feat: add fiat checkout and nostr + email notification (#50)

* feat: fiat and email/nostr notifications

* make n bake

services.py

@@ -1,3 +1,12 @@
+from __future__ import annotations
+
+from asyncio.tasks import create_task
+
+from lnbits.core.models.users import UserNotifications
+from lnbits.core.services.nostr import send_nostr_dm
+from lnbits.core.services.notifications import send_user_notification
+from lnbits.settings import settings
+from lnbits.utils.nostr import normalize_private_key, normalize_public_key
 from lnurl import execute
 from loguru import logger
 
@@ -10,6 +19,12 @@ from .crud import (
 )
 from .models import Ticket
 
+DEFAULT_NOSTR_RELAYS = [
+    "wss://relay.damus.io",
+    "wss://relay.primal.net",
+    "wss://relay.nostr.band",
+]
+
 
 async def set_ticket_paid(ticket: Ticket) -> Ticket:
     if ticket.paid:
@@ -27,6 +42,77 @@ async def set_ticket_paid(ticket: Ticket) -> Ticket:
     return ticket
 
 
+def send_ticket_notification_in_background(ticket: Ticket) -> None:
+    create_task(_send_ticket_notification(ticket))
+
+
+async def _send_ticket_notification(ticket: Ticket) -> None:
+    event = await get_event(ticket.event)
+    if not event:
+        logger.warning(f"Event {ticket.event} not found for ticket notification.")
+        return
+
+    ticket_url = _ticket_url(ticket)
+    message = (
+        f"{settings.lnbits_site_title}\n"
+        f"Your ticket for '{event.name}' is ready.\n"
+        f"Open it here: {ticket_url}"
+    )
+    updated = False
+
+    if (
+        event.extra.email_notifications
+        and settings.lnbits_email_notifications_enabled
+        and ticket.email
+    ):
+        try:
+            await send_user_notification(
+                UserNotifications(email_address=ticket.email),
+                message,
+                "text_message",
+            )
+            ticket.extra.email_notification_sent = True
+            updated = True
+        except Exception as exc:
+            logger.warning(f"Failed to email ticket {ticket.id}: {exc}")
+
+    if (
+        event.extra.nostr_notifications
+        and settings.is_nostr_notifications_configured()
+        and ticket.extra.nostr_identifier
+    ):
+        try:
+            await _send_nostr_ticket_notification(
+                ticket.extra.nostr_identifier, message
+            )
+            ticket.extra.nostr_notification_sent = True
+            updated = True
+        except Exception as exc:
+            logger.warning(f"Failed to send nostr DM for ticket {ticket.id}: {exc}")
+
+    if updated:
+        await update_ticket(ticket)
+
+
+async def _send_nostr_ticket_notification(identifier: str, message: str) -> None:
+    if "@" in identifier:
+        await send_user_notification(
+            UserNotifications(nostr_identifier=identifier),
+            message,
+            "text_message",
+        )
+        return
+
+    private_key = normalize_private_key(settings.lnbits_nostr_notifications_private_key)
+    public_key = normalize_public_key(identifier)
+    await send_nostr_dm(private_key, public_key, message, DEFAULT_NOSTR_RELAYS)
+
+
+def _ticket_url(ticket: Ticket) -> str:
+    base_url = (ticket.extra.ticket_base_url or settings.lnbits_baseurl).rstrip("/")
+    return f"{base_url}/events/ticket/{ticket.id}"
+
+
 async def refund_tickets(event_id: str):
     """
     Refund tickets for an event that has not met the minimum ticket requirement.