def put(self, request, repo_id, org_id, format=None):
        """ Update repo group share permission.

        Permission checking:
        1. is group admin
        """

        # parameter check
        to_group_id = request.data.get('group_id', None)
        if not to_group_id:
            error_msg = 'group_id invalid.'
            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)

        try:
            to_group_id = int(to_group_id)
        except ValueError:
            error_msg = 'group_id invalid.'
            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)

        permission = request.data.get('permission', PERMISSION_READ)
        if permission not in [PERMISSION_READ, PERMISSION_READ_WRITE]:
            error_msg = 'permission invalid.'
            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)

        # resource check
        repo = seafile_api.get_repo(repo_id)
        if not repo:
            error_msg = 'Library %s not found.' % repo_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        repo_owner = get_repo_owner(request, repo_id)
        group_id = get_group_id_by_repo_owner(repo_owner)
        if not ccnet_api.get_group(group_id):
            error_msg = 'Group %s not found.' % group_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        if not ccnet_api.get_group(to_group_id):
            error_msg = 'Group %s not found.' % to_group_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        path = request.data.get('path', '/')
        if not seafile_api.get_dir_id_by_path(repo_id, path):
            error_msg = 'Folder %s not found.' % path
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        # permission check
        username = request.user.username
        if not is_group_admin(group_id, username):
            error_msg = 'Permission denied.'
            return api_error(status.HTTP_403_FORBIDDEN, error_msg)

        update_group_dir_permission(
            repo_id, path, repo_owner, to_group_id, permission, org_id)

        send_perm_audit_msg('modify-repo-perm',
                username, to_group_id, repo_id, path, permission)

        return Response({'success': True})

    def format_add_user_to_group(self):
        """

        Arguments:
        - `self`:
        """
        try:
            d = json.loads(self.detail)
        except Exception as e:
            logger.error(e)
            return _(u"Internal error")

        group_staff = d['group_staff']
        group_id = d['group_id']

        group = ccnet_api.get_group(group_id)
        if group is None:
            self.delete()
            return None

        msg = _(u"User <a href='%(user_profile)s'>%(group_staff)s</a> has added you to group <a href='%(href)s'>%(group_name)s</a>") % {
            'user_profile': reverse('user_profile', args=[group_staff]),
            'group_staff': escape(email2nickname(group_staff)),
            'href': reverse('group', args=[group_id]),
            'group_name': escape(group.group_name)}
        return msg

    def delete(self, request, group_id):
        """ Dismiss a specific group
        """

        group_id = int(group_id)
        group = ccnet_api.get_group(group_id)
        if not group:
            return Response({'success': True})

        group_owner = group.creator_name
        group_name = group.group_name

        try:
            ccnet_api.remove_group(group_id)
            seafile_api.remove_group_repos(group_id)
        except Exception as e:
            logger.error(e)
            error_msg = 'Internal Server Error'
            return api_error(status.HTTP_500_INTERNAL_SERVER_ERROR, error_msg)

        # send admin operation log signal
        admin_op_detail = {
            "id": group_id,
            "name": group_name,
            "owner": group_owner,
        }
        admin_operation.send(sender=None, admin_name=request.user.username,
                operation=GROUP_DELETE, detail=admin_op_detail)

        return Response({'success': True})

    def get(self, request, format=None):
        """ List all shared out folders.

        Permission checking:
        1. all authenticated user can perform this action.
        """

        shared_repos = []
        username = request.user.username

        try:
            if is_org_context(request):
                org_id = request.user.org.org_id
                shared_repos += seafile_api.get_org_share_out_repo_list(org_id, username, -1, -1)
                shared_repos += seaserv.seafserv_threaded_rpc.get_org_group_repos_by_owner(org_id, username)
            else:
                shared_repos += seafile_api.get_share_out_repo_list(username, -1, -1)
                shared_repos += seafile_api.get_group_repos_by_owner(username)
        except Exception as e:
            logger.error(e)
            error_msg = 'Internal Server Error'
            return api_error(status.HTTP_500_INTERNAL_SERVER_ERROR, error_msg)

        returned_result = []
        shared_repos.sort(lambda x, y: cmp(x.repo_name, y.repo_name))
        for repo in shared_repos:
            if not repo.is_virtual:
                    continue

            result = {}
            result['repo_id'] = repo.origin_repo_id
            result['repo_name'] = repo.origin_repo_name
            result['path'] = repo.origin_path
            result['folder_name'] = repo.name
            result['share_type'] = repo.share_type
            result['share_permission'] = repo.permission

            if repo.share_type == 'personal':
                result['user_name'] = email2nickname(repo.user)
                result['user_email'] = repo.user
                result['contact_email'] = Profile.objects.get_contact_email_by_user(repo.user)

            if repo.share_type == 'group':
                group = ccnet_api.get_group(repo.group_id)

                if not group:
                    if is_org_context(request):
                        seafile_api.org_unshare_subdir_for_group(org_id,
                                repo.repo_id, repo.origin_path, username, repo.group_id)
                    else:
                        seafile_api.unshare_subdir_for_group(
                                repo.repo_id, repo.origin_path, username, repo.group_id)
                    continue

                result['group_id'] = repo.group_id
                result['group_name'] = group.group_name

            returned_result.append(result)

        return Response(returned_result)

    def format_repo_share_to_group_msg(self, notice):
        d = json.loads(notice.detail)

        repo_id = d['repo_id']
        repo = seafile_api.get_repo(repo_id)
        group_id = d['group_id']
        group = ccnet_api.get_group(group_id)
        org_id = d.get('org_id', None)

        path = d['path']
        if path == '/':
            shared_type = 'library'
        else:
            shared_type = 'folder'
            if org_id:
                owner = seafile_api.get_org_repo_owner(repo_id)
                repo = seafile_api.get_org_virtual_repo(
                    org_id, repo_id, path, owner)
            else:
                owner = seafile_api.get_repo_owner(repo_id)
                repo = seafile_api.get_virtual_repo(repo_id, path, owner)

        repo_url = reverse('lib_view', args=[repo_id, repo.name, ''])
        notice.repo_url = repo_url
        notice.notice_from = escape(email2nickname(d['share_from']))
        notice.repo_name = repo.name
        notice.avatar_src = self.get_avatar_src(d['share_from'])
        notice.group_url = reverse('group', args=[group.id])
        notice.group_name = group.group_name
        notice.shared_type = shared_type

        return notice

def get_group_member_info(request, group_id, email, avatar_size=AVATAR_DEFAULT_SIZE):
    p = Profile.objects.get_profile_by_user(email)
    if p:
        login_id = p.login_id if p.login_id else ''
    else:
        login_id = ''

    try:
        avatar_url, is_default, date_uploaded = api_avatar_url(email, avatar_size)
    except Exception as e:
        logger.error(e)
        avatar_url = get_default_avatar_url()

    role = 'Member'
    group = ccnet_api.get_group(int(group_id))
    is_admin = bool(ccnet_api.check_group_staff(int(group_id), email))
    if email == group.creator_name:
        role = 'Owner'
    elif is_admin:
        role = 'Admin'

    member_info = {
        'group_id': group_id,
        "name": email2nickname(email),
        'email': email,
        "contact_email": Profile.objects.get_contact_email_by_user(email),
        "login_id": login_id,
        "avatar_url": request.build_absolute_uri(avatar_url),
        "is_admin": is_admin,
        "role": role,
    }

    return member_info

    def _get_address_book_group_memeber_info(self, request, group_member_obj, avatar_size):

        email = group_member_obj.user_name
        try:
            avatar_url, is_default, date_uploaded = api_avatar_url(email, avatar_size)
        except Exception as e:
            logger.error(e)
            avatar_url = get_default_avatar_url()

        group_id = group_member_obj.group_id
        group = ccnet_api.get_group(group_member_obj.group_id)

        role = 'Member'
        is_admin = bool(group_member_obj.is_staff)
        if email == group.creator_name:
            role = 'Owner'
        elif is_admin:
            role = 'Admin'

        member_info = {
            'group_id': group_id,
            'group_name': group.group_name,
            'email': email,
            "name": email2nickname(email),
            "contact_email": email2contact_email(email),
            "avatar_url": request.build_absolute_uri(avatar_url),
            "is_admin": is_admin,
            "role": role,
        }

        return member_info

    def format_group_message_title(self):
        """

        Arguments:
        - `self`:
        """
        try:
            d = self.group_message_detail_to_dict()
        except self.InvalidDetailError as e:
            logger.error(e)
            return _(u"Internal error")

        group_id = d.get('group_id')
        group = ccnet_api.get_group(group_id)
        if group is None:
            self.delete()
            return None

        msg_from = d.get('msg_from')

        if msg_from is None:
            msg = _(u"<a href='%(href)s'>%(group_name)s</a> has a new discussion.") % {
                'href': HASH_URLS['GROUP_DISCUSS'] % {'group_id': group.id},
                'group_name': group.group_name}
        else:
            msg = _(u"%(user)s posted a new discussion in <a href='%(href)s'>%(group_name)s</a>.") % {
                'href': HASH_URLS['GROUP_DISCUSS'] % {'group_id': group.id},
                'user': escape(email2nickname(msg_from)),
                'group_name': escape(group.group_name)
            }
        return msg

    def format_group_join_request(self):
        """

        Arguments:
        - `self`:
        """
        try:
            d = json.loads(self.detail)
        except Exception as e:
            logger.error(e)
            return _(u"Internal error")

        username = d['username']
        group_id = d['group_id']
        join_request_msg = d['join_request_msg']

        group = ccnet_api.get_group(group_id)
        if group is None:
            self.delete()
            return None

        msg = _(u"User <a href='%(user_profile)s'>%(username)s</a> has asked to join group <a href='%(href)s'>%(group_name)s</a>, verification message: %(join_request_msg)s") % {
            'user_profile': reverse('user_profile', args=[username]),
            'username': username,
            'href': HASH_URLS['GROUP_MEMBERS'] % {'group_id': group_id},
            'group_name': escape(group.group_name),
            'join_request_msg': escape(join_request_msg),
            }
        return msg

    def get(self, request, repo_id):
        """ List repo user share info.

        Permission checking:
        1. is group admin
        """

        # resource check
        repo = seafile_api.get_repo(repo_id)
        if not repo:
            error_msg = 'Library %s not found.' % repo_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        repo_owner = get_repo_owner(request, repo_id)
        group_id = get_group_id_by_repo_owner(repo_owner)
        if not ccnet_api.get_group(group_id):
            error_msg = 'Group %s not found.' % group_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        path = request.GET.get('path', '/')
        if not seafile_api.get_dir_id_by_path(repo_id, path):
            error_msg = 'Folder %s not found.' % path
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        # permission check
        username = request.user.username
        if not is_group_admin(group_id, username):
            error_msg = 'Permission denied.'
            return api_error(status.HTTP_403_FORBIDDEN, error_msg)

        result = self.list_user_shared_items(request, repo_id, path)
        return Response(result)

    def post(self, request, group_id):
        """
        Bulk add group members.

        Permission checking:
        1. only admin can perform this action.
        """

        # argument check
        group_id = int(group_id)
        group = ccnet_api.get_group(group_id)
        if not group:
            error_msg = 'Group %d not found.' % group_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        emails = request.POST.getlist('email', '')
        if not emails:
            error_msg = 'Email invalid.'
            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)

        result = {}
        result['failed'] = []
        result['success'] = []
        emails_need_add = []

        for email in emails:
            try:
                User.objects.get(email=email)
            except User.DoesNotExist:
                result['failed'].append({
                    'email': email,
                    'error_msg': 'User %s not found.' % email
                    })
                continue

            if is_group_member(group_id, email, in_structure=False):
                result['failed'].append({
                    'email': email,
                    'error_msg': 'User %s is already a group member.' % email2nickname(email)
                    })
                continue

            emails_need_add.append(email)

        # Add user to group.
        for email in emails_need_add:
            try:
                ccnet_api.group_add_member(group_id, group.creator_name, email)
                member_info = get_group_member_info(request, group_id, email)
                result['success'].append(member_info)
            except Exception as e:
                logger.error(e)
                result['failed'].append({
                    'email': email,
                    'error_msg': 'Internal Server Error'
                    })

        return Response(result)

    def format_repo_share_to_group_msg(self):
        """

        Arguments:
        - `self`:
        """
        try:
            d = json.loads(self.detail)
        except Exception as e:
            logger.error(e)
            return _(u"Internal error")

        share_from = email2nickname(d['share_from'])
        repo_id = d['repo_id']
        group_id = d['group_id']
        path = d.get('path', '/')
        org_id = d.get('org_id', None)

        repo = None
        try:
            group = ccnet_api.get_group(group_id)
            if path == '/':
                repo = seafile_api.get_repo(repo_id)
            else:
                if org_id:
                    owner = seafile_api.get_org_repo_owner(repo_id)
                    repo = seafile_api.get_org_virtual_repo(
                        org_id, repo_id, path, owner)
                else:
                    owner = seafile_api.get_repo_owner(repo_id)
                    repo = seafile_api.get_virtual_repo(repo_id, path, owner)
        except Exception as e:
            logger.error(e)
            return None

        if not repo or not group:
            self.delete()
            return None

        if path == '/':
            tmpl = 'notifications/notice_msg/repo_share_to_group_msg.html'
        else:
            tmpl = 'notifications/notice_msg/folder_share_to_group_msg.html'

        lib_url = reverse('lib_view', args=[repo.id, repo.name, ''])
        group_url = reverse('group', args=[group.id])
        msg = render_to_string(tmpl, {
            'user': share_from,
            'lib_url': lib_url,
            'lib_name': repo.name,
            'group_url': group_url,
            'group_name': group.group_name,
        })

        return msg

def get_group_info(group_id):
    group = ccnet_api.get_group(group_id)
    isoformat_timestr = timestamp_to_isoformat_timestr(group.timestamp)
    group_info = {
        "id": group.id,
        "name": group.group_name,
        "owner": group.creator_name,
        "created_at": isoformat_timestr,
    }

    return group_info

    def get(self, request, group_id):
        """List child groups and members in an address book group."""
        group_id = int(group_id)

        group = ccnet_api.get_group(group_id)
        if not group:
            error_msg = 'Group %d not found.' % group_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        try:
            avatar_size = int(request.GET.get('avatar_size',
                                              AVATAR_DEFAULT_SIZE))
        except ValueError:
            avatar_size = AVATAR_DEFAULT_SIZE

        try:
            return_ancestors = to_python_boolean(request.GET.get(
                'return_ancestors', 'f'))
        except ValueError:
            return_ancestors = False

        ret_dict = address_book_group_to_dict(group)
        ret_groups = []
        ret_members = []

        groups = ccnet_api.get_child_groups(group_id)
        for group in groups:
            ret_groups.append(address_book_group_to_dict(group))

        try:
            members = ccnet_api.get_group_members(group_id)
        except Exception as e:
            logger.error(e)
            error_msg = 'Internal Server Error'
            return api_error(status.HTTP_500_INTERNAL_SERVER_ERROR, error_msg)

        for m in members:
            member_info = self._get_address_book_group_memeber_info(request,
                    m, avatar_size)
            ret_members.append(member_info)

        ret_dict['groups'] = ret_groups
        ret_dict['members'] = ret_members

        if return_ancestors:
            # get ancestor groups and remove last group which is self
            ancestor_groups = ccnet_api.get_ancestor_groups(group_id)[:-1]
            ret_dict['ancestor_groups'] = [address_book_group_to_dict(grp)
                                           for grp in ancestor_groups]
        else:
            ret_dict['ancestor_groups'] = []

        return Response(ret_dict)

    def _get_group_folder_perm_info(self, group_id, repo_id, path, perm):
        result = {}
        if group_id and repo_id and path and perm:
            group = ccnet_api.get_group(group_id)
            result['repo_id'] = repo_id
            result['group_id'] = group_id
            result['group_name'] = group.group_name
            result['folder_path'] = path
            result['folder_name'] = path if path == '/' else os.path.basename(path.rstrip('/'))
            result['permission'] = perm

        return result

def address_book_group_to_dict(group):
    if isinstance(group, int):
        group = ccnet_api.get_group(group)

    return {
        "id": group.id,
        "name": group.group_name,
        "owner": group.creator_name,
        "created_at": timestamp_to_isoformat_timestr(group.timestamp),
        "parent_group_id": group.parent_group_id,
        "quota": seafile_api.get_group_quota(group.id),
    }

    def format_group_message(self, notice):
        d = notice.group_message_detail_to_dict()
        group_id = d['group_id']
        message = d['message']
        group = ccnet_api.get_group(int(group_id))

        notice.group_url = reverse('group_discuss', args=[group.id])
        notice.notice_from = escape(email2nickname(d['msg_from']))
        notice.group_name = group.group_name
        notice.avatar_src = self.get_avatar_src(d['msg_from'])
        notice.grp_msg = message
        return notice

    def format_group_message(self, notice):
        d = notice.group_message_detail_to_dict()
        group_id = d['group_id']
        message = d['message']
        group = ccnet_api.get_group(int(group_id))

        notice.group_url = HASH_URLS['GROUP_DISCUSS'] % {'group_id': group.id}
        notice.notice_from = escape(email2nickname(d['msg_from']))
        notice.group_name = group.group_name
        notice.avatar_src = self.get_avatar_src(d['msg_from'])
        notice.grp_msg = message
        return notice

    def delete(self, request, repo_id):
        """ Delete repo user folder perm.

        Permission checking:
        1. is group admin
        """

        # argument check
        user = request.data.get('user_email', None)
        if not user:
            error_msg = 'user_email invalid.'
            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)

        path = request.data.get('folder_path', None)
        if not path:
            error_msg = 'folder_path invalid.'
            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)

        # resource check
        repo = seafile_api.get_repo(repo_id)
        if not repo:
            error_msg = 'Library %s not found.' % repo_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        repo_owner = get_repo_owner(request, repo_id)
        group_id = get_group_id_by_repo_owner(repo_owner)
        if not ccnet_api.get_group(group_id):
            error_msg = 'Group %s not found.' % group_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        # permission check
        username = request.user.username
        if not is_group_admin(group_id, username):
            error_msg = 'Permission denied.'
            return api_error(status.HTTP_403_FORBIDDEN, error_msg)

        # delete permission
        path = normalize_dir_path(path)
        permission = seafile_api.get_folder_user_perm(repo_id, path, user)
        if not permission:
            return Response({'success': True})

        try:
            seafile_api.rm_folder_user_perm(repo_id, path, user)
            send_perm_audit_msg('delete-repo-perm', username,
                    user, repo_id, path, permission)
            return Response({'success': True})
        except Exception as e:
            logger.error(e)
            error_msg = 'Internal Server Error'
            return api_error(status.HTTP_500_INTERNAL_SERVER_ERROR, error_msg)

    def put(self, request, group_id):
        """ Admin transfer a group

        Permission checking:
        1. Admin user;
        """

        # argument check
        new_owner = request.data.get('new_owner', None)
        if not new_owner or not is_valid_username(new_owner):
            error_msg = 'new_owner %s invalid.' % new_owner
            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)

        # recourse check
        group_id = int(group_id) # Checked by URL Conf
        group = ccnet_api.get_group(group_id)
        if not group:
            error_msg = 'Group %d not found.' % group_id
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        # check if new_owner exists,
        # NOT need to check old_owner for old_owner may has been deleted.
        try:
            User.objects.get(email=new_owner)
        except User.DoesNotExist:
            error_msg = 'User %s not found.' % new_owner
            return api_error(status.HTTP_404_NOT_FOUND, error_msg)

        old_owner = group.creator_name
        if new_owner == old_owner:
            error_msg = _(u'User %s is already group owner.') % new_owner
            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)

        # transfer a group
        try:
            if not is_group_member(group_id, new_owner):
                ccnet_api.group_add_member(group_id, old_owner, new_owner)

            if not is_group_admin(group_id, new_owner):
                ccnet_api.group_set_admin(group_id, new_owner)

            ccnet_api.set_group_creator(group_id, new_owner)
            ccnet_api.group_unset_admin(group_id, old_owner)
        except SearpcError as e:
            logger.error(e)
            error_msg = 'Internal Server Error'
            return api_error(status.HTTP_500_INTERNAL_SERVER_ERROR, error_msg)

        group_info = get_group_info(group_id)

        return Response(group_info)