package org.apache.maven.model.interpolation;
   
   /*
    * 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 java.io.File;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import org.apache.maven.api.model.Model;
  import org.apache.maven.model.building.ModelBuildingRequest;
  import org.apache.maven.model.building.ModelProblem.Severity;
  import org.apache.maven.model.building.ModelProblem.Version;
  import org.apache.maven.model.building.ModelProblemCollector;
  import org.apache.maven.model.building.ModelProblemCollectorRequest;
  import org.apache.maven.model.v4.MavenTransformer;
  import org.apache.maven.model.path.PathTranslator;
  import org.apache.maven.model.path.UrlNormalizer;
  import org.codehaus.plexus.interpolation.InterpolationException;
  import org.codehaus.plexus.interpolation.InterpolationPostProcessor;
  import org.codehaus.plexus.interpolation.RecursionInterceptor;
  import org.codehaus.plexus.interpolation.StringSearchInterpolator;
  import org.codehaus.plexus.interpolation.ValueSource;
  
  /**
   * StringVisitorModelInterpolator
   *
   * @since 3.6.2
   */
  @Named
  @Singleton
  public class StringVisitorModelInterpolator
      extends AbstractStringBasedModelInterpolator
  {
      @Inject
      public StringVisitorModelInterpolator( PathTranslator pathTranslator,
                                             UrlNormalizer urlNormalizer )
      {
          super( pathTranslator, urlNormalizer );
      }
  
      interface InnerInterpolator
      {
          String interpolate( String value );
      }
  
      @Override
      public Model interpolateModel( Model model, File projectDir, ModelBuildingRequest config,
                                     ModelProblemCollector problems )
      {
          List<? extends ValueSource> valueSources = createValueSources( model, projectDir, config );
          List<? extends InterpolationPostProcessor> postProcessors =
              createPostProcessors( model, projectDir, config );
  
          InnerInterpolator innerInterpolator = createInterpolator( valueSources, postProcessors, problems );
  
          return new MavenTransformer( innerInterpolator::interpolate ).visit( model );
      }
  
      private InnerInterpolator createInterpolator( List<? extends ValueSource> valueSources,
                                                    List<? extends InterpolationPostProcessor> postProcessors,
                                                    final ModelProblemCollector problems )
      {
          final Map<String, String> cache = new HashMap<>();
          final StringSearchInterpolator interpolator = new StringSearchInterpolator();
          interpolator.setCacheAnswers( true );
          for ( ValueSource vs : valueSources )
          {
              interpolator.addValueSource( vs );
          }
          for ( InterpolationPostProcessor postProcessor : postProcessors )
          {
              interpolator.addPostProcessor( postProcessor );
          }
          final RecursionInterceptor recursionInterceptor = createRecursionInterceptor();
          return value ->
          {
              if ( value != null && value.contains( "${" ) )
             {
                 String c = cache.get( value );
                 if ( c == null )
                 {
                     try
                     {
                         c = interpolator.interpolate( value, recursionInterceptor );
                     }
                     catch ( InterpolationException e )
                     {
                         problems.add( new ModelProblemCollectorRequest( Severity.ERROR, Version.BASE )
                                 .setMessage( e.getMessage() ).setException( e ) );
                     }
                     cache.put( value, c );
                 }
                 return c;
             }
             return value;
         };
     }
 
 }