:returns: new committed changeset after deletion

        """

        user = User.guess_instance(user)

        scm_instance = repo.scm_instance_no_cache()

        processed_nodes = []

        for f_path in nodes:

            f_path = self._sanitize_path(f_path)

            # content can be empty but for compatibility it allows same dicts

            # structure as add_nodes

            content = nodes[f_path].get('content')

            processed_nodes.append((f_path, content))

        message = safe_unicode(message)

        committer = user.full_contact

        author = safe_unicode(author) if author else committer

        IMC = self._get_IMC_module(scm_instance.alias)

        imc = IMC(scm_instance)

        if not parent_cs:

            parent_cs = EmptyChangeset(alias=scm_instance.alias)

        if isinstance(parent_cs, EmptyChangeset):

            # EmptyChangeset means we we're editing empty repository

            parents = None

        else:

            parents = [parent_cs]

        # add multiple nodes

        for path, content in processed_nodes:

            imc.remove(FileNode(path, content=content))

        tip = imc.commit(message=message,

                         author=author,

                         parents=parents,

                         branch=parent_cs.branch)

        self.mark_for_invalidation(repo.repo_name)

        if trigger_push_hook:

            self._handle_push(scm_instance,

                              username=user.username,

                              action='push_local',

                              repo_name=repo.repo_name,

                              revisions=[tip.raw_id])

        return tip

    def get_unread_journal(self):

        return UserLog.query().count()

    def get_repo_landing_revs(self, repo=None):

        """

        Generates select option with tags branches and bookmarks (for hg only)

        grouped by type

        :param repo:

        """

        hist_l = []

        choices = []

        repo = self.__get_repo(repo)

        hist_l.append(['rev:tip', _('latest tip')])

        choices.append('rev:tip')

        if repo is None:

            return choices, hist_l

        repo = repo.scm_instance

        branches_group = ([(u'branch:%s' % k, k) for k, v in

                           repo.branches.iteritems()], _("Branches"))

        hist_l.append(branches_group)

        choices.extend([x[0] for x in branches_group[0]])

        if repo.alias == 'hg':

            bookmarks_group = ([(u'book:%s' % k, k) for k, v in

                                repo.bookmarks.iteritems()], _("Bookmarks"))

            hist_l.append(bookmarks_group)

            choices.extend([x[0] for x in bookmarks_group[0]])

        tags_group = ([(u'tag:%s' % k, k) for k, v in

                       repo.tags.iteritems()], _("Tags"))

        hist_l.append(tags_group)

        choices.extend([x[0] for x in tags_group[0]])

        return choices, hist_l

    def _get_git_hook_interpreter(self):

        """Return a suitable interpreter for Git hooks.

        Return a suitable string to be written in the POSIX #! shebang line for

        Git hook scripts so they invoke Kallithea code with the right Python

        interpreter and in the right environment.

        """

        # FIXME This may not work on Windows and may need a shell wrapper script.

        return (sys.executable

    def install_git_hooks(self, repo, force_create=False):

        """

        Creates a kallithea hook inside a git repository

        :param repo: Instance of VCS repo

        :param force_create: Create even if same name hook exists

        """

        loc = os.path.join(repo.path, 'hooks')

        if not repo.bare:

            loc = os.path.join(repo.path, '.git', 'hooks')

        if not os.path.isdir(loc):

            os.makedirs(loc)

        tmpl_post += pkg_resources.resource_string(

            'kallithea', os.path.join('config', 'post_receive_tmpl.py')

        )

        tmpl_pre += pkg_resources.resource_string(

            'kallithea', os.path.join('config', 'pre_receive_tmpl.py')

        )

        for h_type, tmpl in [('pre', tmpl_pre), ('post', tmpl_post)]:

            _hook_file = os.path.join(loc, '%s-receive' % h_type)

            has_hook = False

            log.debug('Installing git hook in repo %s', repo)

            if os.path.exists(_hook_file):

                # let's take a look at this hook, maybe it's kallithea ?

                log.debug('hook exists, checking if it is from kallithea')

                with open(_hook_file, 'rb') as f:

                    data = f.read()

                    matches = re.compile(r'(?:%s)\s*=\s*(.*)'

                                         % 'KALLITHEA_HOOK_VER').search(data)

                    if matches:

                        try:

                            ver = matches.groups()[0]

                            log.debug('got %s it is kallithea', ver)

                            has_hook = True

                        except Exception:

                            log.error(traceback.format_exc())

            else:

                # there is no hook in this dir, so we want to create one

                has_hook = True

            if has_hook or force_create:

                log.debug('writing %s hook file !', h_type)

                try:

                    with open(_hook_file, 'wb') as f:

                        tmpl = tmpl.replace('_TMPL_', kallithea.__version__)

                        f.write(tmpl)

                    os.chmod(_hook_file, 0755)

                except IOError as e:

                    log.error('error writing %s: %s', _hook_file, e)

            else:

                log.debug('skipping writing hook file')

def AvailableRepoGroupChoices(top_perms, repo_group_perm_level, extras=()):

    """Return group_id,string tuples with choices for all the repo groups where

    the user has the necessary permissions.

    Top level is -1.

    """

    groups = RepoGroup.query().all()

    if HasPermissionAny('hg.admin')('available repo groups'):

        groups.append(None)

    else:

        groups = list(RepoGroupList(groups, perm_level=repo_group_perm_level))

        if top_perms and HasPermissionAny(*top_perms)('available repo groups'):

            groups.append(None)

        for extra in extras:

            if not any(rg == extra for rg in groups):

                groups.append(extra)

    return RepoGroup.groups_choices(groups=groups)