/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program 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.
*
* Copyright (c) 2006 - 2013 Pentaho Corporation and Contributors.  All rights reserved.
*/

package org.pentaho.reporting.libraries.formula.operators;

import org.pentaho.reporting.libraries.formula.EvaluationException;
import org.pentaho.reporting.libraries.formula.FormulaContext;
import org.pentaho.reporting.libraries.formula.lvalues.TypeValuePair;
import org.pentaho.reporting.libraries.formula.typing.ExtendedComparator;
import org.pentaho.reporting.libraries.formula.typing.TypeRegistry;
import org.pentaho.reporting.libraries.formula.typing.coretypes.LogicalType;

/**
 * Creation-Date: 31.10.2006, 16:34:11
 *
 * @author Thomas Morgner
 */
public class NotEqualOperator implements InfixOperator {
  private static final TypeValuePair RETURN_TRUE = new TypeValuePair( LogicalType.TYPE, Boolean.TRUE );
  private static final TypeValuePair RETURN_FALSE = new TypeValuePair( LogicalType.TYPE, Boolean.FALSE );
  private static final long serialVersionUID = -3928772250539654675L;

  public NotEqualOperator() {
  }

  public TypeValuePair evaluate( final FormulaContext context,
                                 final TypeValuePair value1, final TypeValuePair value2 )
    throws EvaluationException {
    final TypeRegistry typeRegistry = context.getTypeRegistry();

    final ExtendedComparator comparator =
      typeRegistry.getComparator( value1.getType(), value2.getType() );
    final boolean result = comparator.isEqual
      ( value1.getType(), value1.getValue(),
        value2.getType(), value2.getValue() );

    if ( result == false ) {
      return RETURN_TRUE;
    } else {
      return RETURN_FALSE;
    }
  }

  public int getLevel() {
    return 400;
  }

  public String toString() {
    return "<>";
  }

  /**
   * Defines the bind-direction of the operator. That direction defines, in which direction a sequence of equal
   * operators is resolved.
   *
   * @return true, if the operation is left-binding, false if right-binding
   */
  public boolean isLeftOperation() {
    return true;
  }

  /**
   * Defines, whether the operation is associative. For associative operations, the evaluation order does not matter, if
   * the operation appears more than once in an expression, and therefore we can optimize them a lot better than
   * non-associative operations (ie. merge constant parts and precompute them once).
   *
   * @return true, if the operation is associative, false otherwise
   */
  public boolean isAssociative() {
    return false;
  }

}