Greenfield: Graceful return for in-flight HTLCs (#4252)

* Greenfield: Graceful return for in-flight HTLCs

Based on btcpayserver/BTCPayServer.Lightning#106 this closes #3781.

* Update descriptions

BTCPayServer.Client/BTCPayServer.Client.csproj

@@ -28,7 +28,7 @@
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
   </ItemGroup>
     <ItemGroup>
-      <PackageReference Include="BTCPayServer.Lightning.Common" Version="1.3.13" />
+      <PackageReference Include="BTCPayServer.Lightning.Common" Version="1.3.15" />
       <PackageReference Include="NBitcoin" Version="7.0.14" />
       <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     </ItemGroup>

BTCPayServer.Client/Models/PayLightningInvoiceRequest.cs

@@ -1,3 +1,4 @@
+using System;
 using BTCPayServer.Client.JsonConverters;
 using BTCPayServer.JsonConverters;
 using BTCPayServer.Lightning;
@@ -19,5 +20,8 @@ namespace BTCPayServer.Client.Models
     
         [JsonConverter(typeof(LightMoneyJsonConverter))]
         public LightMoney Amount { get; set; }
+
+        [JsonConverter(typeof(TimeSpanJsonConverter.Seconds))]
+        public TimeSpan? SendTimeout { get; set; }
     }
 }

BTCPayServer/BTCPayServer.csproj

@@ -41,7 +41,7 @@
   <ItemGroup>
     <PackageReference Include="BIP78.Sender" Version="0.2.2" />
     <PackageReference Include="BTCPayServer.Hwi" Version="2.0.2" />
-    <PackageReference Include="BTCPayServer.Lightning.All" Version="1.4.7" />
+    <PackageReference Include="BTCPayServer.Lightning.All" Version="1.4.8" />
     <PackageReference Include="CsvHelper" Version="15.0.5" />
     <PackageReference Include="Dapper" Version="2.0.123" />
     <PackageReference Include="Fido2" Version="2.0.2" />

BTCPayServer/Controllers/GreenField/GreenfieldLightningNodeApiController.cs

@@ -2,7 +2,6 @@ using System;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
-using BTCPayServer.Abstractions.Contracts;
 using BTCPayServer.Abstractions.Extensions;
 using BTCPayServer.Client;
 using BTCPayServer.Client.Models;
@@ -222,16 +221,26 @@ namespace BTCPayServer.Controllers.Greenfield
                 return this.CreateValidationError(ModelState);
             }
             
-            var param = lightningInvoice.MaxFeeFlat != null || lightningInvoice.MaxFeePercent != null || lightningInvoice.Amount != null
+            var param = lightningInvoice.MaxFeeFlat != null || lightningInvoice.MaxFeePercent != null
-                ? new PayInvoiceParams { MaxFeePercent = lightningInvoice.MaxFeePercent, MaxFeeFlat = lightningInvoice.MaxFeeFlat, Amount = lightningInvoice.Amount }
+                    || lightningInvoice.Amount != null || lightningInvoice.SendTimeout != null
+                ? new PayInvoiceParams
+                {
+                    MaxFeePercent = lightningInvoice.MaxFeePercent,
+                    MaxFeeFlat = lightningInvoice.MaxFeeFlat,
+                    Amount = lightningInvoice.Amount,
+                    SendTimeout = lightningInvoice.SendTimeout
+                }
                 : null;
             var result = await lightningClient.Pay(lightningInvoice.BOLT11, param, cancellationToken);
             
-            if (result.Result == PayResult.Ok && bolt11?.PaymentHash is not null)
+            if (result.Result is PayResult.Ok or PayResult.Unknown && bolt11?.PaymentHash is not null)
             {
+                // get a new instance of the LN client, because the old one might have disposed its HTTPClient
+                lightningClient = await GetLightningClient(cryptoCode, true);
+                
                 var paymentHash = bolt11.PaymentHash.ToString();
                 var payment = await lightningClient.GetPayment(paymentHash, cancellationToken);
-                return Ok(new LightningPaymentData
+                var data = new LightningPaymentData
                 {
                     Id = payment.Id,
                     PaymentHash = paymentHash,
@@ -241,19 +250,25 @@ namespace BTCPayServer.Controllers.Greenfield
                     CreatedAt = payment.CreatedAt,
                     TotalAmount = payment.AmountSent,
                     FeeAmount = payment.Fee,
-                });
+                };
+                return result.Result is PayResult.Ok ? Ok(data) : Accepted(data);
             }
             
             return result.Result switch
             {
                 PayResult.CouldNotFindRoute => this.CreateAPIError("could-not-find-route", "Impossible to find a route to the peer"),
                 PayResult.Error => this.CreateAPIError("generic-error", result.ErrorDetail),
+                PayResult.Unknown => Accepted(new LightningPaymentData
+                {
+                    Status = LightningPaymentStatus.Unknown
+                }),
                 PayResult.Ok => Ok(new LightningPaymentData
                 {
+                    Status = LightningPaymentStatus.Complete,
                     TotalAmount = result.Details?.TotalAmount, 
                     FeeAmount = result.Details?.FeeAmount
                 }),
-                _ => throw new NotSupportedException("Unsupported Payresult")
+                _ => throw new NotSupportedException("Unsupported PayResult")
             };
         }
 

BTCPayServer/Data/Payouts/LightningLike/UILightningLikePayoutController.cs

@@ -281,6 +281,8 @@ namespace BTCPayServer.Data.Payouts.LightningLike
             var proofBlob = new PayoutLightningBlob() {PaymentHash = bolt11PaymentRequest.PaymentHash.ToString()};
             try
             {
+                // TODO: Incorporate the changes from this PR here:
+                // https://github.com/btcpayserver/BTCPayServer.Lightning/pull/106
                 using var cts = new CancellationTokenSource(SendTimeout);
                 var result = await lightningClient.Pay(bolt11PaymentRequest.ToString(),
                     new PayInvoiceParams()

BTCPayServer/wwwroot/swagger/v1/swagger.template.json

@@ -100,7 +100,6 @@
             },
             "TimeSpanSeconds": {
                 "allOf": [ { "$ref": "#/components/schemas/TimeSpan" } ],
-
                 "format": "seconds",
                 "description": "A span of times in seconds"
             },

BTCPayServer/wwwroot/swagger/v1/swagger.template.lightning.common.json

@@ -323,6 +323,17 @@
                         "nullable": true,
                         "description": "The fee limit expressed as a fixed amount in satoshi",
                         "example": "21"
+                    },
+                    "sendTimeout": {
+                        "nullable": true,
+                        "example": 30,
+                        "default": 30,
+                        "description": "The number of seconds after which the payment times out",
+                        "allOf": [
+                            {
+                                "$ref": "#/components/schemas/TimeSpanSeconds"
+                            }
+                        ]
                     }
                 }
             },

BTCPayServer/wwwroot/swagger/v1/swagger.template.lightning.internal.json

@@ -465,7 +465,7 @@
                         "example": "BTC"
                     }
                 ],
-                "description": "Pay a lightning invoice.",
+                "description": "Pay a lightning invoice. In case the payment response times out, the status will be reported as pending and the final status can be resolved using the [Get payment](#operation/InternalLightningNodeApi_GetPayment) endpoint. The default wait time for payment responses is 30 seconds — it might take longer if multiple routes are tried or a hold invoice is getting paid.",
                 "operationId": "InternalLightningNodeApi_PayInvoice",
                 "responses": {
                     "200": {
@@ -478,6 +478,16 @@
                             }
                         }
                     },
+                    "202": {
+                        "description": "Payment initiated",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/LightningPaymentData"
+                                }
+                            }
+                        }
+                    },
                     "422": {
                         "description": "Unable to validate the request",
                         "content": {

BTCPayServer/wwwroot/swagger/v1/swagger.template.lightning.store.json

@@ -548,7 +548,7 @@
                         }
                     }
                 ],
-                "description": "Pay a lightning invoice.",
+                "description": "Pay a lightning invoice. In case the payment response times out, the status will be reported as pending and the final status can be resolved using the [Get payment](#operation/StoreLightningNodeApi_GetPayment) endpoint. The default wait time for payment responses is 30 seconds — it might take longer if multiple routes are tried or a hold invoice is getting paid.",
                 "operationId": "StoreLightningNodeApi_PayInvoice",
                 "responses": {
                     "200": {
@@ -561,6 +561,16 @@
                             }
                         }
                     },
+                    "202": {
+                        "description": "Payment initiated",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/LightningPaymentData"
+                                }
+                            }
+                        }
+                    },
                     "422": {
                         "description": "Unable to validate the request",
                         "content": {