Use a drop down for preferred exchange list

BTCPayServer/Controllers/StoresController.cs

@@ -5,6 +5,7 @@ using BTCPayServer.HostedServices;
 using BTCPayServer.Models;
 using BTCPayServer.Models.StoreViewModels;
 using BTCPayServer.Services;
+using BTCPayServer.Services.Rates;
 using BTCPayServer.Services.Stores;
 using BTCPayServer.Services.Wallets;
 using Microsoft.AspNetCore.Authorization;
@@ -47,7 +48,8 @@ namespace BTCPayServer.Controllers
             ExplorerClientProvider explorerProvider,
             IFeeProviderFactory feeRateProvider,
             LanguageService langService,
-            IHostingEnvironment env)
+            IHostingEnvironment env,
+            CoinAverageSettings coinAverage)
         {
             _Dashboard = dashboard;
             _Repo = repo;
@@ -64,7 +66,9 @@ namespace BTCPayServer.Controllers
             _ServiceProvider = serviceProvider;
             _BtcpayServerOptions = btcpayServerOptions;
             _BTCPayEnv = btcpayEnv;
+            _CoinAverage = coinAverage;
         }
+        CoinAverageSettings _CoinAverage;
         NBXplorerDashboard _Dashboard;
         BTCPayServerOptions _BtcpayServerOptions;
         BTCPayServerEnvironment _BTCPayEnv;
@@ -237,7 +241,7 @@ namespace BTCPayServer.Controllers
             model.SetCryptoCurrencies(_ExplorerProvider, model.DefaultCryptoCurrency);
             model.SetLanguages(_LangService, model.DefaultLang);
 
-            if(!ModelState.IsValid)
+            if (!ModelState.IsValid)
             {
                 return View(model);
             }
@@ -273,6 +277,7 @@ namespace BTCPayServer.Controllers
 
             var storeBlob = store.GetStoreBlob();
             var vm = new StoreViewModel();
+            vm.SetExchangeRates(GetSupportedExchanges(), storeBlob.PreferredExchange.IsCoinAverage() ? "coinaverage" : storeBlob.PreferredExchange);
             vm.Id = store.Id;
             vm.StoreName = store.StoreName;
             vm.StoreWebsite = store.StoreWebsite;
@@ -283,7 +288,6 @@ namespace BTCPayServer.Controllers
             vm.InvoiceExpiration = storeBlob.InvoiceExpiration;
             vm.RateMultiplier = (double)storeBlob.GetRateMultiplier();
             vm.LightningDescriptionTemplate = storeBlob.LightningDescriptionTemplate;
-            vm.PreferredExchange = storeBlob.PreferredExchange.IsCoinAverage() ? "coinaverage" : storeBlob.PreferredExchange;
             return View(vm);
         }
 
@@ -325,6 +329,7 @@ namespace BTCPayServer.Controllers
         [Route("{storeId}")]
         public async Task<IActionResult> UpdateStore(string storeId, StoreViewModel model)
         {
+            model.SetExchangeRates(GetSupportedExchanges(), model.PreferredExchange);
             if (!ModelState.IsValid)
             {
                 return View(model);
@@ -371,14 +376,11 @@ namespace BTCPayServer.Controllers
 
             if (!blob.PreferredExchange.IsCoinAverage() && newExchange)
             {
-                using (HttpClient client = new HttpClient())
+
+                if (!GetSupportedExchanges().Select(c => c.Name).Contains(blob.PreferredExchange, StringComparer.OrdinalIgnoreCase))
                 {
-                    var rate = await client.GetAsync(model.RateSource);
+                    ModelState.AddModelError(nameof(model.PreferredExchange), $"Unsupported exchange ({model.RateSource})");
-                    if (rate.StatusCode == System.Net.HttpStatusCode.NotFound)
+                    return View(model);
-                    {
-                        ModelState.AddModelError(nameof(model.PreferredExchange), $"Unsupported exchange ({model.RateSource})");
-                        return View(model);
-                    }
                 }
             }
 
@@ -394,6 +396,11 @@ namespace BTCPayServer.Controllers
             });
         }
 
+        private (String DisplayName, String Name)[] GetSupportedExchanges()
+        {
+            return new[] { ("Coin Average", "coinaverage") }.Concat(_CoinAverage.AvailableExchanges).ToArray();
+        }
+
         private DerivationStrategy ParseDerivationStrategy(string derivationScheme, Script hint, BTCPayNetwork network)
         {
             var parser = new DerivationSchemeParser(network.NBitcoinNetwork, network.DefaultSettings.ChainType);

BTCPayServer/HostedServices/RatesHostedService.cs

@@ -63,9 +63,14 @@ namespace BTCPayServer.HostedServices
         }
         Task RefreshCoinAverageSupportedExchanges(CancellationToken cancellation)
         {
-            return Timer(async () => 
+            return Timer(async () =>
             {
                 var tickers = await new CoinAverageRateProvider("BTC").GetExchangeTickersAsync();
+                _coinAverageSettings.AvailableExchanges = tickers
+                    .Exchanges
+                    .Select(c => (c.DisplayName, c.Name))
+                    .ToArray();
+
                 await Task.Delay(TimeSpan.FromHours(5), cancellation);
             }, cancellation);
         }

BTCPayServer/Models/StoreViewModels/StoreViewModel.cs

@@ -12,6 +12,11 @@ namespace BTCPayServer.Models.StoreViewModels
 {
     public class StoreViewModel
     {
+        class Format
+        {
+            public string Name { get; set; }
+            public string Value { get; set; }
+        }
         public class DerivationScheme
         {
             public string Crypto { get; set; }
@@ -44,6 +49,17 @@ namespace BTCPayServer.Models.StoreViewModels
 
         public List<StoreViewModel.DerivationScheme> DerivationSchemes { get; set; } = new List<StoreViewModel.DerivationScheme>();
 
+        public void SetExchangeRates((String DisplayName, String Name)[] supportedList, string preferredExchange)
+        {
+            var defaultStore = preferredExchange ?? "coinaverage";
+            var choices = supportedList.Select(o => new Format() { Name = o.DisplayName, Value = o.Name }).ToArray();
+            var chosen = choices.FirstOrDefault(f => f.Value == defaultStore) ?? choices.FirstOrDefault();
+            Exchanges = new SelectList(choices, nameof(chosen.Value), nameof(chosen.Name), chosen);
+            PreferredExchange = chosen.Value;
+        }
+
+        public SelectList Exchanges { get; set; }
+
         [Display(Name = "Preferred price source (eg. bitfinex, bitstamp...)")]
         public string PreferredExchange { get; set; }
 

BTCPayServer/Services/Rates/CoinAverageSettings.cs

@@ -13,7 +13,7 @@ namespace BTCPayServer.Services.Rates
         private static readonly DateTime _epochUtc = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
 
         public (String PublicKey, String PrivateKey)? KeyPair { get; set; }
-        public string[] AvailableExchanges { get; set; } = Array.Empty<string>();
+        public (String DisplayName, String Name)[] AvailableExchanges { get; set; } = Array.Empty<(String DisplayName, String Name)>();
 
         public Task AddHeader(HttpRequestMessage message)
         {

BTCPayServer/Views/Stores/UpdateStore.cshtml

@@ -36,10 +36,10 @@
             </div>
             <div class="form-group">
                 <label asp-for="PreferredExchange"></label>
-                <input asp-for="PreferredExchange" class="form-control" />
+                <select asp-for="PreferredExchange" asp-items="Model.Exchanges" class="form-control"></select>
                 <span asp-validation-for="PreferredExchange" class="text-danger"></span>
                 <p id="PreferredExchangeHelpBlock" class="form-text text-muted">
-                    Current price source is <a href="@Model.RateSource" target="_blank">@Model.PreferredExchange</a>.<small> (using 1 minute cache)</small>
+                    Current price source is <a href="@Model.RateSource" target="_blank">@Model.PreferredExchange</a>.
                 </p>
             </div>
             <div class="form-group">
@@ -81,13 +81,13 @@
                         </tr>
                     </thead>
                     <tbody>
-                        @foreach (var scheme in Model.DerivationSchemes)
+                        @foreach(var scheme in Model.DerivationSchemes)
                         {
                             <tr>
                                 <td>@scheme.Crypto</td>
                                 <td style="max-width:300px;overflow:hidden;">@scheme.Value</td>
                                 <td style="text-align:right">
-                                    @if (!string.IsNullOrWhiteSpace(scheme.Value))
+                                    @if(!string.IsNullOrWhiteSpace(scheme.Value))
                                     {
                                         <a asp-action="Wallet" asp-route-cryptoCode="@scheme.Crypto">Wallet</a><span> - </span>
                                     }
@@ -117,7 +117,7 @@
                             </tr>
                         </thead>
                         <tbody>
-                            @foreach (var scheme in Model.LightningNodes)
+                            @foreach(var scheme in Model.LightningNodes)
                             {
                                 <tr>
                                     <td>@scheme.CryptoCode</td>