package org.apache.maven.model.transform;
   
   /*
    * 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.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.List;
  import java.util.Objects;
  import java.util.Optional;
  import java.util.function.Function;
  
  import org.apache.maven.model.transform.pull.NodeBufferingParser;
  import org.codehaus.plexus.util.xml.pull.XmlPullParser;
  
  /**
   * <p>
   * Transforms relativePath to version.
   * We could decide to simply allow {@code <parent/>}, but let's require the GA for now for checking
   * This filter does NOT remove the relativePath (which is done by {@link RelativePathXMLFilter}, it will only
   * optionally include the version based on the path
   * </p>
   *
   * @author Robert Scholte
   * @author Guillaume Nodet
   * @since 4.0.0
   */
  class ParentXMLFilter
      extends NodeBufferingParser
  {
  
      private final Function<Path, Optional<RelativeProject>> relativePathMapper;
  
      private final Path projectPath;
  
      /**
       * @param relativePathMapper
       */
      ParentXMLFilter( XmlPullParser parser,
                       Function<Path, Optional<RelativeProject>> relativePathMapper, Path projectPath )
      {
          super( parser, "parent" );
          this.relativePathMapper = relativePathMapper;
          this.projectPath = projectPath;
      }
  
      protected void process( List<Event> buffer )
      {
          String tagName = null;
          String groupId = null;
          String artifactId = null;
          String version = null;
          String relativePath = null;
          String whitespaceAfterParentStart = "";
          boolean hasVersion = false;
          boolean hasRelativePath = false;
          for ( int i = 0; i < buffer.size(); i++ )
          {
              Event event = buffer.get( i );
              if ( event.event == START_TAG )
              {
                  tagName = event.name;
                  hasVersion |= "version".equals( tagName );
                  hasRelativePath |= "relativePath".equals( tagName );
              }
              else if ( event.event == TEXT )
              {
                  if ( event.text.matches( "\\s+" ) )
                  {
                      if ( whitespaceAfterParentStart.isEmpty() )
                      {
                          whitespaceAfterParentStart = event.text;
                      }
                  }
                  else if ( "groupId".equals( tagName ) )
                  {
                      groupId = nullSafeAppend( groupId, event.text );
                  }
                  else if ( "artifactId".equals( tagName ) )
                  {
                      artifactId = nullSafeAppend( artifactId, event.text );
                  }
                 else if ( "relativePath".equals( tagName ) )
                 {
                     relativePath = nullSafeAppend( relativePath, event.text );
                 }
                 else if ( "version".equals( tagName ) )
                 {
                     version = nullSafeAppend( version, event.text );
                 }
             }
             else if ( event.event == END_TAG && "parent".equals( event.name ) )
             {
                 Optional<RelativeProject> resolvedParent;
                 if ( !hasVersion && ( !hasRelativePath || relativePath != null ) )
                 {
                     Path relPath = Paths.get( Objects.toString( relativePath, "../pom.xml" ) );
                     resolvedParent = resolveRelativePath( relPath, groupId, artifactId );
                 }
                 else
                 {
                     resolvedParent = Optional.empty();
                 }
                 if ( !hasVersion && resolvedParent.isPresent() )
                 {
                     int pos = buffer.get( i - 1 ).event == TEXT ? i - 1  : i;
                     Event e = new Event();
                     e.event = TEXT;
                     e.text = whitespaceAfterParentStart;
                     buffer.add( pos++, e );
                     e = new Event();
                     e.event = START_TAG;
                     e.namespace = buffer.get( 0 ).namespace;
                     e.prefix = buffer.get( 0 ).prefix;
                     e.name = "version";
                     buffer.add( pos++, e );
                     e = new Event();
                     e.event = TEXT;
                     e.text = resolvedParent.get().getVersion();
                     buffer.add( pos++, e );
                     e = new Event();
                     e.event = END_TAG;
                     e.name = "version";
                     e.namespace = buffer.get( 0 ).namespace;
                     e.prefix = buffer.get( 0 ).prefix;
                     buffer.add( pos++, e );
                 }
                 break;
             }
         }
         buffer.forEach( this::pushEvent );
    }
 
 
     protected Optional<RelativeProject> resolveRelativePath( Path relativePath, String groupId, String artifactId )
     {
         Path pomPath = projectPath.resolve( relativePath );
         if ( Files.isDirectory( pomPath ) )
         {
             pomPath = pomPath.resolve( "pom.xml" );
         }
 
         Optional<RelativeProject> mappedProject = relativePathMapper.apply( pomPath.normalize() );
 
         if ( mappedProject.isPresent() )
         {
             RelativeProject project = mappedProject.get();
 
             if ( Objects.equals( groupId, project.getGroupId() )
                 && Objects.equals( artifactId, project.getArtifactId() ) )
             {
                 return mappedProject;
             }
         }
         return Optional.empty();
     }
 
 }