package org.andromda.maven.plugin.andromdapp.utils;
   
   import java.io.File;
   import java.util.HashMap;
   import java.util.Map;
   import org.apache.maven.execution.MavenSession;
   import org.apache.maven.plugin.logging.Log;
   import org.apache.maven.profiles.DefaultProfileManager;
   import org.apache.maven.project.MavenProject;
  import org.apache.maven.project.MavenProjectBuilder;
  import org.apache.maven.project.ProjectBuildingException;
  
  /**
   * Contains utilities for dealing with Maven projects.
   *
   * @author Chad Brandon
   */
  public class ProjectUtils
  {
      /**
       * Stores previously discovered projects.
       */
      private static final Map<File, MavenProject> projectCache = new HashMap<File, MavenProject>();
  
      /**
       * Gets a project for the given <code>pom</code>.
       * @param projectBuilder
       * @param session
       * @param pom the pom from which to build the project.
       * @param logger
       * @return the built project.
       * @throws ProjectBuildingException
       */
      public static synchronized MavenProject getProject(
          final MavenProjectBuilder projectBuilder,
          final MavenSession session,
          final File pom,
          final Log logger)
          throws ProjectBuildingException
      {
          // - first attempt to get a project from the cache
          MavenProject project = projectCache.get(pom);
          if (project == null)
          {
              // - next attempt to get the existing project from the session
              project = getProjectFromSession(session, pom);
              if (project == null)
              {
                  // - if we didn't find it in the session, create it
                  try
                  {
                      project = projectBuilder.build(pom, session.getLocalRepository(),
                              new DefaultProfileManager(session.getContainer()));
                      projectCache.put(pom, project);
                  }
                  catch (Exception ex)
                  {
                      if (logger.isDebugEnabled())
                      {
                          logger.debug("Failed to build project from pom: " + pom, ex);
                      }
                  }
              }
          }
          return project;
      }
  
      /**
       * The POM file name.
       */
      private static final String POM_FILE = "pom.xml";
  
      /**
       * Attempts to retrieve the Maven project for the given <code>pom</code>.
       *
       * @param pom the POM to find.
       * @return the maven project with the matching POM.
       */
      private static MavenProject getProjectFromSession(
          final MavenSession session,
          final File pom)
      {
          MavenProject foundProject = null;
          for (final MavenProject project : session.getSortedProjects())
          {
              final File projectPom = new File(
                      project.getBasedir(),
                      POM_FILE);
              if (projectPom.equals(pom))
              {
                  foundProject = project;
              }
          }
          return foundProject;
      }
  }