package org.codehaus.mojo.build;
   
   /*
    * Copyright 2001-2005 The Apache Software Foundation.
    *
    * Licensed 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 org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.scm.ScmException;
  import org.apache.maven.scm.ScmFileStatus;
  import org.apache.maven.scm.ScmResult;
  import org.apache.maven.scm.log.ScmLogDispatcher;
  import org.apache.maven.scm.log.ScmLogger;
  import org.apache.maven.scm.provider.hg.HgUtils;
  import org.apache.maven.scm.provider.hg.command.HgConsumer;
  import org.codehaus.plexus.util.StringUtils;
  
  /**
   * Goal which sets project properties for changeSet and changeSetDate from the
   * current Mercurial repository.
   * 
   * @author Tomas Pollak
   * @goal hgchangeset
   * @phase initialize
   * @requiresProject
   * @since 1.0-beta-4
   */
  public class HgChangeSetMojo
      extends AbstractMojo
  {
  
      private ScmLogDispatcher logger = new ScmLogDispatcher();
  
      /**
       * The maven project.
       * 
       * @parameter expression="${project}"
       * @readonly
       */
      private MavenProject project;
  
      /**
       * Local directory to be used to issue SCM actions
       * 
       * @parameter expression="${maven.changeSet.scmDirectory}" default-value="${basedir}
       * @since 1.0
       */
      private File scmDirectory;
  
      private void checkResult( ScmResult result )
          throws MojoExecutionException
      {
          if ( !result.isSuccess() )
          {
              getLog().debug( "Provider message:" );
              getLog().debug( result.getProviderMessage() == null ? "" : result.getProviderMessage() );
              getLog().debug( "Command output:" );
              getLog().debug( result.getCommandOutput() == null ? "" : result.getCommandOutput() );
              throw new MojoExecutionException( "Command failed."
                  + StringUtils.defaultString( result.getProviderMessage() ) );
          }
      }
  
      public void execute()
          throws MojoExecutionException
      {
          try
          {
              String previousChangeSet = getChangeSetProperty();
              String previousChangeSetDate = getChangeSetDateProperty();
              if ( previousChangeSet == null || previousChangeSetDate == null )
              {
                  String changeSet = getChangeSet();
                  String changeSetDate = getChangeSetDate();
                  getLog().info( "Setting Mercurial Changeset: " + changeSet );
                  getLog().info( "Setting Mercurial Changeset Date: " + changeSetDate );
                  setChangeSetProperty( changeSet );
                  setChangeSetDateProperty( changeSetDate );
              }
          }
          catch ( ScmException e )
          {
              throw new MojoExecutionException( "SCM Exception", e );
          }
     }
 
     protected String getChangeSet()
         throws ScmException, MojoExecutionException
     {
         HgOutputConsumer consumer = new HgOutputConsumer( logger );
         ScmResult result = HgUtils.execute( consumer, logger, scmDirectory, new String[] { "id", "-i" } );
         checkResult( result );
         return consumer.getOutput();
     }
 
     protected String getChangeSetDate()
         throws ScmException, MojoExecutionException
     {
         HgOutputConsumer consumer = new HgOutputConsumer( logger );
         ScmResult result =
             HgUtils.execute( consumer, logger, scmDirectory, new String[] { "log", "-r", ".",
                 "--template", "\"{date|isodate}\"" } );
         checkResult( result );
         return consumer.getOutput();
     }
 
     protected String getChangeSetDateProperty()
     {
         return getProperty( "changeSetDate" );
     }
 
     protected String getChangeSetProperty()
     {
         return getProperty( "changeSet" );
     }
 
     protected String getProperty( String property )
     {
         return project.getProperties().getProperty( property );
     }
 
     private void setChangeSetDateProperty( String changeSetDate )
     {
         setProperty( "changeSetDate", changeSetDate );
     }
 
     private void setChangeSetProperty( String changeSet )
     {
         setProperty( "changeSet", changeSet );
     }
 
     private void setProperty( String property, String value )
     {
         if ( value != null )
         {
             project.getProperties().put( property, value );
         }
     }
 
     private static class HgOutputConsumer
         extends HgConsumer
     {
 
         private String output;
 
         private HgOutputConsumer( ScmLogger logger )
         {
             super( logger );
         }
 
         public void doConsume( ScmFileStatus status, String line )
         {
             output = line;
         }
 
         private String getOutput()
         {
             return output;
         }
     }    
 }