/*
 * Copyright (C) 2009 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.xcmis.search.model.operand;

import org.xcmis.search.QueryObjectModelVisitor;
import org.xcmis.search.VisitException;
import org.xcmis.search.Visitors;
import org.xcmis.search.model.constraint.Comparison;
import org.xcmis.search.model.source.SelectorName;

/**
 * A dynamic operand that evaluates to the lower-case representation of the supplied operand, used in a {@link Comparison}
 * constraint.
 */

public class LowerCase extends DynamicOperand
{
   private static final long serialVersionUID = 1L;

   private final DynamicOperand operand;

   /**
    * Create a dynamic operand that evaluates to the lower-case representation of the supplied operand.
    * 
    * @param operand the operand that is to be lower-cased
    */
   public LowerCase(DynamicOperand operand)
   {
      super(operand);
      this.operand = operand;
   }

   /**
   * @see org.xcmis.search.model.QueryElement#accept(org.xcmis.search.QueryObjectModelVisitor)
   */
   public void accept(QueryObjectModelVisitor visitor) throws VisitException
   {
      visitor.visit(this);
   }

   /**
    * {@inheritDoc}
    * 
    * @see java.lang.Object#equals(java.lang.Object)
    */
   @Override
   public boolean equals(Object obj)
   {
      if (obj == this)
      {
         return true;
      }
      if (obj instanceof LowerCase)
      {
         LowerCase that = (LowerCase)obj;
         return this.operand.equals(that.operand);
      }
      return false;
   }

   /**
    * Get the dynamic operand that is to be lower-cased.
    * 
    * @return the dynamic operand; never null
    */
   public final DynamicOperand getOperand()
   {
      return operand;
   }

   /**
    * Get the selector symbol upon which this operand applies.
    * 
    * @return the one selector names used by this operand; never null
    */
   public SelectorName getSelectorName()
   {
      return getSelectorNames().iterator().next();
   }

   /**
     * {@inheritDoc}
     * 
     * @see java.lang.Object#hashCode()
     */
   @Override
   public int hashCode()
   {
      return operand.hashCode();
   }

   /**
    * {@inheritDoc}
    * 
    * @see java.lang.Object#toString()
    */
   @Override
   public String toString()
   {
      return Visitors.readable(this);
   }
}