From 3d21d2724efb27ea4a2c511019ae72c6e2d9c2b5 Mon Sep 17 00:00:00 2001
From: Umar Bolatov <bolatovumar@gmail.com>
Date: Mon, 14 Jun 2021 02:19:52 -0700
Subject: [PATCH] Fix bug with LN payment method API endpoint throwing 500
 (#2567)

close #2566
---
 .../StoreLightningNetworkPaymentMethodsController.cs  | 10 +++++++---
 .../Lightning/LightningSupportedPaymentMethod.cs      | 11 +++++------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/BTCPayServer/Controllers/GreenField/StoreLightningNetworkPaymentMethodsController.cs b/BTCPayServer/Controllers/GreenField/StoreLightningNetworkPaymentMethodsController.cs
index e7fc926d9..1377a17b5 100644
--- a/BTCPayServer/Controllers/GreenField/StoreLightningNetworkPaymentMethodsController.cs
+++ b/BTCPayServer/Controllers/GreenField/StoreLightningNetworkPaymentMethodsController.cs
@@ -1,3 +1,4 @@
+#nullable enable
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
@@ -11,7 +12,6 @@ using BTCPayServer.Lightning;
 using BTCPayServer.Payments;
 using BTCPayServer.Payments.Lightning;
 using BTCPayServer.Security;
-using BTCPayServer.Services;
 using BTCPayServer.Services.Stores;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -56,8 +56,12 @@ namespace BTCPayServer.Controllers.GreenField
                 .Where((method) => method.PaymentId.PaymentType == PaymentTypes.LightningLike)
                 .OfType<LightningSupportedPaymentMethod>()
                 .Select(paymentMethod =>
-                    new LightningNetworkPaymentMethodData(paymentMethod.PaymentId.CryptoCode,
-                        paymentMethod.GetExternalLightningUrl().ToString(), !excludedPaymentMethods.Match(paymentMethod.PaymentId)))
+                    new LightningNetworkPaymentMethodData(
+                        paymentMethod.PaymentId.CryptoCode,
+                        paymentMethod.GetExternalLightningUrl()?.ToString() ?? paymentMethod.GetDisplayableConnectionString(), 
+                        !excludedPaymentMethods.Match(paymentMethod.PaymentId)
+                    )
+                )
                 .Where((result) => !enabledOnly || result.Enabled)
                 .ToList()
             );
diff --git a/BTCPayServer/Payments/Lightning/LightningSupportedPaymentMethod.cs b/BTCPayServer/Payments/Lightning/LightningSupportedPaymentMethod.cs
index ac0592af8..30331aee9 100644
--- a/BTCPayServer/Payments/Lightning/LightningSupportedPaymentMethod.cs
+++ b/BTCPayServer/Payments/Lightning/LightningSupportedPaymentMethod.cs
@@ -1,24 +1,23 @@
+#nullable enable
 using System;
-using System.Collections.Generic;
 using BTCPayServer.Lightning;
 using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
 
 namespace BTCPayServer.Payments.Lightning
 {
     public class LightningSupportedPaymentMethod : ISupportedPaymentMethod
     {
         public const string InternalNode = "Internal Node";
-        public string CryptoCode { get; set; }
+        public string? CryptoCode { get; set; }
 
         [JsonIgnore]
         public PaymentMethodId PaymentId => new PaymentMethodId(CryptoCode, PaymentTypes.LightningLike);
 
         [Obsolete("Use Get/SetLightningUrl")]
         [JsonProperty(DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string LightningConnectionString { get; set; }
+        public string? LightningConnectionString { get; set; }
 
-        public LightningConnectionString GetExternalLightningUrl()
+        public LightningConnectionString? GetExternalLightningUrl()
         {
 #pragma warning disable CS0618 // Type or member is obsolete
             if (!string.IsNullOrEmpty(LightningConnectionString))
@@ -64,7 +63,7 @@ namespace BTCPayServer.Payments.Lightning
         }
 
         [JsonProperty(DefaultValueHandling = DefaultValueHandling.Ignore)]
-        public string InternalNodeRef { get; set; }
+        public string? InternalNodeRef { get; set; }
         [JsonIgnore]
         public bool IsInternalNode
         {