HgChangeLogConsumer.java

/*
The MIT License

Copyright (c) 2004, The Codehaus

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
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 */
package org.codehaus.mojo.scmchangelog.scm.hg.command.changelog;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Locale;

import org.apache.maven.scm.ChangeFile;
import org.apache.maven.scm.ScmFileStatus;
import org.apache.maven.scm.log.ScmLogger;
import org.apache.maven.scm.provider.hg.command.HgConsumer;

/**
 * Command consumer that parses the output from a <code>hg log --verbose -rx:y</code> 
 * command, using a grammar to build  the changelog.
 * @author ehsavoie
 * @version $Id$
 *
 * @see org.apache.maven.scm.provider.hg.command.HgConsumer
 * @see org.codehaus.mojo.scmchangelog.scm.hg.changelog.HgChangeLogCommand
 */
public class HgChangeLogConsumer
    extends HgConsumer
{

  /**
   * The time stamp format.
   */
  private static final String TIME_PATTERN = "EEE MMM dd HH:mm:ss yyyy Z";
  /**
   * The changeset element in the changelog.
   */
  private static final String REVNO_TAG = "changeset: ";
  /**
   * The tag element in the changelog.
   */
  private static final String TAG_TAG = "tag:         ";
  /**
   * The author element in the changelog.
   */
  private static final String AUTHOR_TAG = "user: ";
  /**
   * The timestamp element in the changelog.
   */
  private static final String TIME_STAMP_TOKEN = "date: ";
  /**
   * The message element in the changelog.
   */
  private static final String MESSAGE_TOKEN = "description:";
  /**
   * The merged element in the changelog.
   */
  private static final String MERGED_TOKEN = "merged: ";
  /**
   * The files element in the changelog.
   */
  private static final String FILES_TOKEN = "files: ";
  /**
   * The previous line to the current parsed line.
   */
  private String prevLine = "";
  /**
   * The previous previous line to the current parsed line.
   */
  private String prevPrevLine = "";
  /**
   * The entries resulting from parsing this changelog output.
   */
  private ArrayList logEntries = new ArrayList();
  /**
   * The current entry.
   */
  private BetterChangeSet currentChange;
  /**
   * Last entry in the current changes.
   */
  private BetterChangeSet lastChange;
  /**
   * Indicates if it is a merge entry.
   */
  private boolean isMergeEntry;
  /**
   * The current revision of the entry.
   */
  private String currentRevision;
  /**
   * Not used.
   */
  private String currentTag; // don't know what to do with this
  /**
   * To specified another date pattern.
   */
  private String userDatePattern;
  /**
   * Used for multiline comments.
   */
  private boolean spoolingComments;
  /**
   * List of comments for the current entry.
   */
  private List currentComment = null;

  /**
   * Construtor for HgChangeLogConsumer.
   * @param logger the logger used for trace.
   * @param userDatePattern the pattern for parsing dates.
   */
  public HgChangeLogConsumer( ScmLogger logger, String userDatePattern )
  {
    super( logger );

    this.userDatePattern = userDatePattern;
  }

  /**
   * Return a list of BetterChangeSet.
   * @return a List<BetterChangeSet>
   * @see org.codehaus.mojo.scmchangelog.scm.hg.changelog.BetterChangeSet
   */
  public List getModifications()
  {
    Collections.reverse( logEntries );
    return logEntries;
  }

  /**
   * Consume a line of the output of the command.
   * @param line the line to be interpreted.
   */
  public void consumeLine( String line )
  {
    // override default behaviour which tries to pick through things for some standard messages.  that
    // does not apply here
    doConsume( null, line );
  }

  /**
   * Consume a line
   * @param status null.
   * @param line a line of the command output.
   */
  public void doConsume( ScmFileStatus status, String line )
  {
    String tmpLine = line;

    // If current status == null then this is a new entry
    // If the line == "" and previous line was "", then this is also a new entry
    if ( ( line.equals( "" ) && ( prevLine.equals( "" ) && prevPrevLine.equals( "" ) ) ) || ( currentComment == null ) )
    {
      if ( currentComment != null )
      {
        StringBuffer comment = new StringBuffer();

        for ( int i = 0; i < ( currentComment.size() - 1 ); i++ )
        {
          comment.append( currentComment.get( i ) );

          if ( ( i + 1 ) < ( currentComment.size() - 1 ) )
          {
            comment.append( '\n' );
          }
        }
        currentChange.setComment( comment.toString() );
      }
      spoolingComments = false;

      //If last entry was part a merged entry
      if ( isMergeEntry 
          && ( lastChange != null ) )
      {
        String comment = lastChange.getComment();
        comment += ( "\n[MAVEN]: Merged from " 
            + currentChange.getAuthor() );
        comment += ( "\n[MAVEN]:    " 
            + currentChange.getDateFormatted() );
        comment += ( "\n[MAVEN]:    " 
            + currentChange.getComment() );
        lastChange.setComment( comment );
      }

      //Init a new changeset
      currentChange = new BetterChangeSet();
      currentChange.setFiles( new ArrayList() );
      logEntries.add( currentChange );

      //Reset memeber vars
      currentComment = new ArrayList();
      currentRevision = "";
      isMergeEntry = false;
    }

    if ( spoolingComments )
    {
      currentComment.add( line );
    } 
    else if ( line.startsWith( MESSAGE_TOKEN ) )
    {
      spoolingComments = true;
    } 
    else if ( line.startsWith( MERGED_TOKEN ) )
    {
      //This is part of lastChange and is not a separate log entry
      isMergeEntry = true;
      logEntries.remove( currentChange );

      if ( logEntries.size() > 0 )
      {
        lastChange = ( BetterChangeSet ) logEntries.get( logEntries.size() - 1 );
      } 
      else
      {
        getLogger().warn( "First entry was unexpectedly a merged entry" );
        lastChange = null;
      }
    } 
    else if ( line.startsWith( REVNO_TAG ) )
    {
      tmpLine = line.substring( REVNO_TAG.length() );
      tmpLine = tmpLine.trim();
      currentRevision = tmpLine;
      currentChange.setRevision( currentRevision.substring( 0,
          currentRevision.indexOf( ':' ) ) );
    } 
    else if ( line.startsWith( TAG_TAG ) )
    {
      tmpLine = line.substring( TAG_TAG.length() ).trim();
      currentTag = tmpLine;
    }
    else if ( line.startsWith( AUTHOR_TAG ) )
    {
      tmpLine = line.substring( AUTHOR_TAG.length() );
      tmpLine = tmpLine.trim();
      currentChange.setAuthor( tmpLine );
    } 
    else if ( line.startsWith( TIME_STAMP_TOKEN ) )
    {
      // TODO: FIX Date Parsing to match Mercurial or fix with template
      tmpLine = line.substring( TIME_STAMP_TOKEN.length() ).trim();

      Date date = parseDate( tmpLine, userDatePattern, TIME_PATTERN,
          Locale.ENGLISH );
      currentChange.setDate( date );
    } 
    else if ( line.startsWith( FILES_TOKEN ) )
    {
      tmpLine = line.substring( FILES_TOKEN.length() ).trim();

      String[] files = tmpLine.split( " " );

      for ( int i = 0; i < files.length; i++ )
      {
        String file = files[i];
        ChangeFile changeFile = new ChangeFile( file, currentRevision );
        currentChange.addFile( changeFile );
      }
    } 
    else
    {
      getLogger().warn( "Could not figure out: " + line );
    }

    // record previous line
    prevLine = line;
    prevPrevLine = prevLine;
  }
}