for tag, tagrev in repo.tags.iteritems():

            if tag == 'tip':

                continue

            n = 'tag:%s:%s' % (tag, tagrev)

            tags.append((n, tag))

            if rev == tagrev:

                selected = n

        # prio 1: rev was selected as existing entry above

        # prio 2: create special entry for rev; rev _must_ be used

        specials = []

        if rev and selected is None:

            selected = 'rev:%s:%s' % (rev, rev)

            specials = [(selected, '%s: %s' % (_("Changeset"), rev[:12]))]

        # prio 3: most recent peer branch

        if peers and not selected:

            selected = peers[0][0]

        # prio 4: tip revision

        if not selected:

            if h.is_hg(repo):

                if tipbranch:

                    selected = 'branch:%s:%s' % (tipbranch, tiprev)

                else:

                    selected = 'tag:null:' + repo.EMPTY_CHANGESET

                    tags.append((selected, 'null'))

            else:

                if 'master' in repo.branches:

                    selected = 'branch:master:%s' % repo.branches['master']

                else:

                    k, v = repo.branches.items()[0]

                    selected = 'branch:%s:%s' % (k, v)

        groups = [(specials, _("Special")),

                  (peers, _("Peer branches")),

                  (bookmarks, _("Bookmarks")),

                  (branches, _("Branches")),

                  (tags, _("Tags")),

                  ]

        return [g for g in groups if g[0]], selected

    def _get_is_allowed_change_status(self, pull_request):

        if pull_request.is_closed():

            return False

        owner = self.authuser.user_id == pull_request.user_id

        return self.authuser.admin or owner or reviewer

    @LoginRequired()

    @HasRepoPermissionAnyDecorator('repository.read', 'repository.write',

                                   'repository.admin')

    def show_all(self, repo_name):

        c.from_ = request.GET.get('from_') or ''

        c.closed = request.GET.get('closed') or ''

        c.pull_requests = PullRequestModel().get_all(repo_name, from_=c.from_, closed=c.closed)

        c.repo_name = repo_name

        p = safe_int(request.GET.get('page', 1), 1)

        c.pullrequests_pager = Page(c.pull_requests, page=p, items_per_page=100)

        return render('/pullrequests/pullrequest_show_all.html')

    @LoginRequired()

    @NotAnonymous()

    def show_my(self):

        c.closed = request.GET.get('closed') or ''

        def _filter(pr):

            s = sorted(pr, key=lambda o: o.created_on, reverse=True)

            if not c.closed:

                s = filter(lambda p: p.status != PullRequest.STATUS_CLOSED, s)

            return s

        c.my_pull_requests = _filter(PullRequest.query() \

                                .filter(PullRequest.user_id ==

                                        self.authuser.user_id) \

                                .all())

        c.participate_in_pull_requests = _filter(PullRequest.query() \

                                .join(PullRequestReviewers) \

                                .filter(PullRequestReviewers.user_id ==

                                        self.authuser.user_id) \

                                                 )

        return render('/pullrequests/pullrequest_show_my.html')

    @LoginRequired()

    @NotAnonymous()

    @HasRepoPermissionAnyDecorator('repository.read', 'repository.write',

                                   'repository.admin')

    def index(self):

        org_repo = c.db_repo

        org_scm_instance = org_repo.scm_instance

        try:

            .filter(ChangesetStatus.repo == repo)

        if not with_revisions:

            q = q.filter(ChangesetStatus.version == 0)

        if revision:

            q = q.filter(ChangesetStatus.revision == revision)

        elif pull_request:

            pull_request = self.__get_pull_request(pull_request)

            q = q.filter(ChangesetStatus.pull_request == pull_request)

        else:

            raise Exception('Please specify revision or pull_request')

        q = q.order_by(ChangesetStatus.version.asc())

        return q

    def _calculate_status(self, statuses):

        """

        Given a list of statuses, calculate the resulting status, according to

        the policy: approve if consensus, reject when at least one reject.

        """

        if not statuses:

            return ChangesetStatus.STATUS_UNDER_REVIEW

        if all(st and st.status == ChangesetStatus.STATUS_APPROVED for st in statuses):

            return ChangesetStatus.STATUS_APPROVED

        if any(st and st.status == ChangesetStatus.STATUS_REJECTED for st in statuses):

            return ChangesetStatus.STATUS_REJECTED

        return ChangesetStatus.STATUS_UNDER_REVIEW

    def calculate_pull_request_result(self, pull_request):

        """

        Return a tuple (reviewers, pending reviewers, pull request status)

        Only approve and reject counts as valid votes.

        """

        # collect latest votes from all voters

        cs_statuses = dict()

        for st in reversed(self.get_statuses(pull_request.org_repo,

                                             pull_request=pull_request,

                                             with_revisions=True)):

            cs_statuses[st.author.username] = st

        # collect votes from official reviewers

        pull_request_reviewers = []

        pull_request_pending_reviewers = []

        relevant_statuses = []

            relevant_statuses.append(st)

            if not st or st.status in (ChangesetStatus.STATUS_NOT_REVIEWED,

                                       ChangesetStatus.STATUS_UNDER_REVIEW):

                st = None

        result = self._calculate_status(relevant_statuses)

        return (pull_request_reviewers,

                pull_request_pending_reviewers,

                result)

    def get_statuses(self, repo, revision=None, pull_request=None,

                     with_revisions=False):

        q = self._get_status_query(repo, revision, pull_request,

                                   with_revisions)

        q = q.options(joinedload('author'))

        return q.all()

    def get_status(self, repo, revision=None, pull_request=None, as_str=True):

        """

        Returns latest status of changeset for given revision or for given

        pull request. Statuses are versioned inside a table itself and

        version == 0 is always the current one

        :param repo:

        :param revision: 40char hash or None

        :param pull_request: pull_request reference

        :param as_str: return status as string not object

        """

        q = self._get_status_query(repo, revision, pull_request)

        # need to use first here since there can be multiple statuses

        # returned from pull_request

        status = q.first()

        if as_str:

            return str(status.status) if status else ChangesetStatus.DEFAULT

        return status

    def set_status(self, repo, status, user, comment, revision=None,

                   pull_request=None, dont_allow_on_closed_pull_request=False):

        """

        Creates new status for changeset or updates the old ones bumping their

        version, leaving the current status at the value of 'status'.

        :param repo:

        :param status:

        :param user:

        :param comment:

        :param revision:

        :param pull_request:

        :param dont_allow_on_closed_pull_request: don't allow a status change

            if last status was for pull request and it's closed. We shouldn't

            recipients = ChangesetComment.get_users(revision=revision)

            # add changeset author if it's known locally

            cs_author = User.get_from_cs_author(cs.author)

            if not cs_author:

                #use repo owner if we cannot extract the author correctly

                cs_author = repo.user

            recipients += [cs_author]

            email_kwargs = {

                'status_change': status_change,

                'cs_comment_user': user.full_name_and_username,

                'cs_target_repo': h.canonical_url('summary_home', repo_name=repo.repo_name),

                'cs_comment_url': comment_url,

                'raw_id': revision,

                'message': cs.message,

                'repo_name': repo.repo_name,

                'short_id': h.short_id(revision),

                'branch': cs.branch,

                'comment_username': user.username,

                'threading': threading,

            }

        #pull request

        elif pull_request:

            notification_type = Notification.TYPE_PULL_REQUEST_COMMENT

            desc = comment.pull_request.title

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

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

                                          pull_request.pull_request_id,

                                          h.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,

                                                          h.canonical_hostname()))

            comment_url = pull_request.url(canonical=True,

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

            subj = safe_unicode(

                h.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 = ChangesetComment.get_users(pull_request_id=

                                                pull_request.pull_request_id)

            # add pull request author

            recipients += [pull_request.owner]

            # add the reviewers to notification

            #set some variables for email notification

            email_kwargs = {

                'pr_title': pull_request.title,

                'pr_nice_id': pull_request.nice_id(),

                'status_change': status_change,

                'closing_pr': closing_pr,

                'pr_comment_url': comment_url,

                'pr_comment_user': user.full_name_and_username,

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

                                   repo_name=pull_request.other_repo.repo_name),

                'repo_name': pull_request.other_repo.repo_name,

                'ref': org_ref_name,

                'comment_username': user.username,

                'threading': threading,

            }

        return subj, body, recipients, notification_type, email_kwargs

    def create(self, text, repo, user, 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 = self._get_repo(repo)

        user = self._get_user(user)

        comment = ChangesetComment()

        comment.repo = repo

        comment.author = user

        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 = self.__get_pull_request(pull_request)

            comment.pull_request = pull_request

        else:

            raise Exception('Please specify revision or pull_request_id')

    __table_args__ = (

        Index('pr_org_repo_id_idx', 'org_repo_id'),

        Index('pr_other_repo_id_idx', 'other_repo_id'),

        _table_args_default_dict,

    )

    # values for .status

    STATUS_NEW = u'new'

    STATUS_CLOSED = u'closed'

    pull_request_id = Column(Integer(), unique=True, primary_key=True)

    title = Column(Unicode(255), nullable=False)

    description = Column(UnicodeText(10240), nullable=False)

    status = Column(Unicode(255), nullable=False, default=STATUS_NEW) # only for closedness, not approve/reject/etc

    created_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    updated_on = Column(DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    user_id = Column(Integer(), ForeignKey('users.user_id'), nullable=False)

    _revisions = Column('revisions', UnicodeText(20500), nullable=False)  # 500 revisions max

    org_repo_id = Column(Integer(), ForeignKey('repositories.repo_id'), nullable=False)

    org_ref = Column(Unicode(255), nullable=False)

    other_repo_id = Column(Integer(), ForeignKey('repositories.repo_id'), nullable=False)

    other_ref = Column(Unicode(255), nullable=False)

    @hybrid_property

    def revisions(self):

        return self._revisions.split(':')

    @revisions.setter

    def revisions(self, val):

        self._revisions = safe_unicode(':'.join(val))

    @property

    def org_ref_parts(self):

        return self.org_ref.split(':')

    @property

    def other_ref_parts(self):

        return self.other_ref.split(':')

    owner = relationship('User')

    reviewers = relationship('PullRequestReviewers',

                             cascade="all, delete-orphan")

    org_repo = relationship('Repository', primaryjoin='PullRequest.org_repo_id==Repository.repo_id')

    other_repo = relationship('Repository', primaryjoin='PullRequest.other_repo_id==Repository.repo_id')

    statuses = relationship('ChangesetStatus', order_by='ChangesetStatus.changeset_status_id')

    comments = relationship('ChangesetComment', order_by='ChangesetComment.comment_id',

                             cascade="all, delete-orphan")

    def is_closed(self):

        return self.status == self.STATUS_CLOSED

    def user_review_status(self, user_id):

        """Return the user's latest status votes on PR"""

        # note: no filtering on repo - that would be redundant

        status = ChangesetStatus.query() \

            .filter(ChangesetStatus.pull_request == self) \

            .filter(ChangesetStatus.user_id == user_id) \

            .order_by(ChangesetStatus.version) \

            .first()

        return str(status.status) if status else ''

    @classmethod

    def make_nice_id(cls, pull_request_id):

        '''Return pull request id nicely formatted for displaying'''

        return '#%s' % pull_request_id

    def nice_id(self):

        '''Return the id of this pull request, nicely formatted for displaying'''

        return self.make_nice_id(self.pull_request_id)

    def __json__(self):

        return dict(

            revisions=self.revisions

        )

    def url(self, **kwargs):

        canonical = kwargs.pop('canonical', None)

        import kallithea.lib.helpers as h

        b = self.org_ref_parts[1]

        if b != self.other_ref_parts[1]:

            s = '/_/' + b

        else:

            s = '/_/' + self.title

        kwargs['extra'] = urlreadable(s)

        if canonical:

            return h.canonical_url('pullrequest_show', repo_name=self.other_repo.repo_name,

                                   pull_request_id=self.pull_request_id, **kwargs)

        return h.url('pullrequest_show', repo_name=self.other_repo.repo_name,

                     pull_request_id=self.pull_request_id, **kwargs)

class PullRequestReviewers(Base, BaseModel):

    __tablename__ = 'pull_request_reviewers'

    __table_args__ = (

        Index('pull_request_reviewers_user_id_idx', 'user_id'),

        _table_args_default_dict,

    )