views.py

                    required=False,
                    initial=default_data.get("restrict_to_same_tag", True))

            layout.append(
                    Div("set_access_rules_tag", "restrict_to_same_tag",
                        css_class="well"))

        access_fields = ["create_access_exception", "access_expires"]

        self.fields["create_access_exception"] = forms.BooleanField(
            required=False, help_text=_("If set, an exception for the "
            "access rules will be created."), initial=True,
            label=_("Create access rule exception"))

        self.fields["access_expires"] = forms.DateTimeField(
            widget=DateTimePicker(
                options={"format": "YYYY-MM-DD HH:mm", "sideBySide": True,
                    "showClear": True}),
            required=False,
            label=pgettext_lazy("Time when access expires", "Access expires"),
            help_text=_("At the specified time, the special access granted below "
            "will expire "
            "and revert to being the same as for the rest of the class. "
            "This field may "
            "be empty, in which case this access does not expire. Note also that "
            "the grading-related entries (such as 'due date' and 'credit percent') "
            "do not expire and remain valid indefinitely, unless overridden by "
            "another exception."))

        for key, name in FLOW_PERMISSION_CHOICES:
            self.fields[key] = forms.BooleanField(label=name, required=False,
                    initial=default_data.get(key) or False)

            access_fields.append(key)

        layout.append(Div(*access_fields, css_class="well"))

        self.fields["create_grading_exception"] = forms.BooleanField(
                required=False, help_text=_("If set, an exception for the "
                "grading rules will be created."), initial=True,
                label=_("Create grading rule exception"))
        self.fields["due_same_as_access_expiration"] = forms.BooleanField(
                required=False, help_text=_("If set, the 'Due time' field will be "
                "disregarded."),
                initial=default_data.get("due_same_as_access_expiration") or False,
                label=_("Due same as access expiration"))
        self.fields["due"] = forms.DateTimeField(
                widget=DateTimePicker(
                    options={"format": "YYYY-MM-DD HH:mm", "sideBySide": True}),
                required=False,
                help_text=_("The due time shown to the student. Also, the "
                "time after which "
                "any session under these rules is subject to expiration."),
                initial=default_data.get("due"),
                label=_("Due time"))

        self.fields["generates_grade"] = forms.BooleanField(required=False,
                initial=default_data.get("generates_grade", True),
                label=_("Generates grade"))
        self.fields["credit_percent"] = forms.FloatField(required=False,
                initial=default_data.get("credit_percent"),
                label=_("Credit percent"))
        self.fields["bonus_points"] = forms.FloatField(required=False,
                initial=default_data.get("bonus_points"),
                label=_("Bonus points"))
        self.fields["max_points"] = forms.FloatField(required=False,
                initial=default_data.get("max_points"),
                label=_("Maximum number of points (for percentage)"))
        self.fields["max_points_enforced_cap"] = forms.FloatField(required=False,
                initial=default_data.get("max_points_enforced_cap"),
                label=_("Maximum number of points (enforced cap)"))

        layout.append(Div("create_grading_exception",
            "due_same_as_access_expiration", "due",
            "generates_grade",
            "credit_percent", "bonus_points", "max_points",
            "max_points_enforced_cap",
            css_class="well"))

        self.fields["comment"] = forms.CharField(
                widget=forms.Textarea, required=True,
                initial=default_data.get("comment"),
                label=_("Comment"))

        layout.append("comment")

        self.helper.add_input(
                Submit(
                    "save", _("Save")))

        self.helper.layout = Layout(*layout)

    def clean(self):
        access_expires = self.cleaned_data.get("access_expires")
        due_same_as_access_expiration = self.cleaned_data.get(
            "due_same_as_access_expiration")
        if (not access_expires and due_same_as_access_expiration):
            self.add_error(
                "access_expires",
                _("Must specify access expiration if 'due same "
                  "as access expiration' is set."))


@course_view
@transaction.atomic
def grant_exception_stage_3(pctx, participation_id, flow_id, session_id):
    # type: (CoursePageContext, int, Text, int) -> http.HttpResponse

    if not pctx.has_permission(pperm.grant_exception):
        raise PermissionDenied(_("may not grant exceptions"))

    participation = get_object_or_404(Participation, id=participation_id)

    from course.content import get_flow_desc
    try:
        flow_desc = get_flow_desc(pctx.repo, pctx.course, flow_id,
                pctx.course_commit_sha)
    except ObjectDoesNotExist:
        raise http.Http404()

    session = FlowSession.objects.get(id=int(session_id))

    now_datetime = get_now_or_fake_time(pctx.request)
    from course.utils import (
            get_session_access_rule,
            get_session_grading_rule)
    access_rule = get_session_access_rule(session, flow_desc, now_datetime)
    grading_rule = get_session_grading_rule(session, flow_desc, now_datetime)

    request = pctx.request
    if request.method == "POST":
        form = ExceptionStage3Form(
                {}, flow_desc, session.access_rules_tag, request.POST)

        from course.constants import flow_rule_kind

        if form.is_valid():
            permissions = [
                    key
                    for key, __ in FLOW_PERMISSION_CHOICES
                    if form.cleaned_data[key]]

            from course.validation import (
                    validate_session_access_rule,
                    validate_session_grading_rule,
                    ValidationContext)
            from relate.utils import dict_to_struct
            vctx = ValidationContext(
                    repo=pctx.repo,
                    commit_sha=pctx.course_commit_sha)

            flow_desc = get_flow_desc(pctx.repo,
                    pctx.course,
                    flow_id, pctx.course_commit_sha)

            tags = []  # type: List[Text]
            if hasattr(flow_desc, "rules"):
                tags = cast(List[Text], getattr(flow_desc.rules, "tags", []))

            exception_created = False

            restricted_to_same_tag = bool(
                form.cleaned_data.get("restrict_to_same_tag")
                and session.access_rules_tag is not None)

            # {{{ put together access rule

            if form.cleaned_data["create_access_exception"]:
                new_access_rule = {"permissions": permissions}

                if restricted_to_same_tag:
                    new_access_rule["if_has_tag"] = session.access_rules_tag

                validate_session_access_rule(
                        vctx, _("newly created exception"),
                        dict_to_struct(new_access_rule), tags)

                fre_access = FlowRuleException(
                    flow_id=flow_id,
                    participation=participation,
                    expiration=form.cleaned_data["access_expires"],
                    creator=pctx.request.user,
                    comment=form.cleaned_data["comment"],
                    kind=flow_rule_kind.access,
                    rule=new_access_rule)
                fre_access.save()
                exception_created = True

            # }}}

            session_access_rules_tag_changed = False
            if not restricted_to_same_tag:
                new_access_rules_tag = form.cleaned_data.get("set_access_rules_tag")
                if new_access_rules_tag == NONE_SESSION_TAG:
                    new_access_rules_tag = None

                if session.access_rules_tag != new_access_rules_tag:
                    session.access_rules_tag = new_access_rules_tag
                    session.save()
                    session_access_rules_tag_changed = True

                    if new_access_rules_tag is not None:
                        msg = _("Access rules tag of the selected session "
                                "updated to '%s'.") % new_access_rules_tag
                    else:
                        msg = _(
                            "Removed access rules tag of the selected session.")

                    messages.add_message(pctx.request, messages.SUCCESS, msg)

            # {{{ put together grading rule

            if form.cleaned_data["create_grading_exception"]:
                due = form.cleaned_data["due"]
                if form.cleaned_data["due_same_as_access_expiration"]:
                    due = form.cleaned_data["access_expires"]

                descr = ugettext("Granted excecption")
                if form.cleaned_data["credit_percent"] is not None:
                    descr += string_concat(" (%.1f%% ", ugettext('credit'), ")") \
                            % form.cleaned_data["credit_percent"]

                due_local_naive = due
                if due_local_naive is not None:
                    from relate.utils import as_local_time
                    due_local_naive = (
                            as_local_time(due_local_naive)
                            .replace(tzinfo=None))

                new_grading_rule = {
                    "description": descr,
                    }

                if due_local_naive is not None:
                    new_grading_rule["due"] = due_local_naive
                    new_grading_rule["if_completed_before"] = due_local_naive

                for attr_name in ["credit_percent", "bonus_points",
                        "max_points", "max_points_enforced_cap", "generates_grade"]:
                    if form.cleaned_data[attr_name] is not None:
                        new_grading_rule[attr_name] = form.cleaned_data[attr_name]

                if restricted_to_same_tag:
                    new_grading_rule["if_has_tag"] = session.access_rules_tag

                validate_session_grading_rule(
                        vctx, _("newly created exception"),
                        dict_to_struct(new_grading_rule), tags,
                        grading_rule.grade_identifier)

                fre_grading = FlowRuleException(
                    flow_id=flow_id,
                    participation=participation,
                    creator=pctx.request.user,
                    comment=form.cleaned_data["comment"],
                    kind=flow_rule_kind.grading,
                    rule=new_grading_rule)
                fre_grading.save()
                exception_created = True

            # }}}

            if exception_created:
                messages.add_message(pctx.request, messages.SUCCESS,
                        _(
                            "Exception granted to '%(participation)s' "
                            "for '%(flow_id)s'.")
                        % {
                            'participation': participation,
                            'flow_id': flow_id})
            else:
                if session_access_rules_tag_changed:
                    messages.add_message(
                        pctx.request, messages.WARNING,
                        _(
                            "No other exception granted to the given flow "
                            "session of '%(participation)s' "
                            "for '%(flow_id)s'.")
                        % {
                            'participation': participation,
                            'flow_id': flow_id})
                else:
                    messages.add_message(pctx.request, messages.WARNING,
                            _(
                                "No exception granted to the given flow "
                                "session of '%(participation)s' "
                                "for '%(flow_id)s'.")
                            % {
                                'participation': participation,
                                'flow_id': flow_id})
            return redirect(
                    "relate-grant_exception",
                    pctx.course.identifier)

    else:
        data = {
                "restrict_to_same_tag": session.access_rules_tag is not None,
                #"due_same_as_access_expiration": True,
                "due": grading_rule.due,
                "generates_grade": grading_rule.generates_grade,
                "credit_percent": grading_rule.credit_percent,
                "bonus_points": grading_rule.bonus_points,
                "max_points": grading_rule.max_points,
                "max_points_enforced_cap": grading_rule.max_points_enforced_cap,
                }
        for perm in access_rule.permissions:
            data[perm] = True

        form = ExceptionStage3Form(data, flow_desc, session.access_rules_tag)

    return render_course_page(pctx, "course/generic-course-form.html", {
        "form": form,
        "form_description": _("Grant Exception"),
        "form_text": string_concat(
            "<div class='well'>",
            _("Granting exception to '%(participation)s' "
            "for '%(flow_id)s' (session %(session)s)."),
            "</div>")
        % {
            'participation': participation,
            'flow_id': flow_id,
            'session': strify_session_for_exception(session)},
    })

# }}}


# {{{ ssh keypair

@login_required
def generate_ssh_keypair(request):
    if not request.user.is_staff:
        raise PermissionDenied(_("only staff may use this tool"))

    from paramiko import RSAKey
    key_class = RSAKey
    prv = key_class.generate(bits=2048)

    import six
    prv_bio = six.StringIO()
    prv.write_private_key(prv_bio)

    prv_bio_read = six.StringIO(prv_bio.getvalue())

    pub = key_class.from_private_key(prv_bio_read)

    pub_bio = six.StringIO()
    pub_bio.write("%s %s relate-course-key" % (pub.get_name(), pub.get_base64()))

    return render(request, "course/keypair.html", {
        "public_key": prv_bio.getvalue(),
        "private_key": pub_bio.getvalue(),
        })

# }}}


# {{{ celery task monitoring

@login_required
def monitor_task(request, task_id):
    from celery.result import AsyncResult
    from celery import states
    async_res = AsyncResult(task_id)

    progress_percent = None
    progress_statement = None

    if async_res.state == "PROGRESS":
        meta = async_res.info
        current = meta["current"]
        total = meta["total"]
        if total > 0:
            progress_percent = 100 * (current / total)

        progress_statement = (
                _("%(current)d out of %(total)d items processed.")
                % {"current": current, "total": total})

    if async_res.state == states.SUCCESS:
        if (isinstance(async_res.result, dict)
                and "message" in async_res.result):
            progress_statement = async_res.result["message"]

    traceback = None
    if request.user.is_staff and async_res.state == states.FAILURE:
        traceback = async_res.traceback

    return render(request, "course/task-monitor.html", {
        "state": async_res.state,
        "progress_percent": progress_percent,
        "progress_statement": progress_statement,
        "traceback": traceback,
        })

# }}}


# {{{ edit course

class EditCourseForm(StyledModelForm):
    def __init__(self, *args, **kwargs):
        super(EditCourseForm, self).__init__(*args, **kwargs)
        self.fields["identifier"].disabled = True
        self.fields["active_git_commit_sha"].disabled = True

        self.helper.add_input(
                Submit("submit", _("Update")))

    class Meta:
        model = Course
        exclude = (
                "participants",
                )
        widgets = {
                "start_date": DateTimePicker(options={"format": "YYYY-MM-DD"}),
                "end_date": DateTimePicker(options={"format": "YYYY-MM-DD"}),
                "force_lang": forms.Select(
                    choices=get_course_specific_language_choices()),
                }


@course_view
def edit_course(pctx):
    if not pctx.has_permission(pperm.edit_course):
        raise PermissionDenied()

    request = pctx.request

    if request.method == 'POST':
        form = EditCourseForm(request.POST, instance=pctx.course)
        if form.is_valid():
            if form.has_changed():
                form.save()
                messages.add_message(
                    request, messages.SUCCESS,
                    _("Successfully updated course settings."))
            else:
                messages.add_message(
                    request, messages.INFO,
                    _("No change was made on the settings."))

        else:
            messages.add_message(request, messages.ERROR,
                                 _("Failed to update course settings."))

    else:
        form = EditCourseForm(instance=pctx.course)

    return render_course_page(pctx, "course/generic-course-form.html", {
        "form_description": _("Edit Course"),
        "form": form
        })

# }}}

# vim: foldmethod=marker