package org.apache.maven.plugin.assembly.interpolation;

 import java.io.File;

 import org.apache.maven.plugin.assembly.AssemblerConfigurationSource;

 import org.apache.maven.plugin.assembly.utils.InterpolationConstants;

 import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;

 import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluator;

 import org.codehaus.plexus.interpolation.InterpolationException;

 import org.codehaus.plexus.interpolation.Interpolator;

 import org.codehaus.plexus.interpolation.PrefixAwareRecursionInterceptor;

 public class AssemblyExpressionEvaluator

     implements ExpressionEvaluator

 {

     private final AssemblerConfigurationSource configSource;

     private Interpolator interpolator;

     private PrefixAwareRecursionInterceptor interceptor;

     public AssemblyExpressionEvaluator( AssemblerConfigurationSource configSource )

     {

         this.configSource = configSource;

         interpolator = AssemblyInterpolator.buildInterpolator( configSource.getProject(), configSource );

         interceptor = new PrefixAwareRecursionInterceptor( InterpolationConstants.PROJECT_PREFIXES, true );

     }

     public File alignToBaseDirectory( File f )

     {

         String basePath = configSource.getBasedir().getAbsolutePath();

         String path = f.getPath();

         if ( !f.isAbsolute() && !path.startsWith( basePath ) )

         {

             return new File( configSource.getBasedir(), path );

         }

         else

         {

             return f;

         }

     }

     public Object evaluate( String expression )

         throws ExpressionEvaluationException

     {

         try

         {

             return interpolator.interpolate( expression, interceptor );

         }

         catch ( InterpolationException e )

         {

             throw new ExpressionEvaluationException( "Interpolation failed for archiver expression: " + expression, e );

         }

     }

 }