From afe096e516fc4c0da7ab55da07a177667a816d9a Mon Sep 17 00:00:00 2001
From: ekzyis <ek@stacker.news>
Date: Thu, 15 Feb 2024 18:20:15 +0100
Subject: [PATCH] Fix QR code interaction with WebLN provider (#834)

* Fix passing of bolt11 for QR payments

* Fix missing provider check

* Only cancel invoice if hash and hmac were given

* Fix duplicate toast on error

* Fix relay might not be set yet when sendPayment is called
---
 components/qr.js          |  9 +++------
 components/webln/index.js |  3 ++-
 components/webln/nwc.js   | 41 +++++++++++++++++++--------------------
 3 files changed, 25 insertions(+), 28 deletions(-)

diff --git a/components/qr.js b/components/qr.js
index 422b9c74..45a499be 100644
--- a/components/qr.js
+++ b/components/qr.js
@@ -3,27 +3,24 @@ import { CopyInput, InputSkeleton } from './form'
 import InvoiceStatus from './invoice-status'
 import { useEffect } from 'react'
 import { useWebLN } from './webln'
-import { useToast } from './toast'
 
 export default function Qr ({ asIs, value, webLn, statusVariant, description, status }) {
   const qrValue = asIs ? value : 'lightning:' + value.toUpperCase()
 
   const provider = useWebLN()
-  const toaster = useToast()
 
   useEffect(() => {
     async function effect () {
-      if (webLn) {
+      if (webLn && provider?.enabled) {
         try {
-          await provider.sendPayment(value)
+          await provider.sendPayment({ bolt11: value })
         } catch (e) {
           console.log(e?.message)
-          toaster.danger(`${provider.name}: ${e?.message}`)
         }
       }
     }
     effect()
-  }, [])
+  }, [provider])
 
   return (
     <>
diff --git a/components/webln/index.js b/components/webln/index.js
index 3f4d072e..da36550b 100644
--- a/components/webln/index.js
+++ b/components/webln/index.js
@@ -87,7 +87,8 @@ function RawWebLNProvider ({ children }) {
       autohide: false,
       onCancel: async () => {
         try {
-          await cancelInvoice({ variables: { hash, hmac } })
+          // hash and hmac are only passed for HODL invoices
+          if (hash && hmac) await cancelInvoice({ variables: { hash, hmac } })
           canceled = true
           toaster.warning('payment canceled')
           removeToast = undefined
diff --git a/components/webln/nwc.js b/components/webln/nwc.js
index f59330e9..190d436c 100644
--- a/components/webln/nwc.js
+++ b/components/webln/nwc.js
@@ -1,6 +1,6 @@
 // https://github.com/getAlby/js-sdk/blob/master/src/webln/NostrWeblnProvider.ts
 
-import { createContext, useCallback, useContext, useEffect, useState } from 'react'
+import { createContext, useCallback, useContext, useEffect, useRef, useState } from 'react'
 import { Relay, finalizeEvent, nip04 } from 'nostr-tools'
 import { parseNwcUrl } from '../../lib/url'
 
@@ -13,11 +13,21 @@ export function NWCProvider ({ children }) {
   const [secret, setSecret] = useState()
   const [enabled, setEnabled] = useState()
   const [initialized, setInitialized] = useState(false)
-  const [relay, setRelay] = useState()
+
+  const relayRef = useRef()
 
   const name = 'NWC'
   const storageKey = 'webln:provider:nwc'
 
+  const updateRelay = async (relayUrl) => {
+    try {
+      relayRef.current?.close()
+      if (relayUrl) relayRef.current = await Relay.connect(relayUrl)
+    } catch (err) {
+      console.error(err)
+    }
+  }
+
   const loadConfig = useCallback(async () => {
     const configStr = window.localStorage.getItem(storageKey)
     if (!configStr) {
@@ -39,6 +49,7 @@ export function NWCProvider ({ children }) {
     try {
       const supported = await validateParams(params)
       setEnabled(supported.includes('pay_invoice'))
+      await updateRelay(params.relayUrl)
     } catch (err) {
       console.error('invalid NWC config:', err)
       setEnabled(false)
@@ -69,6 +80,7 @@ export function NWCProvider ({ children }) {
     try {
       const supported = await validateParams(params)
       setEnabled(supported.includes('pay_invoice'))
+      await updateRelay(params.relayUrl)
     } catch (err) {
       console.error('invalid NWC config:', err)
       setEnabled(false)
@@ -85,25 +97,12 @@ export function NWCProvider ({ children }) {
     setEnabled(undefined)
   }, [])
 
-  useEffect(() => {
-    let relay
-    (async function () {
-      if (relayUrl) {
-        relay = await Relay.connect(relayUrl)
-        setRelay(relay)
-      }
-    })().catch((err) => {
-      console.error(err)
-      setRelay(null)
-    })
-    return () => {
-      relay?.close()
-      setRelay(null)
-    }
-  }, [relayUrl])
-
   const sendPayment = useCallback((bolt11) => {
     return new Promise(function (resolve, reject) {
+      const relay = relayRef.current
+      if (!relay) {
+        return reject(new Error('not connected to relay'))
+      }
       (async function () {
         // XXX set this to mock NWC relays
         const MOCK_NWC_RELAY = false
@@ -168,9 +167,9 @@ export function NWCProvider ({ children }) {
         })
       })().catch(reject)
     })
-  }, [relay, walletPubkey, secret])
+  }, [walletPubkey, secret])
 
-  const getInfo = useCallback(() => getInfoWithRelay(relay, walletPubkey), [relay, walletPubkey])
+  const getInfo = useCallback(() => getInfoWithRelay(relayRef?.current, walletPubkey), [relayRef?.current, walletPubkey])
 
   useEffect(() => {
     loadConfig().catch(console.error)