/*
    * Copyright 2006-2012 smartics, Kronseder & Reiner GmbH
    *
    * 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.
   */
  package de.smartics.maven.plugin.buildmetadata.common;
  
  import java.text.DateFormat;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.Locale;
  import java.util.Properties;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.maven.scm.ScmFileSet;
  import org.apache.maven.scm.manager.ScmManager;
  
  import de.smartics.maven.plugin.buildmetadata.scm.LocallyModifiedInfo;
  import de.smartics.maven.plugin.buildmetadata.scm.Revision;
  import de.smartics.maven.plugin.buildmetadata.scm.RevisionNumberFetcher;
  import de.smartics.maven.plugin.buildmetadata.scm.ScmException;
  import de.smartics.maven.plugin.buildmetadata.scm.ScmNoRevisionException;
  import de.smartics.maven.plugin.buildmetadata.scm.maven.MavenScmRevisionNumberFetcher;
  import de.smartics.maven.plugin.buildmetadata.scm.maven.ScmAccessInfo;
  import de.smartics.maven.plugin.buildmetadata.scm.maven.ScmConnectionInfo;
  
  /**
   * Helper to access the revision information.
   *
   * @author <a href="mailto:robert.reiner@smartics.de">Robert Reiner</a>
   * @version $Revision:591 $
   */
  public final class RevisionHelper
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    /**
     * Reference to the logger for this class.
     */
    private static final Log LOG = LogFactory.getLog(RevisionHelper.class);
  
    // --- members --------------------------------------------------------------
  
    /**
     * The manager instance to access the SCM system. Provides access to the
     * repository and the provider information.
     */
    private final ScmManager scmManager;
  
    /**
     * The information to connect to the SCM.
     */
    private final ScmConnectionInfo scmConnectionInfo;
  
    /**
     * The information to query the SCM.
     */
    private final ScmAccessInfo scmAccessInfo;
  
    /**
     * The date pattern to use to format revision dates.
     */
    private final String buildDatePattern;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    /**
     * Default constructor.
     *
     * @param scmManager the manager instance to access the SCM system.
     * @param scmConnectionInfo the information to connect to the SCM.
     * @param scmAccessInfo the information to query the SCM.
     * @param buildDatePattern the date pattern to use to format revision dates.
     */
    public RevisionHelper(final ScmManager scmManager,
        final ScmConnectionInfo scmConnectionInfo,
        final ScmAccessInfo scmAccessInfo, final String buildDatePattern)
    {
      this.scmManager = scmManager;
      this.scmConnectionInfo = scmConnectionInfo;
      this.scmAccessInfo = scmAccessInfo;
      this.buildDatePattern = buildDatePattern;
    }
  
   // ****************************** Inner Classes *****************************
 
   // ********************************* Methods ********************************
 
   // --- init -----------------------------------------------------------------
 
   // --- get&set --------------------------------------------------------------
 
   // --- business -------------------------------------------------------------
 
   /**
    * Fetches the revision information and adds it to the property sets.
    *
    * @param buildMetaDataProperties the build meta data properties.
    * @param scmControl the properties to control the gathering of SCM info.
    * @throws ScmException if the creation of the SCM information failed.
    */
   public void provideScmBuildInfo(final Properties buildMetaDataProperties,
       final ScmControl scmControl) throws ScmException
   {
     final boolean failOnMissingRevision = scmControl.isFailOnMissingRevision();
 
     final RevisionNumberFetcher revisionFetcher =
         new MavenScmRevisionNumberFetcher(scmManager, scmConnectionInfo,
             scmAccessInfo);
     final Revision revision = revisionFetcher.fetchLatestRevisionNumber();
     if (revision != null)
     {
       buildMetaDataProperties.setProperty(Constant.PROP_NAME_SCM_URL,
           scmConnectionInfo.getConnectionUrl());
       final String revisionId = revision.getId();
       buildMetaDataProperties.setProperty(Constant.PROP_NAME_SCM_REVISION_ID,
           revisionId);
       final Date revisionDate = revision.getDate();
       final DateFormat format =
           new SimpleDateFormat(buildDatePattern, Locale.ENGLISH);
       final String revisionDateString = format.format(revisionDate);
       buildMetaDataProperties.setProperty(Constant.PROP_NAME_SCM_REVISION_DATE,
           revisionDateString);
 
       final boolean validateCheckout = scmControl.isValidateCheckout();
       if (validateCheckout)
       {
         provideLocallyModifiedInfo(buildMetaDataProperties, revisionFetcher);
       }
     }
     else if (failOnMissingRevision)
     {
       throw new ScmNoRevisionException("Cannot fetch SCM revision. "
                                        + scmConnectionInfo);
     }
   }
 
   // --- object basics --------------------------------------------------------
 
   /**
    * Provides the information of locally modified files to the build properties.
    *
    * @param buildMetaDataProperties the build meta data properties.
    * @param revisionFetcher the fetcher to use.
    * @throws ScmException if the creation of the modification information
    *           failed.
    */
   private void provideLocallyModifiedInfo(
       final Properties buildMetaDataProperties,
       final RevisionNumberFetcher revisionFetcher) throws ScmException
   {
     try
     {
       final ScmFileSet fileSet =
           new ScmFileSet(scmAccessInfo.getRootDirectory(), "**/*", null);
       final LocallyModifiedInfo info =
           revisionFetcher.containsModifications(fileSet);
       buildMetaDataProperties.setProperty(
           Constant.PROP_NAME_SCM_LOCALLY_MODIFIED,
           String.valueOf(info.isLocallyModified()));
       if (info.isLocallyModified())
       {
         buildMetaDataProperties.setProperty(
             Constant.PROP_NAME_SCM_LOCALLY_MODIFIED_FILES, info.getFiles());
         if (scmAccessInfo.isFailIndicated())
         {
           throw new ScmException("Local Modifications detected ("
                                  + info.getFiles() + ").");
         }
       }
     }
     catch (final Exception e)
     {
       if (scmAccessInfo.isFailIndicated())
       {
         throw new ScmException(e);
       }
       else
       {
         buildMetaDataProperties.setProperty(
             Constant.PROP_NAME_SCM_LOCALLY_MODIFIED, "unknown");
         if (LOG.isInfoEnabled())
         {
           LOG.info("Failed to check modification status.");
         }
       }
     }
   }
 }