Close pre-sale registration a configurable time before events start.

Events gain nullable presale_closure_enabled / presale_close_minutes_before
overrides; null inherits the new site_settings defaults (enabled, 120 min).
A shared resolver computes the effective cutoff, which the public event API
exposes as presaleClosesAt and the public booking endpoint enforces. Door and
admin ticket creation are not gated.

Admin: toggle + duration picker in the event modal (pre-filled from the site
default) and a matching default card on Settings › General. Public: the event
page shows "Registration Closed" after the cutoff and the checkout page
redirects back.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

frontend/src/app/admin/events/_components/EventFormModal.tsx

@@ -6,10 +6,11 @@ import Card from '@/components/ui/Card';
 import Button from '@/components/ui/Button';
 import Input from '@/components/ui/Input';
 import MediaPicker from '@/components/MediaPicker';
+import DurationInput from '@/components/admin/DurationInput';
 import { StarIcon, TrashIcon, XMarkIcon } from '@heroicons/react/24/outline';
 import toast from 'react-hot-toast';
 import { useLanguage } from '@/context/LanguageContext';
-import { parseDate, EVENT_TIMEZONE } from '@/lib/utils';
+import { parseDate, EVENT_TIMEZONE, minutesToDuration } from '@/lib/utils';
 
 interface EventFormData {
   title: string;
@@ -30,6 +31,22 @@ interface EventFormData {
   bannerUrl: string;
   externalBookingEnabled: boolean;
   externalBookingUrl: string;
+  presaleClosureEnabled: boolean;
+  presaleCloseMinutesBefore: number;
+}
+
+// Site-wide pre-sale defaults, used to pre-fill events that haven't overridden them
+interface PresaleDefaults {
+  enabled: boolean;
+  minutesBefore: number;
+}
+
+const FALLBACK_PRESALE_DEFAULTS: PresaleDefaults = { enabled: true, minutesBefore: 120 };
+
+function describeDuration(minutes: number): string {
+  const { value, unit } = minutesToDuration(minutes);
+  const label = value === 1 ? unit.slice(0, -1) : unit;
+  return `${value} ${label}`;
 }
 
 const EMPTY_FORM: EventFormData = {
@@ -38,6 +55,8 @@ const EMPTY_FORM: EventFormData = {
   startDatetime: '', endDatetime: '', location: '', locationUrl: '',
   price: 0, currency: 'PYG', capacity: 50, status: 'draft',
   bannerUrl: '', externalBookingEnabled: false, externalBookingUrl: '',
+  presaleClosureEnabled: FALLBACK_PRESALE_DEFAULTS.enabled,
+  presaleCloseMinutesBefore: FALLBACK_PRESALE_DEFAULTS.minutesBefore,
 };
 
 function isoToLocalDatetime(isoString: string): string {
@@ -89,6 +108,30 @@ export default function EventFormModal({
   const [slugAliases, setSlugAliases] = useState<{ slug: string; createdAt: string }[]>([]);
   const [saving, setSaving] = useState(false);
   const [settingFeatured, setSettingFeatured] = useState(false);
+  const [presaleDefaults, setPresaleDefaults] = useState<PresaleDefaults>(FALLBACK_PRESALE_DEFAULTS);
+
+  useEffect(() => {
+    if (!open) return;
+    let cancelled = false;
+    // Site defaults fill in whatever the event hasn't overridden (null = inherit)
+    siteSettingsApi.get()
+      .then(({ settings }) => {
+        if (cancelled) return;
+        const defaults: PresaleDefaults = {
+          enabled: settings.presaleClosureEnabled ?? FALLBACK_PRESALE_DEFAULTS.enabled,
+          minutesBefore: settings.presaleCloseMinutesBefore ?? FALLBACK_PRESALE_DEFAULTS.minutesBefore,
+        };
+        setPresaleDefaults(defaults);
+        setFormData((prev) => ({
+          ...prev,
+          presaleClosureEnabled: event?.presaleClosureEnabled ?? defaults.enabled,
+          presaleCloseMinutesBefore: event?.presaleCloseMinutesBefore ?? defaults.minutesBefore,
+        }));
+      })
+      .catch(() => { /* keep fallback defaults */ });
+    return () => { cancelled = true; };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [open, event]);
 
   useEffect(() => {
     if (!open) return;
@@ -104,6 +147,8 @@ export default function EventFormModal({
         status: event.status, bannerUrl: event.bannerUrl || '',
         externalBookingEnabled: event.externalBookingEnabled || false,
         externalBookingUrl: event.externalBookingUrl || '',
+        presaleClosureEnabled: event.presaleClosureEnabled ?? presaleDefaults.enabled,
+        presaleCloseMinutesBefore: event.presaleCloseMinutesBefore ?? presaleDefaults.minutesBefore,
       });
       loadSlugAliases(event.id);
     } else {
@@ -161,6 +206,14 @@ export default function EventFormModal({
         setSaving(false);
         return;
       }
+      if (
+        formData.presaleClosureEnabled &&
+        (!Number.isFinite(formData.presaleCloseMinutesBefore) || formData.presaleCloseMinutesBefore < 0)
+      ) {
+        toast.error('Pre-sale closure time must be zero or more');
+        setSaving(false);
+        return;
+      }
       const eventData: Partial<Event> = {
         title: formData.title, titleEs: formData.titleEs || undefined,
         description: formData.description, descriptionEs: formData.descriptionEs || undefined,
@@ -172,6 +225,9 @@ export default function EventFormModal({
         status: formData.status, bannerUrl: formData.bannerUrl || undefined,
         externalBookingEnabled: formData.externalBookingEnabled,
         externalBookingUrl: formData.externalBookingEnabled ? formData.externalBookingUrl : undefined,
+        // Saving from the modal always writes explicit values (overrides the site default)
+        presaleClosureEnabled: formData.presaleClosureEnabled,
+        presaleCloseMinutesBefore: formData.presaleCloseMinutesBefore,
       };
       if (event) {
         // Only send slug when editing so creates still auto-generate from title
@@ -346,6 +402,35 @@ export default function EventFormModal({
             )}
           </div>
 
+          <div className="border border-secondary-light-gray rounded-lg p-4 space-y-4">
+            <div className="flex items-center justify-between">
+              <div>
+                <label className="block text-sm font-medium text-gray-700">Pre-sale Closure</label>
+                <p className="text-xs text-gray-500">Stop online registration before the event starts</p>
+              </div>
+              <button type="button"
+                onClick={() => setFormData({ ...formData, presaleClosureEnabled: !formData.presaleClosureEnabled })}
+                className={`relative inline-flex h-6 w-11 flex-shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors ${
+                  formData.presaleClosureEnabled ? 'bg-primary-yellow' : 'bg-gray-200'
+                }`}>
+                <span className={`inline-block h-5 w-5 transform rounded-full bg-white shadow transition ${
+                  formData.presaleClosureEnabled ? 'translate-x-5' : 'translate-x-0'
+                }`} />
+              </button>
+            </div>
+            {formData.presaleClosureEnabled && (
+              <DurationInput label="Close pre-sale this long before the start"
+                valueMinutes={formData.presaleCloseMinutesBefore}
+                onChange={(minutes) => setFormData({ ...formData, presaleCloseMinutesBefore: minutes })} />
+            )}
+            <p className="text-xs text-gray-500">
+              Site default: {presaleDefaults.enabled
+                ? `closes ${describeDuration(presaleDefaults.minutesBefore)} before the start`
+                : 'off'}
+              {' '}(Admin › Settings › General).
+            </p>
+          </div>
+
           <MediaPicker value={formData.bannerUrl}
             onChange={(url) => setFormData({ ...formData, bannerUrl: url })}
             relatedId={event?.id} relatedType="event" />