[kt-sdk] Added create_lnurl_invoice mutation support.

lightspark-sdk/src/commonJvmAndroidMain/kotlin/com/lightspark/sdk/LightsparkFuturesClient.kt

@@ -127,6 +127,23 @@ class LightsparkFuturesClient(config: ClientConfig) {
     ): CompletableFuture<InvoiceData> =
         coroutineScope.future { coroutinesClient.createInvoice(nodeId, amountMsats, memo, type) }
 
+    /**
+     * Creates a Lightning invoice for the given node. This should only be used for generating invoices for LNURLs, with
+     * [LightsparkCoroutinesClient.createInvoice] preferred in the general case.
+     *
+     * @param nodeId The ID of the node for which to create the invoice.
+     * @param amountMsats The amount of the invoice in milli-satoshis.
+     * @param metadata The LNURL metadata payload field from the initial payreq response. This will be hashed and
+     * present in the h-tag (SHA256 purpose of payment) of the resulting Bolt 11 invoice.
+     */
+    @JvmOverloads
+    fun createLnurlInvoice(
+        nodeId: String,
+        amountMsats: Long,
+        metadata: String
+    ): CompletableFuture<InvoiceData> =
+        coroutineScope.future { coroutinesClient.createLnurlInvoice(nodeId, amountMsats, metadata) }
+
     /**
      * Pay a lightning invoice for the given node.
      *

lightspark-sdk/src/commonMain/kotlin/com/lightspark/sdk/LightsparkCoroutinesClient.kt

@@ -15,6 +15,7 @@ import com.lightspark.sdk.graphql.*
 import com.lightspark.sdk.model.*
 import com.lightspark.sdk.util.serializerFormat
 import saschpe.kase64.base64DecodedBytes
+import java.security.MessageDigest
 import kotlinx.coroutines.flow.Flow
 import kotlinx.serialization.json.*
 
@@ -205,6 +206,44 @@ class LightsparkCoroutinesClient private constructor(
         )
     }
 
+    /**
+     * Creates a Lightning invoice for the given node. This should only be used for generating invoices for LNURLs, with
+     * [LightsparkCoroutinesClient.createInvoice] preferred in the general case.
+     *
+     * @param nodeId The ID of the node for which to create the invoice.
+     * @param amountMsats The amount of the invoice in milli-satoshis.
+     * @param metadata The LNURL metadata payload field from the initial payreq response. This will be hashed and
+     * present in the h-tag (SHA256 purpose of payment) of the resulting Bolt 11 invoice.
+     */
+    suspend fun createLnurlInvoice(
+        nodeId: String,
+        amountMsats: Long,
+        metadata: String,
+    ): InvoiceData {
+        requireValidAuth()
+
+        val md = MessageDigest.getInstance("SHA-256")
+        val digest = md.digest(metadata.toByteArray())
+        val metadataHash = digest.fold(StringBuilder()) { sb, it -> sb.append("%02x".format(it)) }.toString()
+
+        return executeQuery(
+            Query(
+                CreateLnurlInvoiceMutation,
+                {
+                    add("nodeId", nodeId)
+                    add("amountMsats", amountMsats)
+                    add("metadataHash", metadataHash)
+                },
+            ) {
+                val invoiceJson =
+                    requireNotNull(
+                        it["create_lnurl_invoice"]?.jsonObject?.get("invoice")?.jsonObject?.get("data"),
+                    ) { "No invoice found in response" }
+                serializerFormat.decodeFromJsonElement(invoiceJson)
+            },
+        )
+    }
+
     /**
      * Pay a lightning invoice for the given node.
      *

lightspark-sdk/src/commonMain/kotlin/com/lightspark/sdk/LightsparkSyncClient.kt

@@ -116,6 +116,22 @@ class LightsparkSyncClient constructor(config: ClientConfig) {
         type: InvoiceType = InvoiceType.STANDARD,
     ): InvoiceData = runBlocking { asyncClient.createInvoice(nodeId, amountMsats, memo, type) }
 
+    /**
+     * Creates a Lightning invoice for the given node. This should only be used for generating invoices for LNURLs, with
+     * [LightsparkCoroutinesClient.createInvoice] preferred in the general case.
+     *
+     * @param nodeId The ID of the node for which to create the invoice.
+     * @param amountMsats The amount of the invoice in milli-satoshis.
+     * @param metadata The LNURL metadata payload field from the initial payreq response. This will be hashed and
+     * present in the h-tag (SHA256 purpose of payment) of the resulting Bolt 11 invoice.
+     */
+    @JvmOverloads
+    fun createLnurlInvoice(
+        nodeId: String,
+        amountMsats: Long,
+        metadata: String
+    ): InvoiceData = runBlocking { asyncClient.createLnurlInvoice(nodeId, amountMsats, metadata) }
+
     /**
      * Pay a lightning invoice for the given node.
      *

lightspark-sdk/src/commonMain/kotlin/com/lightspark/sdk/graphql/CreateLnurlInvoice.kt

@@ -0,0 +1,21 @@
+package com.lightspark.sdk.graphql
+
+import com.lightspark.sdk.model.InvoiceData
+
+const val CreateLnurlInvoiceMutation = """
+  mutation CreateLnurlInvoice(
+    ${'$'}nodeId: ID!
+    ${'$'}amountMsats: Long!
+    ${'$'}metadataHash: String!
+    ) {
+    create_lnurl_invoice(input: { node_id: ${'$'}nodeId, amount_msats: ${'$'}amountMsats, metadata_hash: ${'$'}metadataHash }) {
+      invoice {
+        data {
+          ...InvoiceDataFragment
+        }
+      }
+    }
+  }
+
+    ${InvoiceData.FRAGMENT}
+"""

lightspark-sdk/src/commonTest/kotlin/com/lightspark/sdk/ClientIntegrationTests.kt

@@ -175,6 +175,15 @@ class ClientIntegrationTests {
         println("decoded invoice: $decoded")
     }
 
+    @Test
+    fun `create an LNURL invoice`() = runTest {
+        val node = getFirstNode()
+        val metadata = "[[\\\"text/plain\\\",\\\"Pay to domain.org user ktfan98\\\"],[\\\"text/identifier\\\",\\\"ktfan98@domain.org\\\"]]"
+        val paymentRequest = client.createLnurlInvoice(node.id, 1000, metadata)
+
+        println("encoded invoice: ${paymentRequest.encodedPaymentRequest}")
+    }
+
     @Test
     fun `send a payment for an invoice`() = runTest {
         val node = getFirstNode()