Add ability to select default payment method for invoice through UI

BTCPayServer/Controllers/InvoiceController.UI.cs

@@ -476,7 +476,7 @@ namespace BTCPayServer.Controllers
             bool isDefaultPaymentId = false;
             if (paymentMethodId is null)
             {
-                paymentMethodId = store.GetDefaultPaymentId(_NetworkProvider);
+                paymentMethodId = _InvoiceRepository.GetDefaultPaymentId(store.GetEnabledPaymentIds(_NetworkProvider), invoice) ?? store.GetDefaultPaymentId(_NetworkProvider);
                 isDefaultPaymentId = true;
             }
             BTCPayNetworkBase network = _NetworkProvider.GetNetwork<BTCPayNetworkBase>(paymentMethodId.CryptoCode);
@@ -854,7 +854,8 @@ namespace BTCPayServer.Controllers
                     SupportedTransactionCurrencies = model.SupportedTransactionCurrencies?.ToDictionary(s => s, s => new InvoiceSupportedTransactionCurrency()
                     {
                         Enabled = true
-                    })
+                    }),
+                    DefaultPaymentMethod = model.DefaultPaymentMethod,
                 }, store, HttpContext.Request.GetAbsoluteRoot(), cancellationToken: cancellationToken);
 
                 TempData[WellKnownTempData.SuccessMessage] = $"Invoice {result.Data.Id} just created!";

BTCPayServer/Controllers/InvoiceController.cs

@@ -151,6 +151,7 @@ namespace BTCPayServer.Controllers
                 excludeFilter = PaymentFilter.Where(p => !supportedTransactionCurrencies.Contains(p));
             }
             entity.PaymentTolerance = storeBlob.PaymentTolerance;
+            entity.DefaultPaymentMethod = invoice.DefaultPaymentMethod;
             return await CreateInvoiceCoreRaw(entity, store, excludeFilter, null, cancellationToken);
         }
 

BTCPayServer/Models/BitpayCreateInvoiceRequest.cs

@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using NBitpayClient;
 using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
 
 namespace BTCPayServer.Models
 {
@@ -52,6 +51,8 @@ namespace BTCPayServer.Models
         public string Currency { get; set; }
         [JsonProperty(PropertyName = "price", DefaultValueHandling = DefaultValueHandling.Ignore)]
         public decimal? Price { get; set; }
+        [JsonProperty(PropertyName = "defaultPaymentMethod", DefaultValueHandling = DefaultValueHandling.Ignore)]
+        public string DefaultPaymentMethod { get; set; }
         [JsonProperty(PropertyName = "notificationEmail", DefaultValueHandling = DefaultValueHandling.Ignore)]
         public string NotificationEmail { get; set; }
         [JsonConverter(typeof(DateTimeJsonConverter))]

BTCPayServer/Models/InvoicingModels/CreateInvoiceModel.cs

@@ -44,6 +44,12 @@ namespace BTCPayServer.Models.InvoicingModels
             get; set;
         }
 
+        [Display(Name = "Default payment method on checkout")]
+        public string DefaultPaymentMethod
+        {
+            get; set;
+        }
+
         [DisplayName("POS Data")]
         public string PosData
         {

BTCPayServer/Services/Invoices/InvoiceEntity.cs

@@ -250,6 +250,7 @@ namespace BTCPayServer.Services.Invoices
 
         public decimal Price { get; set; }
         public string Currency { get; set; }
+        public string DefaultPaymentMethod { get; set; }
 
         [JsonExtensionData]
         public IDictionary<string, JToken> AdditionalData { get; set; }

BTCPayServer/Services/Invoices/InvoiceExtensions.cs

@@ -10,8 +10,8 @@ namespace BTCPayServer.Services.Invoices
 {
     public static class InvoiceExtensions
     {
-        
+
-        public static async Task ActivateInvoicePaymentMethod(this InvoiceRepository invoiceRepository, 
+        public static async Task ActivateInvoicePaymentMethod(this InvoiceRepository invoiceRepository,
             EventAggregator eventAggregator, BTCPayNetworkProvider btcPayNetworkProvider, PaymentMethodHandlerDictionary paymentMethodHandlerDictionary,
             StoreData store,InvoiceEntity invoice, PaymentMethodId paymentMethodId)
         {
@@ -49,5 +49,18 @@ namespace BTCPayServer.Services.Invoices
             }
         }
 
+        public static PaymentMethodId GetDefaultPaymentId(
+            this InvoiceRepository invoiceRepository,
+            PaymentMethodId[] paymentMethodIds,
+            InvoiceEntity invoice
+        )
+        {
+            PaymentMethodId.TryParse(invoice.DefaultPaymentMethod, out var defaultPaymentId);
+            var chosen = paymentMethodIds.FirstOrDefault(f => f == defaultPaymentId) ??
+                         paymentMethodIds.FirstOrDefault(f => f.CryptoCode == defaultPaymentId?.CryptoCode) ??
+                         paymentMethodIds.FirstOrDefault();
+            return chosen;
+        }
+
     }
 }

BTCPayServer/Views/Invoice/CreateInvoice.cshtml

@@ -79,6 +79,11 @@
                         <select asp-for="SupportedTransactionCurrencies" asp-items="Model.AvailablePaymentMethods" class="form-select" multiple="multiple"></select>
                         <span asp-validation-for="SupportedTransactionCurrencies" class="text-danger"></span>
                     </div>
+                    <div class="form-group">
+                        <label asp-for="DefaultPaymentMethod" class="form-label"></label>
+                        <select asp-for="DefaultPaymentMethod" asp-items="Model.AvailablePaymentMethods" class="form-select"></select>
+                        <span asp-validation-for="DefaultPaymentMethod" class="text-danger"></span>
+                    </div>
                     <div class="form-group">
                         <input type="submit" value="Create" class="btn btn-primary" id="Create" />
                         <a asp-action="ListInvoices" class="text-muted ms-3">Back to list</a>