desc = comment.pull_request.title

            _org_ref_type, org_ref_name, _org_rev = comment.pull_request.org_ref.split(':')

            _other_ref_type, other_ref_name, _other_rev = comment.pull_request.other_ref.split(':')

            threading = ['%s-pr-%s@%s' % (pull_request.other_repo.repo_name,

                                          pull_request.pull_request_id,

                                          webutils.canonical_hostname())]

            if line_no: # TODO: url to file _and_ line number

                threading.append('%s-pr-%s-line-%s@%s' % (pull_request.other_repo.repo_name,

                                                          pull_request.pull_request_id, line_no,

                                                          webutils.canonical_hostname()))

            comment_url = pull_request.url(canonical=True,

                anchor='comment-%s' % comment.comment_id)

            subj = webutils.link_to(

                'Re pull request %(pr_nice_id)s: %(desc)s %(line)s' %

                          {'desc': desc,

                           'pr_nice_id': comment.pull_request.nice_id(),

                           'line': line},

                comment_url)

            # get the current participants of this pull request

            recipients = _list_pull_request_commenters(pull_request)

            recipients.append(pull_request.owner)

            recipients += pull_request.get_reviewer_users()

            # set some variables for email notification

            email_kwargs = {

                'pr_title': pull_request.title,

                'pr_title_short': shorter(pull_request.title, 50),

                'pr_nice_id': pull_request.nice_id(),

                'status_change': status_change,

                'closing_pr': closing_pr,

                'pr_comment_url': comment_url,

                'pr_url': pull_request.url(canonical=True),

                'pr_comment_user': author.full_name_and_username,

                'pr_target_repo': webutils.canonical_url('summary_home',

                                   repo_name=pull_request.other_repo.repo_name),

                'pr_target_branch': other_ref_name,

                'pr_source_repo': webutils.canonical_url('summary_home',

                                   repo_name=pull_request.org_repo.repo_name),

                'pr_source_branch': org_ref_name,

                'pr_owner': pull_request.owner,

                'pr_owner_username': pull_request.owner.username,

                'repo_name': pull_request.other_repo.repo_name,

                'comment_username': author.username,

                'threading': threading,

            }

        return subj, body, recipients, notification_type, email_kwargs

    def create(self, text, repo, author, revision=None, pull_request=None,

               f_path=None, line_no=None, status_change=None, closing_pr=False,

               send_email=True):

        """

        Creates a new comment for either a changeset or a pull request.

        status_change and closing_pr is only for the optional email.

        Returns the created comment.

        """

        if not status_change and not text:

            log.warning('Missing text for comment, skipping...')

            return None

        repo = db.Repository.guess_instance(repo)

        author = db.User.guess_instance(author)

        comment = db.ChangesetComment()

        comment.repo = repo

        comment.author = author

        comment.text = text

        comment.f_path = f_path

        comment.line_no = line_no

        if revision is not None:

            comment.revision = revision

        elif pull_request is not None:

            pull_request = db.PullRequest.guess_instance(pull_request)

            comment.pull_request = pull_request

        else:

            raise Exception('Please specify revision or pull_request_id')

        meta.Session().add(comment)

        meta.Session().flush()

        if send_email:

            )

        return comment

    def delete(self, comment):

        comment = db.ChangesetComment.guess_instance(comment)

        meta.Session().delete(comment)

        return comment

    def get_comments(self, repo_id, revision=None, pull_request=None):

        """

        Gets general comments for either revision or pull_request.

        Returns a list, ordered by creation date.

        """

        return self._get_comments(repo_id, revision=revision, pull_request=pull_request,

                                  inline=False)

    def get_inline_comments(self, repo_id, revision=None, pull_request=None,

                f_path=None, line_no=None):

        """

        Gets inline comments for either revision or pull_request.

        Returns a list of tuples with file path and list of comments per line number.

        """

        comments = self._get_comments(repo_id, revision=revision, pull_request=pull_request,

                                      inline=True, f_path=f_path, line_no=line_no)

        paths = defaultdict(lambda: defaultdict(list))

        for co in comments:

            paths[co.f_path][co.line_no].append(co)

        return sorted(paths.items())

    def _get_comments(self, repo_id, revision=None, pull_request=None,

                inline=False, f_path=None, line_no=None):

        """

        Gets comments for either revision or pull_request_id, either inline or general.

        If a file path and optionally line number are given, return only the matching inline comments.

        """

        if f_path is None and line_no is not None:

            raise Exception("line_no only makes sense if f_path is given.")

        if inline is None and f_path is not None:

            raise Exception("f_path only makes sense for inline comments.")

        q = meta.Session().query(db.ChangesetComment)

        if inline:

            if f_path is not None: