package org.apache.maven.plugin.assembly.utils;
   
   /*
    * 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.project.MavenProject;
  import org.codehaus.plexus.logging.Logger;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  
  /**
   * @version $Id: ProjectUtils.java 1001089 2010-09-24 21:39:37Z jdcasey $
   */
  public final class ProjectUtils
  {
  
      private ProjectUtils()
      {
      }
  
      public static Set<MavenProject> getProjectModules( final MavenProject project,
                                                         final List<MavenProject> reactorProjects,
                                                         final boolean includeSubModules, final Logger logger )
          throws IOException
      {
          final Set<MavenProject> singleParentSet = Collections.singleton( project );
  
          final Set<MavenProject> moduleCandidates = new LinkedHashSet<MavenProject>( reactorProjects );
  
          final Set<MavenProject> modules = new LinkedHashSet<MavenProject>();
  
          // we temporarily add the master project to the modules set, since this
          // set is pulling double duty as a set of
          // potential module parents in the tree rooted at the master
          // project...this allows us to use the same looping
          // algorithm below to discover both direct modules of the master project
          // AND modules of those direct modules.
          modules.add( project );
  
          int changed = 0;
  
          do
          {
              changed = 0;
  
              for ( final Iterator<MavenProject> candidateIterator = moduleCandidates.iterator(); candidateIterator.hasNext(); )
              {
                  final MavenProject moduleCandidate = candidateIterator.next();
  
                  if ( moduleCandidate.getFile() == null )
                  {
                      logger.warn( "Cannot compute whether " + moduleCandidate.getId() + " is a module of: "
                                      + project.getId()
                                      + "; it does not have an associated POM file on the local filesystem." );
                      continue;
                  }
  
                  Set<MavenProject> currentPotentialParents;
                  if ( includeSubModules )
                  {
                      currentPotentialParents = new LinkedHashSet<MavenProject>( modules );
                  }
                  else
                  {
                      currentPotentialParents = singleParentSet;
                  }
  
                  for ( final Iterator<MavenProject> parentIterator = currentPotentialParents.iterator(); parentIterator.hasNext(); )
                  {
                      final MavenProject potentialParent = parentIterator.next();
  
                      if ( potentialParent.getFile() == null )
                      {
                          logger.warn( "Cannot use: " + moduleCandidate.getId()
                                          + " as a potential module-parent while computing the module set for: "
                                          + project.getId()
                                          + "; it does not have an associated POM file on the local filesystem." );
                         continue;
                     }
 
                     // if this parent has an entry for the module candidate in
                     // the path adjustments map, it's a direct
                     // module of that parent.
                     if ( projectContainsModule( potentialParent, moduleCandidate ) )
                     {
                         // add the candidate to the list of modules (and
                         // potential parents)
                         modules.add( moduleCandidate );
 
                         // remove the candidate from the candidate pool, because
                         // it's been verified.
                         candidateIterator.remove();
 
                         // increment the change counter, to show that we
                         // verified a new module on this pass.
                         changed++;
                     }
                 }
             }
         }
         while ( changed != 0 );
 
         // remove the master project from the modules set, now that we're done
         // using it as a set of potential module
         // parents...
         modules.remove( project );
 
         return modules;
     }
 
     private static boolean projectContainsModule( final MavenProject mainProject, final MavenProject moduleProject )
         throws IOException
     {
         @SuppressWarnings( "unchecked" )
         final List<String> modules = mainProject.getModules();
         final File basedir = mainProject.getBasedir();
 
         final File moduleFile = moduleProject.getFile()
                                              .getCanonicalFile();
 
         File moduleBasedir = moduleProject.getBasedir();
 
         if ( moduleBasedir == null )
         {
             if ( moduleFile != null )
             {
                 moduleBasedir = moduleFile.getParentFile();
             }
 
             if ( moduleBasedir == null )
             {
                 moduleBasedir = new File( "." );
             }
         }
 
         moduleBasedir = moduleBasedir.getCanonicalFile();
 
         for ( final Iterator<String> it = modules.iterator(); it.hasNext(); )
         {
             final String moduleSubpath = it.next();
 
             final File moduleDir = new File( basedir, moduleSubpath ).getCanonicalFile();
 
             if ( moduleDir.equals( moduleFile ) || moduleDir.equals( moduleBasedir ) )
             {
                 return true;
             }
         }
 
         return false;
     }
 
 }