Allow LN Address to customize invoice metadata, and various bug fixes on LNUrl (#4855)

* Allow LN Address to customize invoice metadata

solves https://github.com/OpenSats/website/issues/8

* Refactor GetLNUrl

* Fix lightningAddresssettings.Max being ignored

* Fix: The payRequest generated by the callback wasn't the same as the original

---------

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

BTCPayServer.Data/Data/LightingAddressData.cs

@@ -1,6 +1,7 @@
 using System;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Infrastructure;
+using Newtonsoft.Json.Linq;
 
 namespace BTCPayServer.Data;
 
@@ -38,4 +39,6 @@ public class LightningAddressDataBlob
     public string CurrencyCode { get; set; }
     public decimal? Min { get; set; }
     public decimal? Max { get; set; }
+    
+    public JObject InvoiceMetadata { get; set; }
 }

BTCPayServer.Tests/SeleniumTests.cs

@@ -4,7 +4,6 @@ using System.Globalization;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
-using System.Reflection.Metadata;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading;
@@ -17,7 +16,6 @@ using BTCPayServer.Lightning;
 using BTCPayServer.Payments;
 using BTCPayServer.Services;
 using BTCPayServer.Services.Invoices;
-using BTCPayServer.Services.Rates;
 using BTCPayServer.Services.Wallets;
 using BTCPayServer.Views.Manage;
 using BTCPayServer.Views.Server;
@@ -29,6 +27,7 @@ using Microsoft.EntityFrameworkCore;
 using NBitcoin;
 using NBitcoin.DataEncoders;
 using NBitcoin.Payment;
+using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 using OpenQA.Selenium;
 using OpenQA.Selenium.Support.Extensions;
@@ -2256,13 +2255,16 @@ namespace BTCPayServer.Tests
             s.FindAlertMessage(StatusMessageModel.StatusSeverity.Success);
 
             s.Driver.ToggleCollapse("AddAddress");
+
             var lnaddress2 = "EUR" + Guid.NewGuid().ToString();
             s.Driver.FindElement(By.Id("Add_Username")).SendKeys(lnaddress2);
+            lnaddress2 = lnaddress2.ToLowerInvariant();
 
             s.Driver.ToggleCollapse("AdvancedSettings");
             s.Driver.FindElement(By.Id("Add_CurrencyCode")).SendKeys("EUR");
             s.Driver.FindElement(By.Id("Add_Min")).SendKeys("2");
             s.Driver.FindElement(By.Id("Add_Max")).SendKeys("10");
+            s.Driver.FindElement(By.Id("Add_InvoiceMetadata")).SendKeys("{\"test\":\"lol\"}");
             s.Driver.FindElement(By.CssSelector("button[value='add']")).Click();
             s.FindAlertMessage(StatusMessageModel.StatusSeverity.Success);
 
@@ -2278,20 +2280,100 @@ namespace BTCPayServer.Tests
                 var lnurl = new Uri(LNURL.LNURL.ExtractUriFromInternetIdentifier(value).ToString()
                     .Replace("https", "http"));
                 var request = (LNURL.LNURLPayRequest)await LNURL.LNURL.FetchInformation(lnurl, new HttpClient());
-
+                var m = request.ParsedMetadata.ToDictionary(o => o.Key, o => o.Value);
                 switch (value)
                 {
                     case { } v when v.StartsWith(lnaddress2):
+                        Assert.StartsWith(lnaddress2 + "@", m["text/identifier"]);
+                        lnaddress2 = m["text/identifier"];
                         Assert.Equal(2, request.MinSendable.ToDecimal(LightMoneyUnit.Satoshi));
                         Assert.Equal(10, request.MaxSendable.ToDecimal(LightMoneyUnit.Satoshi));
                         break;
 
                     case { } v when v.StartsWith(lnaddress1):
+                        Assert.StartsWith(lnaddress1 + "@", m["text/identifier"]);
+                        lnaddress1 = m["text/identifier"];
                         Assert.Equal(1, request.MinSendable.ToDecimal(LightMoneyUnit.Satoshi));
                         Assert.Equal(6.12m, request.MaxSendable.ToDecimal(LightMoneyUnit.BTC));
                         break;
+                    default:
+                        Assert.False(true, "Should have matched");
+                        break;
                 }
             }
+            var repo = s.Server.PayTester.GetService<InvoiceRepository>();
+            var invoices = await repo.GetInvoices(new InvoiceQuery() { StoreId = new[] { s.StoreId } });
+            Assert.Equal(2, invoices.Length);
+            var emailSuffix = $"@{s.Server.PayTester.HostName}:{s.Server.PayTester.Port}";
+
+            foreach (var i in invoices)
+            {
+                var lightningPaymentMethod = i.GetPaymentMethod(new PaymentMethodId("BTC", PaymentTypes.LNURLPay));
+                var paymentMethodDetails =
+                    lightningPaymentMethod.GetPaymentMethodDetails() as LNURLPayPaymentMethodDetails;
+                Assert.Contains(
+                    paymentMethodDetails.ConsumedLightningAddress,
+                    new[] { lnaddress1, lnaddress2 });
+
+                if (paymentMethodDetails.ConsumedLightningAddress == lnaddress2)
+                {
+                    Assert.Equal("lol", i.Metadata.AdditionalData["test"].Value<string>());
+                }
+            }
+
+            var lnUsername = lnaddress1.Split('@')[0];
+            LNURLPayRequest req;
+            using (var resp = await s.Server.PayTester.HttpClient.GetAsync($"/.well-known/lnurlp/{lnUsername}"))
+            {
+                var str = await resp.Content.ReadAsStringAsync();
+                req = JsonConvert.DeserializeObject<LNURLPayRequest>(str);
+                Assert.Contains(req.ParsedMetadata, m => m.Key == "text/identifier" && m.Value == lnaddress1);
+                Assert.Contains(req.ParsedMetadata, m => m.Key == "text/plain" && m.Value.StartsWith("Paid to"));
+                Assert.NotNull(req.Callback);
+                Assert.Equal(new LightMoney(1000), req.MinSendable);
+                Assert.Equal(LightMoney.FromUnit(6.12m, LightMoneyUnit.BTC), req.MaxSendable);
+            }
+            lnUsername = lnaddress2.Split('@')[0];
+            using (var resp = await s.Server.PayTester.HttpClient.GetAsync($"/.well-known/lnurlp/{lnUsername}"))
+            {
+                var str = await resp.Content.ReadAsStringAsync();
+                req = JsonConvert.DeserializeObject<LNURLPayRequest>(str);
+                Assert.Equal(new LightMoney(2000), req.MinSendable);
+                Assert.Equal(new LightMoney(10_000), req.MaxSendable);
+            }
+            // Check if we can get the same payrequest through the callback
+            using (var resp = await s.Server.PayTester.HttpClient.GetAsync(req.Callback))
+            {
+                var str = await resp.Content.ReadAsStringAsync();
+                req = JsonConvert.DeserializeObject<LNURLPayRequest>(str);
+                Assert.Equal(new LightMoney(2000), req.MinSendable);
+                Assert.Equal(new LightMoney(10_000), req.MaxSendable);
+            }
+
+            // Can we ask for invoice? (Should fail, below minSpendable)
+            using (var resp = await s.Server.PayTester.HttpClient.GetAsync(req.Callback + "?amount=1999"))
+            {
+                var str = await resp.Content.ReadAsStringAsync();
+                var err = JsonConvert.DeserializeObject<LNUrlStatusResponse>(str);
+                Assert.Equal("Amount is out of bounds.", err.Reason);
+            }
+            // Can we ask for invoice?
+            using (var resp = await s.Server.PayTester.HttpClient.GetAsync(req.Callback + "?amount=2000"))
+            {
+                var str = await resp.Content.ReadAsStringAsync();
+                var succ = JsonConvert.DeserializeObject<LNURLPayRequest.LNURLPayRequestCallbackResponse>(str);
+                Assert.NotNull(succ.Pr);
+                Assert.Equal(new LightMoney(2000), BOLT11PaymentRequest.Parse(succ.Pr, Network.RegTest).MinimumAmount);
+            }
+
+            // Can we change comment?
+            using (var resp = await s.Server.PayTester.HttpClient.GetAsync(req.Callback + "?amount=2001"))
+            {
+                var str = await resp.Content.ReadAsStringAsync();
+                var succ = JsonConvert.DeserializeObject<LNURLPayRequest.LNURLPayRequestCallbackResponse>(str);
+                Assert.NotNull(succ.Pr);
+                Assert.Equal(new LightMoney(2001), BOLT11PaymentRequest.Parse(succ.Pr, Network.RegTest).MinimumAmount);
+            }
         }
 
         [Fact]

BTCPayServer/Controllers/UILNURLController.cs

@@ -35,6 +35,7 @@ using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Routing;
 using NBitcoin;
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 using LightningAddressData = BTCPayServer.Data.LightningAddressData;
 using MarkPayoutRequest = BTCPayServer.HostedServices.MarkPayoutRequest;
 
@@ -244,17 +245,6 @@ namespace BTCPayServer
                 return NotFound();
             }
 
-            var pmi = new PaymentMethodId(cryptoCode, PaymentTypes.LNURLPay);
-            var lnpmi = new PaymentMethodId(cryptoCode, PaymentTypes.LightningLike);
-            var methods = store.GetSupportedPaymentMethods(_btcPayNetworkProvider);
-            var lnUrlMethod =
-                methods.FirstOrDefault(method => method.PaymentId == pmi) as LNURLPaySupportedPaymentMethod;
-            var lnMethod = methods.FirstOrDefault(method => method.PaymentId == lnpmi);
-            if (lnUrlMethod is null || lnMethod is null)
-            {
-                return NotFound();
-            }
-
             ViewPointOfSaleViewModel.Item[] items;
             string currencyCode;
             PointOfSaleSettings posS = null;
@@ -278,6 +268,9 @@ namespace BTCPayServer
             ViewPointOfSaleViewModel.Item item = null;
             if (!string.IsNullOrEmpty(itemCode))
             {
+                var pmi = GetLNUrlPaymentMethodId(cryptoCode, store, out _);
+                if (pmi is null)
+                    return NotFound("LNUrl or LN is disabled");
                 var escapedItemId = Extensions.UnescapeBackSlashUriString(itemCode);
                 item = items.FirstOrDefault(item1 =>
                     item1.Id.Equals(itemCode, StringComparison.InvariantCultureIgnoreCase) ||
@@ -296,8 +289,38 @@ namespace BTCPayServer
                 return NotFound();
             }
 
-            return await GetLNURL(cryptoCode, app.StoreDataId, currencyCode, null, null,
+            var createInvoice = new CreateInvoiceRequest()
-                () => (null, app, item, new List<string> { AppService.GetAppInternalTag(appId) }, item?.Price.Value, true));
+            {
+                Amount = item?.Price.Value,
+                Currency = currencyCode,
+                Checkout = new InvoiceDataBase.CheckoutOptions()
+                {
+                    RedirectURL = app.AppType switch
+                    {
+                        PointOfSaleAppType.AppType => app.GetSettings<PointOfSaleSettings>().RedirectUrl ??
+                                                       HttpContext.Request.GetAbsoluteUri($"/apps/{app.Id}/pos"),
+                        _ => null
+                    }
+                }
+            };
+
+            var invoiceMetadata = new InvoiceMetadata();
+            invoiceMetadata.OrderId =AppService.GetAppOrderId(app);
+            if (item != null)
+            {
+                invoiceMetadata.ItemCode = item.Id;
+                invoiceMetadata.ItemDesc = item.Description;
+            }
+            createInvoice.Metadata = invoiceMetadata.ToJObject();
+
+
+            return await GetLNURLRequest(
+                cryptoCode,
+                store,
+                store.GetStoreBlob(),
+                createInvoice,
+                additionalTags: new List<string> { AppService.GetAppInternalTag(appId) },
+                allowOverpay: false);
         }
 
         public class EditLightningAddressVM
@@ -327,6 +350,9 @@ namespace BTCPayServer
                 [Display(Name = "Max sats")]
                 [Range(1, double.PositiveInfinity)]
                 public decimal? Max { get; set; }
+
+                [Display(Name = "Invoice metadata")]
+                public string InvoiceMetadata { get; set; }
             }
 
             public ConcurrentDictionary<string, LightningAddressItem> Items { get; } = new ();
@@ -344,111 +370,103 @@ namespace BTCPayServer
         public async Task<IActionResult> ResolveLightningAddress(string username)
         {
             var lightningAddressSettings = await _lightningAddressService.ResolveByAddress(username);
-            if (lightningAddressSettings is null)
+            if (lightningAddressSettings is null || username is null)
-            {
+                return NotFound("Unknown username");
+
+            var store = await _storeRepository.FindStore(lightningAddressSettings.StoreDataId);
+            if (store is null)
                 return NotFound("Unknown username");
-            }
 
             var blob = lightningAddressSettings.GetBlob();
-            return await GetLNURL("BTC", lightningAddressSettings.StoreDataId, blob.CurrencyCode, blob.Min, blob.Max,
+
-                () => (username, null, null, null, null, true));
+            return await GetLNURLRequest(
+               "BTC",
+               store,
+               store.GetStoreBlob(),
+               new CreateInvoiceRequest()
+               {
+                   Currency = blob?.CurrencyCode,
+                   Metadata = blob?.InvoiceMetadata
+               },
+               new LNURLPayRequest()
+               {
+                   MinSendable = blob?.Min is decimal min ? new LightMoney(min, LightMoneyUnit.Satoshi) : null,
+                   MaxSendable = blob?.Max is decimal max ? new LightMoney(max, LightMoneyUnit.Satoshi) : null,
+               },
+               new Dictionary<string, string>()
+               {
+                   { "text/identifier", $"{username}@{Request.Host}" }
+               });
         }
 
+
         [HttpGet("pay")]
-        public async Task<IActionResult> GetLNURL(string cryptoCode, string storeId, string currencyCode = null,
+        [EnableCors(CorsPolicies.All)]
-            decimal? min = null, decimal? max = null,
+        [IgnoreAntiforgeryToken]
-            Func<(string username, AppData app, ViewPointOfSaleViewModel.Item item, List<string> additionalTags, decimal? invoiceAmount, bool? anyoneCanInvoice)>
+        public async Task<IActionResult> GetLNUrlForStore(
-                internalDetails = null)
+            string cryptoCode,
+            string storeId,
+            string currencyCode = null)
         {
-            var network = _btcPayNetworkProvider.GetNetwork<BTCPayNetwork>(cryptoCode);
+            var store = this.HttpContext.GetStoreData();
-            if (network is null || !network.SupportLightning)
-            {
-                return NotFound("This network does not support Lightning");
-            }
-
-            var store = await _storeRepository.FindStore(storeId);
             if (store is null)
-            {
+                return NotFound();
-                return NotFound("Store not found");
-            }
-
-            var storeBlob = store.GetStoreBlob();
-            currencyCode ??= storeBlob.DefaultCurrency ?? cryptoCode;
-            var pmi = new PaymentMethodId(cryptoCode, PaymentTypes.LNURLPay);
-            var lnpmi = new PaymentMethodId(cryptoCode, PaymentTypes.LightningLike);
-            var methods = store.GetSupportedPaymentMethods(_btcPayNetworkProvider);
-            var lnUrlMethod =
-                methods.FirstOrDefault(method => method.PaymentId == pmi) as LNURLPaySupportedPaymentMethod;
-            var lnMethod = methods.FirstOrDefault(method => method.PaymentId == lnpmi);
-            if (lnUrlMethod is null || lnMethod is null)
-            {
-                return NotFound("LNURL or Lightning payment method not found");
-            }
 
             var blob = store.GetStoreBlob();
-            if (blob.GetExcludedPaymentMethods().Match(pmi) || blob.GetExcludedPaymentMethods().Match(lnpmi))
+            if (!blob.AnyoneCanInvoice)
+                return NotFound("'Anyone can invoice' is turned off");
+            return await GetLNURLRequest(
+                cryptoCode,
+                store,
+                blob,
+                new CreateInvoiceRequest
                 {
-                return NotFound("LNURL or Lightning payment method disabled");
+                    Currency = currencyCode
+                });
         }
 
-            (string username, AppData app, ViewPointOfSaleViewModel.Item item, List<string> additionalTags, decimal? invoiceAmount, bool? anyoneCanInvoice) =
+        private async Task<IActionResult> GetLNURLRequest(
-                (internalDetails ?? (() => (null, null, null, null, null, null)))();
+            string cryptoCode,
+            Data.StoreData store,
+            Data.StoreBlob blob,
+            CreateInvoiceRequest createInvoice,
+            LNURLPayRequest lnurlRequest = null,
+            Dictionary<string, string> lnUrlMetadata = null,
+            List<string> additionalTags = null,
+            bool allowOverpay = true)
+        {
+            if (GetLNUrlPaymentMethodId(cryptoCode, store, out _) is null)
+                return NotFound("LNUrl or LN is disabled");
 
-            if ((anyoneCanInvoice ?? blob.AnyoneCanInvoice) is false)
-            {
-                return NotFound();
-            }
-
-            var lnAddress = username is null ? null : $"{username}@{Request.Host}";
-            List<string[]> lnurlMetadata = new();
-
-            var redirectUrl = app?.AppType switch
-            {
-                PointOfSaleAppType.AppType => app.GetSettings<PointOfSaleSettings>().RedirectUrl ??
-                                               HttpContext.Request.GetAbsoluteUri($"/apps/{app.Id}/pos"),
-                _ => null
-            };
-            var invoiceRequest = new CreateInvoiceRequest
-            {
-                Amount = invoiceAmount,
-                Checkout = new InvoiceDataBase.CheckoutOptions
-                {
-                    PaymentMethods = new[] { pmi.ToStringNormalized() },
-                    Expiration = blob.InvoiceExpiration < TimeSpan.FromMinutes(2)
-                        ? blob.InvoiceExpiration
-                        : TimeSpan.FromMinutes(2),
-                    RedirectURL = redirectUrl
-                },
-                Currency = currencyCode,
-                Type = invoiceAmount is null ? InvoiceType.TopUp : InvoiceType.Standard,
-            };
-
-            if (item != null)
-            {
-                invoiceRequest.Metadata =
-                    new InvoiceMetadata
-                    {
-                        ItemCode = item.Id,
-                        ItemDesc = item.Description,
-                        OrderId = AppService.GetAppOrderId(app)
-                    }.ToJObject();
-            }
             InvoiceEntity i;
             try
             {
-                i = await _invoiceController.CreateInvoiceCoreRaw(invoiceRequest, store, Request.GetAbsoluteRoot(), additionalTags);
+                i = await _invoiceController.CreateInvoiceCoreRaw(createInvoice, store, Request.GetAbsoluteRoot(), additionalTags);
             }
             catch (Exception e)
             {
                 return this.CreateAPIError(null, e.Message);
             }
-            if (i.Type != InvoiceType.TopUp)
+            lnurlRequest = await CreateLNUrlRequestFromInvoice(cryptoCode, i, store, blob, lnurlRequest, lnUrlMetadata, allowOverpay);
-            {
+            return lnurlRequest is null ? NotFound() : Ok(lnurlRequest);
-                min = i.GetPaymentMethod(pmi).Calculate().Due.ToDecimal(MoneyUnit.Satoshi);
-                max = item?.Price?.Type == ViewPointOfSaleViewModel.Item.ItemPrice.ItemPriceType.Minimum ? null : min;
         }
 
-            if (!string.IsNullOrEmpty(username))
+        private async Task<LNURLPayRequest> CreateLNUrlRequestFromInvoice(
+            string cryptoCode,
+            InvoiceEntity i,
+            Data.StoreData store,
+            StoreBlob blob,
+            LNURLPayRequest lnurlRequest = null,
+            Dictionary<string, string> lnUrlMetadata = null,
+            bool allowOverpay = true)
+        {
+            var pmi = GetLNUrlPaymentMethodId(cryptoCode, store, out var lnUrlMethod);
+            if (pmi is null)
+                return null;
+            lnurlRequest ??= new LNURLPayRequest();
+            lnUrlMetadata ??= new Dictionary<string, string>();
+
+            if (lnUrlMetadata?.TryGetValue("text/identifier", out var lnAddress) is true && lnAddress is string)
             {
                 var pm = i.GetPaymentMethod(pmi);
                 var paymentMethodDetails = (LNURLPayPaymentMethodDetails)pm.GetPaymentMethodDetails();
@@ -457,36 +475,68 @@ namespace BTCPayServer
                 await _invoiceRepository.UpdateInvoicePaymentMethod(i.Id, pm);
             }
 
+            if (!lnUrlMetadata.ContainsKey("text/plain"))
+            {
                 var invoiceDescription = blob.LightningDescriptionTemplate
                         .Replace("{StoreName}", store.StoreName ?? "", StringComparison.OrdinalIgnoreCase)
                         .Replace("{ItemDescription}", i.Metadata.ItemDesc ?? "", StringComparison.OrdinalIgnoreCase)
                         .Replace("{OrderId}", i.Metadata.OrderId ?? "", StringComparison.OrdinalIgnoreCase);
-
+                lnUrlMetadata.Add("text/plain", invoiceDescription);
-            lnurlMetadata.Add(new[] { "text/plain", invoiceDescription });
-            if (!string.IsNullOrEmpty(username))
-            {
-                lnurlMetadata.Add(new[] { "text/identifier", lnAddress });
             }
 
-            if (await _pluginHookService.ApplyFilter("modify-lnurlp-request", new LNURLPayRequest
+            lnurlRequest.Tag = "payRequest";
-                {
+            lnurlRequest.CommentAllowed = lnUrlMethod.LUD12Enabled ? 2000 : 0;
-                    Tag = "payRequest",
+            lnurlRequest.Callback = new Uri(_linkGenerator.GetUriByAction(
-                    MinSendable = new LightMoney(min ?? 1m, LightMoneyUnit.Satoshi),
-                    MaxSendable =
-                        max is null
-                            ? LightMoney.FromUnit(6.12m, LightMoneyUnit.BTC)
-                            : new LightMoney(max.Value, LightMoneyUnit.Satoshi),
-                    CommentAllowed = lnUrlMethod.LUD12Enabled ? 2000 : 0,
-                    Metadata = JsonConvert.SerializeObject(lnurlMetadata),
-                    Callback = new Uri(_linkGenerator.GetUriByAction(
                         action: nameof(GetLNURLForInvoice),
                         controller: "UILNURL",
-                        values: new {cryptoCode, invoiceId = i.Id}, Request.Scheme, Request.Host, Request.PathBase))
+                        values: new { pmi.CryptoCode, invoiceId = i.Id }, Request.Scheme, Request.Host, Request.PathBase));
-                }) is not LNURLPayRequest lnurlp)
+            lnurlRequest.Metadata = JsonConvert.SerializeObject(lnUrlMetadata.Select(kv => new[] { kv.Key, kv.Value }));
+            if (i.Type != InvoiceType.TopUp)
             {
-                return NotFound();
+                lnurlRequest.MinSendable = new LightMoney(i.GetPaymentMethod(pmi).Calculate().Due.ToDecimal(MoneyUnit.Satoshi), LightMoneyUnit.Satoshi);
+                if (!allowOverpay)
+                    lnurlRequest.MaxSendable = lnurlRequest.MinSendable;
             }
-            return Ok(lnurlp);
+
+            // We don't think BTCPay handle well 0 sats payments, just in case make it minimum one sat.
+            if (lnurlRequest.MinSendable is null || lnurlRequest.MinSendable < LightMoney.Satoshis(1.0m))
+                lnurlRequest.MinSendable = LightMoney.Satoshis(1.0m);
+
+            if (lnurlRequest.MaxSendable is null)
+                lnurlRequest.MaxSendable = LightMoney.FromUnit(6.12m, LightMoneyUnit.BTC);
+
+            lnurlRequest = await _pluginHookService.ApplyFilter("modify-lnurlp-request", lnurlRequest) as LNURLPayRequest;
+
+            i.Metadata ??= new InvoiceMetadata();
+            var metadata = i.Metadata.ToJObject();
+            if (metadata.Property("payRequest") is null)
+            {
+                metadata.Add("payRequest", JToken.FromObject(lnurlRequest));
+                await _invoiceRepository.UpdateInvoiceMetadata(i.Id, i.StoreId, metadata);
+            }
+
+            return lnurlRequest;
+        }
+
+        PaymentMethodId GetLNUrlPaymentMethodId(string cryptoCode, Data.StoreData store, out LNURLPaySupportedPaymentMethod lnUrlSettings)
+        {
+            lnUrlSettings = null;
+            var network = _btcPayNetworkProvider.GetNetwork<BTCPayNetwork>(cryptoCode);
+            if (network is null || !network.SupportLightning)
+                return null;
+            var pmi = new PaymentMethodId(cryptoCode, PaymentTypes.LNURLPay);
+            var lnpmi = new PaymentMethodId(cryptoCode, PaymentTypes.LightningLike);
+            var methods = store.GetSupportedPaymentMethods(_btcPayNetworkProvider);
+            var lnUrlMethod =
+                methods.FirstOrDefault(method => method.PaymentId == pmi) as LNURLPaySupportedPaymentMethod;
+            var lnMethod = methods.FirstOrDefault(method => method.PaymentId == lnpmi);
+            if (lnUrlMethod is null || lnMethod is null)
+                return null;
+            var blob = store.GetStoreBlob();
+            if (blob.GetExcludedPaymentMethods().Match(pmi) || blob.GetExcludedPaymentMethods().Match(lnpmi))
+                return null;
+            lnUrlSettings = lnUrlMethod;
+            return pmi;
         }
 
         [HttpGet("pay/i/{invoiceId}")]
@@ -501,60 +551,45 @@ namespace BTCPayServer
                 return NotFound();
             }
 
-            if (comment is not null)
-                comment = comment.Truncate(2000);
-
-            var pmi = new PaymentMethodId(cryptoCode, PaymentTypes.LNURLPay);
             var i = await _invoiceRepository.GetInvoice(invoiceId, true);
+            if (i is null)
+                return NotFound();
 
             var store = await _storeRepository.FindStore(i.StoreId);
             if (store is null)
-            {
                 return NotFound();
-            }
 
             if (i.Status == InvoiceStatusLegacy.New)
             {
-                var isTopup = i.IsUnsetTopUp();
+                var pmi = GetLNUrlPaymentMethodId(cryptoCode, store, out var lnurlSupportedPaymentMethod);
-                var lnurlSupportedPaymentMethod =
+                if (pmi is null)
-                    i.GetSupportedPaymentMethod<LNURLPaySupportedPaymentMethod>(pmi).FirstOrDefault();
-                if (lnurlSupportedPaymentMethod is null)
-                {
                     return NotFound();
-                }
 
                 var lightningPaymentMethod = i.GetPaymentMethod(pmi);
-                var accounting = lightningPaymentMethod.Calculate();
                 var paymentMethodDetails =
                     lightningPaymentMethod.GetPaymentMethodDetails() as LNURLPayPaymentMethodDetails;
                 if (paymentMethodDetails.LightningSupportedPaymentMethod is null)
+                    return NotFound();
+
+                LNURLPayRequest lnurlPayRequest;
+                var blob = store.GetStoreBlob();
+                if (i.Metadata.AdditionalData.TryGetValue("payRequest", out var t) && t is JObject jo)
                 {
+                    lnurlPayRequest = jo.ToObject<LNURLPayRequest>();
+                }
+                else
+                {
+                    lnurlPayRequest = await CreateLNUrlRequestFromInvoice(cryptoCode, i, store, blob, allowOverpay: false);
+                    if (lnurlPayRequest is null)
                         return NotFound();
                 }
 
-                var amt = amount.HasValue ? new LightMoney(amount.Value) : null;
+                if (amount is null)
-                var min = new LightMoney(isTopup ? 1m : accounting.Due.ToUnit(MoneyUnit.Satoshi), LightMoneyUnit.Satoshi);
+                    return Ok(lnurlPayRequest);
-                var max = isTopup ? LightMoney.FromUnit(6.12m, LightMoneyUnit.BTC) : min;
 
-                List<string[]> lnurlMetadata = new();
+                var amt = new LightMoney(amount.Value);
-
+                if (amt < lnurlPayRequest.MinSendable || amount > lnurlPayRequest.MaxSendable)
-                var blob = store.GetStoreBlob();
-                var invoiceDescription = blob.LightningDescriptionTemplate
-                    .Replace("{StoreName}", store.StoreName ?? "", StringComparison.OrdinalIgnoreCase)
-                    .Replace("{ItemDescription}", i.Metadata.ItemDesc ?? "", StringComparison.OrdinalIgnoreCase)
-                    .Replace("{OrderId}", i.Metadata.OrderId ?? "", StringComparison.OrdinalIgnoreCase);
-
-                lnurlMetadata.Add(new[] { "text/plain", invoiceDescription });
-                if (!string.IsNullOrEmpty(paymentMethodDetails.ConsumedLightningAddress))
-                {
-                    lnurlMetadata.Add(new[] { "text/identifier", paymentMethodDetails.ConsumedLightningAddress });
-                }
-
-                var metadata = JsonConvert.SerializeObject(lnurlMetadata);
-                if (amt != null && (amt < min || amount > max))
-                {
                     return BadRequest(new LNUrlStatusResponse { Status = "ERROR", Reason = "Amount is out of bounds." });
-                }
 
                 LNURLPayRequest.LNURLPayRequestCallbackResponse.ILNURLPayRequestSuccessAction successAction = null;
                 if ((i.ReceiptOptions?.Enabled ?? blob.ReceiptOptions.Enabled) is true)
@@ -574,22 +609,15 @@ namespace BTCPayServer
                         };
                 }
 
-                if (amt is null)
+                bool updatePaymentMethod = false;
+                if (lnurlSupportedPaymentMethod.LUD12Enabled)
                 {
-                    if (await _pluginHookService.ApplyFilter("modify-lnurlp-request", new LNURLPayRequest
+                    comment = comment?.Truncate(2000);
+                    if (paymentMethodDetails.ProvidedComment != comment)
                     {
-                            Tag = "payRequest",
+                        paymentMethodDetails.ProvidedComment = comment;
-                            MinSendable = min,
+                        updatePaymentMethod = true;
-                            MaxSendable = max,
-                            CommentAllowed = lnurlSupportedPaymentMethod.LUD12Enabled ? 2000 : 0,
-                            Metadata = metadata,
-                            Callback = new Uri(Request.GetCurrentUrl())
-                        }) is not LNURLPayRequest lnurlp)
-                    {
-                        return NotFound();
                     }
-                    
-                    return Ok(lnurlp);
                 }
 
                 if (string.IsNullOrEmpty(paymentMethodDetails.BOLT11) || paymentMethodDetails.GeneratedBoltAmount != amt)
@@ -613,11 +641,11 @@ namespace BTCPayServer
                     try
                     {
                         var expiry = i.ExpirationTime.ToUniversalTime() - DateTimeOffset.UtcNow;
+                        var metadata = JsonConvert.SerializeObject(lnurlPayRequest.Metadata);
                         var description = (await  _pluginHookService.ApplyFilter("modify-lnurlp-description", metadata)) as string;
                         if (description is null)
-                        {
                             return NotFound();
-                        }
+
                         var param = new CreateInvoiceParams(amt, description, expiry)
                         {
                             PrivateRouteHints = blob.LightningPrivateRouteHints,
@@ -649,30 +677,14 @@ namespace BTCPayServer
                     paymentMethodDetails.Preimage = string.IsNullOrEmpty(invoice.Preimage) ? null : uint256.Parse(invoice.Preimage);
                     paymentMethodDetails.InvoiceId = invoice.Id;
                     paymentMethodDetails.GeneratedBoltAmount = amt;
-                    if (lnurlSupportedPaymentMethod.LUD12Enabled)
+                    updatePaymentMethod = true;
-                    {
-                        paymentMethodDetails.ProvidedComment = comment;
-                    }
-
-                    lightningPaymentMethod.SetPaymentMethodDetails(paymentMethodDetails);
-                    await _invoiceRepository.UpdateInvoicePaymentMethod(invoiceId, lightningPaymentMethod);
 
                     _eventAggregator.Publish(new InvoiceNewPaymentDetailsEvent(invoiceId,
                         paymentMethodDetails, pmi));
-                    return Ok(new LNURLPayRequest.LNURLPayRequestCallbackResponse
-                    {
-                        Disposable = true,
-                        Routes = Array.Empty<string>(),
-                        Pr = paymentMethodDetails.BOLT11,
-                        SuccessAction = successAction
-                    });
                 }
 
-                if (paymentMethodDetails.GeneratedBoltAmount == amt)
+                if (updatePaymentMethod)
                 {
-                    if (lnurlSupportedPaymentMethod.LUD12Enabled && paymentMethodDetails.ProvidedComment != comment)
-                    {
-                        paymentMethodDetails.ProvidedComment = comment;
                     lightningPaymentMethod.SetPaymentMethodDetails(paymentMethodDetails);
                     await _invoiceRepository.UpdateInvoicePaymentMethod(invoiceId, lightningPaymentMethod);
                 }
@@ -685,7 +697,6 @@ namespace BTCPayServer
                     SuccessAction = successAction
                 });
             }
-            }
 
             return BadRequest(new LNUrlStatusResponse
             {
@@ -725,6 +736,7 @@ namespace BTCPayServer
                             CurrencyCode = blob.CurrencyCode,
                             StoreId = storeId,
                             Username = s.Username,
+                            InvoiceMetadata = blob.InvoiceMetadata?.ToString(Formatting.Indented)
                         };
                     }
                 ).ToList()
@@ -746,6 +758,18 @@ namespace BTCPayServer
                     vm.AddModelError(addressVm => addressVm.Add.CurrencyCode, "Currency is invalid", this);
                 }
 
+                JObject metadata = null;
+                if (!string.IsNullOrEmpty(vm.Add.InvoiceMetadata) )
+                {
+                    try
+                    {
+                        metadata =  JObject.Parse(vm.Add.InvoiceMetadata);
+                    }
+                    catch (Exception e)
+                    {
+                        vm.AddModelError(addressVm => addressVm.Add.InvoiceMetadata, "Metadata must be a valid json object", this);
+                    }
+                }
                 if (!ModelState.IsValid)
                 {
                     return View(vm);
@@ -760,7 +784,8 @@ namespace BTCPayServer
                 {
                     Max = vm.Add.Max,
                     Min = vm.Add.Min,
-                    CurrencyCode = vm.Add.CurrencyCode
+                    CurrencyCode = vm.Add.CurrencyCode,
+                    InvoiceMetadata = metadata
                 })))
                 {
                     TempData.SetStatusMessageModel(new StatusMessageModel

BTCPayServer/Views/UILNURL/EditLightningAddress.cshtml

@@ -67,26 +67,33 @@
         <div id="AdvancedSettings" class="collapse @(showAdvancedOptions ? "show" : "")">
             <div class="row">
                 <div class="col-12 col-sm-auto">
-                    <div class="form-group">
+                    <div class="form-group" title="The currency to generate the invoice in when generated through this lightning address ">
                         <label asp-for="Add.CurrencyCode" class="form-label"></label>
                         <input asp-for="Add.CurrencyCode" class="form-control w-auto" currency-selection style="max-width:16ch;"/>
                         <span asp-validation-for="Add.CurrencyCode" class="text-danger"></span>
                     </div>
                 </div>
                 <div class="col-12 col-sm-auto">
-                    <div class="form-group">
+                    <div class="form-group" title="Minimum amount of sats to allow to be sent to this ln address">
                         <label asp-for="Add.Min" class="form-label"></label>
                         <input asp-for="Add.Min" class="form-control" type="number" inputmode="numeric" min="1" style="max-width:16ch;"/>
                         <span asp-validation-for="Add.Min" class="text-danger"></span>
                     </div>
                 </div>
                 <div class="col-12 col-sm-auto">
-                    <div class="form-group">
+                    <div class="form-group" title="Maximum amount of sats to allow to be sent to this ln address">
                         <label asp-for="Add.Max" class="form-label"></label>
                         <input asp-for="Add.Max" class="form-control" type="number" inputmode="numeric" min="1" max="@int.MaxValue" style="max-width:16ch;"/>
                         <span asp-validation-for="Add.Max" class="text-danger"></span>
                     </div>
                 </div>
+                <div class="col-12 col-sm-auto">
+                    <div class="form-group" title="Metadata (in JSON) to add to the invoice when created through this lightning address.">
+                        <label asp-for="Add.InvoiceMetadata" class="form-label"></label>
+                        <textarea asp-for="Add.InvoiceMetadata" class="form-control"  ></textarea>
+                        <span asp-validation-for="Add.InvoiceMetadata" class="text-danger"></span>
+                    </div>
+                </div>
             </div>
         </div>
     
@@ -114,6 +121,7 @@
                         <input asp-for="Items[index].Min" type="hidden"/>
                         <input asp-for="Items[index].Max" type="hidden"/>
                         <input asp-for="Items[index].Username" type="hidden"/>
+                        <input asp-for="Items[index].InvoiceMetadata" type="hidden"/>
                         var address = $"{Model.Items[index].Username}@{Context.Request.Host.ToUriComponent()}";
                         <tr>
                             <td>
@@ -138,6 +146,10 @@
                                 {
                                     <span>tracked in @Model.Items[index].CurrencyCode</span>
                                 }
+                                @if (!string.IsNullOrEmpty(Model.Items[index].InvoiceMetadata))
+                                {
+                                    <span>with invoice metadata @Model.Items[index].InvoiceMetadata</span>
+                                }
                             </td>
                             <td class="text-end">
                                 <button type="submit" title="Remove" name="command" value="@($"remove:{Model.Items[index].Username}")"