package org.apache.commons.ognl;

 /*

  * 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.

  */

 import org.apache.commons.ognl.enhance.UnsupportedCompilationException;

 /**

  * Base class for types that compare values.

  */

 public abstract class ComparisonExpression

     extends BooleanExpression

 {

     private static final long serialVersionUID = -5945855000509930682L;

     public ComparisonExpression( int id )

     {

         super( id );

     }

     public ComparisonExpression( OgnlParser p, int id )

     {

         super( p, id );

     }

     public abstract String getComparisonFunction();

     /**

      * {@inheritDoc}

      */

     @Override

     public String toGetSourceString( OgnlContext context, Object target )

     {

         if ( target == null )

         {

             throw new UnsupportedCompilationException( "Current target is null, can't compile." );

         }

         try

         {

             Object value = getValueBody( context, target );

             if ( value != null && Boolean.class.isAssignableFrom( value.getClass() ) )

             {

                 getterClass = Boolean.TYPE;

             }

             else if ( value != null )

             {

                 getterClass = value.getClass();

             }

             else

             {

                 getterClass = Boolean.TYPE;

             }

             // iterate over children to make numeric type detection work properly

             OgnlRuntime.getChildSource( context, target, children[0] );

             OgnlRuntime.getChildSource( context, target, children[1] );

             // System.out.println("comparison expression currentType: " + context.getCurrentType() + " previousType: " +

             // context.getPreviousType());

             boolean conversion = OgnlRuntime.shouldConvertNumericTypes( context );

             StringBuilder result = new StringBuilder( "(" );

             if ( conversion )

             {

                 result.append( getComparisonFunction() ).append( "( ($w) (" );

             }

             result.append( OgnlRuntime.getChildSource( context, target, children[0], conversion ) )

                     .append( " " );

             if ( conversion )

             {

                 result.append( "), ($w) " );

             }

             else

             {

                 result.append( getExpressionOperator( 0 ) );

             }

             result.append( "" ).append( OgnlRuntime.getChildSource( context, target, children[1], conversion ) );

             if ( conversion )

             {

                 result.append( ")" );

             }

             context.setCurrentType( Boolean.TYPE );

             result.append( ")" );

             return result.toString();

         }

         catch ( NullPointerException e )

         {

             // expected to happen in some instances

             throw new UnsupportedCompilationException( "evaluation resulted in null expression." );

         }

         catch ( Throwable t )

         {

             throw OgnlOps.castToRuntime( t );

         }

     }

 }