From 90f2c9ca5ca7e34ea6f9ac390ea218afb29d377b Mon Sep 17 00:00:00 2001
From: Riccardo Balbo <riccardo0blb@gmail.com>
Date: Wed, 18 Dec 2024 15:30:44 +0100
Subject: [PATCH] add support for max_fee_mtokens in bolt12 interface

---
 lib/bolt11.js       |  3 ++-
 lib/bolt12.js       |  4 ++--
 lib/boltInvoices.js |  6 +++---
 lib/lndk.js         | 11 ++++++++---
 4 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/lib/bolt11.js b/lib/bolt11.js
index 42ee584e6..c6a0fc9f3 100644
--- a/lib/bolt11.js
+++ b/lib/bolt11.js
@@ -13,12 +13,13 @@ export async function parseBolt11 ({ request }) {
   return parsePaymentRequest({ request })
 }
 
-export async function payBolt11 ({ lnd, request, max_fee, ...args }) {
+export async function payBolt11 ({ lnd, request, max_fee, max_fee_mtokens, ...args }) {
   if (!isBolt11(request)) throw new Error('not a bolt11 invoice')
   return payViaPaymentRequest({
     lnd,
     request,
     max_fee,
+    max_fee_mtokens,
     ...args
   })
 }
diff --git a/lib/bolt12.js b/lib/bolt12.js
index cb6d671a9..71a2c09f4 100644
--- a/lib/bolt12.js
+++ b/lib/bolt12.js
@@ -19,9 +19,9 @@ export function isBolt12 (invoice) {
   return isBolt12Offer(invoice) || isBolt12Invoice(invoice)
 }
 
-export async function payBolt12 ({ lnd, request: invoice, max_fee }) {
+export async function payBolt12 ({ lnd, request: invoice, max_fee, max_fee_mtokens }) {
   if (!isBolt12Invoice(invoice)) throw new Error('not a bolt12 invoice')
-  return await payViaBolt12PaymentRequest({ lnd, request: invoice, max_fee })
+  return await payViaBolt12PaymentRequest({ lnd, request: invoice, max_fee, max_fee_mtokens })
 }
 
 export async function parseBolt12 ({ lnd, request: invoice }) {
diff --git a/lib/boltInvoices.js b/lib/boltInvoices.js
index 57e7092c1..32937c125 100644
--- a/lib/boltInvoices.js
+++ b/lib/boltInvoices.js
@@ -4,11 +4,11 @@ import { payBolt11, parseBolt11, isBolt11 } from './bolt11'
 import { estimateBolt12RouteFee } from '@/lib/lndk'
 import { estimateRouteFee } from '@/api/lnd'
 
-export async function payInvoice ({ lnd, request: invoice, max_fee, ...args }) {
+export async function payInvoice ({ lnd, request: invoice, max_fee, max_fee_mtokens, ...args }) {
   if (isBolt12Invoice(invoice)) {
-    return await payBolt12({ lnd, request: invoice, max_fee, ...args })
+    return await payBolt12({ lnd, request: invoice, max_fee, max_fee_mtokens, ...args })
   } else if (isBolt11(invoice)) {
-    return await payBolt11({ lnd, request: invoice, max_fee, ...args })
+    return await payBolt11({ lnd, request: invoice, max_fee, max_fee_mtokens, ...args })
   } else if (isBolt12Offer(invoice)) {
     throw new Error('cannot pay bolt12 offer directly, please fetch a bolt12 invoice from the offer first')
   } else {
diff --git a/lib/lndk.js b/lib/lndk.js
index 564eb1d43..880deba82 100644
--- a/lib/lndk.js
+++ b/lib/lndk.js
@@ -1,4 +1,4 @@
-import { msatsToSats, toPositiveNumber } from '@/lib/format'
+import { msatsToSats, satsToMsats, toPositiveNumber } from '@/lib/format'
 import { loadPackageDefinition } from '@grpc/grpc-js'
 import LNDK_RPC_PROTO from '@/lib/lndkrpc-proto'
 import protobuf from 'protobufjs'
@@ -179,19 +179,24 @@ export async function fetchBolt12InvoiceFromOffer ({ lnd, offer, msats, descript
 export async function payViaBolt12PaymentRequest ({
   lnd,
   request: invoice_hex_str,
-  max_fee
+  max_fee,
+  max_fee_mtokens
 }) {
   const lndk = lnd?.lndk
   if (!lndk) throw new Error('lndk not installed, please use installLNDK')
 
   const parsedInvoice = await parseBolt12Request({ lnd, request: invoice_hex_str })
 
+  if (!max_fee_mtokens && max_fee) {
+    max_fee_mtokens = toPositiveNumber(satsToMsats(max_fee))
+  }
+
   return new Promise((resolve, reject) => {
     lndk.PayInvoice({
       invoice: parsedInvoice.payment,
       // expects msats amount: https://github.com/lndk-org/lndk/blob/bce93885f5fc97f3ceb15dc470117e10061de018/src/lib.rs#L403
       amount: toPositiveNumber(parsedInvoice.mtokens),
-      max_fee
+      max_fee: toPositiveNumber(max_fee_mtokens)
     }, (error, response) => {
       if (error) {
         return reject(error)