package com.explosion.utilities.preferences.groups;
   
   /*
    * =============================================================================
    * 
    * Copyright 2004 Stephen Cowx
    * 
    * Licensed 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.
   * 
   * =============================================================================
   */
  
  import java.util.Hashtable;
  import java.util.Vector;
  
  import org.apache.log4j.LogManager;
  import org.apache.log4j.Logger;
  
  import com.explosion.utilities.preferences.Preference;
  import com.explosion.utilities.preferences.persist.PreferenceGroupPersister;
  import com.explosion.utilities.preferences.persist.PreferenceGroupPersisterFactory;
  
  /***
   * @author Stephen Cowx Date created:@25-Jan-2003
   */
  public class PreferenceGroup 
  {
      private static Logger log = LogManager.getLogger(PreferenceGroup.class);
      
      private Hashtable preferencesHash;
  
      private Vector preferencesVector;
  
      private String identifier;
  
      private PreferenceGroupPersister pgPersister;
  
      private Object object;
  
      private Object referenceToStore;
  
      private boolean editable = true;
  
      /***
       * Constructor for InMemoryPreferenceGroup.
       */
      public PreferenceGroup(Object referenceToStore, String identifier) throws PreferencePersistenceException
      {
          this.identifier = identifier;
          this.referenceToStore = referenceToStore;
          preferencesHash = new Hashtable();
          preferencesVector = new Vector();
          pgPersister = PreferenceGroupPersisterFactory.createPreferenceGroupPersister(referenceToStore);
          if (pgPersister == null)
          {
              throw new PreferencePersistenceException("No suitable persister found for preference " + identifier + " using store of type " + referenceToStore.getClass().getName());
          }
      }
  
      /***
       * Returns the identifier.
       * 
       * @return String
       */
      public String getIdentifier()
      {
          return identifier;
      }
  
      /***
       * Sets the identifier.
       * 
       * @param identifier The identifier to set
       */
      public void setIdentifier(String identifier) throws Exception
      {
      	if (!editable) 
  		{
  		   log.warn("Attempt to edit non editable preference group " + identifier);
  		   return;
  		}
      		
      	pgPersister.renameGroup(this, identifier);
          this.identifier = identifier;
      }
  
      /***
       * Returns the preferencesHash.
       * 
      * @return Hashtable
      */
     public Hashtable getPreferencesHash()
     {
         return preferencesHash;
     }
 
     /***
      * Sets the preferencesHash.
      * 
      * @param preferencesHash The preferencesHash to set
      */
     public void setPreferencesHash(Hashtable preferencesHash)
     {
         if (!editable) 
         {
            log.warn("Attempt to edit non editable preference group " + identifier);
            return;
         }
 
         this.preferencesHash = preferencesHash;
     }
 
     /***
      * Returns the preferencesVector.
      * 
      * @return Vector
      */
     public Vector getPreferencesVector()
     {
         return preferencesVector;
     }
 
     /***
      * Sets the preferencesVector.
      * 
      * @param preferencesVector The preferencesVector to set
      */
     public void setPreferencesVector(Vector preferencesVector)
     {
         if (!editable) 
         {
            log.warn("Attempt to edit non editable preference group " + identifier);
            return;
         }
 
         this.preferencesVector = preferencesVector;
     }
 
     /***
      * Sets the object.
      * 
      * @param object The object to set
      */
     public void setObject(Object object)
     {
         this.object = object;
     }
 
     /***
      * Returns the object.
      * 
      * @return Object
      */
     public Object getObject()
     {
         return object;
     }
 
     /***
      * @see com.explosion.utilities.preferences.groups.PreferenceGroup#commit()
      */
     public void commit() throws Exception
     {
         /* Assign the old preferences to the new node */
         pgPersister.saveGroup(this);
     }
 
     /***
      * @see com.explosion.utilities.preferences.groups.PreferenceGroup#delete()
      */
     public void delete() throws Exception
     {
         if (!editable) 
         {
            log.warn("Attempt to edit non editable preference group " + identifier);
            return;
         }
 
         pgPersister.deleteGroup(this);
 
         /* Clear up local objects */
         preferencesVector = null;
         preferencesHash = null;
         referenceToStore = null;
         identifier = null;
 
     }
 
     /***
      * @see com.explosion.utilities.preferences.groups.PreferenceGroup#getAttributeValue()
      */
     public Object getPreferenceValue(String preferenceName)
     {
         return ((Preference) preferencesHash.get(preferenceName)).getValue();
     }
 
     /***
      * @see com.explosion.utilities.preferences.groups.PreferenceGroup#getAttribute()
      */
     public Preference getPreference(String preferenceName)
     {
         return (Preference) preferencesHash.get(preferenceName);
     }
 
     /***
      * @see com.explosion.utilities.preferences.groups.PreferenceGroup#setPreferenceValue(String,
      *      Object)
      */
     public void setPreferenceValue(String preferenceName, Object preferenceValue) throws Exception
     {
         if (!editable) 
         {
            log.warn("Attempt to edit non editable preference group " + identifier);
            return;
         }
 
         ((Preference) preferencesHash.get(preferenceName)).setValue(preferenceValue);
     }
 
     /***
      * @see com.explosion.utilities.preferences.groups.PreferenceGroup#addPreference(String,
      *      Object)
      */
     public void addPreference(String preferenceName, Preference preference) throws Exception
     {
         if (!editable) 
         {
            log.warn("Attempt to edit non editable preference group " + identifier);
            return;
         }
 
         if (preferencesHash.get(preferenceName) != null)
             throw new Exception("Attribute with the name " + preferenceName + " already exists.");
         else
         {
             preferencesHash.put(preferenceName, preference);
             preferencesVector.addElement(preference);
         }
     }
 
     /***
      * @see com.explosion.utilities.preferences.groups.PreferenceGroup#removePreference(String)
      */
     public void removePreference(String preferenceName) throws Exception
     {
         if (!editable) 
         {
            log.warn("Attempt to edit non editable preference group " + identifier);
            return;
         }
 
         if (preferencesHash.get(preferenceName) != null)
         {
             preferencesVector.remove(preferencesHash.get(preferenceName));
             preferencesHash.remove(preferenceName);
         }
     }
 
     public boolean isEditable()
     {
         return editable;
     }
 
     public void setEditable(boolean editable)
     {
         this.editable = editable;
 
         /* set the editability of each prefence */
         for (int i = 0; i < preferencesVector.size(); i++)
         {
             Preference pref = (Preference) preferencesVector.elementAt(i);
             pref.setEditable(false);
         }
     }
 
     /***
      * @return Returns the referenceToStore.
      */
     public Object getReferenceToStore()
     {
         return referenceToStore;
     }
     
     /***
      * @param referenceToStore The referenceToStore to set.
      */
     public void setReferenceToStore(Object referenceToStore)
     {
         this.referenceToStore = referenceToStore;
         pgPersister = PreferenceGroupPersisterFactory.createPreferenceGroupPersister(referenceToStore);
         
     }
 }