fix: populate lnurl/lnurl_url in nostr-transport handlers (#1)

The HTTP views populate `link.lnurl` and `link.lnurl_url` from
`request.url_for(...)`; the nostr-transport RPC handlers had no
`Request` and so left both fields as `None`. Consumers (ATMs over
nostr) were forced to provision a separate `LNBITS_HTTP_URL` env var
and compose the LNURL callback themselves.

Add `helpers.create_lnurl_from_baseurl(link)` that mirrors
`create_lnurl` but composes the callback URL from
`settings.lnbits_baseurl` instead, and thread it through the
create/get/update/list RPC handlers via a `_populate_lnurl` shim
so the response shape matches the HTTP path. Encoding errors are
swallowed (fields stay `None`) so a misconfigured baseurl falls
back to current behavior rather than failing the RPC.

Closes #1.

transport_rpcs.py

@@ -20,12 +20,11 @@ link_id:...})` enforce ownership without core importing this module.
 
 from __future__ import annotations
 
-from shortuuid import uuid
-
 from lnbits.core.crud.wallets import get_wallets
 from lnbits.core.models import Account
 from lnbits.core.models.wallets import WalletTypeInfo
 from lnbits.core.services.nostr_transport.models import NostrRpcRequest
+from shortuuid import uuid
 
 from .crud import (
     create_withdraw_link,
@@ -34,7 +33,8 @@ from .crud import (
     get_withdraw_links,
     update_withdraw_link,
 )
-from .models import CreateWithdrawData
+from .helpers import create_lnurl_from_baseurl
+from .models import CreateWithdrawData, WithdrawLink
 
 
 async def handle_lnurlw_create_link(
@@ -43,7 +43,7 @@ async def handle_lnurlw_create_link(
     body = request.body or {}
     data = CreateWithdrawData(**body)
     link = await create_withdraw_link(data, auth.wallet.id)
-    return _to_dict(link)
+    return _to_dict(_populate_lnurl(link))
 
 
 async def handle_lnurlw_get_link(
@@ -51,7 +51,7 @@ async def handle_lnurlw_get_link(
 ) -> dict:
     link_id = _require_id(request)
     link = await _require_owned_link(link_id, auth.wallet.id)
-    return _to_dict(link)
+    return _to_dict(_populate_lnurl(link))
 
 
 async def handle_lnurlw_update_link(
@@ -77,7 +77,7 @@ async def handle_lnurlw_update_link(
         if k in _MUTABLE:
             setattr(link, k, v)
     updated = await update_withdraw_link(link)
-    return _to_dict(updated)
+    return _to_dict(_populate_lnurl(updated))
 
 
 async def handle_lnurlw_delete_link(
@@ -89,9 +89,7 @@ async def handle_lnurlw_delete_link(
     return {"ok": True}
 
 
-async def handle_lnurlw_list_links(
-    auth: Account, request: NostrRpcRequest
-) -> dict:
+async def handle_lnurlw_list_links(auth: Account, request: NostrRpcRequest) -> dict:
     """List withdraw links across all wallets owned by the calling account.
     Useful for ATMs to re-discover their links after a reconnect.
 
@@ -114,7 +112,7 @@ async def handle_lnurlw_list_links(
 
     page = await get_withdraw_links(wallet_ids, limit, offset)
     return {
-        "data": [_to_dict(link) for link in page.data],
+        "data": [_to_dict(_populate_lnurl(link)) for link in page.data],
         "total": page.total,
     }
 
@@ -199,12 +197,29 @@ async def _require_owned_link(link_id: str, wallet_id: str):
     if link is None:
         raise ValueError(f"withdraw: link not found: {link_id}")
     if link.wallet != wallet_id:
-        raise PermissionError(
-            "withdraw: link does not belong to caller's wallet"
-        )
+        raise PermissionError("withdraw: link does not belong to caller's wallet")
+    return link
+
+
+def _populate_lnurl(link: WithdrawLink) -> WithdrawLink:
+    """
+    Compose `lnurl` / `lnurl_url` from `settings.lnbits_baseurl` so
+    nostr-transport responses match the HTTP `views_api` shape, where
+    these fields are populated from `request.url_for(...)`. Without
+    this, consumers (ATMs, etc.) would have to re-derive the callback
+    URL themselves from a separately-provisioned LNbits HTTPS URL —
+    duplicating state LNbits already knows. See aiolabs/withdraw#1.
+    """
+    try:
+        encoded = create_lnurl_from_baseurl(link)
+        link.lnurl = str(encoded.bech32)
+        link.lnurl_url = str(encoded.url)
+    except ValueError:
+        pass
     return link
 
 
 def _to_dict(link) -> dict:
     import json
+
     return json.loads(link.json())