Add Greenfield API endpoint for pull payment LNURL items (#4472)

* Add Greenfield API endpoint for pull payment LNURL items

close #4365

* Rename GetLNURLs to GetPullPaymentLNURL

* update "ln-url-not-supported" to "lnurl-not-supported"

* remove hardcoding of "BTC"

* update "PullPayments_LNURL" to "PullPayments_GetPullPaymentLNURL"

* update description of 400 status code response

Co-authored-by: Nicolas Dorier <nicolas.dorier@gmail.com>

BTCPayServer.Client/BTCPayServerClient.PullPayments.cs

@@ -97,5 +97,15 @@ namespace BTCPayServer.Client
                     method: HttpMethod.Post, bodyPayload: request), cancellationToken);
             await HandleResponse(response);
         }
+
+        public virtual async Task<PullPaymentLNURL> GetPullPaymentLNURL(string pullPaymentId,
+            CancellationToken cancellationToken = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest(
+                    $"/api/v1/pull-payments/{pullPaymentId}/lnurl",
+                    method: HttpMethod.Get), cancellationToken);
+            return await HandleResponse<PullPaymentLNURL>(response);
+        }
     }
 }

BTCPayServer.Client/Models/PullPaymentLNURL.cs

@@ -0,0 +1,8 @@
+namespace BTCPayServer.Client.Models
+{
+    public class PullPaymentLNURL
+    {
+        public string LNURLBech32 { get; set; }
+        public string LNURLUri { get; set; }
+    }
+}

BTCPayServer.Tests/GreenfieldAPITests.cs

@@ -672,10 +672,12 @@ namespace BTCPayServer.Tests
         public async Task CanUsePullPaymentViaAPI()
         {
             using var tester = CreateServerTester();
+            tester.ActivateLightning();
             await tester.StartAsync();
+            await tester.EnsureChannelsSetup();
             var acc = tester.NewAccount();
-            acc.Register();
+            await acc.GrantAccessAsync(true);
-            await acc.CreateStoreAsync();
+            acc.RegisterLightningNode("BTC", LightningConnectionType.CLightning, false);
             var storeId = (await acc.RegisterDerivationSchemeAsync("BTC", importKeysToNBX: true)).StoreId;
             var client = await acc.CreateClient();
             var result = await client.CreatePullPayment(storeId, new CreatePullPaymentRequest()
@@ -856,6 +858,8 @@ namespace BTCPayServer.Tests
                 PaymentMethods = new[] { "BTC" }
             });
 
+            await this.AssertAPIError("lnurl-not-supported", async () => await unauthenticated.GetPullPaymentLNURL(pp.Id));
+
             destination = (await tester.ExplorerNode.GetNewAddressAsync()).ToString();
             TestLogs.LogInformation("Try to pay it in BTC");
             payout = await unauthenticated.CreatePayout(pp.Id, new CreatePayoutRequest()
@@ -907,6 +911,17 @@ namespace BTCPayServer.Tests
             Assert.Equal(PayoutState.Completed, payout.State);
             await AssertAPIError("invalid-state", async () => await client.MarkPayoutPaid(storeId, payout.Id));
 
+            // Test LNURL values
+            var test4 = await client.CreatePullPayment(storeId, new Client.Models.CreatePullPaymentRequest()
+            {
+                Name = "Test 3",
+                Amount = 12.303228134m,
+                Currency = "BTC",
+                PaymentMethods = new[] { "BTC", "BTC-LightningNetwork", "BTC_LightningLike" }
+            });
+            var lnrURLs = await unauthenticated.GetPullPaymentLNURL(test4.Id);
+            Assert.IsType<string>(lnrURLs.LNURLBech32);
+            Assert.IsType<string>(lnrURLs.LNURLUri);
             
             //permission test around auto approved pps and payouts
             var nonApproved = await acc.CreateClient(Policies.CanCreateNonApprovedPullPayments);

BTCPayServer/Controllers/GreenField/GreenfieldPullPaymentController.cs

@@ -34,6 +34,7 @@ namespace BTCPayServer.Controllers.Greenfield
         private readonly CurrencyNameTable _currencyNameTable;
         private readonly BTCPayNetworkJsonSerializerSettings _serializerSettings;
         private readonly IEnumerable<IPayoutHandler> _payoutHandlers;
+        private readonly BTCPayNetworkProvider _networkProvider;
         private readonly IAuthorizationService _authorizationService;
 
         public GreenfieldPullPaymentController(PullPaymentHostedService pullPaymentService,
@@ -42,6 +43,7 @@ namespace BTCPayServer.Controllers.Greenfield
             CurrencyNameTable currencyNameTable,
             Services.BTCPayNetworkJsonSerializerSettings serializerSettings,
             IEnumerable<IPayoutHandler> payoutHandlers,
+            BTCPayNetworkProvider btcPayNetworkProvider,
             IAuthorizationService authorizationService)
         {
             _pullPaymentService = pullPaymentService;
@@ -50,6 +52,7 @@ namespace BTCPayServer.Controllers.Greenfield
             _currencyNameTable = currencyNameTable;
             _serializerSettings = serializerSettings;
             _payoutHandlers = payoutHandlers;
+            _networkProvider = btcPayNetworkProvider;
             _authorizationService = authorizationService;
         }
 
@@ -243,6 +246,33 @@ namespace BTCPayServer.Controllers.Greenfield
             return base.Ok(ToModel(payout));
         }
 
+        [HttpGet("~/api/v1/pull-payments/{pullPaymentId}/lnurl")]
+        [AllowAnonymous]
+        public async Task<IActionResult> GetPullPaymentLNURL(string pullPaymentId)
+        {
+            var pp = await _pullPaymentService.GetPullPayment(pullPaymentId, false);
+            if (pp is null)
+                return PullPaymentNotFound();
+
+            var blob = pp.GetBlob();
+            var pms = blob.SupportedPaymentMethods.FirstOrDefault(id => id.PaymentType == LightningPaymentType.Instance && _networkProvider.DefaultNetwork.CryptoCode == id.CryptoCode);
+            if (pms is not null && blob.Currency.Equals(pms.CryptoCode, StringComparison.InvariantCultureIgnoreCase))
+            {
+                var lnurlEndpoint = new Uri(Url.Action("GetLNURLForPullPayment", "UILNURL", new
+                {
+                    cryptoCode = _networkProvider.DefaultNetwork.CryptoCode,
+                    pullPaymentId = pullPaymentId
+                }, Request.Scheme, Request.Host.ToString()));
+
+                return base.Ok(new PullPaymentLNURL() {
+                    LNURLBech32 = LNURL.LNURL.EncodeUri(lnurlEndpoint, "withdrawRequest", true).ToString(),
+                    LNURLUri = LNURL.LNURL.EncodeUri(lnurlEndpoint, "withdrawRequest", false).ToString()
+                });
+            }
+
+            return this.CreateAPIError("lnurl-not-supported", "LNURL not supported for this pull payment");
+        }
+
         private Client.Models.PayoutData ToModel(Data.PayoutData p)
         {
             var blob = p.GetBlob(_serializerSettings);

BTCPayServer/Controllers/GreenField/LocalBTCPayServerClient.cs

@@ -1242,6 +1242,11 @@ namespace BTCPayServer.Controllers.Greenfield
             return GetFromActionResult<PayoutData>(await GetController<GreenfieldPullPaymentController>().GetPayout(pullPaymentId, payoutId));
         }
 
+        public override async Task<PullPaymentLNURL> GetPullPaymentLNURL(string pullPaymentId, CancellationToken cancellationToken = default)
+        {
+            return GetFromActionResult<PullPaymentLNURL>(await GetController<GreenfieldPullPaymentController>().GetPullPaymentLNURL(pullPaymentId));
+        }
+
         public override async Task<PayoutData> GetStorePayout(string storeId, string payoutId,
             CancellationToken cancellationToken = default)
         {

BTCPayServer/wwwroot/swagger/v1/swagger.template.pull-payments.json

@@ -402,6 +402,46 @@
                 "security": []
             }
         },
+        "/api/v1/pull-payments/{pullPaymentId}/lnurl": {
+          "parameters": [
+              {
+                  "name": "pullPaymentId",
+                  "in": "path",
+                  "required": true,
+                  "description": "The ID of the pull payment",
+                  "schema": {
+                      "type": "string"
+                  }
+              }
+          ],
+          "get": {
+              "summary": "Get Pull Payment LNURL details",
+              "operationId": "PullPayments_GetPullPaymentLNURL",
+              "description": "Get Pull Payment LNURL details",
+              "responses": {
+                  "200": {
+                      "description": "Pull payment LNURL details",
+                      "content": {
+                          "application/json": {
+                              "schema": {
+                                  "$ref": "#/components/schemas/LNURLData"
+                              }
+                          }
+                      }
+                  },
+                  "404": {
+                      "description": "Pull payment not found"
+                  },
+                  "400": {
+                      "description": "Pull payment found but does not support LNURL"
+                  }
+              },
+              "tags": [
+                  "Pull payments (Public)"
+              ],
+              "security": []
+          }
+        },
         "/api/v1/stores/{storeId}/payouts": {
             "parameters": [
                 {
@@ -1028,6 +1068,21 @@
                         "description": "The link to a page to claim payouts to this pull payment"
                     }
                 }
+            },
+            "LNURLData": {
+              "type": "object",
+              "properties": {
+                "lnurlBech32": {
+                  "type": "string",
+                  "description": "Bech32 representation of LNRURL",
+                  "example": "lightning:lnurl1dp68gup69uhnzv3h9cczuvpwxyarzdp3xsez7sj5gvh42j2vfe24ynp0wa5hg6rywfshwtmswqhngvntdd6x6uzvx4jrvu2kvvur23n8v46rwjpexcc45563fn53w7"
+                },
+                "lnurlUri": {
+                  "type": "string",
+                  "description": "Bech32 representation of LNURL",
+                  "example": "lnurlw://example.com/BTC/UILNURL/withdraw/pp/42kktmpL5d6qVc85Fget7H961ZSQ"
+                }
+              }
             }
         }
     },