we have a Collection which contains a switcher
       //which in turn contains another Collection, and UIPanel was returned instead of
       //the origional collection.  Therefore, this UIPanel should ALWAYS only have one
       //Item.  If the facet contained more then one item, we would ALWAYS have a UIPanel
       //and therefore we would be using a different stamp state.
       UIXCollection myChild = (child instanceof UIPanel)?(UIXCollection)child.getChildren().get(0):(UIXCollection)child;
       
       myChild.__setMyStampState(_state);
     }
 
     @Override
     public boolean isNull()
     {
       return _state == null;
     }
 
     private Object _state = null;
 
     private static final long serialVersionUID = 1L;
   }
 
   static private class EVHState extends RowState
   {
     public EVHState()
     {
       _valid = true;
     }
 
     @Override
     public void saveRowState(UIComponent child)
     {
       assert _assertIsStampCorrect(child);
 
       EditableValueHolder evh = (EditableValueHolder) child;
       _submitted = evh.getSubmittedValue();
       _localSet = evh.isLocalValueSet();
       _local = evh.getLocalValue();
       _valid = evh.isValid();
     }
 
     @Override
     public void restoreRowState(UIComponent child)
     {
       assert _assertIsStampCorrect(child);
 
       EditableValueHolder evh = (EditableValueHolder) child;
       evh.setSubmittedValue(_submitted);
       evh.setValue(_local);
       evh.setLocalValueSet(_localSet);
       evh.setValid(_valid);
 
       assert _assertStampHonoursState(evh);
     }
 
     @Override
     public boolean isNull()
     {
       return (_valid && (!_localSet) && (_submitted == null));
     }
 
 
     @Override
     public String toString()
     {
       return "EVHState[value=" + _local + ",submitted=" + _submitted + "]";
     }
 
     private boolean _assertStampHonoursState(EditableValueHolder evh)
     {
       return (evh.getSubmittedValue() == _submitted) &&
         (evh.getLocalValue() == _local) &&
         (evh.isLocalValueSet() == _localSet) &&
         (evh.isValid() == _valid);
     }
 
     /**
      * Make sure that this stampState is used to save/restore state from the
      * same stamp each time.
      */
     private boolean _assertIsStampCorrect(UIComponent stamp)
     {
       if (_assertStamp != null)
       {
         String stampId = stamp.getId();
         String assertStampId = _assertStamp.getId();
         assert (((assertStampId == null) && (stampId == null)) ||
                 ((assertStampId != null) && assertStampId.equals(stampId))) :
           "Current stamp:"+stamp+
           " with id:"+stamp.getId()+
           ". Previously stamp was:"+_assertStamp+
           " with id:"+_assertStamp.getId();
       }
       else
       {
         _assertStamp = stamp;
       }
       return true;
     }
 
     private Object _submitted;
     private Object _local;
     private boolean _localSet;
     private boolean _valid;
     private transient UIComponent _assertStamp = null;
 
     private static final long serialVersionUID = 1L;
   }
 
   private static final class DualKey implements Serializable
   {
     public DualKey(Object key1, Object key2)
     {
       _key1 = key1;
       _key2 = key2;
 
       _hash = _hash(key1) + _hash(key2);
     }
 
     @Override
     public boolean equals(Object other)
     {
       if (other == this)
         return true;
       if (other instanceof DualKey)
       {
         DualKey otherKey = (DualKey) other;
         if (hashCode() != otherKey.hashCode())
           return false;
 
         return _eq(_key1, otherKey._key1) && _eq(_key2, otherKey._key2);
       }
       return false;
     }
 
     @Override
     public int hashCode()
     {
       return _hash;
     }
 
     @Override
     public String toString()
     {
       return "<"+_key1+","+_key2+">";
     }
 
     private static int _hash(Object k)
     {
       return (k==null) ? 0 : k.hashCode();
     }
 
     private final Object _key1, _key2;
     private final int _hash;
 
     private static final long serialVersionUID = 1L;
   }
 
   private static final TrinidadLogger _LOG =
      TrinidadLogger.createTrinidadLogger(StampState.class);
 
   private Map<DualKey, Object> _rows;
   private static final Object[] _EMPTY_ARRAY = new Object[0];
   private static final long serialVersionUID = 1L;
 }