/*
    *  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.directory.api.ldap.model.filter;
  
  
  import org.apache.directory.api.ldap.model.message.AliasDerefMode;
  import org.apache.directory.api.ldap.model.message.SearchScope;
  import org.apache.directory.api.ldap.model.name.Dn;
  
  
  /**
   * Node used not to represent a published assertion but an assertion on the
   * scope of the search.
   * 
   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
   */
  public class ScopeNode extends AbstractExprNode
  {
      /** the scope of this node */
      private final SearchScope scope;
  
      /** the search base */
      private final Dn baseDn;
  
      /** the search ID */
      private final String baseId;
  
      /** the alias dereferencing mode */
      private final AliasDerefMode aliasDerefAliases;
  
  
      /**
       * Creates a new ScopeNode object.
       * 
       * @param aliasDerefAliases the alias dereferencing mode
       * @param baseDn the search base
       * @param baseId the search ID
       * @param scope the search scope
       */
      public ScopeNode( AliasDerefMode aliasDerefAliases, Dn baseDn, String baseId, SearchScope scope )
      {
          super( AssertionType.SCOPE );
          this.scope = scope;
          this.baseDn = baseDn;
          this.aliasDerefAliases = aliasDerefAliases;
          this.baseId = baseId;
          isSchemaAware = true;
      }
  
  
      /**
       * Always returns true since a scope node has no children.
       * 
       * @see ExprNode#isLeaf()
       * @return <code>true</code>
       */
      @Override
      public boolean isLeaf()
      {
          return true;
      }
  
  
      /**
       * Gets the search scope.
       * 
       * @return the search scope 
       */
      public SearchScope getScope()
      {
          return scope;
      }
  
  
      /**
       * Gets the base dn.
       * 
       * @return the base dn
       */
      public Dn getBaseDn()
      {
          return baseDn;
     }
 
 
     /**
      * Gets the base ID.
      * 
      * @return the base ID
      */
     public String getBaseId()
     {
         return baseId;
     }
 
 
     /**
      * Gets the alias dereferencing mode type safe enumeration.
      * 
      * @return the alias dereferencing enumeration constant.
      */
     public AliasDerefMode getDerefAliases()
     {
         return aliasDerefAliases;
     }
 
 
     /**
      * @see ExprNode#accept(
      *FilterVisitor)
      * 
      * @param visitor the filter expression tree structure visitor
      * @return The modified element
      */
     @Override
     public Object accept( FilterVisitor visitor )
     {
         if ( visitor.canVisit( this ) )
         {
             return visitor.visit( this );
         }
         else
         {
             return null;
         }
     }
 
 
     /**
      * {@inheritDoc}
      */
     @Override
     public boolean equals( Object obj )
     {
         if ( obj == this )
         {
             return true;
         }
 
         if ( ( obj == null ) || !( obj instanceof ScopeNode ) )
         {
             return false;
         }
         ScopeNode that = ( ScopeNode ) obj;
         if ( aliasDerefAliases == null )
         {
             if ( that.aliasDerefAliases != null )
             {
                 return false;
             }
         }
         else
         {
             if ( !aliasDerefAliases.equals( that.aliasDerefAliases ) )
             {
                 return false;
             }
         }
         if ( baseDn == null )
         {
             if ( that.baseDn != null )
             {
                 return false;
             }
         }
         else
         {
             if ( !baseDn.equals( that.baseDn ) )
             {
                 return false;
             }
         }
         if ( scope.getScope() != that.scope.getScope() )
         {
             return false;
         }
         return super.equals( obj );
     }
 
 
     /**
      * @see Object#hashCode()
      * @return the instance's hash code 
      */
     @Override
     public int hashCode()
     {
         int h = 37;
 
         h = h * 17 + super.hashCode();
         h = h * 17 + ( aliasDerefAliases != null ? aliasDerefAliases.hashCode() : 0 );
         h = h * 17 + ( baseDn != null ? baseDn.hashCode() : 0 );
         h = h * 17 + scope.getScope();
 
         return h;
     }
 
 
     /**
      * @see Object#toString()
      * @return A string representing the AndNode
      */
     @Override
     public String toString()
     {
         StringBuilder buf = new StringBuilder();
 
         buf.append( "(#{" );
 
         switch ( scope )
         {
             case OBJECT:
                 buf.append( "OBJECT_SCOPE" );
 
                 break;
 
             case ONELEVEL:
                 buf.append( "ONE_LEVEL_SCOPE" );
 
                 break;
 
             case SUBTREE:
                 buf.append( "SUBTREE_SCOPE (Estimated)" );
 
                 break;
 
             default:
                 buf.append( "UNKNOWN" );
                 break;
         }
 
         buf.append( ", '" );
         buf.append( baseDn );
         buf.append( "', " );
         buf.append( aliasDerefAliases );
         buf.append( "}" );
         buf.append( super.toString() );
         buf.append( ')' );
 
         return buf.toString();
     }
 }