private void signalCopiedTranslation(
      HTextFlowTarget target, ContentState previousState, Long wordCount) {
    /*
     * Using a direct method call instead of an event because it's easier to
     * read. Since these events are being called synchronously (as opposed
     * to an 'after Transaction' events), there is no big performance gain
     * and makes the code easier to read and navigate.
     */
    // TODO how was this not causing duplicate events?  Is this bypassing TranslationServiceImpl?
    // FIXME other observers may not be notified
    HDocument document = target.getTextFlow().getDocument();

    DocumentLocaleKey key = new DocumentLocaleKey(document.getId(), target.getLocaleId());

    Map<ContentState, Long> contentStates = Maps.newHashMap();
    DocStatsEvent.updateContentStateDeltas(
        contentStates, target.getState(), previousState, wordCount);

    DocStatsEvent docEvent =
        new DocStatsEvent(
            key, document.getProjectIteration().getId(), contentStates, target.getId());

    versionStateCacheImpl.docStatsUpdated(docEvent);
  }
  private Integer mergeTranslations(
      final Long sourceVersionId,
      final Long targetVersionId,
      final int batchStart,
      final int batchLength,
      final boolean useNewerTranslation,
      final List<HLocale> supportedLocales)
      throws Exception {

    final Stopwatch stopwatch = Stopwatch.createUnstarted();
    stopwatch.start();

    List<HTextFlow[]> matches =
        textFlowDAO.getSourceByMatchedContext(
            sourceVersionId, targetVersionId, batchStart, batchLength);

    Multimap<DocumentLocaleKey, TextFlowTargetStateChange> eventMap = HashMultimap.create();

    Map<DocumentLocaleKey, Map<ContentState, Long>> docStatsMap = Maps.newHashMap();

    Map<DocumentLocaleKey, Long> lastUpdatedTargetId = Maps.newHashMap();
    ;

    for (HTextFlow[] results : matches) {
      HTextFlow sourceTf = results[0];
      HTextFlow targetTf = results[1];
      boolean foundChange = false;
      Map<Long, ContentState> localeContentStateMap = Maps.newHashMap();

      for (HLocale hLocale : supportedLocales) {
        HTextFlowTarget sourceTft = sourceTf.getTargets().get(hLocale.getId());
        // only process translated state
        if (sourceTft == null || !sourceTft.getState().isTranslated()) {
          continue;
        }

        HTextFlowTarget targetTft = targetTf.getTargets().get(hLocale.getId());
        if (targetTft == null) {
          targetTft = new HTextFlowTarget(targetTf, hLocale);
          targetTft.setVersionNum(0);
          targetTf.getTargets().put(hLocale.getId(), targetTft);
        }

        if (MergeTranslationsServiceImpl.shouldMerge(sourceTft, targetTft, useNewerTranslation)) {
          foundChange = true;

          ContentState oldState = targetTft.getState();
          localeContentStateMap.put(hLocale.getId(), oldState);
          mergeTextFlowTarget(sourceTft, targetTft);
        }
      }
      if (foundChange) {
        translationStateCacheImpl.clearDocumentStatistics(targetTf.getDocument().getId());
        textFlowDAO.makePersistent(targetTf);
        textFlowDAO.flush();

        for (Map.Entry<Long, ContentState> entry : localeContentStateMap.entrySet()) {
          HTextFlowTarget updatedTarget = targetTf.getTargets().get(entry.getKey());

          DocumentLocaleKey key =
              new DocumentLocaleKey(
                  targetTf.getDocument().getId(), updatedTarget.getLocale().getLocaleId());

          eventMap.put(
              key,
              new TextFlowTargetStateEvent.TextFlowTargetStateChange(
                  targetTf.getId(),
                  updatedTarget.getId(),
                  updatedTarget.getState(),
                  entry.getValue()));

          lastUpdatedTargetId.put(key, updatedTarget.getId());

          Map<ContentState, Long> contentStateDeltas =
              docStatsMap.get(key) == null ? Maps.newHashMap() : docStatsMap.get(key);

          DocStatsEvent.updateContentStateDeltas(
              contentStateDeltas,
              updatedTarget.getState(),
              entry.getValue(),
              targetTf.getWordCount());

          docStatsMap.put(key, contentStateDeltas);
        }
      }
    }
    Long actorId = authenticatedAccount.getPerson().getId();
    for (Map.Entry<DocumentLocaleKey, Collection<TextFlowTargetStateChange>> entry :
        eventMap.asMap().entrySet()) {
      TextFlowTargetStateEvent tftUpdatedEvent =
          new TextFlowTargetStateEvent(
              entry.getKey(), targetVersionId, actorId, ImmutableList.copyOf(entry.getValue()));
      textFlowTargetStateEvent.fire(tftUpdatedEvent);
    }
    for (Map.Entry<DocumentLocaleKey, Map<ContentState, Long>> entry : docStatsMap.entrySet()) {
      DocStatsEvent docEvent =
          new DocStatsEvent(
              entry.getKey(),
              targetVersionId,
              entry.getValue(),
              lastUpdatedTargetId.get(entry.getKey()));
      docStatsEvent.fire(docEvent);
    }
    stopwatch.stop();
    log.info(
        "Complete merge translations of {} in {}",
        matches.size() * supportedLocales.size(),
        stopwatch);
    return matches.size() * supportedLocales.size();
  }