From a2ca5ade685e9a7dc57c9fa226858769cacca728 Mon Sep 17 00:00:00 2001
From: michael1011 <me@michael1011.at>
Date: Wed, 25 Sep 2024 14:21:54 +0900
Subject: [PATCH] feat: BIP-353 resolver

---
 src/components/CreateButton.tsx | 49 +++++++++++++++++++++++++--------
 src/config.ts                   |  1 +
 src/utils/invoice.ts            | 28 +++++++++++++++++++
 3 files changed, 66 insertions(+), 12 deletions(-)

diff --git a/src/components/CreateButton.tsx b/src/components/CreateButton.tsx
index ad784ca8..1664bf66 100644
--- a/src/components/CreateButton.tsx
+++ b/src/components/CreateButton.tsx
@@ -14,7 +14,7 @@ import { fetchBolt12Invoice, getPairs } from "../utils/boltzClient";
 import { formatAmount } from "../utils/denomination";
 import { formatError } from "../utils/errors";
 import { coalesceLn } from "../utils/helper";
-import { fetchLnurl } from "../utils/invoice";
+import { fetchBip353, fetchLnurl } from "../utils/invoice";
 import {
     SomeSwap,
     createChain,
@@ -153,17 +153,42 @@ export const CreateButton = () => {
     const create = async () => {
         if (validWayToFetchInvoice()) {
             if (lnurl() !== undefined && lnurl() !== "") {
-                log.info("Fetching invoice from lnurl", lnurl());
-                try {
-                    const inv = await fetchLnurl(
-                        lnurl(),
-                        Number(receiveAmount()),
-                    );
-                    setInvoice(inv);
+                log.info("Fetching invoice from LNURL or BIP-353", lnurl());
+
+                const fetchResults = await Promise.allSettled([
+                    (() => {
+                        try {
+                            return fetchLnurl(lnurl(), Number(receiveAmount()));
+                        } catch (e) {
+                            log.warn("Fetching invoice from LNURL failed", e);
+                            throw e;
+                        }
+                    })(),
+                    (() => {
+                        try {
+                            return fetchBip353(
+                                lnurl(),
+                                Number(receiveAmount()),
+                            );
+                        } catch (e) {
+                            log.warn("Fetching invoice from BIP-353 failed", e);
+                            throw e;
+                        }
+                    })(),
+                ]);
+
+                const fetched = fetchResults.find(
+                    (res) => res.status === "fulfilled",
+                );
+                if (fetched !== undefined) {
+                    setInvoice(fetched.value);
                     setLnurl("");
-                } catch (e) {
-                    notify("error", e.message);
-                    log.warn("fetch lnurl failed", e);
+                } else {
+                    // All failed, so we can safely cast the first one
+                    notify(
+                        "error",
+                        (fetchResults[0] as PromiseRejectedResult).reason,
+                    );
                     return;
                 }
             } else {
@@ -177,7 +202,7 @@ export const CreateButton = () => {
                     setBolt12Offer(undefined);
                 } catch (e) {
                     notify("error", formatError(e));
-                    log.warn("Fetching invoice from bol12 failed", e);
+                    log.warn("Fetching invoice from bolt12 failed", e);
                     return;
                 }
             }
diff --git a/src/config.ts b/src/config.ts
index 1ce8410e..b88832cc 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -23,6 +23,7 @@ const defaults = {
     testnetUrl: "https://testnet.boltz.exchange",
     telegramUrl: "https://t.me/boltzhq",
     email: "hi@bol.tz",
+    dnsOverHttps: "https://1.1.1.1/dns-query",
 };
 
 type Asset = {
diff --git a/src/utils/invoice.ts b/src/utils/invoice.ts
index c918a161..a4e71e7b 100644
--- a/src/utils/invoice.ts
+++ b/src/utils/invoice.ts
@@ -5,6 +5,7 @@ import { Invoice, Offer } from "boltz-bolt12";
 import log from "loglevel";
 
 import { config } from "../config";
+import { fetchBolt12Invoice } from "./boltzClient";
 import { checkResponse } from "./http";
 
 type LnurlResponse = {
@@ -104,6 +105,33 @@ export const fetchLnurl = (
     });
 };
 
+export const fetchBip353 = async (
+    hrn: string,
+    amountSat: number,
+): Promise<string> => {
+    const split = hrn.split("@");
+    if (split.length !== 2) {
+        throw "invalid BIP-353";
+    }
+
+    log.debug(`Fetching BIP-353: ${hrn}`);
+
+    const params = new URLSearchParams({
+        type: "TXT",
+        name: `${split[0]}.user._bitcoin-payment.${split[1]}`,
+    });
+    const res = await fetch(`${config.dnsOverHttps}?${params.toString()}`, {
+        headers: {
+            Accept: "application/dns-json",
+        },
+    });
+    const resBody = await res.json();
+    const paymentRequest = resBody.Answer[0].data;
+    const offer = new URLSearchParams(paymentRequest.split("?")[1]).get("lno");
+    return (await fetchBolt12Invoice(offer.replaceAll('"', ""), amountSat))
+        .invoice;
+};
+
 const checkLnurlResponse = (amount: number, data: LnurlResponse) => {
     log.debug(
         "amount check: (x, min, max)",