from contextlib import contextmanager

from django.contrib.auth import get_user_model
from django.db.models import Count
from django.http import Http404, HttpResponse
from django.shortcuts import get_object_or_404, redirect
from django.urls import reverse
from django.utils import timezone
from django.utils.formats import date_format
from django.utils.translation import gettext_lazy as _
from django.utils.translation import ngettext
from django.views.generic import CreateView, DetailView, FormView, ListView, TemplateView, UpdateView, View
from waffle import get_waffle_flag_model, get_waffle_switch_model

from billing.models import Due, Plan, PlanPrice
from billing.services import BillingError
from billing.services.dues import next_period_start, open_period, reactivate, record_payment, start_trial, subscribe, waive
from billing.services.invoices import invoice_pdf, issue_invoice
from billing.services.plans import delete_plan, plan_deletion_impact
from club.models import Club, ClubRole
from events.models import Competition, Location
from features.jobs import JOB_REGISTRY
from features.models import JobToggle, Maintenance

from .forms import ClubAdminForm, ClubForm, CompetitionForm, DuePaymentForm, FlagForm, HomeLocationForm, MaintenanceForm, OpenPeriodForm, PlanForm, PlanPriceForm, PlatformAdminForm, SubscriptionForm, TrialForm
from .messages import notify
from .mixins import PlatformStaffRequiredMixin, PlatformSuperuserRequiredMixin, RedirectOnInvalidMixin
from .services.admins import grant_club_admin, revoke_club_admin
from .services.jobs import job_overview, recent_job_runs
from .services.platform_admins import (
    PlatformAdminError,
    grant_platform_access,
    platform_admins,
    revoke_platform_access,
    set_platform_access,
)
from .services.statistics import club_attention, club_charts, club_statistics, clubs_by_risk, clubs_with_health, flag_adoption, flags_for_club, onboarding_funnel, platform_attention, platform_charts, platform_totals

Flag = get_waffle_flag_model()
Switch = get_waffle_switch_model()


@contextmanager
def suppress_billing_errors(request, title="Billing error"):
    """Turn a BillingError into an error message rather than letting it propagate.

    Fits call sites that fall through to the same redirect on the happy and unhappy path
    alike — the success message is set inside the block, the failure message by this
    context manager, and whichever fired, the caller's next line runs unchanged.
    """
    try:
        yield
    except BillingError as error:
        notify(request, f"e|{title}|{error}")


class DashboardView(PlatformStaffRequiredMixin, TemplateView):
    template_name = "controlpanel/dashboard.html"

    def get_context_data(self, **kwargs):
        return super().get_context_data(
            nav="dashboard",
            totals=platform_totals(),
            attention=platform_attention(),
            funnel=onboarding_funnel(),
            flags=flag_adoption(),
            charts=platform_charts(),
            clubs=clubs_by_risk(),
            # failed_jobs itself comes from controlpanel.context_processors.job_health, on
            # every controlpanel page (the command bar's status indicator needs it too) --
            # not re-fetched here, so the query only runs once per request.
            job_log=recent_job_runs(),
            today=timezone.localdate(),
            **kwargs,
        )


class JobsView(PlatformStaffRequiredMixin, TemplateView):
    """Status and recent history of the scheduled platform jobs -- see features/jobs.py for
    the registry and features/models.JobRun for what a Celery task run writes. These still
    run on Celery Beat's own schedule (rosterchief/settings.py) -- there is no "run now"
    here -- but each one can be paused/resumed individually via JobToggleView below, without
    reaching for the platform-wide Maintenance lock."""

    template_name = "controlpanel/jobs.html"

    def get_context_data(self, **kwargs):
        return super().get_context_data(nav="jobs", jobs=job_overview(), **kwargs)


class JobToggleView(PlatformStaffRequiredMixin, View):
    """Pause or resume one scheduled job -- see features.models.JobToggle. `name` is the
    job's dotted Celery task name (a features.jobs.JOB_REGISTRY key), not a database id: a
    toggle row only exists once a job has actually been flipped off at least once."""

    def post(self, request, name):
        if name not in JOB_REGISTRY:
            raise Http404

        enabled = not JobToggle.is_enabled(name)
        JobToggle.set_enabled(name, enabled)

        label = JOB_REGISTRY[name]["label"]
        if enabled:
            notify(request, f"s|Job resumed|“{label}” will run on its schedule again.")
        else:
            notify(request, f"w|Job paused|“{label}” will stand down until resumed.")

        return redirect("controlpanel:jobs")


class ClubListView(PlatformStaffRequiredMixin, ListView):
    template_name = "controlpanel/club_list.html"
    context_object_name = "clubs"

    @property
    def show_archived(self):
        return self.request.GET.get("archived") == "1"

    def get_queryset(self):
        clubs = Club.objects.archived() if self.show_archived else Club.objects.active()
        search = self.request.GET.get("q", "").strip()
        if search:
            clubs = clubs.filter(name__icontains=search)
        return clubs_with_health(clubs)

    def get_context_data(self, **kwargs):
        return super().get_context_data(nav="clubs", show_archived=self.show_archived, search=self.request.GET.get("q", ""), today=timezone.localdate(), **kwargs)


class ClubCreateView(PlatformStaffRequiredMixin, CreateView):
    model = Club
    form_class = ClubForm
    template_name = "controlpanel/club_form.html"

    def form_valid(self, form):
        response = super().form_valid(form)
        notify(self.request, f"s|Club created|Club “{self.object}” created.")
        return response

    def get_success_url(self):
        return reverse("controlpanel:club_detail", args=[self.object.pk])

    def get_context_data(self, **kwargs):
        return super().get_context_data(nav="clubs", **kwargs)


class ClubUpdateView(PlatformStaffRequiredMixin, UpdateView):
    model = Club
    form_class = ClubForm
    template_name = "controlpanel/club_form.html"

    def form_valid(self, form):
        response = super().form_valid(form)
        notify(self.request, f"s|Club updated|Club “{self.object}” updated.")
        return response

    def get_success_url(self):
        return reverse("controlpanel:club_detail", args=[self.object.pk])

    def get_context_data(self, **kwargs):
        return super().get_context_data(nav="clubs", update_view=True, **kwargs)


class ClubDetailView(PlatformStaffRequiredMixin, DetailView):
    model = Club
    template_name = "controlpanel/club_detail.html"
    context_object_name = "club"

    def get_context_data(self, **kwargs):
        subscription = getattr(self.object, "subscription", None)
        next_start = next_period_start(self.object)

        # Bound per-row so each due's "Add payment" modal can render its own form without
        # the template calling DuePaymentForm(initial=...) itself.
        dues = list(self.object.dues.select_related("plan", "invoice").prefetch_related("payments"))
        for due in dues:
            if due.is_owing:
                due.payment_form = DuePaymentForm(initial={"amount": due.balance})

        home_location = Location.objects.filter(club=self.object, is_home=True).first()

        return super().get_context_data(
            # Drives the "archived but owes nothing -- reactivate?" prompt. Computed from the
            # dues already fetched above rather than re-querying.
            dues_settled=not any(due.is_owing for due in dues),
            home_location=home_location,
            home_location_form=HomeLocationForm(instance=home_location),
            nav="clubs",
            groups=club_statistics(self.object),
            attention=club_attention(self.object),
            charts=club_charts(self.object),
            subscription=subscription,
            dues=dues,
            today=timezone.localdate(),
            admins=ClubRole.objects.filter(club=self.object, role=ClubRole.Roles.ADMIN).select_related("member", "member__user"),
            admin_form=ClubAdminForm(),
            flags=flags_for_club(self.object),
            open_period_form=OpenPeriodForm(),
            open_period_blurb=f"Next period starts {date_format(next_start, 'j M Y')} unless you say otherwise. By default it continues from the end of the last one, so a lapsed year is still owed — pick a start date to forgive the gap.",
            subscription_form=SubscriptionForm(instance=subscription) if subscription else SubscriptionForm(),
            trial_form=TrialForm(),
            **kwargs,
        )


class ClubArchiveView(PlatformStaffRequiredMixin, View):
    """Clubs are archived, never destroyed — their data (and invoices) are kept."""

    def post(self, request, pk):
        club = get_object_or_404(Club, pk=pk)
        club.archive()
        notify(request, f"w|Club archived|Club “{club}” archived. Its subdomain no longer resolves.")
        return redirect("controlpanel:club_detail", pk=club.pk)


class ClubRestoreView(PlatformStaffRequiredMixin, View):
    def post(self, request, pk):
        club = get_object_or_404(Club, pk=pk)
        club.restore()
        notify(request, f"s|Club restored|Club “{club}” restored.")
        return redirect("controlpanel:club_detail", pk=club.pk)


class ClubAdminAddView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, FormView):
    """Reachable only via the "Add admin" modal on the club detail page — POST-only, and
    there is no standalone template to render on GET or on a rejected submission."""

    form_class = ClubAdminForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:club_detail"

    @property
    def club(self):
        return get_object_or_404(Club, pk=self.kwargs["pk"])

    def get_invalid_redirect_kwargs(self):
        return {"pk": self.kwargs["pk"]}

    def form_valid(self, form):
        role = grant_club_admin(self.club, **form.cleaned_data)
        notify(self.request, f"s|Admin added|{role.member} is now an admin of {role.club}. They must set up two-factor authentication before they can sign in.")
        return redirect("controlpanel:club_detail", pk=self.kwargs["pk"])


class ClubHomeLocationSetView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, FormView):
    """Create or update the club's home Location -- reachable only via the "Home
    location" modal on the club detail page. Binds to the existing home Location
    (if any) so submitting the form edits it in place rather than ever creating
    a second one; ``unique_home_location_per_club`` backs that up at the DB level."""

    form_class = HomeLocationForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:club_detail"

    @property
    def club(self):
        return get_object_or_404(Club, pk=self.kwargs["pk"])

    def get_invalid_redirect_kwargs(self):
        return {"pk": self.kwargs["pk"]}

    def get_form_kwargs(self):
        return super().get_form_kwargs() | {"instance": Location.objects.filter(club=self.club, is_home=True).first()}

    def form_valid(self, form):
        location = form.save(commit=False)
        location.club = self.club
        location.is_home = True
        location.save()
        notify(self.request, f"s|Home location set|{location} is now {self.club}'s home location.")
        return redirect("controlpanel:club_detail", pk=self.kwargs["pk"])


class ClubAdminRemoveView(PlatformStaffRequiredMixin, View):
    def post(self, request, pk, role_pk):
        role = get_object_or_404(ClubRole, pk=role_pk, club_id=pk, role=ClubRole.Roles.ADMIN)
        member = role.member
        revoke_club_admin(role)
        notify(request, f"w|Admin removed|{member} is no longer an admin of this club.")
        return redirect("controlpanel:club_detail", pk=pk)


class ClubFeatureToggleView(PlatformStaffRequiredMixin, View):
    """Turn a feature on or off for one club."""

    def post(self, request, pk, flag_pk):
        club = get_object_or_404(Club, pk=pk)
        flag = get_object_or_404(Flag, pk=flag_pk)

        if flag.clubs.filter(pk=club.pk).exists():
            flag.clubs.remove(club)
            notify(request, f"w|Feature disabled|“{flag.name}” turned off for {club}.")
        else:
            flag.clubs.add(club)
            notify(request, f"s|Feature enabled|“{flag.name}” turned on for {club}.")

        return redirect("controlpanel:club_detail", pk=club.pk)


class FeatureListView(PlatformStaffRequiredMixin, TemplateView):
    template_name = "controlpanel/features.html"

    def get_context_data(self, **kwargs):
        # Bound per-row so each flag's "Edit" modal can render its own form: the template
        # can't call FlagForm(instance=flag) itself, so the form rides along on the flag.
        flags = list(Flag.objects.prefetch_related("clubs").order_by("name"))
        for flag in flags:
            flag.edit_form = FlagForm(instance=flag)

        competitions = list(Competition.objects.select_related("flag").order_by("name"))
        for competition in competitions:
            competition.edit_form = CompetitionForm(instance=competition)

        return super().get_context_data(
            nav="features",
            flags=flags,
            flag_form=FlagForm(),
            competitions=competitions,
            competition_form=CompetitionForm(),
            switches=Switch.objects.order_by("name"),
            maintenance=Maintenance.current(),
            maintenance_form=MaintenanceForm(),
            **kwargs,
        )


class MaintenanceView(PlatformStaffRequiredMixin, View):
    """Close the platform, or open it again."""

    def post(self, request):
        if Maintenance.is_on():
            Maintenance.stop()
            notify(request, "s|Maintenance ended|The clubs are back.")
        else:
            form = MaintenanceForm(request.POST)
            message = form.cleaned_data["message"] if form.is_valid() else ""
            Maintenance.start(message=message, user=request.user)
            notify(request, "w|Platform closed|Every club subdomain now serves a maintenance page, and the scheduled jobs stand down.")

        return redirect("controlpanel:features")


class FlagCreateView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, CreateView):
    """Reachable only via the "New feature" modal on the features page — POST-only, and
    there is no standalone template to render on GET or on a rejected submission."""

    model = Flag
    form_class = FlagForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:features"

    def form_valid(self, form):
        response = super().form_valid(form)
        notify(self.request, f"s|Feature created|Feature “{self.object.name}” created.")
        return response

    def get_success_url(self):
        return reverse("controlpanel:features")


class FlagUpdateView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, UpdateView):
    """Reachable only via a flag's "Edit" modal on the features page — POST-only, and
    there is no standalone template to render on GET or on a rejected submission."""

    model = Flag
    form_class = FlagForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:features"

    def form_valid(self, form):
        response = super().form_valid(form)
        notify(self.request, f"s|Feature updated|Feature “{self.object.name}” updated.")
        return response

    def get_success_url(self):
        return reverse("controlpanel:features")


class CompetitionCreateView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, CreateView):
    """Reachable only via the "New competition" modal on the features page --
    POST-only, and there is no standalone template to render on GET or on a
    rejected submission."""

    model = Competition
    form_class = CompetitionForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:features"

    def form_valid(self, form):
        response = super().form_valid(form)
        notify(self.request, f"s|Competition created|Competition “{self.object.name}” created.")
        return response

    def get_success_url(self):
        return reverse("controlpanel:features")


class CompetitionUpdateView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, UpdateView):
    """Reachable only via a competition's "Edit" modal on the features page --
    POST-only, and there is no standalone template to render on GET or on a
    rejected submission."""

    model = Competition
    form_class = CompetitionForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:features"

    def form_valid(self, form):
        response = super().form_valid(form)
        notify(self.request, f"s|Competition updated|Competition “{self.object.name}” updated.")
        return response

    def get_success_url(self):
        return reverse("controlpanel:features")


class CompetitionDeleteView(PlatformStaffRequiredMixin, View):
    """No cascading consequences to weigh (Event.competition matches by name, not
    a foreign key -- see events.services.competitions), so this is a plain confirm
    modal rather than PlanDeleteView's dedicated impact page."""

    def post(self, request, pk):
        competition = get_object_or_404(Competition, pk=pk)
        name = competition.name
        competition.delete()

        notify(request, f"w|Competition deleted|Competition “{name}” has been deleted.")
        return redirect("controlpanel:features")


class SwitchToggleView(PlatformStaffRequiredMixin, View):
    """Global kill-switch: on or off for the whole platform."""

    def post(self, request, pk):
        switch = get_object_or_404(Switch, pk=pk)
        switch.active = not switch.active
        switch.save()
        title = "Switch on" if switch.active else "Switch off"
        notify(request, f"s|{title}|Switch “{switch.name}” is now {'on' if switch.active else 'off'}.")
        return redirect("controlpanel:features")


class PlatformAdminListView(PlatformSuperuserRequiredMixin, TemplateView):
    template_name = "controlpanel/admins.html"

    def get_context_data(self, **kwargs):
        return super().get_context_data(nav="admins", admins=platform_admins(), admin_form=PlatformAdminForm(), **kwargs)


class PlatformAdminAddView(PlatformSuperuserRequiredMixin, RedirectOnInvalidMixin, FormView):
    """Reachable only via the "Grant access" modal on the admins page — POST-only, and
    there is no standalone template to render on GET or on a rejected submission."""

    form_class = PlatformAdminForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:admins"

    def form_valid(self, form):
        user = grant_platform_access(form.cleaned_data["email"], is_superuser=form.cleaned_data["is_superuser"])
        notify(self.request, f"s|Platform access granted|{user.email} now has platform access. They must set up two-factor authentication before they can sign in.")
        return redirect("controlpanel:admins")


class PlatformAdminUpdateView(PlatformSuperuserRequiredMixin, View):
    def post(self, request, pk):
        user = get_object_or_404(get_user_model(), pk=pk)
        try:
            set_platform_access(
                request.user,
                user,
                is_staff=request.POST.get("is_staff") == "1",
                is_superuser=request.POST.get("is_superuser") == "1",
            )
        except PlatformAdminError as error:
            notify(request, f"e|Couldn't update access|{error}")
        else:
            notify(request, f"s|Access updated|Updated platform access for {user.email}.")
        return redirect("controlpanel:admins")


class PlatformAdminRevokeView(PlatformSuperuserRequiredMixin, View):
    def post(self, request, pk):
        user = get_object_or_404(get_user_model(), pk=pk)
        try:
            revoke_platform_access(request.user, user)
        except PlatformAdminError as error:
            notify(request, f"e|Couldn't revoke access|{error}")
        else:
            notify(request, f"w|Access revoked|{user.email} no longer has platform access.")
        return redirect("controlpanel:admins")


class BillingView(PlatformStaffRequiredMixin, TemplateView):
    """Plans and their prices, plus every period we are owed money for."""

    template_name = "controlpanel/billing.html"

    def get_context_data(self, **kwargs):
        today = timezone.localdate()

        # Bound per-row so each "Edit" / "New price" modal can render its own form: the
        # template can't call PlanForm(instance=plan) itself, so the form rides along on
        # the object it belongs to.
        plans = list(Plan.objects.visible().prefetch_related("prices").annotate(club_count=Count("subscriptions")))
        for plan in plans:
            plan.edit_form = PlanForm(instance=plan)
            plan.price_form = PlanPriceForm()

        owing = list(Due.objects.filter(status__in=Due.OWING).select_related("club", "plan").order_by("grace_until"))
        for due in owing:
            due.payment_form = DuePaymentForm(initial={"amount": due.balance})

        return super().get_context_data(
            nav="billing",
            plans=plans,
            plan_form=PlanForm(),
            owing=owing,
            today=today,
            **kwargs,
        )


class PlanCreateView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, CreateView):
    """Reachable only via the "New plan" modal on the billing page — POST-only, and there
    is no standalone template to render on GET or on a rejected submission."""

    model = Plan
    form_class = PlanForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:billing"

    def get_success_url(self):
        notify(self.request, f"s|Plan created|Plan “{self.object}” created. Give it a price before billing anyone.")
        return reverse("controlpanel:billing")


class PlanUpdateView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, UpdateView):
    """Reachable only via a plan's "Edit" modal on the billing page — POST-only, and there
    is no standalone template to render on GET or on a rejected submission."""

    model = Plan
    form_class = PlanForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:billing"

    def get_success_url(self):
        notify(self.request, f"s|Plan updated|Plan “{self.object}” updated.")
        return reverse("controlpanel:billing")


class PlanDeleteView(PlatformStaffRequiredMixin, TemplateView):
    """Confirm-then-delete for a plan. Unlike every other billing action, this is a real
    page rather than a modal: the whole point is naming exactly which clubs lose their plan
    (or lose their trial's scheduled landing plan), and that list can be long -- see
    billing.services.plans for what "delete" actually does to a plan with billing history.
    """

    template_name = "controlpanel/plan_delete.html"

    @property
    def plan(self):
        return get_object_or_404(Plan, pk=self.kwargs["pk"])

    def get(self, request, *args, **kwargs):
        plan = self.plan
        if plan.is_deleted:
            notify(request, f"i|{_('Already deleted')}|" + _("“%(plan)s” has already been deleted.") % {"plan": plan.name})
            return redirect("controlpanel:billing")
        return super().get(request, *args, **kwargs)

    def get_context_data(self, **kwargs):
        return super().get_context_data(nav="billing", plan=self.plan, impact=plan_deletion_impact(self.plan), **kwargs)

    def post(self, request, *args, **kwargs):
        plan = self.plan
        plan_name = plan.name
        impact = delete_plan(plan)

        if impact.will_hard_delete:
            body = _("“%(plan)s” has been deleted.") % {"plan": plan_name}
        else:
            body = _("“%(plan)s” has been deleted. It has billing history, so it's hidden rather than removed — past invoices still show it.") % {"plan": plan_name}
        notify(request, f"w|{_('Plan deleted')}|{body}")

        if impact.unsubscribed_clubs:
            count = len(impact.unsubscribed_clubs)
            club_body = ngettext("%(count)d club now has no plan.", "%(count)d clubs now have no plan.", count) % {"count": count}
            notify(request, f"w|{_('Clubs affected')}|{club_body}")

        if impact.broken_trial_clubs:
            count = len(impact.broken_trial_clubs)
            trial_body = ngettext("%(count)d club's trial lost its scheduled plan and needs a new one picked.", "%(count)d clubs' trials lost their scheduled plan and need a new one picked.", count) % {"count": count}
            notify(request, f"w|{_('Trials affected')}|{trial_body}")

        return redirect("controlpanel:billing")


class PlanPriceCreateView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, CreateView):
    """A rate change is a new dated price, never an edit of the old one — periods already
    billed keep the amount they were billed at.

    Reachable only via a plan's "New price" modal on the billing page — POST-only, and
    there is no standalone template to render on GET or on a rejected submission.
    """

    model = PlanPrice
    form_class = PlanPriceForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:billing"

    @property
    def plan(self):
        return get_object_or_404(Plan, pk=self.kwargs["pk"])

    def form_valid(self, form):
        form.instance.plan = self.plan
        response = super().form_valid(form)
        notify(self.request, f"s|Price added|{self.plan} is €{self.object.amount} for periods opening from {self.object.active_from}.")
        return response

    def get_success_url(self):
        return reverse("controlpanel:billing")


class SubscribeClubView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, FormView):
    """Put a club on a plan, which opens its first period.

    Reachable only via the "Change plan" modal on the club detail page — POST-only, and
    there is no standalone template to render on GET or on a rejected submission.
    """

    form_class = SubscriptionForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:club_detail"

    @property
    def club(self):
        return get_object_or_404(Club, pk=self.kwargs["pk"])

    def get_invalid_redirect_kwargs(self):
        return {"pk": self.club.pk}

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        subscription = getattr(self.club, "subscription", None)
        if subscription:
            kwargs["instance"] = subscription
        return kwargs

    def form_valid(self, form):
        club = self.club
        existing = getattr(club, "subscription", None)
        with suppress_billing_errors(self.request, title="Couldn't change plan"):
            if existing:
                # Changing plan does not re-bill: the current period keeps the amount it was
                # issued at, and the new rate applies from the next one.
                was_on_trial = existing.trial_ends_at is not None
                subscription = form.save(commit=False)
                subscription.club = club
                if was_on_trial:
                    # A manual plan change while on a trial is a deliberate override --
                    # left in place, the trial fields would silently swap the plan again
                    # later, onto a plan the admin didn't just choose.
                    subscription.trial_ends_at = None
                    subscription.post_trial_plan = None
                subscription.save()
                notify(self.request, f"s|Plan changed|{club} is now on {subscription.plan}. The current period keeps the amount it was billed at.")
            else:
                subscribe(club, form.cleaned_data["plan"], start=form.cleaned_data.get("start"), auto_archive=form.cleaned_data["auto_archive"], auto_renew=form.cleaned_data["auto_renew"])
                notify(self.request, f"s|Billing started|{club} is on {form.cleaned_data['plan']}. Its first period is open.")

        return redirect("controlpanel:club_detail", pk=club.pk)


class ClubStartTrialView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, FormView):
    """Put a club with no subscription yet on a short trial -- reachable only via the
    "Start trial" modal on the club detail page, shown alongside "Start billing" only
    while the club has no subscription. POST-only, no standalone template."""

    form_class = TrialForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:club_detail"

    @property
    def club(self):
        return get_object_or_404(Club, pk=self.kwargs["pk"])

    def get_invalid_redirect_kwargs(self):
        return {"pk": self.kwargs["pk"]}

    def form_valid(self, form):
        club = self.club
        with suppress_billing_errors(self.request, title="Couldn't start trial"):
            trial_plan = form.cleaned_data["trial_plan"]
            start_trial(
                club,
                trial_plan,
                post_trial_plan=form.cleaned_data["post_trial_plan"],
                start=form.cleaned_data.get("start"),
                auto_renew=form.cleaned_data["auto_renew"],
                auto_archive=form.cleaned_data["auto_archive"],
            )
            notify(self.request, f"s|Trial started|{club} is on a {trial_plan.duration_months}-month trial of {trial_plan}, then switches to {form.cleaned_data['post_trial_plan']}.")

        return redirect("controlpanel:club_detail", pk=club.pk)


class RecordPaymentView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, FormView):
    """Reachable only via a due's "Record payment" modal on the club or billing page —
    POST-only, and there is no standalone template to render on GET or on a rejected
    submission."""

    form_class = DuePaymentForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:club_detail"

    @property
    def due(self):
        return get_object_or_404(Due.objects.select_related("club", "plan"), pk=self.kwargs["pk"])

    def get_invalid_redirect_kwargs(self):
        return {"pk": self.due.club_id}

    def form_valid(self, form):
        due = self.due
        with suppress_billing_errors(self.request, title="Couldn't record payment"):
            record_payment(
                due,
                form.cleaned_data["amount"],
                method=form.cleaned_data["method"],
                reference=form.cleaned_data["reference"],
                paid_at=form.cleaned_data["paid_at"],
                note=form.cleaned_data["note"],
                user=self.request.user,
            )
            due.refresh_from_db()
            notify(self.request, f"s|Payment recorded|€{form.cleaned_data['amount']} recorded. {due.get_status_display().capitalize()} — €{due.balance} outstanding.")

        return redirect("controlpanel:club_detail", pk=due.club_id)


class WaiveDueView(PlatformStaffRequiredMixin, View):
    def post(self, request, pk):
        due = get_object_or_404(Due, pk=pk)
        with suppress_billing_errors(request, title="Couldn't waive period"):
            waive(due)
            notify(request, f"w|Period waived|Period {due.period_start} to {due.period_end} waived. Nothing is owed and the club will not be archived for it.")

        return redirect("controlpanel:club_detail", pk=due.club_id)


class OpenPeriodView(PlatformStaffRequiredMixin, RedirectOnInvalidMixin, FormView):
    """Renew a club, or reactivate an archived one.

    Reachable only via the "Open period" modal on the club detail page — POST-only, and
    there is no standalone template to render on GET or on a rejected submission.
    """

    form_class = OpenPeriodForm
    http_method_names = ["post"]
    invalid_redirect_url_name = "controlpanel:club_detail"

    @property
    def club(self):
        return get_object_or_404(Club, pk=self.kwargs["pk"])

    def get_invalid_redirect_kwargs(self):
        return {"pk": self.club.pk}

    def form_valid(self, form):
        club = self.club
        start = form.cleaned_data.get("start")
        with suppress_billing_errors(self.request, title="Couldn't open period"):
            due = reactivate(club, start=start) if club.is_archived else open_period(club, start=start)
            notify(self.request, f"s|Period opened|Period {due.period_start} to {due.period_end} opened for €{due.amount}. Invoice {due.invoice.number}.")

        return redirect("controlpanel:club_detail", pk=club.pk)


class InvoicePdfView(PlatformStaffRequiredMixin, View):
    def get(self, request, pk):
        due = get_object_or_404(Due.objects.select_related("club", "plan", "invoice"), pk=pk)
        invoice = issue_invoice(due)
        try:
            pdf = invoice_pdf(invoice)
        except BillingError as error:
            # The native PDF libraries are missing: say so rather than 500.
            notify(request, f"e|PDF unavailable|{error}")
            return redirect("controlpanel:club_detail", pk=due.club_id)

        response = HttpResponse(pdf, content_type="application/pdf")
        response["Content-Disposition"] = f'attachment; filename="{invoice.number}.pdf"'
        return response