Merge pull request 'feat: issue free tickets without minting an invoice' (#31) from feat/free-tickets into main

Reviewed-on: #31

config.json

@@ -1,6 +1,6 @@
 {
   "id": "events",
-  "version": "1.6.1-aio.5",
+  "version": "1.6.1-aio.7",
   "name": "Events",
   "repo": "https://git.atitlan.io/aiolabs/events",
   "short_description": "Sell and register event tickets",

models.py

@@ -183,6 +183,10 @@ class TicketPaymentRequest(BaseModel):
     fiat_payment_request: str | None = None
     fiat_provider: str | None = None
     is_fiat: bool = False
+    # True when the tickets are already issued + paid with no invoice to
+    # settle — free events (price 0) or a 100%-off promo. The client skips
+    # the QR / payment-poll step and goes straight to the ticket QRs.
+    paid: bool = False
     # Row ids created on this invoice — one for single-ticket
     # purchases, N for multi-ticket (each independently scannable at
     # the door). Buyers fetch these after payment to render N QRs in

nostr_publisher.py

@@ -19,6 +19,7 @@ from loguru import logger
 
 from .models import Event
 from .nostr.event import NostrEvent
+from .nostr_timestamp import monotonic_created_at
 
 
 def _has_time(value: str | None) -> bool:
@@ -110,9 +111,15 @@ def build_nip52_event(event: Event, pubkey: str) -> NostrEvent:
         if event.fiat_currency:
             tags.append(["tickets_fiat_currency", event.fiat_currency])
 
+    # NIP-52 calendar events are replaceable: this d-tag is republished
+    # whenever inventory changes (a ticket sells). Use a strictly-monotonic
+    # created_at anchored on the last published value so a same-second
+    # republish still outranks the prior version and relays push it to open
+    # subscriptions — a bare int(time.time()) can tie and be silently
+    # dropped, stalling clients' live "tickets remaining" badge.
     nostr_event = NostrEvent(
         pubkey=pubkey,
-        created_at=int(time.time()),
+        created_at=monotonic_created_at(event.nostr_event_created_at),
         kind=kind,
         tags=tags,
         content=event.info or "",

nostr_timestamp.py

@@ -0,0 +1,34 @@
+"""Monotonic ``created_at`` for replaceable / addressable Nostr events.
+
+Relays only push a replaceable update to OPEN subscriptions when its
+``created_at`` is strictly newer than the version they already hold.
+``created_at`` is integer seconds, so a publisher that stamps
+``int(time.time())`` can emit two versions within the same wall-clock
+second (e.g. two ticket sales republishing the NIP-52 calendar event) —
+the relay treats the second as not-newer and never propagates it to live
+subscribers (it only surfaces on a reload / fresh REQ).
+
+Returning ``max(now, last_created_at + 1)`` guarantees a strictly
+increasing timestamp across successive publishes of the same replaceable
+event. When enough real seconds have elapsed it tracks wall-clock; only
+same-second (or clock-skewed) republishes get nudged forward.
+
+Mirrors the webapp's ``monotonicCreatedAt`` (src/lib/nostr/timestamp.ts)
+and ``docs/nostr-patterns/replaceable-events.md``.
+"""
+
+import time
+
+
+def monotonic_created_at(last_created_at: int | None, now: int | None = None) -> int:
+    """Strictly-newer ``created_at`` for the next publish of a coord.
+
+    :param last_created_at: ``created_at`` of the previously published
+        version (seconds), or ``None`` if none has been published yet.
+    :param now: Current time in seconds — injectable for tests; defaults
+        to ``int(time.time())``.
+    """
+    base = int(time.time()) if now is None else now
+    if last_created_at is None:
+        return base
+    return max(base, last_created_at + 1)

tests/test_nostr_timestamp.py

@@ -0,0 +1,32 @@
+from itertools import pairwise
+
+from ..nostr_timestamp import monotonic_created_at
+
+
+def test_no_prior_uses_now():
+    assert monotonic_created_at(None, now=1000) == 1000
+
+
+def test_same_second_bumps_past_prior():
+    # now == last: a naive int(time.time()) would tie and the relay would
+    # drop the update; we must produce a strictly newer stamp.
+    assert monotonic_created_at(1000, now=1000) == 1001
+
+
+def test_tracks_wallclock_once_seconds_elapse():
+    assert monotonic_created_at(1000, now=1005) == 1005
+
+
+def test_steps_past_future_dated_prior():
+    # clock skew / rapid bursts left the stored value ahead of now
+    assert monotonic_created_at(2000, now=1000) == 2001
+
+
+def test_strictly_increasing_same_second_burst():
+    last = None
+    stamps = []
+    for _ in range(5):
+        last = monotonic_created_at(last, now=1000)  # clock frozen at 1000
+        stamps.append(last)
+    assert stamps == [1000, 1001, 1002, 1003, 1004]
+    assert all(b > a for a, b in pairwise(stamps))

views_api.py

@@ -66,7 +66,12 @@ from .models import (
     TicketPaymentRequest,
 )
 from .nostr_hooks import publish_or_delete_nostr_event
-from .services import refund_tickets, resend_ticket_email_notification
+from .services import (
+    refund_tickets,
+    resend_ticket_email_notification,
+    send_ticket_notification_in_background,
+    set_ticket_paid,
+)
 from .tasks import deregister_payment_listener, register_payment_listener
 
 events_api_router = APIRouter(prefix="/api/v1/events")
@@ -508,6 +513,62 @@ async def api_get_ticket(ticket_id: str) -> Ticket:
     return ticket
 
 
+async def _issue_free_tickets(
+    *,
+    event: Event,
+    quantity: int,
+    name: str | None,
+    email: str | None,
+    user_id: str | None,
+    promo_code: str | None,
+    nostr_identifier: str | None,
+    request: Request,
+) -> TicketPaymentRequest:
+    """Issue `quantity` free tickets without minting an invoice.
+
+    Each row is created then run through `set_ticket_paid` — the exact path
+    `on_invoice_paid` drives for a settled payment: it flips `paid`, bumps
+    the sold / available counters under the per-event lock, and republishes
+    the NIP-52 calendar event so connected clients see the new counts.
+    Notifications fire the same way. No invoice exists, so `sats_paid` is 0
+    and these tickets are naturally skipped by `refund_tickets`.
+
+    All rows in the batch share one synthetic `payment_hash` — the join key
+    the poll / WebSocket / My-Tickets lookups use — mirroring how the paid
+    multi-ticket path shares the real invoice hash.
+    """
+    payment_hash = urlsafe_short_hash()
+    ticket_ids: list[str] = []
+    for _ in range(quantity):
+        row_id = urlsafe_short_hash()
+        ticket = await create_ticket(
+            payment_hash=payment_hash,
+            wallet=event.wallet,
+            event=event.id,
+            name=name,
+            email=email,
+            user_id=user_id,
+            ticket_id=row_id,
+            extra={
+                "applied_promo_code": promo_code,
+                "nostr_identifier": nostr_identifier,
+                "ticket_base_url": str(request.base_url).rstrip("/"),
+                "sats_paid": 0,
+            },
+        )
+        await set_ticket_paid(ticket)
+        send_ticket_notification_in_background(ticket)
+        ticket_ids.append(row_id)
+
+    return TicketPaymentRequest(
+        payment_hash=payment_hash,
+        payment_request=None,
+        is_fiat=False,
+        paid=True,
+        ticket_ids=ticket_ids,
+    )
+
+
 @tickets_api_router.post("/{event_id}")
 async def api_ticket_create(
     event_id: str, data: CreateTicket, request: Request
@@ -571,6 +632,22 @@ async def api_ticket_create(
     # Scale by quantity AFTER the promo applies. One invoice, N tickets.
     price = unit_price * quantity
 
+    # Free tickets (final charge 0 — a free event or a 100%-off promo).
+    # Short-circuit before any invoice / fiat-provider logic: no Lightning
+    # invoice can settle for 0, so we issue the rows and mark them paid
+    # directly. payment_method is irrelevant here (nothing is charged).
+    if price <= 0:
+        return await _issue_free_tickets(
+            event=event,
+            quantity=quantity,
+            name=name,
+            email=email,
+            user_id=user_id,
+            promo_code=promo_code,
+            nostr_identifier=nostr_identifier,
+            request=request,
+        )
+
     if payment_method == "fiat" and not event.allow_fiat:
         raise HTTPException(
             status_code=HTTPStatus.BAD_REQUEST,