From dcaf5d3679d57e0908f7f60ab99d806a20c8c2c9 Mon Sep 17 00:00:00 2001
From: Jeremy Klein <jklein24@gmail.com>
Date: Tue, 9 Jan 2024 19:28:23 -0800
Subject: [PATCH] Use a synchronous invoice creator for the sync payreq
 response funtion

---
 .../test/java/me/uma/javatest/UmaTest.java    | 11 +++++++-
 .../kotlin/me/uma/UmaProtocolHelper.kt        | 26 ++++++++++++++++---
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/javatest/src/test/java/me/uma/javatest/UmaTest.java b/javatest/src/test/java/me/uma/javatest/UmaTest.java
index fe370a8..a4c9a43 100644
--- a/javatest/src/test/java/me/uma/javatest/UmaTest.java
+++ b/javatest/src/test/java/me/uma/javatest/UmaTest.java
@@ -13,6 +13,7 @@
 
 import kotlin.coroutines.Continuation;
 import me.uma.InMemoryPublicKeyCache;
+import me.uma.SyncUmaInvoiceCreator;
 import me.uma.UmaInvoiceCreator;
 import me.uma.UmaProtocolHelper;
 import me.uma.UmaRequester;
@@ -111,7 +112,7 @@ public void testGetPayReqResponseSync() throws Exception {
         );
         PayReqResponse response = umaProtocolHelper.getPayReqResponseSync(
                 request,
-                new TestUmaInvoiceCreator(),
+                new TestSyncUmaInvoiceCreator(),
                 "metadata",
                 "USD",
                 2,
@@ -189,3 +190,11 @@ public CompletableFuture<String> createUmaInvoice(long amountMsats, @NotNull Str
         return CompletableFuture.completedFuture("lnbc12345");
     }
 }
+
+class TestSyncUmaInvoiceCreator implements SyncUmaInvoiceCreator {
+    @NotNull
+    @Override
+    public String createUmaInvoice(long amountMsats, @NotNull String metadata) {
+        return "lnbc12345";
+    }
+}
diff --git a/uma-sdk/src/commonMain/kotlin/me/uma/UmaProtocolHelper.kt b/uma-sdk/src/commonMain/kotlin/me/uma/UmaProtocolHelper.kt
index 4e6b6d7..0607a0f 100644
--- a/uma-sdk/src/commonMain/kotlin/me/uma/UmaProtocolHelper.kt
+++ b/uma-sdk/src/commonMain/kotlin/me/uma/UmaProtocolHelper.kt
@@ -2,6 +2,8 @@
 
 package me.uma
 
+import me.uma.crypto.Secp256k1
+import me.uma.protocol.*
 import java.security.MessageDigest
 import java.util.concurrent.CompletableFuture
 import java.util.concurrent.Future
@@ -18,8 +20,6 @@ import kotlinx.serialization.SerializationException
 import kotlinx.serialization.decodeFromString
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
-import me.uma.crypto.Secp256k1
-import me.uma.protocol.*
 
 /**
  * A helper class for interacting with the UMA protocol. It provides methods for creating and verifying UMA requests
@@ -429,7 +429,7 @@ class UmaProtocolHelper @JvmOverloads constructor(
     @Throws(Exception::class, IllegalArgumentException::class, CancellationException::class)
     fun getPayReqResponseSync(
         query: PayRequest,
-        invoiceCreator: UmaInvoiceCreator,
+        invoiceCreator: SyncUmaInvoiceCreator,
         metadata: String,
         currencyCode: String,
         currencyDecimals: Int,
@@ -439,9 +439,14 @@ class UmaProtocolHelper @JvmOverloads constructor(
         receiverNodePubKey: String?,
         utxoCallback: String,
     ): PayReqResponse = runBlocking {
+        val futureInvoiceCreator = object : UmaInvoiceCreator {
+            override fun createUmaInvoice(amountMsats: Long, metadata: String): CompletableFuture<String> {
+                return coroutineScope.future { invoiceCreator.createUmaInvoice(amountMsats, metadata) }
+            }
+        }
         getPayReqResponse(
             query,
-            invoiceCreator,
+            futureInvoiceCreator,
             metadata,
             currencyCode,
             currencyDecimals,
@@ -544,3 +549,16 @@ interface UmaInvoiceCreator {
      */
     fun createUmaInvoice(amountMsats: Long, metadata: String): CompletableFuture<String>
 }
+
+interface SyncUmaInvoiceCreator {
+    /**
+     * Synchronously creates an invoice with the given amount and encoded LNURL metadata.
+     *
+     * This method is synchronous and should only be used in cases where the caller is already on a background thread.
+     *
+     * @param amountMsats The amount of the invoice in millisatoshis.
+     * @param metadata The metadata that will be added to the invoice's metadata hash field.
+     * @return The encoded BOLT-11 invoice that should be returned to the sender for the given [PayRequest].
+     */
+    fun createUmaInvoice(amountMsats: Long, metadata: String): String
+}