fix(events): ticket waves inherit the event's fiat setting

Reported from aio-demo: an event with card enabled, Card offered at
checkout, and the purchase refused with "Fiat payments are not enabled
for this ticket wave."

Two causes, both introduced with wave support in #176.

**New waves never carried the flag.** `newWaveRow` set id, title, dates,
currency, capacity and price — not `allow_fiat`. Fiat is a per-wave
opt-in, so every wave the webapp created silently refused card payments
however the event-level toggle was set. The editor now seeds new waves
from the event, the way the LNbits admin dialog seeds one from the
primary wave, and exposes a per-wave switch so an existing wave can be
corrected — the LNbits admin has had that control all along, which is
why the event looked fiat-enabled there while its waves were not.

**The rail list ignored the wave.** `effectivePaymentMethods` returned
the organiser's explicit `payment_methods` before consulting anything
else, so the card button appeared regardless. That list is event-level
while fiat is per-wave, and the webapp always sets it, so the explicit
path is the normal one rather than the exception.

The wave is now a separate argument rather than being folded into
`allowFiat`: that one is the event's legacy flag and means something
different, and conflating them broke two existing tests — correctly,
which is how the design fault showed up. Matches the backend's
`effective_payment_methods(event, wave)` (aiolabs/events b55d686).

7 tests, including that an unset wave flag reads as no-fiat (how the
backend reads it) and that the event-level question stays unfiltered.
79 pass; vue-tsc, prettier and the production build clean.

Needs the matching events release to be deployed for the published
NIP-52 tags to agree; the webapp half stands alone.

src/modules/events/components/CreateEventDialog.vue

@@ -342,8 +342,12 @@ const waveErrors = computed(() =>
   validateWaveRows(extraWaves.value, new Set(knownWaveIds.value)),
 );
 const hasWaveErrors = computed(() => Object.keys(waveErrors.value).length > 0);
-/** New waves inherit the primary wave's currency. */
+/** New waves inherit the primary wave's currency and fiat settings. */
 const primaryCurrency = computed(() => form.values.currency ?? "sat");
+const primaryAllowsFiat = computed(
+  () => form.values.payment_methods?.includes("fiat") ?? false,
+);
+const primaryFiatCurrency = computed(() => form.values.fiat_currency ?? "USD");
 
 async function populateFromEvent(event: TicketedEvent) {
   isPopulating.value = true;
@@ -1215,6 +1219,8 @@ const handleOpenChange = (open: boolean) => {
                 v-model="extraWaves"
                 :known-ids="knownWaveIds"
                 :currency="primaryCurrency"
+                :allow-fiat="primaryAllowsFiat"
+                :fiat-currency="primaryFiatCurrency"
                 :disabled="isLoading"
               />
             </CollapsibleContent>

src/modules/events/components/PurchaseTicketDialog.vue

@@ -298,12 +298,16 @@ const isFiatPending = ref(false);
 const fiatError = ref<string | null>(null);
 
 const enabledRails = computed(() =>
-  effectivePaymentMethods({
-    // Fiat is a per-wave opt-in; `event.allow_fiat` is only the primary
-    // wave's and can disagree with the tier being bought.
-    allowFiat: pricing.value.allow_fiat,
-    paymentMethods: props.event.payment_methods,
-  }),
+  effectivePaymentMethods(
+    {
+      allowFiat: props.event.allow_fiat,
+      paymentMethods: props.event.payment_methods,
+    },
+    // Fiat is a per-wave opt-in, and the organiser's explicit rail list is
+    // event-level — without the wave here the dialog offers a card button
+    // the purchase endpoint then refuses.
+    pricing.value,
+  ),
 );
 const canChooseFiat = computed(() => enabledRails.value.includes("fiat"));
 const isPriceInSats = computed(

src/modules/events/components/TicketWavesEditor.vue

@@ -1,6 +1,7 @@
 <script setup lang="ts">
 import { computed } from "vue";
 import { Button } from "@/components/ui/button";
+import { Switch } from "@/components/ui/switch";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import { Plus, Trash2 } from "lucide-vue-next";
@@ -27,6 +28,11 @@ const props = defineProps<{
   knownIds?: string[];
   /** Currency of the primary wave; new rows inherit it. */
   currency?: string;
+  /** Whether the event accepts fiat, and in what. New rows inherit both:
+   *  fiat is a per-wave opt-in, so a wave created without it refuses card
+   *  payments no matter what the event-level toggle says. */
+  allowFiat?: boolean;
+  fiatCurrency?: string;
   disabled?: boolean;
 }>();
 const emit = defineEmits<{ "update:modelValue": [waves: TicketWave[]] }>();
@@ -47,7 +53,11 @@ function update(index: number, patch: Partial<TicketWave>) {
 function add() {
   emit("update:modelValue", [
     ...props.modelValue,
-    newWaveRow({ currency: props.currency ?? "sat" }),
+    newWaveRow({
+      currency: props.currency ?? "sat",
+      allow_fiat: props.allowFiat ?? false,
+      fiat_currency: props.fiatCurrency ?? "USD",
+    }),
   ]);
 }
 
@@ -176,6 +186,21 @@ function isSoldOut(row: TicketWave): boolean {
         </div>
       </div>
 
+      <div
+        v-if="allowFiat"
+        class="flex items-center justify-between rounded-md bg-muted/40 px-2 py-1.5"
+      >
+        <span class="text-xs">
+          Accept card for this wave
+          <span class="text-muted-foreground">({{ row.fiat_currency }})</span>
+        </span>
+        <Switch
+          :model-value="row.allow_fiat ?? false"
+          :disabled="disabled"
+          @update:model-value="update(index, { allow_fiat: Boolean($event) })"
+        />
+      </div>
+
       <p v-if="errors[index]" class="text-xs text-destructive">
         {{ errors[index] }}
       </p>

src/modules/events/lib/paymentMethods.spec.ts

@@ -1,21 +1,79 @@
-import { describe, it, expect } from 'vitest'
-import { effectivePaymentMethods } from './paymentMethods'
+import { describe, it, expect } from "vitest";
+import { effectivePaymentMethods } from "./paymentMethods";
 
-describe('effectivePaymentMethods', () => {
-  it('falls back to the legacy allowFiat rule when no list is published', () => {
-    expect(effectivePaymentMethods({ allowFiat: false })).toEqual(['lightning'])
-    expect(effectivePaymentMethods({ allowFiat: true })).toEqual(['lightning', 'fiat'])
-    expect(effectivePaymentMethods(undefined)).toEqual(['lightning'])
-  })
+describe("effectivePaymentMethods", () => {
+  it("falls back to the legacy allowFiat rule when no list is published", () => {
+    expect(effectivePaymentMethods({ allowFiat: false })).toEqual([
+      "lightning",
+    ]);
+    expect(effectivePaymentMethods({ allowFiat: true })).toEqual([
+      "lightning",
+      "fiat",
+    ]);
+    expect(effectivePaymentMethods(undefined)).toEqual(["lightning"]);
+  });
 
-  it('honours an explicit list, including fiat-only events', () => {
-    expect(effectivePaymentMethods({ allowFiat: true, paymentMethods: ['fiat'] })).toEqual(['fiat'])
-    expect(effectivePaymentMethods({ allowFiat: false, paymentMethods: ['lightning', 'fiat'] }))
-      .toEqual(['lightning', 'fiat'])
-  })
+  it("honours an explicit list, including fiat-only events", () => {
+    expect(
+      effectivePaymentMethods({ allowFiat: true, paymentMethods: ["fiat"] }),
+    ).toEqual(["fiat"]);
+    expect(
+      effectivePaymentMethods({
+        allowFiat: false,
+        paymentMethods: ["lightning", "fiat"],
+      }),
+    ).toEqual(["lightning", "fiat"]);
+  });
 
-  it('drops unknown rails and falls back when nothing known remains', () => {
-    expect(effectivePaymentMethods({ allowFiat: false, paymentMethods: ['onchain'] })).toEqual(['lightning'])
-    expect(effectivePaymentMethods({ allowFiat: false, paymentMethods: ['onchain', 'fiat'] })).toEqual(['fiat'])
-  })
-})
+  it("drops unknown rails and falls back when nothing known remains", () => {
+    expect(
+      effectivePaymentMethods({
+        allowFiat: false,
+        paymentMethods: ["onchain"],
+      }),
+    ).toEqual(["lightning"]);
+    expect(
+      effectivePaymentMethods({
+        allowFiat: false,
+        paymentMethods: ["onchain", "fiat"],
+      }),
+    ).toEqual(["fiat"]);
+  });
+});
+
+describe("effectivePaymentMethods — per-wave fiat", () => {
+  const railsOn = { allowFiat: true, paymentMethods: ["lightning", "fiat"] };
+
+  it("drops card for a wave that cannot take fiat", () => {
+    // Reported from aio-demo: event fiat on, Card offered, purchase
+    // refused with "Fiat payments are not enabled for this ticket wave".
+    expect(effectivePaymentMethods(railsOn, { allow_fiat: false })).toEqual([
+      "lightning",
+    ]);
+  });
+
+  it("keeps card for a wave that can", () => {
+    expect(effectivePaymentMethods(railsOn, { allow_fiat: true })).toEqual([
+      "lightning",
+      "fiat",
+    ]);
+  });
+
+  it("treats an unset wave flag as no fiat — it is how the backend reads it", () => {
+    expect(effectivePaymentMethods(railsOn, {})).toEqual(["lightning"]);
+  });
+
+  it("leaves the event-level question unfiltered", () => {
+    expect(effectivePaymentMethods(railsOn)).toEqual(["lightning", "fiat"]);
+    expect(effectivePaymentMethods(railsOn, null)).toEqual([
+      "lightning",
+      "fiat",
+    ]);
+  });
+
+  it("filters the legacy allowFiat path too", () => {
+    expect(
+      effectivePaymentMethods({ allowFiat: true }, { allow_fiat: false }),
+    ).toEqual(["lightning"]);
+  });
+});

src/modules/events/lib/paymentMethods.ts

@@ -1,6 +1,6 @@
-export type PaymentRailId = 'lightning' | 'fiat'
+export type PaymentRailId = "lightning" | "fiat";
 
-const KNOWN_RAILS: PaymentRailId[] = ['lightning', 'fiat']
+const KNOWN_RAILS: PaymentRailId[] = ["lightning", "fiat"];
 
 /**
  * Rails a buyer may use for an event.
@@ -13,10 +13,31 @@ const KNOWN_RAILS: PaymentRailId[] = ['lightning', 'fiat']
  */
 export function effectivePaymentMethods(
   info: { allowFiat?: boolean; paymentMethods?: string[] } | null | undefined,
+  /** The wave being bought. Omit for the event-level question ("which
+   *  rails did the organiser enable at all"). */
+  wave?: { allow_fiat?: boolean } | null,
 ): PaymentRailId[] {
   const explicit = (info?.paymentMethods ?? []).filter(
     (m): m is PaymentRailId => (KNOWN_RAILS as string[]).includes(m),
-  )
-  if (explicit.length > 0) return explicit
-  return info?.allowFiat ? ['lightning', 'fiat'] : ['lightning']
+  );
+  const rails =
+    explicit.length > 0
+      ? explicit
+      : info?.allowFiat
+        ? (["lightning", "fiat"] as PaymentRailId[])
+        : (["lightning"] as PaymentRailId[]);
+
+  // Fiat is a PER-WAVE opt-in, while the rail list above is event-level.
+  // Asking about a specific wave means asking what a buyer can actually
+  // use for it, so drop a rail that wave cannot honour — otherwise the
+  // dialog renders a card button that `api_ticket_create` refuses with
+  // "Fiat payments are not enabled for this ticket wave".
+  //
+  // A separate argument rather than reusing `info.allowFiat`: that one is
+  // the EVENT's legacy flag and means something different. The backend
+  // keeps the same split (`effective_payment_methods(event, wave)`).
+  if (wave && wave.allow_fiat !== true) {
+    return rails.filter((m) => m !== "fiat");
+  }
+  return rails;
 }

src/modules/events/lib/ticketWaves.spec.ts

@@ -327,3 +327,21 @@ describe("the primary-wave write-through a create/edit form performs", () => {
     expect(waves[1]).toEqual(REGULAR);
   });
 });
+
+describe("newWaveRow — fiat inheritance", () => {
+  it("defaults to no fiat, matching what the backend stores", () => {
+    expect(newWaveRow().allow_fiat).toBe(false);
+  });
+
+  it("inherits the event settings when the editor passes them", () => {
+    // Without this a wave created on a fiat-enabled event silently refuses
+    // card payments, and the organiser has no way to see why.
+    const row = newWaveRow({
+      allow_fiat: true,
+      fiat_currency: "EUR",
+      currency: "EUR",
+    });
+    expect(row.allow_fiat).toBe(true);
+    expect(row.fiat_currency).toBe("EUR");
+  });
+});

src/modules/events/lib/ticketWaves.ts

@@ -289,6 +289,14 @@ export function newWaveRow(defaults: Partial<TicketWave> = {}): TicketWave {
     // unlimited (aiolabs/events#34).
     amount_tickets: 1,
     price_per_ticket: 0,
+    // Fiat is a PER-WAVE opt-in. A wave created without it cannot take
+    // card payments however the event-level toggle is set, and the
+    // organiser gets "Fiat payments are not enabled for this ticket wave"
+    // at checkout with no way to see why. Callers pass the event's
+    // setting so a new wave inherits it, the way the LNbits admin dialog
+    // seeds one from the primary wave.
+    allow_fiat: false,
+    fiat_currency: "USD",
     ...defaults,
   };
 }