package org.apache.maven.project.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 org.apache.maven.model.Model;

 import org.apache.maven.model.io.xpp3.MavenXpp3Reader;

 import org.apache.maven.model.io.xpp3.MavenXpp3Writer;

 import org.codehaus.plexus.logging.AbstractLogEnabled;

 import org.codehaus.plexus.logging.Logger;

 import org.codehaus.plexus.util.StringUtils;

 import org.codehaus.plexus.util.cli.CommandLineUtils;

 import org.codehaus.plexus.util.introspection.ReflectionValueExtractor;

 import org.codehaus.plexus.util.xml.pull.XmlPullParserException;

 import java.io.IOException;

 import java.io.StringReader;

 import java.io.StringWriter;

 import java.util.Map;

 import java.util.Properties;

 import java.util.regex.Matcher;

 import java.util.regex.Pattern;

 /**

  * Use a regular expression search to find and resolve expressions within the POM.

  *

  * @author jdcasey Created on Feb 3, 2005

  * @version $Id: RegexBasedModelInterpolator.java 688884 2008-08-25 21:11:19Z jdcasey $

  * @todo Consolidate this logic with the PluginParameterExpressionEvaluator, minus deprecations/bans.

  */

 public class RegexBasedModelInterpolator

     extends AbstractLogEnabled

     implements ModelInterpolator

 {

     private static final Pattern EXPRESSION_PATTERN = Pattern.compile( "\\$\\{(pom\\.|project\\.|env\\.)?([^}]+)\\}" );

     private Properties envars;

     public RegexBasedModelInterpolator( Properties envars )

     {

         this.envars = envars;

     }

     public RegexBasedModelInterpolator()

         throws IOException

     {

         envars = CommandLineUtils.getSystemEnvVars();

     }

     public Model interpolate( Model model, Map context )

         throws ModelInterpolationException

     {

         return interpolate( model, context, true );

     }

     /**

      * Serialize the inbound Model instance to a StringWriter, perform the regex replacement to resolve

      * POM expressions, then re-parse into the resolved Model instance.

      * <br/>

      * <b>NOTE:</b> This will result in a different instance of Model being returned!!!

      *

      * @param model   The inbound Model instance, to serialize and reference for expression resolution

      * @param context The other context map to be used during resolution

      * @return The resolved instance of the inbound Model. This is a different instance!

      */

     public Model interpolate( Model model, Map context, boolean strict )

         throws ModelInterpolationException

     {

         StringWriter sWriter = new StringWriter();

         MavenXpp3Writer writer = new MavenXpp3Writer();

         try

         {

             writer.write( sWriter, model );

         }

         catch ( IOException e )

         {

             throw new ModelInterpolationException( "Cannot serialize project model for interpolation.", e );

         }

         String serializedModel = sWriter.toString();

         serializedModel = interpolateInternal( serializedModel, model, context );

         StringReader sReader = new StringReader( serializedModel );

         MavenXpp3Reader modelReader = new MavenXpp3Reader();

         try

         {

             model = modelReader.read( sReader );

         }

         catch ( IOException e )

         {

             throw new ModelInterpolationException(

                 "Cannot read project model from interpolating filter of serialized version.", e );

         }

         catch ( XmlPullParserException e )

         {

             throw new ModelInterpolationException(

                 "Cannot read project model from interpolating filter of serialized version.", e );

         }

         return model;

     }

     private String interpolateInternal( String src, Model model, Map context )

         throws ModelInterpolationException

     {

         String result = src;

         Matcher matcher = EXPRESSION_PATTERN.matcher( result );

         while ( matcher.find() )

         {

             String wholeExpr = matcher.group( 0 );

             String realExpr = matcher.group( 2 );

             Object value = context.get( realExpr );

             if ( value == null )

             {

                 // This may look out of place, but its here for the MNG-2124/MNG-1927 fix described in the project builder

                 if ( context.containsKey( realExpr ) )

                 {

                     // It existed, but was null. Leave it alone.

                     continue;

                 }

                 value = model.getProperties().getProperty( realExpr );

             }

             if ( value == null )

             {

                 try

                 {

                     // NOTE: We've already trimmed off any leading expression parts like 'project.'

                     // or 'pom.', and now we have to ensure that the ReflectionValueExtractor

                     // doesn't try to do it again.

                     value = ReflectionValueExtractor.evaluate( realExpr, model, false );

                 }

                 catch ( Exception e )

                 {

                     Logger logger = getLogger();

                     if ( logger != null )

                     {

                         logger.debug( "POM interpolation cannot proceed with expression: " + wholeExpr + ". Skipping...", e );

                     }

                 }

             }

             if ( value == null )

             {

                 value = envars.getProperty( realExpr );

             }

             // if the expression refers to itself, skip it.

             if ( String.valueOf( value ).indexOf( wholeExpr ) > -1 )

             {

                 throw new ModelInterpolationException( wholeExpr, "Expression value '" + value + "' references itself in '" + model.getId() + "'." );

             }

             if ( value != null )

             {

                 result = StringUtils.replace( result, wholeExpr, String.valueOf( value ) );

                 // could use:

                 // result = matcher.replaceFirst( stringValue );

                 // but this could result in multiple lookups of stringValue, and replaceAll is not correct behaviour

                 matcher.reset( result );

             }

 /*

         // This is the desired behaviour, however there are too many crappy poms in the repo and an issue with the

         // timing of executing the interpolation

             else

             {

                 throw new ModelInterpolationException(

                     "Expression '" + wholeExpr + "' did not evaluate to anything in the model" );

             }

 */

         }

         return result;

     }

 }