From 6ab7468c25df5b4f5cb673ea28e14aacfefc6102 Mon Sep 17 00:00:00 2001
From: Anders Magnusson <anders14magnusson@gmail.com>
Date: Sat, 19 Nov 2022 16:57:36 +0100
Subject: [PATCH] Make the fee limit the sum of base + percentage

---
 boltcard.service | 5 ++---
 lightning.go     | 5 +----
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/boltcard.service b/boltcard.service
index db82a32..be2c9fb 100644
--- a/boltcard.service
+++ b/boltcard.service
@@ -43,10 +43,9 @@ Environment="LN_PORT=10009"
 Environment="LN_TLS_FILE=/home/ubuntu/boltcard/tls.cert"
 Environment="LN_MACAROON_FILE=/home/ubuntu/boltcard/SendPaymentV2.macaroon"
 
-# The maximum lightning network fee to be paid in percent of the payment amount.
+# The maximum lightning network fee to be paid is the base FEE_LIMIT_SAT + the FEE_LIMIT_PERCENT of the amount.
+Environment="FEE_LIMIT_SAT=5"
 Environment="FEE_LIMIT_PERCENT=0.5"
-# Acceptable flat fee in sats that can exceed the percentage limit.
-Environment="FEE_LIMIT_SAT=10"
 
 # email
 # Environment="AWS_SES_ID="
diff --git a/lightning.go b/lightning.go
index 4d74a63..c104505 100644
--- a/lightning.go
+++ b/lightning.go
@@ -228,9 +228,6 @@ func pay_invoice(card_payment_id int, invoice string) {
 	invoice_msats := bolt11.MSatoshi
 
 	fee_limit_product := int64((fee_limit_percent / 100) * (float64(invoice_msats) / 1000))
-	if fee_limit_product > fee_limit_sat {
-		fee_limit_sat = fee_limit_product
-	}
 
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
@@ -239,7 +236,7 @@ func pay_invoice(card_payment_id int, invoice string) {
 		PaymentRequest:    invoice,
 		NoInflightUpdates: true,
 		TimeoutSeconds:    30,
-		FeeLimitSat:       fee_limit_sat})
+		FeeLimitSat:       fee_limit_sat + fee_limit_product})
 
 	if err != nil {
        	        log.WithFields(log.Fields{"card_payment_id": card_payment_id}).Warn(err)